godot/thirdparty/vulkan/vk_mem_alloc.h

//
// Copyright (c) 2017-2024 Advanced Micro Devices, Inc. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#ifndef AMD_VULKAN_MEMORY_ALLOCATOR_H
#define AMD_VULKAN_MEMORY_ALLOCATOR_H

/** \mainpage Vulkan Memory Allocator

<b>Version 3.1.0</b>

Copyright (c) 2017-2024 Advanced Micro Devices, Inc. All rights reserved. \n
License: MIT \n
See also: [product page on GPUOpen](https://gpuopen.com/gaming-product/vulkan-memory-allocator/),
[repository on GitHub](https://github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator)


<b>API documentation divided into groups:</b> [Topics](topics.html)

<b>General documentation chapters:</b>

- <b>User guide</b>
  - \subpage quick_start
    - [Project setup](@ref quick_start_project_setup)
    - [Initialization](@ref quick_start_initialization)
    - [Resource allocation](@ref quick_start_resource_allocation)
  - \subpage choosing_memory_type
    - [Usage](@ref choosing_memory_type_usage)
    - [Required and preferred flags](@ref choosing_memory_type_required_preferred_flags)
    - [Explicit memory types](@ref choosing_memory_type_explicit_memory_types)
    - [Custom memory pools](@ref choosing_memory_type_custom_memory_pools)
    - [Dedicated allocations](@ref choosing_memory_type_dedicated_allocations)
  - \subpage memory_mapping
    - [Copy functions](@ref memory_mapping_copy_functions)
    - [Mapping functions](@ref memory_mapping_mapping_functions)
    - [Persistently mapped memory](@ref memory_mapping_persistently_mapped_memory)
    - [Cache flush and invalidate](@ref memory_mapping_cache_control)
  - \subpage staying_within_budget
    - [Querying for budget](@ref staying_within_budget_querying_for_budget)
    - [Controlling memory usage](@ref staying_within_budget_controlling_memory_usage)
  - \subpage resource_aliasing
  - \subpage custom_memory_pools
    - [Choosing memory type index](@ref custom_memory_pools_MemTypeIndex)
    - [When not to use custom pools](@ref custom_memory_pools_when_not_use)
    - [Linear allocation algorithm](@ref linear_algorithm)
      - [Free-at-once](@ref linear_algorithm_free_at_once)
      - [Stack](@ref linear_algorithm_stack)
      - [Double stack](@ref linear_algorithm_double_stack)
      - [Ring buffer](@ref linear_algorithm_ring_buffer)
  - \subpage defragmentation
  - \subpage statistics
    - [Numeric statistics](@ref statistics_numeric_statistics)
    - [JSON dump](@ref statistics_json_dump)
  - \subpage allocation_annotation
    - [Allocation user data](@ref allocation_user_data)
    - [Allocation names](@ref allocation_names)
  - \subpage virtual_allocator
  - \subpage debugging_memory_usage
    - [Memory initialization](@ref debugging_memory_usage_initialization)
    - [Margins](@ref debugging_memory_usage_margins)
    - [Corruption detection](@ref debugging_memory_usage_corruption_detection)
    - [Leak detection features](@ref debugging_memory_usage_leak_detection)
  - \subpage other_api_interop
- \subpage usage_patterns
    - [GPU-only resource](@ref usage_patterns_gpu_only)
    - [Staging copy for upload](@ref usage_patterns_staging_copy_upload)
    - [Readback](@ref usage_patterns_readback)
    - [Advanced data uploading](@ref usage_patterns_advanced_data_uploading)
    - [Other use cases](@ref usage_patterns_other_use_cases)
- \subpage configuration
  - [Pointers to Vulkan functions](@ref config_Vulkan_functions)
  - [Custom host memory allocator](@ref custom_memory_allocator)
  - [Device memory allocation callbacks](@ref allocation_callbacks)
  - [Device heap memory limit](@ref heap_memory_limit)
- <b>Extension support</b>
    - \subpage vk_khr_dedicated_allocation
    - \subpage enabling_buffer_device_address
    - \subpage vk_ext_memory_priority
    - \subpage vk_amd_device_coherent_memory
- \subpage general_considerations
  - [Thread safety](@ref general_considerations_thread_safety)
  - [Versioning and compatibility](@ref general_considerations_versioning_and_compatibility)
  - [Validation layer warnings](@ref general_considerations_validation_layer_warnings)
  - [Allocation algorithm](@ref general_considerations_allocation_algorithm)
  - [Features not supported](@ref general_considerations_features_not_supported)

\defgroup group_init Library initialization

\brief API elements related to the initialization and management of the entire library, especially #VmaAllocator object.

\defgroup group_alloc Memory allocation

\brief API elements related to the allocation, deallocation, and management of Vulkan memory, buffers, images.
Most basic ones being: vmaCreateBuffer(), vmaCreateImage().

\defgroup group_virtual Virtual allocator

\brief API elements related to the mechanism of \ref virtual_allocator - using the core allocation algorithm
for user-defined purpose without allocating any real GPU memory.

\defgroup group_stats Statistics

\brief API elements that query current status of the allocator, from memory usage, budget, to full dump of the internal state in JSON format.
See documentation chapter: \ref statistics.
*/

#include "drivers/vulkan/godot_vulkan.h"

#ifdef __cplusplus
extern …
#endif

#endif // AMD_VULKAN_MEMORY_ALLOCATOR_H

////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
//
//    IMPLEMENTATION
//
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

// For Visual Studio IntelliSense.
#if defined(__cplusplus) && defined(__INTELLISENSE__)
#define VMA_IMPLEMENTATION
#endif

#ifdef VMA_IMPLEMENTATION
#undef VMA_IMPLEMENTATION

#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <cinttypes>
#include <utility>
#include <type_traits>

#if !defined(VMA_CPP20)
    #if __cplusplus >= 202002L || _MSVC_LANG >= 202002L // C++20
        #define VMA_CPP20 …
    #else
        #define VMA_CPP20 …
    #endif
#endif

#ifdef _MSC_VER
    #include <intrin.h> // For functions like __popcnt, _BitScanForward etc.
#endif
#if VMA_CPP20
    #include <bit>
#endif

#if VMA_STATS_STRING_ENABLED
    #include <cstdio> // For snprintf
#endif

/*******************************************************************************
CONFIGURATION SECTION

Define some of these macros before each #include of this header or change them
here if you need other then default behavior depending on your environment.
*/
#ifndef _VMA_CONFIGURATION

/*
Define this macro to 1 to make the library fetch pointers to Vulkan functions
internally, like:

    vulkanFunctions.vkAllocateMemory = &vkAllocateMemory;
*/
#if !defined(VMA_STATIC_VULKAN_FUNCTIONS) && !defined(VK_NO_PROTOTYPES)
    #define VMA_STATIC_VULKAN_FUNCTIONS …
#endif

/*
Define this macro to 1 to make the library fetch pointers to Vulkan functions
internally, like:

    vulkanFunctions.vkAllocateMemory = (PFN_vkAllocateMemory)vkGetDeviceProcAddr(device, "vkAllocateMemory");

To use this feature in new versions of VMA you now have to pass
VmaVulkanFunctions::vkGetInstanceProcAddr and vkGetDeviceProcAddr as
VmaAllocatorCreateInfo::pVulkanFunctions. Other members can be null.
*/
#if !defined(VMA_DYNAMIC_VULKAN_FUNCTIONS)
    #define VMA_DYNAMIC_VULKAN_FUNCTIONS …
#endif

#ifndef VMA_USE_STL_SHARED_MUTEX
    #if __cplusplus >= 201703L || _MSVC_LANG >= 201703L // C++17
        #define VMA_USE_STL_SHARED_MUTEX …
    // Visual studio defines __cplusplus properly only when passed additional parameter: /Zc:__cplusplus
    // Otherwise it is always 199711L, despite shared_mutex works since Visual Studio 2015 Update 2.
    #elif defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 190023918 && __cplusplus == 199711L && _MSVC_LANG >= 201703L
        #define VMA_USE_STL_SHARED_MUTEX …
    #else
        #define VMA_USE_STL_SHARED_MUTEX …
    #endif
#endif

/*
Define this macro to include custom header files without having to edit this file directly, e.g.:

    // Inside of "my_vma_configuration_user_includes.h":

    #include "my_custom_assert.h" // for MY_CUSTOM_ASSERT
    #include "my_custom_min.h" // for my_custom_min
    #include <algorithm>
    #include <mutex>

    // Inside a different file, which includes "vk_mem_alloc.h":

    #define VMA_CONFIGURATION_USER_INCLUDES_H "my_vma_configuration_user_includes.h"
    #define VMA_ASSERT(expr) MY_CUSTOM_ASSERT(expr)
    #define VMA_MIN(v1, v2)  (my_custom_min(v1, v2))
    #include "vk_mem_alloc.h"
    ...

The following headers are used in this CONFIGURATION section only, so feel free to
remove them if not needed.
*/
#if !defined(VMA_CONFIGURATION_USER_INCLUDES_H)
    #include <cassert> // for assert
    #include <algorithm> // for min, max, swap
    #include <mutex>
#else
    #include VMA_CONFIGURATION_USER_INCLUDES_H
#endif

#ifndef VMA_NULL
   // Value used as null pointer. Define it to e.g.: nullptr, NULL, 0, (void*)0.
   #define VMA_NULL …
#endif

#ifndef VMA_FALLTHROUGH
    #if __cplusplus >= 201703L || _MSVC_LANG >= 201703L // C++17
        #define VMA_FALLTHROUGH …
    #else
        #define VMA_FALLTHROUGH
    #endif
#endif

// Normal assert to check for programmer's errors, especially in Debug configuration.
#ifndef VMA_ASSERT
   #ifdef NDEBUG
       #define VMA_ASSERT(expr) …
   #else
       #define VMA_ASSERT …
   #endif
#endif

// Assert that will be called very often, like inside data structures e.g. operator[].
// Making it non-empty can make program slow.
#ifndef VMA_HEAVY_ASSERT
   #ifdef NDEBUG
       #define VMA_HEAVY_ASSERT(expr) …
   #else
       #define VMA_HEAVY_ASSERT …
   #endif
#endif

// Assert used for reporting memory leaks - unfreed allocations.
#ifndef VMA_ASSERT_LEAK
    #define VMA_ASSERT_LEAK(expr) …
#endif

// If your compiler is not compatible with C++17 and definition of
// aligned_alloc() function is missing, uncommenting following line may help:

//#include <malloc.h>

#if defined(__ANDROID_API__) && (__ANDROID_API__ < 16)
#include <cstdlib>
static void* vma_aligned_alloc(size_t alignment, size_t size)
{
    // alignment must be >= sizeof(void*)
    if(alignment < sizeof(void*))
    {
        alignment = sizeof(void*);
    }

    return memalign(alignment, size);
}
#elif defined(__APPLE__) || defined(__ANDROID__) || (defined(__linux__) && defined(__GLIBCXX__) && !defined(_GLIBCXX_HAVE_ALIGNED_ALLOC))
#include <cstdlib>

#if defined(__APPLE__)
#include <AvailabilityMacros.h>
#endif

static void* vma_aligned_alloc(size_t alignment, size_t size)
{
    // Unfortunately, aligned_alloc causes VMA to crash due to it returning null pointers. (At least under 11.4)
    // Therefore, for now disable this specific exception until a proper solution is found.
    //#if defined(__APPLE__) && (defined(MAC_OS_X_VERSION_10_16) || defined(__IPHONE_14_0))
    //#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_16 || __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_14_0
    //    // For C++14, usr/include/malloc/_malloc.h declares aligned_alloc()) only
    //    // with the MacOSX11.0 SDK in Xcode 12 (which is what adds
    //    // MAC_OS_X_VERSION_10_16), even though the function is marked
    //    // available for 10.15. That is why the preprocessor checks for 10.16 but
    //    // the __builtin_available checks for 10.15.
    //    // People who use C++17 could call aligned_alloc with the 10.15 SDK already.
    //    if (__builtin_available(macOS 10.15, iOS 13, *))
    //        return aligned_alloc(alignment, size);
    //#endif
    //#endif

    // alignment must be >= sizeof(void*)
    if(alignment < sizeof(void*))
    {
        alignment = sizeof(void*);
    }

    void *pointer;
    if(posix_memalign(&pointer, alignment, size) == 0)
        return pointer;
    return VMA_NULL;
}
#elif defined(_WIN32)
static void* vma_aligned_alloc(size_t alignment, size_t size)
{
    return _aligned_malloc(size, alignment);
}
#elif __cplusplus >= 201703L || _MSVC_LANG >= 201703L // C++17
static void* vma_aligned_alloc(size_t alignment, size_t size)
{ … }
#else
static void* vma_aligned_alloc(size_t alignment, size_t size)
{
    VMA_ASSERT(0 && "Could not implement aligned_alloc automatically. Please enable C++17 or later in your compiler or provide custom implementation of macro VMA_SYSTEM_ALIGNED_MALLOC (and VMA_SYSTEM_ALIGNED_FREE if needed) using the API of your system.");
    return VMA_NULL;
}
#endif

#if defined(_WIN32)
static void vma_aligned_free(void* ptr)
{
    _aligned_free(ptr);
}
#else
static void vma_aligned_free(void* VMA_NULLABLE ptr)
{ … }
#endif

#ifndef VMA_ALIGN_OF
   #define VMA_ALIGN_OF(type) …
#endif

#ifndef VMA_SYSTEM_ALIGNED_MALLOC
   #define VMA_SYSTEM_ALIGNED_MALLOC(size, alignment) …
#endif

#ifndef VMA_SYSTEM_ALIGNED_FREE
   // VMA_SYSTEM_FREE is the old name, but might have been defined by the user
   #if defined(VMA_SYSTEM_FREE)
      #define VMA_SYSTEM_ALIGNED_FREE …
   #else
      #define VMA_SYSTEM_ALIGNED_FREE(ptr) …
    #endif
#endif

#ifndef VMA_COUNT_BITS_SET
    // Returns number of bits set to 1 in (v)
    #define VMA_COUNT_BITS_SET(v) …
#endif

#ifndef VMA_BITSCAN_LSB
    // Scans integer for index of first nonzero value from the Least Significant Bit (LSB). If mask is 0 then returns UINT8_MAX
    #define VMA_BITSCAN_LSB(mask) …
#endif

#ifndef VMA_BITSCAN_MSB
    // Scans integer for index of first nonzero value from the Most Significant Bit (MSB). If mask is 0 then returns UINT8_MAX
    #define VMA_BITSCAN_MSB(mask) …
#endif

#ifndef VMA_MIN
   #define VMA_MIN(v1, v2) …
#endif

#ifndef VMA_MAX
   #define VMA_MAX(v1, v2) …
#endif

#ifndef VMA_SORT
   #define VMA_SORT(beg, end, cmp) …
#endif

#ifndef VMA_DEBUG_LOG_FORMAT
   #define VMA_DEBUG_LOG_FORMAT(format, ...) …
   /*
   #define VMA_DEBUG_LOG_FORMAT(format, ...) do { \
       printf((format), __VA_ARGS__); \
       printf("\n"); \
   } while(false)
   */
#endif

#ifndef VMA_DEBUG_LOG
    #define VMA_DEBUG_LOG(str) …
#endif

#ifndef VMA_LEAK_LOG_FORMAT
    #define VMA_LEAK_LOG_FORMAT(format, ...) …
#endif

#ifndef VMA_CLASS_NO_COPY
    #define VMA_CLASS_NO_COPY(className) …
#endif
#ifndef VMA_CLASS_NO_COPY_NO_MOVE
    #define VMA_CLASS_NO_COPY_NO_MOVE(className) …
#endif

// Define this macro to 1 to enable functions: vmaBuildStatsString, vmaFreeStatsString.
#if VMA_STATS_STRING_ENABLED
    static inline void VmaUint32ToStr(char* VMA_NOT_NULL outStr, size_t strLen, uint32_t num)
    { … }
    static inline void VmaUint64ToStr(char* VMA_NOT_NULL outStr, size_t strLen, uint64_t num)
    { … }
    static inline void VmaPtrToStr(char* VMA_NOT_NULL outStr, size_t strLen, const void* ptr)
    { … }
#endif

#ifndef VMA_MUTEX
    class VmaMutex
    { … };
    #define VMA_MUTEX …
#endif

// Read-write mutex, where "read" is shared access, "write" is exclusive access.
#ifndef VMA_RW_MUTEX
    #if VMA_USE_STL_SHARED_MUTEX
        // Use std::shared_mutex from C++17.
        #include <shared_mutex>
        class VmaRWMutex
        { … };
        #define VMA_RW_MUTEX …
    #elif defined(_WIN32) && defined(WINVER) && WINVER >= 0x0600
        // Use SRWLOCK from WinAPI.
        // Minimum supported client = Windows Vista, server = Windows Server 2008.
        class VmaRWMutex
        {
        public:
            VmaRWMutex() { InitializeSRWLock(&m_Lock); }
            void LockRead() { AcquireSRWLockShared(&m_Lock); }
            void UnlockRead() { ReleaseSRWLockShared(&m_Lock); }
            bool TryLockRead() { return TryAcquireSRWLockShared(&m_Lock) != FALSE; }
            void LockWrite() { AcquireSRWLockExclusive(&m_Lock); }
            void UnlockWrite() { ReleaseSRWLockExclusive(&m_Lock); }
            bool TryLockWrite() { return TryAcquireSRWLockExclusive(&m_Lock) != FALSE; }
        private:
            SRWLOCK m_Lock;
        };
        #define VMA_RW_MUTEX …
    #else
        // Less efficient fallback: Use normal mutex.
        class VmaRWMutex
        {
        public:
            void LockRead() { m_Mutex.Lock(); }
            void UnlockRead() { m_Mutex.Unlock(); }
            bool TryLockRead() { return m_Mutex.TryLock(); }
            void LockWrite() { m_Mutex.Lock(); }
            void UnlockWrite() { m_Mutex.Unlock(); }
            bool TryLockWrite() { return m_Mutex.TryLock(); }
        private:
            VMA_MUTEX m_Mutex;
        };
        #define VMA_RW_MUTEX …
    #endif // #if VMA_USE_STL_SHARED_MUTEX
#endif // #ifndef VMA_RW_MUTEX

/*
If providing your own implementation, you need to implement a subset of std::atomic.
*/
#ifndef VMA_ATOMIC_UINT32
    #include <atomic>
    #define VMA_ATOMIC_UINT32 …
#endif

#ifndef VMA_ATOMIC_UINT64
    #include <atomic>
    #define VMA_ATOMIC_UINT64 …
#endif

#ifndef VMA_DEBUG_ALWAYS_DEDICATED_MEMORY
    /**
    Every allocation will have its own memory block.
    Define to 1 for debugging purposes only.
    */
    #define VMA_DEBUG_ALWAYS_DEDICATED_MEMORY …
#endif

#ifndef VMA_MIN_ALIGNMENT
    /**
    Minimum alignment of all allocations, in bytes.
    Set to more than 1 for debugging purposes. Must be power of two.
    */
    #ifdef VMA_DEBUG_ALIGNMENT // Old name
        #define VMA_MIN_ALIGNMENT …
    #else
        #define VMA_MIN_ALIGNMENT …
    #endif
#endif

#ifndef VMA_DEBUG_MARGIN
    /**
    Minimum margin after every allocation, in bytes.
    Set nonzero for debugging purposes only.
    */
    #define VMA_DEBUG_MARGIN …
#endif

#ifndef VMA_DEBUG_INITIALIZE_ALLOCATIONS
    /**
    Define this macro to 1 to automatically fill new allocations and destroyed
    allocations with some bit pattern.
    */
    #define VMA_DEBUG_INITIALIZE_ALLOCATIONS …
#endif

#ifndef VMA_DEBUG_DETECT_CORRUPTION
    /**
    Define this macro to 1 together with non-zero value of VMA_DEBUG_MARGIN to
    enable writing magic value to the margin after every allocation and
    validating it, so that memory corruptions (out-of-bounds writes) are detected.
    */
    #define VMA_DEBUG_DETECT_CORRUPTION …
#endif

#ifndef VMA_DEBUG_GLOBAL_MUTEX
    /**
    Set this to 1 for debugging purposes only, to enable single mutex protecting all
    entry calls to the library. Can be useful for debugging multithreading issues.
    */
    #define VMA_DEBUG_GLOBAL_MUTEX …
#endif

#ifndef VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY
    /**
    Minimum value for VkPhysicalDeviceLimits::bufferImageGranularity.
    Set to more than 1 for debugging purposes only. Must be power of two.
    */
    #define VMA_DEBUG_MIN_BUFFER_IMAGE_GRANULARITY …
#endif

#ifndef VMA_DEBUG_DONT_EXCEED_MAX_MEMORY_ALLOCATION_COUNT
    /*
    Set this to 1 to make VMA never exceed VkPhysicalDeviceLimits::maxMemoryAllocationCount
    and return error instead of leaving up to Vulkan implementation what to do in such cases.
    */
    #define VMA_DEBUG_DONT_EXCEED_MAX_MEMORY_ALLOCATION_COUNT …
#endif

#ifndef VMA_SMALL_HEAP_MAX_SIZE
   /// Maximum size of a memory heap in Vulkan to consider it "small".
   #define VMA_SMALL_HEAP_MAX_SIZE …
#endif

#ifndef VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE
   /// Default size of a block allocated as single VkDeviceMemory from a "large" heap.
   #define VMA_DEFAULT_LARGE_HEAP_BLOCK_SIZE …
#endif

/*
Mapping hysteresis is a logic that launches when vmaMapMemory/vmaUnmapMemory is called
or a persistently mapped allocation is created and destroyed several times in a row.
It keeps additional +1 mapping of a device memory block to prevent calling actual
vkMapMemory/vkUnmapMemory too many times, which may improve performance and help
tools like RenderDoc.
*/
#ifndef VMA_MAPPING_HYSTERESIS_ENABLED
    #define VMA_MAPPING_HYSTERESIS_ENABLED …
#endif

#define VMA_VALIDATE(cond) …

/*******************************************************************************
END OF CONFIGURATION
*/
#endif // _VMA_CONFIGURATION


static const uint8_t VMA_ALLOCATION_FILL_PATTERN_CREATED = …;
static const uint8_t VMA_ALLOCATION_FILL_PATTERN_DESTROYED = …;
// Decimal 2139416166, float NaN, little-endian binary 66 E6 84 7F.
static const uint32_t VMA_CORRUPTION_DETECTION_MAGIC_VALUE = …;

// Copy of some Vulkan definitions so we don't need to check their existence just to handle few constants.
static const uint32_t VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD_COPY = …;
static const uint32_t VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD_COPY = …;
static const uint32_t VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT_COPY = …;
static const uint32_t VK_IMAGE_CREATE_DISJOINT_BIT_COPY = …;
static const int32_t VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT_COPY = …;
static const uint32_t VMA_ALLOCATION_INTERNAL_STRATEGY_MIN_OFFSET = …;
static const uint32_t VMA_ALLOCATION_TRY_COUNT = …;
static const uint32_t VMA_VENDOR_ID_AMD = …;

// This one is tricky. Vulkan specification defines this code as available since
// Vulkan 1.0, but doesn't actually define it in Vulkan SDK earlier than 1.2.131.
// See pull request #207.
#define VK_ERROR_UNKNOWN_COPY …


#if VMA_STATS_STRING_ENABLED
// Correspond to values of enum VmaSuballocationType.
static const char* VMA_SUBALLOCATION_TYPE_NAMES[] = …;
#endif

static VkAllocationCallbacks VmaEmptyAllocationCallbacks = …;


#ifndef _VMA_ENUM_DECLARATIONS

enum VmaSuballocationType
{ … };

enum VMA_CACHE_OPERATION
{ … };

enum class VmaAllocationRequestType
{ … };

#endif // _VMA_ENUM_DECLARATIONS

#ifndef _VMA_FORWARD_DECLARATIONS
// Opaque handle used by allocation algorithms to identify single allocation in any conforming way.
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VmaAllocHandle);

struct VmaMutexLock;
struct VmaMutexLockRead;
struct VmaMutexLockWrite;

template<typename T>
struct AtomicTransactionalIncrement;

template<typename T>
struct VmaStlAllocator;

template<typename T, typename AllocatorT>
class VmaVector;

template<typename T, typename AllocatorT, size_t N>
class VmaSmallVector;

template<typename T>
class VmaPoolAllocator;

template<typename T>
struct VmaListItem;

template<typename T>
class VmaRawList;

template<typename T, typename AllocatorT>
class VmaList;

template<typename ItemTypeTraits>
class VmaIntrusiveLinkedList;

#if VMA_STATS_STRING_ENABLED
class VmaStringBuilder;
class VmaJsonWriter;
#endif

class VmaDeviceMemoryBlock;

struct VmaDedicatedAllocationListItemTraits;
class VmaDedicatedAllocationList;

struct VmaSuballocation;
struct VmaSuballocationOffsetLess;
struct VmaSuballocationOffsetGreater;
struct VmaSuballocationItemSizeLess;

VmaSuballocationList;

struct VmaAllocationRequest;

class VmaBlockMetadata;
class VmaBlockMetadata_Linear;
class VmaBlockMetadata_TLSF;

class VmaBlockVector;

struct VmaPoolListItemTraits;

struct VmaCurrentBudgetData;

class VmaAllocationObjectAllocator;

#endif // _VMA_FORWARD_DECLARATIONS


#ifndef _VMA_FUNCTIONS

/*
Returns number of bits set to 1 in (v).

On specific platforms and compilers you can use intrinsics like:

Visual Studio:
    return __popcnt(v);
GCC, Clang:
    return static_cast<uint32_t>(__builtin_popcount(v));

Define macro VMA_COUNT_BITS_SET to provide your optimized implementation.
But you need to check in runtime whether user's CPU supports these, as some old processors don't.
*/
static inline uint32_t VmaCountBitsSet(uint32_t v)
{ … }

static inline uint8_t VmaBitScanLSB(uint64_t mask)
{ … }

static inline uint8_t VmaBitScanLSB(uint32_t mask)
{ … }

static inline uint8_t VmaBitScanMSB(uint64_t mask)
{ … }

static inline uint8_t VmaBitScanMSB(uint32_t mask)
{ … }

/*
Returns true if given number is a power of two.
T must be unsigned integer number or signed integer but always nonnegative.
For 0 returns true.
*/
template <typename T>
inline bool VmaIsPow2(T x)
{ … }

// Aligns given value up to nearest multiply of align value. For example: VmaAlignUp(11, 8) = 16.
// Use types like uint32_t, uint64_t as T.
template <typename T>
static inline T VmaAlignUp(T val, T alignment)
{ … }

// Aligns given value down to nearest multiply of align value. For example: VmaAlignDown(11, 8) = 8.
// Use types like uint32_t, uint64_t as T.
template <typename T>
static inline T VmaAlignDown(T val, T alignment)
{ … }

// Division with mathematical rounding to nearest number.
template <typename T>
static inline T VmaRoundDiv(T x, T y)
{ … }

// Divide by 'y' and round up to nearest integer.
template <typename T>
static inline T VmaDivideRoundingUp(T x, T y)
{ … }

// Returns smallest power of 2 greater or equal to v.
static inline uint32_t VmaNextPow2(uint32_t v)
{ … }

static inline uint64_t VmaNextPow2(uint64_t v)
{ … }

// Returns largest power of 2 less or equal to v.
static inline uint32_t VmaPrevPow2(uint32_t v)
{ … }

static inline uint64_t VmaPrevPow2(uint64_t v)
{ … }

static inline bool VmaStrIsEmpty(const char* pStr)
{ … }

/*
Returns true if two memory blocks occupy overlapping pages.
ResourceA must be in less memory offset than ResourceB.

Algorithm is based on "Vulkan 1.0.39 - A Specification (with all registered Vulkan extensions)"
chapter 11.6 "Resource Memory Association", paragraph "Buffer-Image Granularity".
*/
static inline bool VmaBlocksOnSamePage(
    VkDeviceSize resourceAOffset,
    VkDeviceSize resourceASize,
    VkDeviceSize resourceBOffset,
    VkDeviceSize pageSize)
{ … }

/*
Returns true if given suballocation types could conflict and must respect
VkPhysicalDeviceLimits::bufferImageGranularity. They conflict if one is buffer
or linear image and another one is optimal image. If type is unknown, behave
conservatively.
*/
static inline bool VmaIsBufferImageGranularityConflict(
    VmaSuballocationType suballocType1,
    VmaSuballocationType suballocType2)
{ … }

static void VmaWriteMagicValue(void* pData, VkDeviceSize offset)
{ … }

static bool VmaValidateMagicValue(const void* pData, VkDeviceSize offset)
{ … }

/*
Fills structure with parameters of an example buffer to be used for transfers
during GPU memory defragmentation.
*/
static void VmaFillGpuDefragmentationBufferCreateInfo(VkBufferCreateInfo& outBufCreateInfo)
{ … }


/*
Performs binary search and returns iterator to first element that is greater or
equal to (key), according to comparison (cmp).

Cmp should return true if first argument is less than second argument.

Returned value is the found element, if present in the collection or place where
new element with value (key) should be inserted.
*/
template <typename CmpLess, typename IterT, typename KeyT>
static IterT VmaBinaryFindFirstNotLess(IterT beg, IterT end, const KeyT& key, const CmpLess& cmp)
{ … }

template<typename CmpLess, typename IterT, typename KeyT>
IterT VmaBinaryFindSorted(const IterT& beg, const IterT& end, const KeyT& value, const CmpLess& cmp)
{ … }

/*
Returns true if all pointers in the array are not-null and unique.
Warning! O(n^2) complexity. Use only inside VMA_HEAVY_ASSERT.
T must be pointer type, e.g. VmaAllocation, VmaPool.
*/
template<typename T>
static bool VmaValidatePointerArray(uint32_t count, const T* arr)
{ … }

template<typename MainT, typename NewT>
static inline void VmaPnextChainPushFront(MainT* mainStruct, NewT* newStruct)
{ … }
// Finds structure with s->sType == sType in mainStruct->pNext chain.
// Returns pointer to it. If not found, returns null.
template<typename FindT, typename MainT>
static inline const FindT* VmaPnextChainFind(const MainT* mainStruct, VkStructureType sType)
{ … }

// An abstraction over buffer or image `usage` flags, depending on available extensions.
struct VmaBufferImageUsage
{ … };

const VmaBufferImageUsage VmaBufferImageUsage::UNKNOWN = …;

static void swap(VmaBufferImageUsage& lhs, VmaBufferImageUsage& rhs) noexcept
{ … }

VmaBufferImageUsage::VmaBufferImageUsage(const VkBufferCreateInfo &createInfo,
    bool useKhrMaintenance5)
{ … }

VmaBufferImageUsage::VmaBufferImageUsage(const VkImageCreateInfo &createInfo)
{ … }

// This is the main algorithm that guides the selection of a memory type best for an allocation -
// converts usage to required/preferred/not preferred flags.
static bool FindMemoryPreferences(
    bool isIntegratedGPU,
    const VmaAllocationCreateInfo& allocCreateInfo,
    VmaBufferImageUsage bufImgUsage,
    VkMemoryPropertyFlags& outRequiredFlags,
    VkMemoryPropertyFlags& outPreferredFlags,
    VkMemoryPropertyFlags& outNotPreferredFlags)
{ … }

////////////////////////////////////////////////////////////////////////////////
// Memory allocation

static void* VmaMalloc(const VkAllocationCallbacks* pAllocationCallbacks, size_t size, size_t alignment)
{ … }

static void VmaFree(const VkAllocationCallbacks* pAllocationCallbacks, void* ptr)
{ … }

template<typename T>
static T* VmaAllocate(const VkAllocationCallbacks* pAllocationCallbacks)
{ … }

template<typename T>
static T* VmaAllocateArray(const VkAllocationCallbacks* pAllocationCallbacks, size_t count)
{ … }

#define vma_new(allocator, type) …

#define vma_new_array(allocator, type, count) …

template<typename T>
static void vma_delete(const VkAllocationCallbacks* pAllocationCallbacks, T* ptr)
{ … }

template<typename T>
static void vma_delete_array(const VkAllocationCallbacks* pAllocationCallbacks, T* ptr, size_t count)
{ … }

static char* VmaCreateStringCopy(const VkAllocationCallbacks* allocs, const char* srcStr)
{ … }

#if VMA_STATS_STRING_ENABLED
static char* VmaCreateStringCopy(const VkAllocationCallbacks* allocs, const char* srcStr, size_t strLen)
{ … }
#endif // VMA_STATS_STRING_ENABLED

static void VmaFreeString(const VkAllocationCallbacks* allocs, char* str)
{ … }

template<typename CmpLess, typename VectorT>
size_t VmaVectorInsertSorted(VectorT& vector, const typename VectorT::value_type& value)
{ … }

template<typename CmpLess, typename VectorT>
bool VmaVectorRemoveSorted(VectorT& vector, const typename VectorT::value_type& value)
{ … }
#endif // _VMA_FUNCTIONS

#ifndef _VMA_STATISTICS_FUNCTIONS

static void VmaClearStatistics(VmaStatistics& outStats)
{ … }

static void VmaAddStatistics(VmaStatistics& inoutStats, const VmaStatistics& src)
{ … }

static void VmaClearDetailedStatistics(VmaDetailedStatistics& outStats)
{ … }

static void VmaAddDetailedStatisticsAllocation(VmaDetailedStatistics& inoutStats, VkDeviceSize size)
{ … }

static void VmaAddDetailedStatisticsUnusedRange(VmaDetailedStatistics& inoutStats, VkDeviceSize size)
{ … }

static void VmaAddDetailedStatistics(VmaDetailedStatistics& inoutStats, const VmaDetailedStatistics& src)
{ … }

#endif // _VMA_STATISTICS_FUNCTIONS

#ifndef _VMA_MUTEX_LOCK
// Helper RAII class to lock a mutex in constructor and unlock it in destructor (at the end of scope).
struct VmaMutexLock
{ … };

// Helper RAII class to lock a RW mutex in constructor and unlock it in destructor (at the end of scope), for reading.
struct VmaMutexLockRead
{ … };

// Helper RAII class to lock a RW mutex in constructor and unlock it in destructor (at the end of scope), for writing.
struct VmaMutexLockWrite
{ … };

#if VMA_DEBUG_GLOBAL_MUTEX
    static VMA_MUTEX gDebugGlobalMutex;
    #define VMA_DEBUG_GLOBAL_MUTEX_LOCK …
#else
    #define VMA_DEBUG_GLOBAL_MUTEX_LOCK
#endif
#endif // _VMA_MUTEX_LOCK

#ifndef _VMA_ATOMIC_TRANSACTIONAL_INCREMENT
// An object that increments given atomic but decrements it back in the destructor unless Commit() is called.
template<typename AtomicT>
struct AtomicTransactionalIncrement
{ … };
#endif // _VMA_ATOMIC_TRANSACTIONAL_INCREMENT

#ifndef _VMA_STL_ALLOCATOR
// STL-compatible allocator.
template<typename T>
struct VmaStlAllocator
{ … };
#endif // _VMA_STL_ALLOCATOR

#ifndef _VMA_VECTOR
/* Class with interface compatible with subset of std::vector.
T must be POD because constructors and destructors are not called and memcpy is
used for these objects. */
template<typename T, typename AllocatorT>
class VmaVector
{ … };

#ifndef _VMA_VECTOR_FUNCTIONS
template<typename T, typename AllocatorT>
VmaVector<T, AllocatorT>::VmaVector(const AllocatorT& allocator)
    : … { … }

template<typename T, typename AllocatorT>
VmaVector<T, AllocatorT>::VmaVector(size_t count, const AllocatorT& allocator)
    : … { … }

template<typename T, typename AllocatorT>
VmaVector<T, AllocatorT>::VmaVector(const VmaVector& src)
    : … { … }

template<typename T, typename AllocatorT>
VmaVector<T, AllocatorT>& VmaVector<T, AllocatorT>::operator=(const VmaVector& rhs)
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::push_back(const T& src)
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::reserve(size_t newCapacity, bool freeMemory)
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::resize(size_t newCount)
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::shrink_to_fit()
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::insert(size_t index, const T& src)
{ … }

template<typename T, typename AllocatorT>
void VmaVector<T, AllocatorT>::remove(size_t index)
{ … }
#endif // _VMA_VECTOR_FUNCTIONS

template<typename T, typename allocatorT>
static void VmaVectorInsert(VmaVector<T, allocatorT>& vec, size_t index, const T& item)
{ … }

template<typename T, typename allocatorT>
static void VmaVectorRemove(VmaVector<T, allocatorT>& vec, size_t index)
{ … }
#endif // _VMA_VECTOR

#ifndef _VMA_SMALL_VECTOR
/*
This is a vector (a variable-sized array), optimized for the case when the array is small.

It contains some number of elements in-place, which allows it to avoid heap allocation
when the actual number of elements is below that threshold. This allows normal "small"
cases to be fast without losing generality for large inputs.
*/
template<typename T, typename AllocatorT, size_t N>
class VmaSmallVector
{ … };

#ifndef _VMA_SMALL_VECTOR_FUNCTIONS
template<typename T, typename AllocatorT, size_t N>
VmaSmallVector<T, AllocatorT, N>::VmaSmallVector(const AllocatorT& allocator)
    : … { … }

template<typename T, typename AllocatorT, size_t N>
VmaSmallVector<T, AllocatorT, N>::VmaSmallVector(size_t count, const AllocatorT& allocator)
    : … { … }

template<typename T, typename AllocatorT, size_t N>
void VmaSmallVector<T, AllocatorT, N>::push_back(const T& src)
{ … }

template<typename T, typename AllocatorT, size_t N>
void VmaSmallVector<T, AllocatorT, N>::resize(size_t newCount, bool freeMemory)
{ … }

template<typename T, typename AllocatorT, size_t N>
void VmaSmallVector<T, AllocatorT, N>::clear(bool freeMemory)
{ … }

template<typename T, typename AllocatorT, size_t N>
void VmaSmallVector<T, AllocatorT, N>::insert(size_t index, const T& src)
{ … }

template<typename T, typename AllocatorT, size_t N>
void VmaSmallVector<T, AllocatorT, N>::remove(size_t index)
{ … }
#endif // _VMA_SMALL_VECTOR_FUNCTIONS
#endif // _VMA_SMALL_VECTOR

#ifndef _VMA_POOL_ALLOCATOR
/*
Allocator for objects of type T using a list of arrays (pools) to speed up
allocation. Number of elements that can be allocated is not bounded because
allocator can create multiple blocks.
*/
template<typename T>
class VmaPoolAllocator
{ … };

#ifndef _VMA_POOL_ALLOCATOR_FUNCTIONS
template<typename T>
VmaPoolAllocator<T>::VmaPoolAllocator(const VkAllocationCallbacks* pAllocationCallbacks, uint32_t firstBlockCapacity)
    : … { … }

template<typename T>
VmaPoolAllocator<T>::~VmaPoolAllocator()
{ … }

template<typename T>
template<typename... Types> T* VmaPoolAllocator<T>::Alloc(Types&&... args)
{ … }

template<typename T>
void VmaPoolAllocator<T>::Free(T* ptr)
{ … }

template<typename T>
typename VmaPoolAllocator<T>::ItemBlock& VmaPoolAllocator<T>::CreateNewBlock()
{ … }
#endif // _VMA_POOL_ALLOCATOR_FUNCTIONS
#endif // _VMA_POOL_ALLOCATOR

#ifndef _VMA_RAW_LIST
template<typename T>
struct VmaListItem
{ … };

// Doubly linked list.
template<typename T>
class VmaRawList
{ … };

#ifndef _VMA_RAW_LIST_FUNCTIONS
template<typename T>
VmaRawList<T>::VmaRawList(const VkAllocationCallbacks* pAllocationCallbacks)
    : … { … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushFront()
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushBack()
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushFront(const T& value)
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::PushBack(const T& value)
{ … }

template<typename T>
void VmaRawList<T>::PopFront()
{ … }

template<typename T>
void VmaRawList<T>::PopBack()
{ … }

template<typename T>
void VmaRawList<T>::Clear()
{ … }

template<typename T>
void VmaRawList<T>::Remove(ItemType* pItem)
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertBefore(ItemType* pItem)
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertAfter(ItemType* pItem)
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertBefore(ItemType* pItem, const T& value)
{ … }

template<typename T>
VmaListItem<T>* VmaRawList<T>::InsertAfter(ItemType* pItem, const T& value)
{ … }
#endif // _VMA_RAW_LIST_FUNCTIONS
#endif // _VMA_RAW_LIST

#ifndef _VMA_LIST
template<typename T, typename AllocatorT>
class VmaList
{ … };

#ifndef _VMA_LIST_FUNCTIONS
template<typename T, typename AllocatorT>
typename VmaList<T, AllocatorT>::iterator& VmaList<T, AllocatorT>::iterator::operator--()
{ … }

template<typename T, typename AllocatorT>
typename VmaList<T, AllocatorT>::reverse_iterator& VmaList<T, AllocatorT>::reverse_iterator::operator--()
{ … }

template<typename T, typename AllocatorT>
typename VmaList<T, AllocatorT>::const_iterator& VmaList<T, AllocatorT>::const_iterator::operator--()
{ … }

template<typename T, typename AllocatorT>
typename VmaList<T, AllocatorT>::const_reverse_iterator& VmaList<T, AllocatorT>::const_reverse_iterator::operator--()
{ … }
#endif // _VMA_LIST_FUNCTIONS
#endif // _VMA_LIST

#ifndef _VMA_INTRUSIVE_LINKED_LIST
/*
Expected interface of ItemTypeTraits:
struct MyItemTypeTraits
{
    typedef MyItem ItemType;
    static ItemType* GetPrev(const ItemType* item) { return item->myPrevPtr; }
    static ItemType* GetNext(const ItemType* item) { return item->myNextPtr; }
    static ItemType*& AccessPrev(ItemType* item) { return item->myPrevPtr; }
    static ItemType*& AccessNext(ItemType* item) { return item->myNextPtr; }
};
*/
template<typename ItemTypeTraits>
class VmaIntrusiveLinkedList
{ … };

#ifndef _VMA_INTRUSIVE_LINKED_LIST_FUNCTIONS
template<typename ItemTypeTraits>
VmaIntrusiveLinkedList<ItemTypeTraits>::VmaIntrusiveLinkedList(VmaIntrusiveLinkedList&& src)
    : … { … }

template<typename ItemTypeTraits>
VmaIntrusiveLinkedList<ItemTypeTraits>& VmaIntrusiveLinkedList<ItemTypeTraits>::operator=(VmaIntrusiveLinkedList&& src)
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::PushBack(ItemType* item)
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::PushFront(ItemType* item)
{ … }

template<typename ItemTypeTraits>
typename VmaIntrusiveLinkedList<ItemTypeTraits>::ItemType* VmaIntrusiveLinkedList<ItemTypeTraits>::PopBack()
{ … }

template<typename ItemTypeTraits>
typename VmaIntrusiveLinkedList<ItemTypeTraits>::ItemType* VmaIntrusiveLinkedList<ItemTypeTraits>::PopFront()
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::InsertBefore(ItemType* existingItem, ItemType* newItem)
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::InsertAfter(ItemType* existingItem, ItemType* newItem)
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::Remove(ItemType* item)
{ … }

template<typename ItemTypeTraits>
void VmaIntrusiveLinkedList<ItemTypeTraits>::RemoveAll()
{ … }
#endif // _VMA_INTRUSIVE_LINKED_LIST_FUNCTIONS
#endif // _VMA_INTRUSIVE_LINKED_LIST

#if !defined(_VMA_STRING_BUILDER) && VMA_STATS_STRING_ENABLED
class VmaStringBuilder
{ … };

#ifndef _VMA_STRING_BUILDER_FUNCTIONS
void VmaStringBuilder::Add(const char* pStr)
{ … }

void VmaStringBuilder::AddNumber(uint32_t num)
{ … }

void VmaStringBuilder::AddNumber(uint64_t num)
{ … }

void VmaStringBuilder::AddPointer(const void* ptr)
{ … }
#endif //_VMA_STRING_BUILDER_FUNCTIONS
#endif // _VMA_STRING_BUILDER

#if !defined(_VMA_JSON_WRITER) && VMA_STATS_STRING_ENABLED
/*
Allows to conveniently build a correct JSON document to be written to the
VmaStringBuilder passed to the constructor.
*/
class VmaJsonWriter
{ … };
const char* const VmaJsonWriter::INDENT = …;

#ifndef _VMA_JSON_WRITER_FUNCTIONS
VmaJsonWriter::VmaJsonWriter(const VkAllocationCallbacks* pAllocationCallbacks, VmaStringBuilder& sb)
    : … { … }

VmaJsonWriter::~VmaJsonWriter()
{ … }

void VmaJsonWriter::BeginObject(bool singleLine)
{ … }

void VmaJsonWriter::EndObject()
{ … }

void VmaJsonWriter::BeginArray(bool singleLine)
{ … }

void VmaJsonWriter::EndArray()
{ … }

void VmaJsonWriter::WriteString(const char* pStr)
{ … }

void VmaJsonWriter::BeginString(const char* pStr)
{ … }

void VmaJsonWriter::ContinueString(const char* pStr)
{ … }

void VmaJsonWriter::ContinueString(uint32_t n)
{ … }

void VmaJsonWriter::ContinueString(uint64_t n)
{ … }

void VmaJsonWriter::ContinueString_Pointer(const void* ptr)
{ … }

void VmaJsonWriter::EndString(const char* pStr)
{ … }

void VmaJsonWriter::WriteNumber(uint32_t n)
{ … }

void VmaJsonWriter::WriteNumber(uint64_t n)
{ … }

void VmaJsonWriter::WriteBool(bool b)
{ … }

void VmaJsonWriter::WriteNull()
{ … }

void VmaJsonWriter::BeginValue(bool isString)
{ … }

void VmaJsonWriter::WriteIndent(bool oneLess)
{ … }
#endif // _VMA_JSON_WRITER_FUNCTIONS

static void VmaPrintDetailedStatistics(VmaJsonWriter& json, const VmaDetailedStatistics& stat)
{ … }
#endif // _VMA_JSON_WRITER

#ifndef _VMA_MAPPING_HYSTERESIS

class VmaMappingHysteresis
{ … };

#endif // _VMA_MAPPING_HYSTERESIS

#ifndef _VMA_DEVICE_MEMORY_BLOCK
/*
Represents a single block of device memory (`VkDeviceMemory`) with all the
data about its regions (aka suballocations, #VmaAllocation), assigned and free.

Thread-safety:
- Access to m_pMetadata must be externally synchronized.
- Map, Unmap, Bind* are synchronized internally.
*/
class VmaDeviceMemoryBlock
{ … };
#endif // _VMA_DEVICE_MEMORY_BLOCK

#ifndef _VMA_ALLOCATION_T
struct VmaAllocation_T
{ … };
#endif // _VMA_ALLOCATION_T

#ifndef _VMA_DEDICATED_ALLOCATION_LIST_ITEM_TRAITS
struct VmaDedicatedAllocationListItemTraits
{ … };
#endif // _VMA_DEDICATED_ALLOCATION_LIST_ITEM_TRAITS

#ifndef _VMA_DEDICATED_ALLOCATION_LIST
/*
Stores linked list of VmaAllocation_T objects.
Thread-safe, synchronized internally.
*/
class VmaDedicatedAllocationList
{ … };

#ifndef _VMA_DEDICATED_ALLOCATION_LIST_FUNCTIONS

VmaDedicatedAllocationList::~VmaDedicatedAllocationList()
{ … }

bool VmaDedicatedAllocationList::Validate()
{ … }

void VmaDedicatedAllocationList::AddDetailedStatistics(VmaDetailedStatistics& inoutStats)
{ … }

void VmaDedicatedAllocationList::AddStatistics(VmaStatistics& inoutStats)
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaDedicatedAllocationList::BuildStatsString(VmaJsonWriter& json)
{ … }
#endif // VMA_STATS_STRING_ENABLED

bool VmaDedicatedAllocationList::IsEmpty()
{ … }

void VmaDedicatedAllocationList::Register(VmaAllocation alloc)
{ … }

void VmaDedicatedAllocationList::Unregister(VmaAllocation alloc)
{ … }
#endif // _VMA_DEDICATED_ALLOCATION_LIST_FUNCTIONS
#endif // _VMA_DEDICATED_ALLOCATION_LIST

#ifndef _VMA_SUBALLOCATION
/*
Represents a region of VmaDeviceMemoryBlock that is either assigned and returned as
allocated memory block or free.
*/
struct VmaSuballocation
{ … };

// Comparator for offsets.
struct VmaSuballocationOffsetLess
{ … };

struct VmaSuballocationOffsetGreater
{ … };

struct VmaSuballocationItemSizeLess
{ … };
#endif // _VMA_SUBALLOCATION

#ifndef _VMA_ALLOCATION_REQUEST
/*
Parameters of planned allocation inside a VmaDeviceMemoryBlock.
item points to a FREE suballocation.
*/
struct VmaAllocationRequest
{ … };
#endif // _VMA_ALLOCATION_REQUEST

#ifndef _VMA_BLOCK_METADATA
/*
Data structure used for bookkeeping of allocations and unused ranges of memory
in a single VkDeviceMemory block.
*/
class VmaBlockMetadata
{ … };

#ifndef _VMA_BLOCK_METADATA_FUNCTIONS
VmaBlockMetadata::VmaBlockMetadata(const VkAllocationCallbacks* pAllocationCallbacks,
    VkDeviceSize bufferImageGranularity, bool isVirtual)
    : … { … }

void VmaBlockMetadata::DebugLogAllocation(VkDeviceSize offset, VkDeviceSize size, void* userData) const
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaBlockMetadata::PrintDetailedMap_Begin(class VmaJsonWriter& json,
    VkDeviceSize unusedBytes, size_t allocationCount, size_t unusedRangeCount) const
{ … }

void VmaBlockMetadata::PrintDetailedMap_Allocation(class VmaJsonWriter& json,
    VkDeviceSize offset, VkDeviceSize size, void* userData) const
{ … }

void VmaBlockMetadata::PrintDetailedMap_UnusedRange(class VmaJsonWriter& json,
    VkDeviceSize offset, VkDeviceSize size) const
{ … }

void VmaBlockMetadata::PrintDetailedMap_End(class VmaJsonWriter& json) const
{ … }
#endif // VMA_STATS_STRING_ENABLED
#endif // _VMA_BLOCK_METADATA_FUNCTIONS
#endif // _VMA_BLOCK_METADATA

#ifndef _VMA_BLOCK_BUFFER_IMAGE_GRANULARITY
// Before deleting object of this class remember to call 'Destroy()'
class VmaBlockBufferImageGranularity final
{ … };

#ifndef _VMA_BLOCK_BUFFER_IMAGE_GRANULARITY_FUNCTIONS
VmaBlockBufferImageGranularity::VmaBlockBufferImageGranularity(VkDeviceSize bufferImageGranularity)
    : … { … }

VmaBlockBufferImageGranularity::~VmaBlockBufferImageGranularity()
{ … }

void VmaBlockBufferImageGranularity::Init(const VkAllocationCallbacks* pAllocationCallbacks, VkDeviceSize size)
{ … }

void VmaBlockBufferImageGranularity::Destroy(const VkAllocationCallbacks* pAllocationCallbacks)
{ … }

void VmaBlockBufferImageGranularity::RoundupAllocRequest(VmaSuballocationType allocType,
    VkDeviceSize& inOutAllocSize,
    VkDeviceSize& inOutAllocAlignment) const
{ … }

bool VmaBlockBufferImageGranularity::CheckConflictAndAlignUp(VkDeviceSize& inOutAllocOffset,
    VkDeviceSize allocSize,
    VkDeviceSize blockOffset,
    VkDeviceSize blockSize,
    VmaSuballocationType allocType) const
{ … }

void VmaBlockBufferImageGranularity::AllocPages(uint8_t allocType, VkDeviceSize offset, VkDeviceSize size)
{ … }

void VmaBlockBufferImageGranularity::FreePages(VkDeviceSize offset, VkDeviceSize size)
{ … }

void VmaBlockBufferImageGranularity::Clear()
{ … }

VmaBlockBufferImageGranularity::ValidationContext VmaBlockBufferImageGranularity::StartValidation(
    const VkAllocationCallbacks* pAllocationCallbacks, bool isVirutal) const
{ … }

bool VmaBlockBufferImageGranularity::Validate(ValidationContext& ctx,
    VkDeviceSize offset, VkDeviceSize size) const
{ … }

bool VmaBlockBufferImageGranularity::FinishValidation(ValidationContext& ctx) const
{ … }

uint32_t VmaBlockBufferImageGranularity::OffsetToPageIndex(VkDeviceSize offset) const
{ … }

void VmaBlockBufferImageGranularity::AllocPage(RegionInfo& page, uint8_t allocType)
{ … }
#endif // _VMA_BLOCK_BUFFER_IMAGE_GRANULARITY_FUNCTIONS
#endif // _VMA_BLOCK_BUFFER_IMAGE_GRANULARITY

#ifndef _VMA_BLOCK_METADATA_LINEAR
/*
Allocations and their references in internal data structure look like this:

if(m_2ndVectorMode == SECOND_VECTOR_EMPTY):

        0 +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
          |       |
          |       |
GetSize() +-------+

if(m_2ndVectorMode == SECOND_VECTOR_RING_BUFFER):

        0 +-------+
          | Alloc |  2nd[0]
          +-------+
          | Alloc |  2nd[1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  2nd[2nd.size() - 1]
          +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
GetSize() +-------+

if(m_2ndVectorMode == SECOND_VECTOR_DOUBLE_STACK):

        0 +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount]
          +-------+
          | Alloc |  1st[m_1stNullItemsBeginCount + 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  1st[1st.size() - 1]
          +-------+
          |       |
          |       |
          |       |
          +-------+
          | Alloc |  2nd[2nd.size() - 1]
          +-------+
          |  ...  |
          +-------+
          | Alloc |  2nd[1]
          +-------+
          | Alloc |  2nd[0]
GetSize() +-------+

*/
class VmaBlockMetadata_Linear : public VmaBlockMetadata
{ … };

#ifndef _VMA_BLOCK_METADATA_LINEAR_FUNCTIONS
VmaBlockMetadata_Linear::VmaBlockMetadata_Linear(const VkAllocationCallbacks* pAllocationCallbacks,
    VkDeviceSize bufferImageGranularity, bool isVirtual)
    : … { … }

void VmaBlockMetadata_Linear::Init(VkDeviceSize size)
{ … }

bool VmaBlockMetadata_Linear::Validate() const
{ … }

size_t VmaBlockMetadata_Linear::GetAllocationCount() const
{ … }

size_t VmaBlockMetadata_Linear::GetFreeRegionsCount() const
{ … }

void VmaBlockMetadata_Linear::AddDetailedStatistics(VmaDetailedStatistics& inoutStats) const
{ … }

void VmaBlockMetadata_Linear::AddStatistics(VmaStatistics& inoutStats) const
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaBlockMetadata_Linear::PrintDetailedMap(class VmaJsonWriter& json) const
{ … }
#endif // VMA_STATS_STRING_ENABLED

bool VmaBlockMetadata_Linear::CreateAllocationRequest(
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    bool upperAddress,
    VmaSuballocationType allocType,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{ … }

VkResult VmaBlockMetadata_Linear::CheckCorruption(const void* pBlockData)
{ … }

void VmaBlockMetadata_Linear::Alloc(
    const VmaAllocationRequest& request,
    VmaSuballocationType type,
    void* userData)
{ … }

void VmaBlockMetadata_Linear::Free(VmaAllocHandle allocHandle)
{ … }

void VmaBlockMetadata_Linear::GetAllocationInfo(VmaAllocHandle allocHandle, VmaVirtualAllocationInfo& outInfo)
{ … }

void* VmaBlockMetadata_Linear::GetAllocationUserData(VmaAllocHandle allocHandle) const
{ … }

VmaAllocHandle VmaBlockMetadata_Linear::GetAllocationListBegin() const
{ … }

VmaAllocHandle VmaBlockMetadata_Linear::GetNextAllocation(VmaAllocHandle prevAlloc) const
{ … }

VkDeviceSize VmaBlockMetadata_Linear::GetNextFreeRegionSize(VmaAllocHandle alloc) const
{ … }

void VmaBlockMetadata_Linear::Clear()
{ … }

void VmaBlockMetadata_Linear::SetAllocationUserData(VmaAllocHandle allocHandle, void* userData)
{ … }

void VmaBlockMetadata_Linear::DebugLogAllAllocations() const
{ … }

VmaSuballocation& VmaBlockMetadata_Linear::FindSuballocation(VkDeviceSize offset) const
{ … }

bool VmaBlockMetadata_Linear::ShouldCompact1st() const
{ … }

void VmaBlockMetadata_Linear::CleanupAfterFree()
{ … }

bool VmaBlockMetadata_Linear::CreateAllocationRequest_LowerAddress(
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{ … }

bool VmaBlockMetadata_Linear::CreateAllocationRequest_UpperAddress(
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{ … }
#endif // _VMA_BLOCK_METADATA_LINEAR_FUNCTIONS
#endif // _VMA_BLOCK_METADATA_LINEAR

#ifndef _VMA_BLOCK_METADATA_TLSF
// To not search current larger region if first allocation won't succeed and skip to smaller range
// use with VMA_ALLOCATION_CREATE_STRATEGY_MIN_MEMORY_BIT as strategy in CreateAllocationRequest().
// When fragmentation and reusal of previous blocks doesn't matter then use with
// VMA_ALLOCATION_CREATE_STRATEGY_MIN_TIME_BIT for fastest alloc time possible.
class VmaBlockMetadata_TLSF : public VmaBlockMetadata
{ … };

#ifndef _VMA_BLOCK_METADATA_TLSF_FUNCTIONS
VmaBlockMetadata_TLSF::VmaBlockMetadata_TLSF(const VkAllocationCallbacks* pAllocationCallbacks,
    VkDeviceSize bufferImageGranularity, bool isVirtual)
    : … { … }

VmaBlockMetadata_TLSF::~VmaBlockMetadata_TLSF()
{ … }

void VmaBlockMetadata_TLSF::Init(VkDeviceSize size)
{ … }

bool VmaBlockMetadata_TLSF::Validate() const
{ … }

void VmaBlockMetadata_TLSF::AddDetailedStatistics(VmaDetailedStatistics& inoutStats) const
{ … }

void VmaBlockMetadata_TLSF::AddStatistics(VmaStatistics& inoutStats) const
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaBlockMetadata_TLSF::PrintDetailedMap(class VmaJsonWriter& json) const
{ … }
#endif

bool VmaBlockMetadata_TLSF::CreateAllocationRequest(
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    bool upperAddress,
    VmaSuballocationType allocType,
    uint32_t strategy,
    VmaAllocationRequest* pAllocationRequest)
{ … }

VkResult VmaBlockMetadata_TLSF::CheckCorruption(const void* pBlockData)
{ … }

void VmaBlockMetadata_TLSF::Alloc(
    const VmaAllocationRequest& request,
    VmaSuballocationType type,
    void* userData)
{ … }

void VmaBlockMetadata_TLSF::Free(VmaAllocHandle allocHandle)
{ … }

void VmaBlockMetadata_TLSF::GetAllocationInfo(VmaAllocHandle allocHandle, VmaVirtualAllocationInfo& outInfo)
{ … }

void* VmaBlockMetadata_TLSF::GetAllocationUserData(VmaAllocHandle allocHandle) const
{ … }

VmaAllocHandle VmaBlockMetadata_TLSF::GetAllocationListBegin() const
{ … }

VmaAllocHandle VmaBlockMetadata_TLSF::GetNextAllocation(VmaAllocHandle prevAlloc) const
{ … }

VkDeviceSize VmaBlockMetadata_TLSF::GetNextFreeRegionSize(VmaAllocHandle alloc) const
{ … }

void VmaBlockMetadata_TLSF::Clear()
{ … }

void VmaBlockMetadata_TLSF::SetAllocationUserData(VmaAllocHandle allocHandle, void* userData)
{ … }

void VmaBlockMetadata_TLSF::DebugLogAllAllocations() const
{ … }

uint8_t VmaBlockMetadata_TLSF::SizeToMemoryClass(VkDeviceSize size) const
{ … }

uint16_t VmaBlockMetadata_TLSF::SizeToSecondIndex(VkDeviceSize size, uint8_t memoryClass) const
{ … }

uint32_t VmaBlockMetadata_TLSF::GetListIndex(uint8_t memoryClass, uint16_t secondIndex) const
{ … }

uint32_t VmaBlockMetadata_TLSF::GetListIndex(VkDeviceSize size) const
{ … }

void VmaBlockMetadata_TLSF::RemoveFreeBlock(Block* block)
{ … }

void VmaBlockMetadata_TLSF::InsertFreeBlock(Block* block)
{ … }

void VmaBlockMetadata_TLSF::MergeBlock(Block* block, Block* prev)
{ … }

VmaBlockMetadata_TLSF::Block* VmaBlockMetadata_TLSF::FindFreeBlock(VkDeviceSize size, uint32_t& listIndex) const
{ … }

bool VmaBlockMetadata_TLSF::CheckBlock(
    Block& block,
    uint32_t listIndex,
    VkDeviceSize allocSize,
    VkDeviceSize allocAlignment,
    VmaSuballocationType allocType,
    VmaAllocationRequest* pAllocationRequest)
{ … }
#endif // _VMA_BLOCK_METADATA_TLSF_FUNCTIONS
#endif // _VMA_BLOCK_METADATA_TLSF

#ifndef _VMA_BLOCK_VECTOR
/*
Sequence of VmaDeviceMemoryBlock. Represents memory blocks allocated for a specific
Vulkan memory type.

Synchronized internally with a mutex.
*/
class VmaBlockVector
{ … };
#endif // _VMA_BLOCK_VECTOR

#ifndef _VMA_DEFRAGMENTATION_CONTEXT
struct VmaDefragmentationContext_T
{ … };
#endif // _VMA_DEFRAGMENTATION_CONTEXT

#ifndef _VMA_POOL_T
struct VmaPool_T
{ … };

struct VmaPoolListItemTraits
{ … };
#endif // _VMA_POOL_T

#ifndef _VMA_CURRENT_BUDGET_DATA
struct VmaCurrentBudgetData
{ … };

#ifndef _VMA_CURRENT_BUDGET_DATA_FUNCTIONS
VmaCurrentBudgetData::VmaCurrentBudgetData()
{ … }

void VmaCurrentBudgetData::AddAllocation(uint32_t heapIndex, VkDeviceSize allocationSize)
{ … }

void VmaCurrentBudgetData::RemoveAllocation(uint32_t heapIndex, VkDeviceSize allocationSize)
{ … }
#endif // _VMA_CURRENT_BUDGET_DATA_FUNCTIONS
#endif // _VMA_CURRENT_BUDGET_DATA

#ifndef _VMA_ALLOCATION_OBJECT_ALLOCATOR
/*
Thread-safe wrapper over VmaPoolAllocator free list, for allocation of VmaAllocation_T objects.
*/
class VmaAllocationObjectAllocator
{ … };

template<typename... Types>
VmaAllocation VmaAllocationObjectAllocator::Allocate(Types&&... args)
{ … }

void VmaAllocationObjectAllocator::Free(VmaAllocation hAlloc)
{ … }
#endif // _VMA_ALLOCATION_OBJECT_ALLOCATOR

#ifndef _VMA_VIRTUAL_BLOCK_T
struct VmaVirtualBlock_T
{ … };

#ifndef _VMA_VIRTUAL_BLOCK_T_FUNCTIONS
VmaVirtualBlock_T::VmaVirtualBlock_T(const VmaVirtualBlockCreateInfo& createInfo)
    : … { … }

VmaVirtualBlock_T::~VmaVirtualBlock_T()
{ … }

const VkAllocationCallbacks* VmaVirtualBlock_T::GetAllocationCallbacks() const
{ … }

void VmaVirtualBlock_T::GetAllocationInfo(VmaVirtualAllocation allocation, VmaVirtualAllocationInfo& outInfo)
{ … }

VkResult VmaVirtualBlock_T::Allocate(const VmaVirtualAllocationCreateInfo& createInfo, VmaVirtualAllocation& outAllocation,
    VkDeviceSize* outOffset)
{ … }

void VmaVirtualBlock_T::GetStatistics(VmaStatistics& outStats) const
{ … }

void VmaVirtualBlock_T::CalculateDetailedStatistics(VmaDetailedStatistics& outStats) const
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaVirtualBlock_T::BuildStatsString(bool detailedMap, VmaStringBuilder& sb) const
{ … }
#endif // VMA_STATS_STRING_ENABLED
#endif // _VMA_VIRTUAL_BLOCK_T_FUNCTIONS
#endif // _VMA_VIRTUAL_BLOCK_T


// Main allocator object.
struct VmaAllocator_T
{ … };


#ifndef _VMA_MEMORY_FUNCTIONS
static void* VmaMalloc(VmaAllocator hAllocator, size_t size, size_t alignment)
{ … }

static void VmaFree(VmaAllocator hAllocator, void* ptr)
{ … }

template<typename T>
static T* VmaAllocate(VmaAllocator hAllocator)
{ … }

template<typename T>
static T* VmaAllocateArray(VmaAllocator hAllocator, size_t count)
{ … }

template<typename T>
static void vma_delete(VmaAllocator hAllocator, T* ptr)
{ … }

template<typename T>
static void vma_delete_array(VmaAllocator hAllocator, T* ptr, size_t count)
{ … }
#endif // _VMA_MEMORY_FUNCTIONS

#ifndef _VMA_DEVICE_MEMORY_BLOCK_FUNCTIONS
VmaDeviceMemoryBlock::VmaDeviceMemoryBlock(VmaAllocator hAllocator)
    : … { … }

VmaDeviceMemoryBlock::~VmaDeviceMemoryBlock()
{ … }

void VmaDeviceMemoryBlock::Init(
    VmaAllocator hAllocator,
    VmaPool hParentPool,
    uint32_t newMemoryTypeIndex,
    VkDeviceMemory newMemory,
    VkDeviceSize newSize,
    uint32_t id,
    uint32_t algorithm,
    VkDeviceSize bufferImageGranularity)
{ … }

void VmaDeviceMemoryBlock::Destroy(VmaAllocator allocator)
{ … }

void VmaDeviceMemoryBlock::PostAlloc(VmaAllocator hAllocator)
{ … }

void VmaDeviceMemoryBlock::PostFree(VmaAllocator hAllocator)
{ … }

bool VmaDeviceMemoryBlock::Validate() const
{ … }

VkResult VmaDeviceMemoryBlock::CheckCorruption(VmaAllocator hAllocator)
{ … }

VkResult VmaDeviceMemoryBlock::Map(VmaAllocator hAllocator, uint32_t count, void** ppData)
{ … }

void VmaDeviceMemoryBlock::Unmap(VmaAllocator hAllocator, uint32_t count)
{ … }

VkResult VmaDeviceMemoryBlock::WriteMagicValueAfterAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize)
{ … }

VkResult VmaDeviceMemoryBlock::ValidateMagicValueAfterAllocation(VmaAllocator hAllocator, VkDeviceSize allocOffset, VkDeviceSize allocSize)
{ … }

VkResult VmaDeviceMemoryBlock::BindBufferMemory(
    const VmaAllocator hAllocator,
    const VmaAllocation hAllocation,
    VkDeviceSize allocationLocalOffset,
    VkBuffer hBuffer,
    const void* pNext)
{ … }

VkResult VmaDeviceMemoryBlock::BindImageMemory(
    const VmaAllocator hAllocator,
    const VmaAllocation hAllocation,
    VkDeviceSize allocationLocalOffset,
    VkImage hImage,
    const void* pNext)
{ … }
#endif // _VMA_DEVICE_MEMORY_BLOCK_FUNCTIONS

#ifndef _VMA_ALLOCATION_T_FUNCTIONS
VmaAllocation_T::VmaAllocation_T(bool mappingAllowed)
    : … { … }

VmaAllocation_T::~VmaAllocation_T()
{ … }

void VmaAllocation_T::InitBlockAllocation(
    VmaDeviceMemoryBlock* block,
    VmaAllocHandle allocHandle,
    VkDeviceSize alignment,
    VkDeviceSize size,
    uint32_t memoryTypeIndex,
    VmaSuballocationType suballocationType,
    bool mapped)
{ … }

void VmaAllocation_T::InitDedicatedAllocation(
    VmaPool hParentPool,
    uint32_t memoryTypeIndex,
    VkDeviceMemory hMemory,
    VmaSuballocationType suballocationType,
    void* pMappedData,
    VkDeviceSize size)
{ … }

void VmaAllocation_T::SetName(VmaAllocator hAllocator, const char* pName)
{ … }

uint8_t VmaAllocation_T::SwapBlockAllocation(VmaAllocator hAllocator, VmaAllocation allocation)
{ … }

VmaAllocHandle VmaAllocation_T::GetAllocHandle() const
{ … }

VkDeviceSize VmaAllocation_T::GetOffset() const
{ … }

VmaPool VmaAllocation_T::GetParentPool() const
{ … }

VkDeviceMemory VmaAllocation_T::GetMemory() const
{ … }

void* VmaAllocation_T::GetMappedData() const
{ … }

void VmaAllocation_T::BlockAllocMap()
{ … }

void VmaAllocation_T::BlockAllocUnmap()
{ … }

VkResult VmaAllocation_T::DedicatedAllocMap(VmaAllocator hAllocator, void** ppData)
{ … }

void VmaAllocation_T::DedicatedAllocUnmap(VmaAllocator hAllocator)
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaAllocation_T::PrintParameters(class VmaJsonWriter& json) const
{ … }
#endif // VMA_STATS_STRING_ENABLED

void VmaAllocation_T::FreeName(VmaAllocator hAllocator)
{ … }
#endif // _VMA_ALLOCATION_T_FUNCTIONS

#ifndef _VMA_BLOCK_VECTOR_FUNCTIONS
VmaBlockVector::VmaBlockVector(
    VmaAllocator hAllocator,
    VmaPool hParentPool,
    uint32_t memoryTypeIndex,
    VkDeviceSize preferredBlockSize,
    size_t minBlockCount,
    size_t maxBlockCount,
    VkDeviceSize bufferImageGranularity,
    bool explicitBlockSize,
    uint32_t algorithm,
    float priority,
    VkDeviceSize minAllocationAlignment,
    void* pMemoryAllocateNext)
    : … { … }

VmaBlockVector::~VmaBlockVector()
{ … }

VkResult VmaBlockVector::CreateMinBlocks()
{ … }

void VmaBlockVector::AddStatistics(VmaStatistics& inoutStats)
{ … }

void VmaBlockVector::AddDetailedStatistics(VmaDetailedStatistics& inoutStats)
{ … }

bool VmaBlockVector::IsEmpty()
{ … }

bool VmaBlockVector::IsCorruptionDetectionEnabled() const
{ … }

VkResult VmaBlockVector::Allocate(
    VkDeviceSize size,
    VkDeviceSize alignment,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{ … }

VkResult VmaBlockVector::AllocatePage(
    VkDeviceSize size,
    VkDeviceSize alignment,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    VmaAllocation* pAllocation)
{ … }

void VmaBlockVector::Free(const VmaAllocation hAllocation)
{ … }

VkDeviceSize VmaBlockVector::CalcMaxBlockSize() const
{ … }

void VmaBlockVector::Remove(VmaDeviceMemoryBlock* pBlock)
{ … }

void VmaBlockVector::IncrementallySortBlocks()
{ … }

void VmaBlockVector::SortByFreeSize()
{ … }

VkResult VmaBlockVector::AllocateFromBlock(
    VmaDeviceMemoryBlock* pBlock,
    VkDeviceSize size,
    VkDeviceSize alignment,
    VmaAllocationCreateFlags allocFlags,
    void* pUserData,
    VmaSuballocationType suballocType,
    uint32_t strategy,
    VmaAllocation* pAllocation)
{ … }

VkResult VmaBlockVector::CommitAllocationRequest(
    VmaAllocationRequest& allocRequest,
    VmaDeviceMemoryBlock* pBlock,
    VkDeviceSize alignment,
    VmaAllocationCreateFlags allocFlags,
    void* pUserData,
    VmaSuballocationType suballocType,
    VmaAllocation* pAllocation)
{ … }

VkResult VmaBlockVector::CreateBlock(VkDeviceSize blockSize, size_t* pNewBlockIndex)
{ … }

bool VmaBlockVector::HasEmptyBlock()
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaBlockVector::PrintDetailedMap(class VmaJsonWriter& json)
{ … }
#endif // VMA_STATS_STRING_ENABLED

VkResult VmaBlockVector::CheckCorruption()
{ … }

#endif // _VMA_BLOCK_VECTOR_FUNCTIONS

#ifndef _VMA_DEFRAGMENTATION_CONTEXT_FUNCTIONS
VmaDefragmentationContext_T::VmaDefragmentationContext_T(
    VmaAllocator hAllocator,
    const VmaDefragmentationInfo& info)
    : … { … }

VmaDefragmentationContext_T::~VmaDefragmentationContext_T()
{ … }

VkResult VmaDefragmentationContext_T::DefragmentPassBegin(VmaDefragmentationPassMoveInfo& moveInfo)
{ … }

VkResult VmaDefragmentationContext_T::DefragmentPassEnd(VmaDefragmentationPassMoveInfo& moveInfo)
{ … }

bool VmaDefragmentationContext_T::ComputeDefragmentation(VmaBlockVector& vector, size_t index)
{ … }

VmaDefragmentationContext_T::MoveAllocationData VmaDefragmentationContext_T::GetMoveData(
    VmaAllocHandle handle, VmaBlockMetadata* metadata)
{ … }

VmaDefragmentationContext_T::CounterStatus VmaDefragmentationContext_T::CheckCounters(VkDeviceSize bytes)
{ … }

bool VmaDefragmentationContext_T::IncrementCounters(VkDeviceSize bytes)
{ … }

bool VmaDefragmentationContext_T::ReallocWithinBlock(VmaBlockVector& vector, VmaDeviceMemoryBlock* block)
{ … }

bool VmaDefragmentationContext_T::AllocInOtherBlock(size_t start, size_t end, MoveAllocationData& data, VmaBlockVector& vector)
{ … }

bool VmaDefragmentationContext_T::ComputeDefragmentation_Fast(VmaBlockVector& vector)
{ … }

bool VmaDefragmentationContext_T::ComputeDefragmentation_Balanced(VmaBlockVector& vector, size_t index, bool update)
{ … }

bool VmaDefragmentationContext_T::ComputeDefragmentation_Full(VmaBlockVector& vector)
{ … }

bool VmaDefragmentationContext_T::ComputeDefragmentation_Extensive(VmaBlockVector& vector, size_t index)
{ … }

void VmaDefragmentationContext_T::UpdateVectorStatistics(VmaBlockVector& vector, StateBalanced& state)
{ … }

bool VmaDefragmentationContext_T::MoveDataToFreeBlocks(VmaSuballocationType currentType,
    VmaBlockVector& vector, size_t firstFreeBlock,
    bool& texturePresent, bool& bufferPresent, bool& otherPresent)
{ … }
#endif // _VMA_DEFRAGMENTATION_CONTEXT_FUNCTIONS

#ifndef _VMA_POOL_T_FUNCTIONS
VmaPool_T::VmaPool_T(
    VmaAllocator hAllocator,
    const VmaPoolCreateInfo& createInfo,
    VkDeviceSize preferredBlockSize)
    : … { … }

VmaPool_T::~VmaPool_T()
{ … }

void VmaPool_T::SetName(const char* pName)
{ … }
#endif // _VMA_POOL_T_FUNCTIONS

#ifndef _VMA_ALLOCATOR_T_FUNCTIONS
VmaAllocator_T::VmaAllocator_T(const VmaAllocatorCreateInfo* pCreateInfo) : … { … }

VkResult VmaAllocator_T::Init(const VmaAllocatorCreateInfo* pCreateInfo)
{ … }

VmaAllocator_T::~VmaAllocator_T()
{ … }

void VmaAllocator_T::ImportVulkanFunctions(const VmaVulkanFunctions* pVulkanFunctions)
{ … }

#if VMA_STATIC_VULKAN_FUNCTIONS == 1

void VmaAllocator_T::ImportVulkanFunctions_Static()
{ … }

#endif // VMA_STATIC_VULKAN_FUNCTIONS == 1

void VmaAllocator_T::ImportVulkanFunctions_Custom(const VmaVulkanFunctions* pVulkanFunctions)
{ … }

#if VMA_DYNAMIC_VULKAN_FUNCTIONS == 1

void VmaAllocator_T::ImportVulkanFunctions_Dynamic()
{ … }

#endif // VMA_DYNAMIC_VULKAN_FUNCTIONS == 1

void VmaAllocator_T::ValidateVulkanFunctions()
{ … }

VkDeviceSize VmaAllocator_T::CalcPreferredBlockSize(uint32_t memTypeIndex)
{ … }

VkResult VmaAllocator_T::AllocateMemoryOfType(
    VmaPool pool,
    VkDeviceSize size,
    VkDeviceSize alignment,
    bool dedicatedPreferred,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    VmaBufferImageUsage dedicatedBufferImageUsage,
    const VmaAllocationCreateInfo& createInfo,
    uint32_t memTypeIndex,
    VmaSuballocationType suballocType,
    VmaDedicatedAllocationList& dedicatedAllocations,
    VmaBlockVector& blockVector,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{ … }

VkResult VmaAllocator_T::AllocateDedicatedMemory(
    VmaPool pool,
    VkDeviceSize size,
    VmaSuballocationType suballocType,
    VmaDedicatedAllocationList& dedicatedAllocations,
    uint32_t memTypeIndex,
    bool map,
    bool isUserDataString,
    bool isMappingAllowed,
    bool canAliasMemory,
    void* pUserData,
    float priority,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    VmaBufferImageUsage dedicatedBufferImageUsage,
    size_t allocationCount,
    VmaAllocation* pAllocations,
    const void* pNextChain)
{ … }

VkResult VmaAllocator_T::AllocateDedicatedMemoryPage(
    VmaPool pool,
    VkDeviceSize size,
    VmaSuballocationType suballocType,
    uint32_t memTypeIndex,
    const VkMemoryAllocateInfo& allocInfo,
    bool map,
    bool isUserDataString,
    bool isMappingAllowed,
    void* pUserData,
    VmaAllocation* pAllocation)
{ … }

void VmaAllocator_T::GetBufferMemoryRequirements(
    VkBuffer hBuffer,
    VkMemoryRequirements& memReq,
    bool& requiresDedicatedAllocation,
    bool& prefersDedicatedAllocation) const
{ … }

void VmaAllocator_T::GetImageMemoryRequirements(
    VkImage hImage,
    VkMemoryRequirements& memReq,
    bool& requiresDedicatedAllocation,
    bool& prefersDedicatedAllocation) const
{ … }

VkResult VmaAllocator_T::FindMemoryTypeIndex(
    uint32_t memoryTypeBits,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VmaBufferImageUsage bufImgUsage,
    uint32_t* pMemoryTypeIndex) const
{ … }

VkResult VmaAllocator_T::CalcMemTypeParams(
    VmaAllocationCreateInfo& inoutCreateInfo,
    uint32_t memTypeIndex,
    VkDeviceSize size,
    size_t allocationCount)
{ … }

VkResult VmaAllocator_T::CalcAllocationParams(
    VmaAllocationCreateInfo& inoutCreateInfo,
    bool dedicatedRequired,
    bool dedicatedPreferred)
{ … }

VkResult VmaAllocator_T::AllocateMemory(
    const VkMemoryRequirements& vkMemReq,
    bool requiresDedicatedAllocation,
    bool prefersDedicatedAllocation,
    VkBuffer dedicatedBuffer,
    VkImage dedicatedImage,
    VmaBufferImageUsage dedicatedBufferImageUsage,
    const VmaAllocationCreateInfo& createInfo,
    VmaSuballocationType suballocType,
    size_t allocationCount,
    VmaAllocation* pAllocations)
{ … }

void VmaAllocator_T::FreeMemory(
    size_t allocationCount,
    const VmaAllocation* pAllocations)
{ … }

void VmaAllocator_T::CalculateStatistics(VmaTotalStatistics* pStats)
{ … }

void VmaAllocator_T::GetHeapBudgets(VmaBudget* outBudgets, uint32_t firstHeap, uint32_t heapCount)
{ … }

void VmaAllocator_T::GetAllocationInfo(VmaAllocation hAllocation, VmaAllocationInfo* pAllocationInfo)
{ … }

void VmaAllocator_T::GetAllocationInfo2(VmaAllocation hAllocation, VmaAllocationInfo2* pAllocationInfo)
{ … }

VkResult VmaAllocator_T::CreatePool(const VmaPoolCreateInfo* pCreateInfo, VmaPool* pPool)
{ … }

void VmaAllocator_T::DestroyPool(VmaPool pool)
{ … }

void VmaAllocator_T::GetPoolStatistics(VmaPool pool, VmaStatistics* pPoolStats)
{ … }

void VmaAllocator_T::CalculatePoolStatistics(VmaPool pool, VmaDetailedStatistics* pPoolStats)
{ … }

void VmaAllocator_T::SetCurrentFrameIndex(uint32_t frameIndex)
{ … }

VkResult VmaAllocator_T::CheckPoolCorruption(VmaPool hPool)
{ … }

VkResult VmaAllocator_T::CheckCorruption(uint32_t memoryTypeBits)
{ … }

VkResult VmaAllocator_T::AllocateVulkanMemory(const VkMemoryAllocateInfo* pAllocateInfo, VkDeviceMemory* pMemory)
{ … }

void VmaAllocator_T::FreeVulkanMemory(uint32_t memoryType, VkDeviceSize size, VkDeviceMemory hMemory)
{ … }

VkResult VmaAllocator_T::BindVulkanBuffer(
    VkDeviceMemory memory,
    VkDeviceSize memoryOffset,
    VkBuffer buffer,
    const void* pNext)
{ … }

VkResult VmaAllocator_T::BindVulkanImage(
    VkDeviceMemory memory,
    VkDeviceSize memoryOffset,
    VkImage image,
    const void* pNext)
{ … }

VkResult VmaAllocator_T::Map(VmaAllocation hAllocation, void** ppData)
{ … }

void VmaAllocator_T::Unmap(VmaAllocation hAllocation)
{ … }

VkResult VmaAllocator_T::BindBufferMemory(
    VmaAllocation hAllocation,
    VkDeviceSize allocationLocalOffset,
    VkBuffer hBuffer,
    const void* pNext)
{ … }

VkResult VmaAllocator_T::BindImageMemory(
    VmaAllocation hAllocation,
    VkDeviceSize allocationLocalOffset,
    VkImage hImage,
    const void* pNext)
{ … }

VkResult VmaAllocator_T::FlushOrInvalidateAllocation(
    VmaAllocation hAllocation,
    VkDeviceSize offset, VkDeviceSize size,
    VMA_CACHE_OPERATION op)
{ … }

VkResult VmaAllocator_T::FlushOrInvalidateAllocations(
    uint32_t allocationCount,
    const VmaAllocation* allocations,
    const VkDeviceSize* offsets, const VkDeviceSize* sizes,
    VMA_CACHE_OPERATION op)
{ … }

VkResult VmaAllocator_T::CopyMemoryToAllocation(
    const void* pSrcHostPointer,
    VmaAllocation dstAllocation,
    VkDeviceSize dstAllocationLocalOffset,
    VkDeviceSize size)
{ … }

VkResult VmaAllocator_T::CopyAllocationToMemory(
    VmaAllocation srcAllocation,
    VkDeviceSize srcAllocationLocalOffset,
    void* pDstHostPointer,
    VkDeviceSize size)
{ … }

void VmaAllocator_T::FreeDedicatedMemory(const VmaAllocation allocation)
{ … }

uint32_t VmaAllocator_T::CalculateGpuDefragmentationMemoryTypeBits() const
{ … }

uint32_t VmaAllocator_T::CalculateGlobalMemoryTypeBits() const
{ … }

bool VmaAllocator_T::GetFlushOrInvalidateRange(
    VmaAllocation allocation,
    VkDeviceSize offset, VkDeviceSize size,
    VkMappedMemoryRange& outRange) const
{ … }

#if VMA_MEMORY_BUDGET
void VmaAllocator_T::UpdateVulkanBudget()
{ … }
#endif // VMA_MEMORY_BUDGET

void VmaAllocator_T::FillAllocation(const VmaAllocation hAllocation, uint8_t pattern)
{ … }

uint32_t VmaAllocator_T::GetGpuDefragmentationMemoryTypeBits()
{ … }

#if VMA_STATS_STRING_ENABLED
void VmaAllocator_T::PrintDetailedMap(VmaJsonWriter& json)
{ … }
#endif // VMA_STATS_STRING_ENABLED
#endif // _VMA_ALLOCATOR_T_FUNCTIONS


#ifndef _VMA_PUBLIC_INTERFACE
VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAllocator(
    const VmaAllocatorCreateInfo* pCreateInfo,
    VmaAllocator* pAllocator)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaDestroyAllocator(
    VmaAllocator allocator)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocatorInfo(VmaAllocator allocator, VmaAllocatorInfo* pAllocatorInfo)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetPhysicalDeviceProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceProperties **ppPhysicalDeviceProperties)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetMemoryProperties(
    VmaAllocator allocator,
    const VkPhysicalDeviceMemoryProperties** ppPhysicalDeviceMemoryProperties)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetMemoryTypeProperties(
    VmaAllocator allocator,
    uint32_t memoryTypeIndex,
    VkMemoryPropertyFlags* pFlags)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaSetCurrentFrameIndex(
    VmaAllocator allocator,
    uint32_t frameIndex)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaCalculateStatistics(
    VmaAllocator allocator,
    VmaTotalStatistics* pStats)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetHeapBudgets(
    VmaAllocator allocator,
    VmaBudget* pBudgets)
{ … }

#if VMA_STATS_STRING_ENABLED

VMA_CALL_PRE void VMA_CALL_POST vmaBuildStatsString(
    VmaAllocator allocator,
    char** ppStatsString,
    VkBool32 detailedMap)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaFreeStatsString(
    VmaAllocator allocator,
    char* pStatsString)
{ … }

#endif // VMA_STATS_STRING_ENABLED

/*
This function is not protected by any mutex because it just reads immutable data.
*/
VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndex(
    VmaAllocator allocator,
    uint32_t memoryTypeBits,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndexForBufferInfo(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndexForImageInfo(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    uint32_t* pMemoryTypeIndex)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreatePool(
    VmaAllocator allocator,
    const VmaPoolCreateInfo* pCreateInfo,
    VmaPool* pPool)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaDestroyPool(
    VmaAllocator allocator,
    VmaPool pool)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetPoolStatistics(
    VmaAllocator allocator,
    VmaPool pool,
    VmaStatistics* pPoolStats)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaCalculatePoolStatistics(
    VmaAllocator allocator,
    VmaPool pool,
    VmaDetailedStatistics* pPoolStats)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCheckPoolCorruption(VmaAllocator allocator, VmaPool pool)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetPoolName(
    VmaAllocator allocator,
    VmaPool pool,
    const char** ppName)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaSetPoolName(
    VmaAllocator allocator,
    VmaPool pool,
    const char* pName)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemory(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryPages(
    VmaAllocator allocator,
    const VkMemoryRequirements* pVkMemoryRequirements,
    const VmaAllocationCreateInfo* pCreateInfo,
    size_t allocationCount,
    VmaAllocation* pAllocations,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryForBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryForImage(
    VmaAllocator allocator,
    VkImage image,
    const VmaAllocationCreateInfo* pCreateInfo,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaFreeMemory(
    VmaAllocator allocator,
    VmaAllocation allocation)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaFreeMemoryPages(
    VmaAllocator allocator,
    size_t allocationCount,
    const VmaAllocation* pAllocations)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocationInfo(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocationInfo2(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VmaAllocationInfo2* pAllocationInfo)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaSetAllocationUserData(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void* pUserData)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaSetAllocationName(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    const char* VMA_NULLABLE pName)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocationMemoryProperties(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    VkMemoryPropertyFlags* VMA_NOT_NULL pFlags)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaMapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    void** ppData)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaUnmapMemory(
    VmaAllocator allocator,
    VmaAllocation allocation)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaFlushAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize offset,
    VkDeviceSize size)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaInvalidateAllocation(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize offset,
    VkDeviceSize size)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaFlushAllocations(
    VmaAllocator allocator,
    uint32_t allocationCount,
    const VmaAllocation* allocations,
    const VkDeviceSize* offsets,
    const VkDeviceSize* sizes)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaInvalidateAllocations(
    VmaAllocator allocator,
    uint32_t allocationCount,
    const VmaAllocation* allocations,
    const VkDeviceSize* offsets,
    const VkDeviceSize* sizes)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCopyMemoryToAllocation(
    VmaAllocator allocator,
    const void* pSrcHostPointer,
    VmaAllocation dstAllocation,
    VkDeviceSize dstAllocationLocalOffset,
    VkDeviceSize size)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCopyAllocationToMemory(
    VmaAllocator allocator,
    VmaAllocation srcAllocation,
    VkDeviceSize srcAllocationLocalOffset,
    void* pDstHostPointer,
    VkDeviceSize size)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCheckCorruption(
    VmaAllocator allocator,
    uint32_t memoryTypeBits)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBeginDefragmentation(
    VmaAllocator allocator,
    const VmaDefragmentationInfo* pInfo,
    VmaDefragmentationContext* pContext)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaEndDefragmentation(
    VmaAllocator allocator,
    VmaDefragmentationContext context,
    VmaDefragmentationStats* pStats)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBeginDefragmentationPass(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaDefragmentationContext VMA_NOT_NULL context,
    VmaDefragmentationPassMoveInfo* VMA_NOT_NULL pPassInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaEndDefragmentationPass(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaDefragmentationContext VMA_NOT_NULL context,
    VmaDefragmentationPassMoveInfo* VMA_NOT_NULL pPassInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBindBufferMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkBuffer buffer)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBindBufferMemory2(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize allocationLocalOffset,
    VkBuffer buffer,
    const void* pNext)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBindImageMemory(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkImage image)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaBindImageMemory2(
    VmaAllocator allocator,
    VmaAllocation allocation,
    VkDeviceSize allocationLocalOffset,
    VkImage image,
    const void* pNext)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateBuffer(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkBuffer* pBuffer,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateBufferWithAlignment(
    VmaAllocator allocator,
    const VkBufferCreateInfo* pBufferCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkDeviceSize minAlignment,
    VkBuffer* pBuffer,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAliasingBuffer(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    const VkBufferCreateInfo* VMA_NOT_NULL pBufferCreateInfo,
    VkBuffer VMA_NULLABLE_NON_DISPATCHABLE* VMA_NOT_NULL pBuffer)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAliasingBuffer2(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    VkDeviceSize allocationLocalOffset,
    const VkBufferCreateInfo* VMA_NOT_NULL pBufferCreateInfo,
    VkBuffer VMA_NULLABLE_NON_DISPATCHABLE* VMA_NOT_NULL pBuffer)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaDestroyBuffer(
    VmaAllocator allocator,
    VkBuffer buffer,
    VmaAllocation allocation)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateImage(
    VmaAllocator allocator,
    const VkImageCreateInfo* pImageCreateInfo,
    const VmaAllocationCreateInfo* pAllocationCreateInfo,
    VkImage* pImage,
    VmaAllocation* pAllocation,
    VmaAllocationInfo* pAllocationInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAliasingImage(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    const VkImageCreateInfo* VMA_NOT_NULL pImageCreateInfo,
    VkImage VMA_NULLABLE_NON_DISPATCHABLE* VMA_NOT_NULL pImage)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAliasingImage2(
    VmaAllocator VMA_NOT_NULL allocator,
    VmaAllocation VMA_NOT_NULL allocation,
    VkDeviceSize allocationLocalOffset,
    const VkImageCreateInfo* VMA_NOT_NULL pImageCreateInfo,
    VkImage VMA_NULLABLE_NON_DISPATCHABLE* VMA_NOT_NULL pImage)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaDestroyImage(
    VmaAllocator VMA_NOT_NULL allocator,
    VkImage VMA_NULLABLE_NON_DISPATCHABLE image,
    VmaAllocation VMA_NULLABLE allocation)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateVirtualBlock(
    const VmaVirtualBlockCreateInfo* VMA_NOT_NULL pCreateInfo,
    VmaVirtualBlock VMA_NULLABLE * VMA_NOT_NULL pVirtualBlock)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaDestroyVirtualBlock(VmaVirtualBlock VMA_NULLABLE virtualBlock)
{ … }

VMA_CALL_PRE VkBool32 VMA_CALL_POST vmaIsVirtualBlockEmpty(VmaVirtualBlock VMA_NOT_NULL virtualBlock)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetVirtualAllocationInfo(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    VmaVirtualAllocation VMA_NOT_NULL_NON_DISPATCHABLE allocation, VmaVirtualAllocationInfo* VMA_NOT_NULL pVirtualAllocInfo)
{ … }

VMA_CALL_PRE VkResult VMA_CALL_POST vmaVirtualAllocate(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    const VmaVirtualAllocationCreateInfo* VMA_NOT_NULL pCreateInfo, VmaVirtualAllocation VMA_NULLABLE_NON_DISPATCHABLE* VMA_NOT_NULL pAllocation,
    VkDeviceSize* VMA_NULLABLE pOffset)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaVirtualFree(VmaVirtualBlock VMA_NOT_NULL virtualBlock, VmaVirtualAllocation VMA_NULLABLE_NON_DISPATCHABLE allocation)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaClearVirtualBlock(VmaVirtualBlock VMA_NOT_NULL virtualBlock)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaSetVirtualAllocationUserData(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    VmaVirtualAllocation VMA_NOT_NULL_NON_DISPATCHABLE allocation, void* VMA_NULLABLE pUserData)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaGetVirtualBlockStatistics(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    VmaStatistics* VMA_NOT_NULL pStats)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaCalculateVirtualBlockStatistics(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    VmaDetailedStatistics* VMA_NOT_NULL pStats)
{ … }

#if VMA_STATS_STRING_ENABLED

VMA_CALL_PRE void VMA_CALL_POST vmaBuildVirtualBlockStatsString(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    char* VMA_NULLABLE * VMA_NOT_NULL ppStatsString, VkBool32 detailedMap)
{ … }

VMA_CALL_PRE void VMA_CALL_POST vmaFreeVirtualBlockStatsString(VmaVirtualBlock VMA_NOT_NULL virtualBlock,
    char* VMA_NULLABLE pStatsString)
{ … }
#endif // VMA_STATS_STRING_ENABLED
#endif // _VMA_PUBLIC_INTERFACE
#endif // VMA_IMPLEMENTATION

/**
\page quick_start Quick start

\section quick_start_project_setup Project setup

Vulkan Memory Allocator comes in form of a "stb-style" single header file.
While you can pull the entire repository e.g. as Git module, there is also Cmake script provided,
you don't need to build it as a separate library project.
You can add file "vk_mem_alloc.h" directly to your project and submit it to code repository next to your other source files.

"Single header" doesn't mean that everything is contained in C/C++ declarations,
like it tends to be in case of inline functions or C++ templates.
It means that implementation is bundled with interface in a single file and needs to be extracted using preprocessor macro.
If you don't do it properly, it will result in linker errors.

To do it properly:

-# Include "vk_mem_alloc.h" file in each CPP file where you want to use the library.
   This includes declarations of all members of the library.
-# In exactly one CPP file define following macro before this include.
   It enables also internal definitions.

\code
#define VMA_IMPLEMENTATION
#include "vk_mem_alloc.h"
\endcode

It may be a good idea to create dedicated CPP file just for this purpose, e.g. "VmaUsage.cpp".

This library includes header `<vulkan/vulkan.h>`, which in turn
includes `<windows.h>` on Windows. If you need some specific macros defined
before including these headers (like `WIN32_LEAN_AND_MEAN` or
`WINVER` for Windows, `VK_USE_PLATFORM_WIN32_KHR` for Vulkan), you must define
them before every `#include` of this library.
It may be a good idea to create a dedicate header file for this purpose, e.g. "VmaUsage.h",
that will be included in other source files instead of VMA header directly.

This library is written in C++, but has C-compatible interface.
Thus, you can include and use "vk_mem_alloc.h" in C or C++ code, but full
implementation with `VMA_IMPLEMENTATION` macro must be compiled as C++, NOT as C.
Some features of C++14 are used and required. Features of C++20 are used optionally when available.
Some headers of standard C and C++ library are used, but STL containers, RTTI, or C++ exceptions are not used.


\section quick_start_initialization Initialization

VMA offers library interface in a style similar to Vulkan, with object handles like #VmaAllocation,
structures describing parameters of objects to be created like #VmaAllocationCreateInfo,
and errors codes returned from functions using `VkResult` type.

The first and the main object that needs to be created is #VmaAllocator.
It represents the initialization of the entire library.
Only one such object should be created per `VkDevice`.
You should create it at program startup, after `VkDevice` was created, and before any device memory allocator needs to be made.
It must be destroyed before `VkDevice` is destroyed.

At program startup:

-# Initialize Vulkan to have `VkInstance`, `VkPhysicalDevice`, `VkDevice` object.
-# Fill VmaAllocatorCreateInfo structure and call vmaCreateAllocator() to create #VmaAllocator object.

Only members `physicalDevice`, `device`, `instance` are required.
However, you should inform the library which Vulkan version do you use by setting
VmaAllocatorCreateInfo::vulkanApiVersion and which extensions did you enable
by setting VmaAllocatorCreateInfo::flags.
Otherwise, VMA would use only features of Vulkan 1.0 core with no extensions.
See below for details.

\subsection quick_start_initialization_selecting_vulkan_version Selecting Vulkan version

VMA supports Vulkan version down to 1.0, for backward compatibility.
If you want to use higher version, you need to inform the library about it.
This is a two-step process.

<b>Step 1: Compile time.</b> By default, VMA compiles with code supporting the highest
Vulkan version found in the included `<vulkan/vulkan.h>` that is also supported by the library.
If this is OK, you don't need to do anything.
However, if you want to compile VMA as if only some lower Vulkan version was available,
define macro `VMA_VULKAN_VERSION` before every `#include "vk_mem_alloc.h"`.
It should have decimal numeric value in form of ABBBCCC, where A = major, BBB = minor, CCC = patch Vulkan version.
For example, to compile against Vulkan 1.2:

\code
#define VMA_VULKAN_VERSION 1002000 // Vulkan 1.2
#include "vk_mem_alloc.h"
\endcode

<b>Step 2: Runtime.</b> Even when compiled with higher Vulkan version available,
VMA can use only features of a lower version, which is configurable during creation of the #VmaAllocator object.
By default, only Vulkan 1.0 is used.
To initialize the allocator with support for higher Vulkan version, you need to set member
VmaAllocatorCreateInfo::vulkanApiVersion to an appropriate value, e.g. using constants like `VK_API_VERSION_1_2`.
See code sample below.

\subsection quick_start_initialization_importing_vulkan_functions Importing Vulkan functions

You may need to configure importing Vulkan functions. There are 3 ways to do this:

-# **If you link with Vulkan static library** (e.g. "vulkan-1.lib" on Windows):
   - You don't need to do anything.
   - VMA will use these, as macro `VMA_STATIC_VULKAN_FUNCTIONS` is defined to 1 by default.
-# **If you want VMA to fetch pointers to Vulkan functions dynamically** using `vkGetInstanceProcAddr`,
   `vkGetDeviceProcAddr` (this is the option presented in the example below):
   - Define `VMA_STATIC_VULKAN_FUNCTIONS` to 0, `VMA_DYNAMIC_VULKAN_FUNCTIONS` to 1.
   - Provide pointers to these two functions via VmaVulkanFunctions::vkGetInstanceProcAddr,
     VmaVulkanFunctions::vkGetDeviceProcAddr.
   - The library will fetch pointers to all other functions it needs internally.
-# **If you fetch pointers to all Vulkan functions in a custom way**, e.g. using some loader like
   [Volk](https://github.com/zeux/volk):
   - Define `VMA_STATIC_VULKAN_FUNCTIONS` and `VMA_DYNAMIC_VULKAN_FUNCTIONS` to 0.
   - Pass these pointers via structure #VmaVulkanFunctions.

\subsection quick_start_initialization_enabling_extensions Enabling extensions

VMA can automatically use following Vulkan extensions.
If you found them available on the selected physical device and you enabled them
while creating `VkInstance` / `VkDevice` object, inform VMA about their availability
by setting appropriate flags in VmaAllocatorCreateInfo::flags.

Vulkan extension              | VMA flag
------------------------------|-----------------------------------------------------
VK_KHR_dedicated_allocation   | #VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT
VK_KHR_bind_memory2           | #VMA_ALLOCATOR_CREATE_KHR_BIND_MEMORY2_BIT
VK_KHR_maintenance4           | #VMA_ALLOCATOR_CREATE_KHR_MAINTENANCE4_BIT
VK_KHR_maintenance5           | #VMA_ALLOCATOR_CREATE_KHR_MAINTENANCE5_BIT
VK_EXT_memory_budget          | #VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT
VK_KHR_buffer_device_address  | #VMA_ALLOCATOR_CREATE_BUFFER_DEVICE_ADDRESS_BIT
VK_EXT_memory_priority        | #VMA_ALLOCATOR_CREATE_EXT_MEMORY_PRIORITY_BIT
VK_AMD_device_coherent_memory | #VMA_ALLOCATOR_CREATE_AMD_DEVICE_COHERENT_MEMORY_BIT

Example with fetching pointers to Vulkan functions dynamically:

\code
#define VMA_STATIC_VULKAN_FUNCTIONS 0
#define VMA_DYNAMIC_VULKAN_FUNCTIONS 1
#include "vk_mem_alloc.h"

...

VmaVulkanFunctions vulkanFunctions = {};
vulkanFunctions.vkGetInstanceProcAddr = &vkGetInstanceProcAddr;
vulkanFunctions.vkGetDeviceProcAddr = &vkGetDeviceProcAddr;

VmaAllocatorCreateInfo allocatorCreateInfo = {};
allocatorCreateInfo.flags = VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT;
allocatorCreateInfo.vulkanApiVersion = VK_API_VERSION_1_2;
allocatorCreateInfo.physicalDevice = physicalDevice;
allocatorCreateInfo.device = device;
allocatorCreateInfo.instance = instance;
allocatorCreateInfo.pVulkanFunctions = &vulkanFunctions;

VmaAllocator allocator;
vmaCreateAllocator(&allocatorCreateInfo, &allocator);

// Entire program...

// At the end, don't forget to:
vmaDestroyAllocator(allocator);
\endcode


\subsection quick_start_initialization_other_config Other configuration options

There are additional configuration options available through preprocessor macros that you can define
before including VMA header and through parameters passed in #VmaAllocatorCreateInfo.
They include a possibility to use your own callbacks for host memory allocations (`VkAllocationCallbacks`),
callbacks for device memory allocations (instead of `vkAllocateMemory`, `vkFreeMemory`),
or your custom `VMA_ASSERT` macro, among others.
For more information, see: @ref configuration.


\section quick_start_resource_allocation Resource allocation

When you want to create a buffer or image:

-# Fill `VkBufferCreateInfo` / `VkImageCreateInfo` structure.
-# Fill VmaAllocationCreateInfo structure.
-# Call vmaCreateBuffer() / vmaCreateImage() to get `VkBuffer`/`VkImage` with memory
   already allocated and bound to it, plus #VmaAllocation objects that represents its underlying memory.

\code
VkBufferCreateInfo bufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufferInfo.size = 65536;
bufferInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocInfo = {};
allocInfo.usage = VMA_MEMORY_USAGE_AUTO;

VkBuffer buffer;
VmaAllocation allocation;
vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr);
\endcode

Don't forget to destroy your buffer and allocation objects when no longer needed:

\code
vmaDestroyBuffer(allocator, buffer, allocation);
\endcode

If you need to map the buffer, you must set flag
#VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT or #VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT
in VmaAllocationCreateInfo::flags.
There are many additional parameters that can control the choice of memory type to be used for the allocation
and other features.
For more information, see documentation chapters: @ref choosing_memory_type, @ref memory_mapping.


\page choosing_memory_type Choosing memory type

Physical devices in Vulkan support various combinations of memory heaps and
types. Help with choosing correct and optimal memory type for your specific
resource is one of the key features of this library. You can use it by filling
appropriate members of VmaAllocationCreateInfo structure, as described below.
You can also combine multiple methods.

-# If you just want to find memory type index that meets your requirements, you
   can use function: vmaFindMemoryTypeIndexForBufferInfo(),
   vmaFindMemoryTypeIndexForImageInfo(), vmaFindMemoryTypeIndex().
-# If you want to allocate a region of device memory without association with any
   specific image or buffer, you can use function vmaAllocateMemory(). Usage of
   this function is not recommended and usually not needed.
   vmaAllocateMemoryPages() function is also provided for creating multiple allocations at once,
   which may be useful for sparse binding.
-# If you already have a buffer or an image created, you want to allocate memory
   for it and then you will bind it yourself, you can use function
   vmaAllocateMemoryForBuffer(), vmaAllocateMemoryForImage().
   For binding you should use functions: vmaBindBufferMemory(), vmaBindImageMemory()
   or their extended versions: vmaBindBufferMemory2(), vmaBindImageMemory2().
-# If you want to create a buffer or an image, allocate memory for it, and bind
   them together, all in one call, you can use function vmaCreateBuffer(),
   vmaCreateImage().
   <b>This is the easiest and recommended way to use this library!</b>

When using 3. or 4., the library internally queries Vulkan for memory types
supported for that buffer or image (function `vkGetBufferMemoryRequirements()`)
and uses only one of these types.

If no memory type can be found that meets all the requirements, these functions
return `VK_ERROR_FEATURE_NOT_PRESENT`.

You can leave VmaAllocationCreateInfo structure completely filled with zeros.
It means no requirements are specified for memory type.
It is valid, although not very useful.

\section choosing_memory_type_usage Usage

The easiest way to specify memory requirements is to fill member
VmaAllocationCreateInfo::usage using one of the values of enum #VmaMemoryUsage.
It defines high level, common usage types.
Since version 3 of the library, it is recommended to use #VMA_MEMORY_USAGE_AUTO to let it select best memory type for your resource automatically.

For example, if you want to create a uniform buffer that will be filled using
transfer only once or infrequently and then used for rendering every frame as a uniform buffer, you can
do it using following code. The buffer will most likely end up in a memory type with
`VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` to be fast to access by the GPU device.

\code
VkBufferCreateInfo bufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufferInfo.size = 65536;
bufferInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocInfo = {};
allocInfo.usage = VMA_MEMORY_USAGE_AUTO;

VkBuffer buffer;
VmaAllocation allocation;
vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr);
\endcode

If you have a preference for putting the resource in GPU (device) memory or CPU (host) memory
on systems with discrete graphics card that have the memories separate, you can use
#VMA_MEMORY_USAGE_AUTO_PREFER_DEVICE or #VMA_MEMORY_USAGE_AUTO_PREFER_HOST.

When using `VMA_MEMORY_USAGE_AUTO*` while you want to map the allocated memory,
you also need to specify one of the host access flags:
#VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT or #VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT.
This will help the library decide about preferred memory type to ensure it has `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT`
so you can map it.

For example, a staging buffer that will be filled via mapped pointer and then
used as a source of transfer to the buffer described previously can be created like this.
It will likely end up in a memory type that is `HOST_VISIBLE` and `HOST_COHERENT`
but not `HOST_CACHED` (meaning uncached, write-combined) and not `DEVICE_LOCAL` (meaning system RAM).

\code
VkBufferCreateInfo stagingBufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
stagingBufferInfo.size = 65536;
stagingBufferInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

VmaAllocationCreateInfo stagingAllocInfo = {};
stagingAllocInfo.usage = VMA_MEMORY_USAGE_AUTO;
stagingAllocInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT;

VkBuffer stagingBuffer;
VmaAllocation stagingAllocation;
vmaCreateBuffer(allocator, &stagingBufferInfo, &stagingAllocInfo, &stagingBuffer, &stagingAllocation, nullptr);
\endcode

For more examples of creating different kinds of resources, see chapter \ref usage_patterns.
See also: @ref memory_mapping.

Usage values `VMA_MEMORY_USAGE_AUTO*` are legal to use only when the library knows
about the resource being created by having `VkBufferCreateInfo` / `VkImageCreateInfo` passed,
so they work with functions like: vmaCreateBuffer(), vmaCreateImage(), vmaFindMemoryTypeIndexForBufferInfo() etc.
If you allocate raw memory using function vmaAllocateMemory(), you have to use other means of selecting
memory type, as described below.

\note
Old usage values (`VMA_MEMORY_USAGE_GPU_ONLY`, `VMA_MEMORY_USAGE_CPU_ONLY`,
`VMA_MEMORY_USAGE_CPU_TO_GPU`, `VMA_MEMORY_USAGE_GPU_TO_CPU`, `VMA_MEMORY_USAGE_CPU_COPY`)
are still available and work same way as in previous versions of the library
for backward compatibility, but they are deprecated.

\section choosing_memory_type_required_preferred_flags Required and preferred flags

You can specify more detailed requirements by filling members
VmaAllocationCreateInfo::requiredFlags and VmaAllocationCreateInfo::preferredFlags
with a combination of bits from enum `VkMemoryPropertyFlags`. For example,
if you want to create a buffer that will be persistently mapped on host (so it
must be `HOST_VISIBLE`) and preferably will also be `HOST_COHERENT` and `HOST_CACHED`,
use following code:

\code
VmaAllocationCreateInfo allocInfo = {};
allocInfo.requiredFlags = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
allocInfo.preferredFlags = VK_MEMORY_PROPERTY_HOST_COHERENT_BIT | VK_MEMORY_PROPERTY_HOST_CACHED_BIT;
allocInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT | VMA_ALLOCATION_CREATE_MAPPED_BIT;

VkBuffer buffer;
VmaAllocation allocation;
vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr);
\endcode

A memory type is chosen that has all the required flags and as many preferred
flags set as possible.

Value passed in VmaAllocationCreateInfo::usage is internally converted to a set of required and preferred flags,
plus some extra "magic" (heuristics).

\section choosing_memory_type_explicit_memory_types Explicit memory types

If you inspected memory types available on the physical device and <b>you have
a preference for memory types that you want to use</b>, you can fill member
VmaAllocationCreateInfo::memoryTypeBits. It is a bit mask, where each bit set
means that a memory type with that index is allowed to be used for the
allocation. Special value 0, just like `UINT32_MAX`, means there are no
restrictions to memory type index.

Please note that this member is NOT just a memory type index.
Still you can use it to choose just one, specific memory type.
For example, if you already determined that your buffer should be created in
memory type 2, use following code:

\code
uint32_t memoryTypeIndex = 2;

VmaAllocationCreateInfo allocInfo = {};
allocInfo.memoryTypeBits = 1u << memoryTypeIndex;

VkBuffer buffer;
VmaAllocation allocation;
vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr);
\endcode

You can also use this parameter to <b>exclude some memory types</b>.
If you inspect memory heaps and types available on the current physical device and
you determine that for some reason you don't want to use a specific memory type for the allocation,
you can enable automatic memory type selection but exclude certain memory type or types
by setting all bits of `memoryTypeBits` to 1 except the ones you choose.

\code
// ...
uint32_t excludedMemoryTypeIndex = 2;
VmaAllocationCreateInfo allocInfo = {};
allocInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocInfo.memoryTypeBits = ~(1u << excludedMemoryTypeIndex);
// ...
\endcode


\section choosing_memory_type_custom_memory_pools Custom memory pools

If you allocate from custom memory pool, all the ways of specifying memory
requirements described above are not applicable and the aforementioned members
of VmaAllocationCreateInfo structure are ignored. Memory type is selected
explicitly when creating the pool and then used to make all the allocations from
that pool. For further details, see \ref custom_memory_pools.

\section choosing_memory_type_dedicated_allocations Dedicated allocations

Memory for allocations is reserved out of larger block of `VkDeviceMemory`
allocated from Vulkan internally. That is the main feature of this whole library.
You can still request a separate memory block to be created for an allocation,
just like you would do in a trivial solution without using any allocator.
In that case, a buffer or image is always bound to that memory at offset 0.
This is called a "dedicated allocation".
You can explicitly request it by using flag #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.
The library can also internally decide to use dedicated allocation in some cases, e.g.:

- When the size of the allocation is large.
- When [VK_KHR_dedicated_allocation](@ref vk_khr_dedicated_allocation) extension is enabled
  and it reports that dedicated allocation is required or recommended for the resource.
- When allocation of next big memory block fails due to not enough device memory,
  but allocation with the exact requested size succeeds.


\page memory_mapping Memory mapping

To "map memory" in Vulkan means to obtain a CPU pointer to `VkDeviceMemory`,
to be able to read from it or write to it in CPU code.
Mapping is possible only of memory allocated from a memory type that has
`VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` flag.
Functions `vkMapMemory()`, `vkUnmapMemory()` are designed for this purpose.
You can use them directly with memory allocated by this library,
but it is not recommended because of following issue:
Mapping the same `VkDeviceMemory` block multiple times is illegal - only one mapping at a time is allowed.
This includes mapping disjoint regions. Mapping is not reference-counted internally by Vulkan.
It is also not thread-safe.
Because of this, Vulkan Memory Allocator provides following facilities:

\note If you want to be able to map an allocation, you need to specify one of the flags
#VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT or #VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT
in VmaAllocationCreateInfo::flags. These flags are required for an allocation to be mappable
when using #VMA_MEMORY_USAGE_AUTO or other `VMA_MEMORY_USAGE_AUTO*` enum values.
For other usage values they are ignored and every such allocation made in `HOST_VISIBLE` memory type is mappable,
but these flags can still be used for consistency.

\section memory_mapping_copy_functions Copy functions

The easiest way to copy data from a host pointer to an allocation is to use convenience function vmaCopyMemoryToAllocation().
It automatically maps the Vulkan memory temporarily (if not already mapped), performs `memcpy`,
and calls `vkFlushMappedMemoryRanges` (if required - if memory type is not `HOST_COHERENT`).

It is also the safest one, because using `memcpy` avoids a risk of accidentally introducing memory reads
(e.g. by doing `pMappedVectors[i] += v`), which may be very slow on memory types that are not `HOST_CACHED`.

\code
struct ConstantBuffer
{
    ...
};
ConstantBuffer constantBufferData = ...

VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = sizeof(ConstantBuffer);
bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT;

VkBuffer buf;
VmaAllocation alloc;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, nullptr);

vmaCopyMemoryToAllocation(allocator, &constantBufferData, alloc, 0, sizeof(ConstantBuffer));
\endcode

Copy in the other direction - from an allocation to a host pointer can be performed the same way using function vmaCopyAllocationToMemory().

\section memory_mapping_mapping_functions Mapping functions

The library provides following functions for mapping of a specific allocation: vmaMapMemory(), vmaUnmapMemory().
They are safer and more convenient to use than standard Vulkan functions.
You can map an allocation multiple times simultaneously - mapping is reference-counted internally.
You can also map different allocations simultaneously regardless of whether they use the same `VkDeviceMemory` block.
The way it is implemented is that the library always maps entire memory block, not just region of the allocation.
For further details, see description of vmaMapMemory() function.
Example:

\code
// Having these objects initialized:
struct ConstantBuffer
{
    ...
};
ConstantBuffer constantBufferData = ...

VmaAllocator allocator = ...
VkBuffer constantBuffer = ...
VmaAllocation constantBufferAllocation = ...

// You can map and fill your buffer using following code:

void* mappedData;
vmaMapMemory(allocator, constantBufferAllocation, &mappedData);
memcpy(mappedData, &constantBufferData, sizeof(constantBufferData));
vmaUnmapMemory(allocator, constantBufferAllocation);
\endcode

When mapping, you may see a warning from Vulkan validation layer similar to this one:

<i>Mapping an image with layout VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL can result in undefined behavior if this memory is used by the device. Only GENERAL or PREINITIALIZED should be used.</i>

It happens because the library maps entire `VkDeviceMemory` block, where different
types of images and buffers may end up together, especially on GPUs with unified memory like Intel.
You can safely ignore it if you are sure you access only memory of the intended
object that you wanted to map.


\section memory_mapping_persistently_mapped_memory Persistently mapped memory

Keeping your memory persistently mapped is generally OK in Vulkan.
You don't need to unmap it before using its data on the GPU.
The library provides a special feature designed for that:
Allocations made with #VMA_ALLOCATION_CREATE_MAPPED_BIT flag set in
VmaAllocationCreateInfo::flags stay mapped all the time,
so you can just access CPU pointer to it any time
without a need to call any "map" or "unmap" function.
Example:

\code
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = sizeof(ConstantBuffer);
bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT |
    VMA_ALLOCATION_CREATE_MAPPED_BIT;

VkBuffer buf;
VmaAllocation alloc;
VmaAllocationInfo allocInfo;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo);

// Buffer is already mapped. You can access its memory.
memcpy(allocInfo.pMappedData, &constantBufferData, sizeof(constantBufferData));
\endcode

\note #VMA_ALLOCATION_CREATE_MAPPED_BIT by itself doesn't guarantee that the allocation will end up
in a mappable memory type.
For this, you need to also specify #VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT or
#VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT.
#VMA_ALLOCATION_CREATE_MAPPED_BIT only guarantees that if the memory is `HOST_VISIBLE`, the allocation will be mapped on creation.
For an example of how to make use of this fact, see section \ref usage_patterns_advanced_data_uploading.

\section memory_mapping_cache_control Cache flush and invalidate

Memory in Vulkan doesn't need to be unmapped before using it on GPU,
but unless a memory types has `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` flag set,
you need to manually **invalidate** cache before reading of mapped pointer
and **flush** cache after writing to mapped pointer.
Map/unmap operations don't do that automatically.
Vulkan provides following functions for this purpose `vkFlushMappedMemoryRanges()`,
`vkInvalidateMappedMemoryRanges()`, but this library provides more convenient
functions that refer to given allocation object: vmaFlushAllocation(),
vmaInvalidateAllocation(),
or multiple objects at once: vmaFlushAllocations(), vmaInvalidateAllocations().

Regions of memory specified for flush/invalidate must be aligned to
`VkPhysicalDeviceLimits::nonCoherentAtomSize`. This is automatically ensured by the library.
In any memory type that is `HOST_VISIBLE` but not `HOST_COHERENT`, all allocations
within blocks are aligned to this value, so their offsets are always multiply of
`nonCoherentAtomSize` and two different allocations never share same "line" of this size.

Also, Windows drivers from all 3 PC GPU vendors (AMD, Intel, NVIDIA)
currently provide `HOST_COHERENT` flag on all memory types that are
`HOST_VISIBLE`, so on PC you may not need to bother.


\page staying_within_budget Staying within budget

When developing a graphics-intensive game or program, it is important to avoid allocating
more GPU memory than it is physically available. When the memory is over-committed,
various bad things can happen, depending on the specific GPU, graphics driver, and
operating system:

- It may just work without any problems.
- The application may slow down because some memory blocks are moved to system RAM
  and the GPU has to access them through PCI Express bus.
- A new allocation may take very long time to complete, even few seconds, and possibly
  freeze entire system.
- The new allocation may fail with `VK_ERROR_OUT_OF_DEVICE_MEMORY`.
- It may even result in GPU crash (TDR), observed as `VK_ERROR_DEVICE_LOST`
  returned somewhere later.

\section staying_within_budget_querying_for_budget Querying for budget

To query for current memory usage and available budget, use function vmaGetHeapBudgets().
Returned structure #VmaBudget contains quantities expressed in bytes, per Vulkan memory heap.

Please note that this function returns different information and works faster than
vmaCalculateStatistics(). vmaGetHeapBudgets() can be called every frame or even before every
allocation, while vmaCalculateStatistics() is intended to be used rarely,
only to obtain statistical information, e.g. for debugging purposes.

It is recommended to use <b>VK_EXT_memory_budget</b> device extension to obtain information
about the budget from Vulkan device. VMA is able to use this extension automatically.
When not enabled, the allocator behaves same way, but then it estimates current usage
and available budget based on its internal information and Vulkan memory heap sizes,
which may be less precise. In order to use this extension:

1. Make sure extensions VK_EXT_memory_budget and VK_KHR_get_physical_device_properties2
   required by it are available and enable them. Please note that the first is a device
   extension and the second is instance extension!
2. Use flag #VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT when creating #VmaAllocator object.
3. Make sure to call vmaSetCurrentFrameIndex() every frame. Budget is queried from
   Vulkan inside of it to avoid overhead of querying it with every allocation.

\section staying_within_budget_controlling_memory_usage Controlling memory usage

There are many ways in which you can try to stay within the budget.

First, when making new allocation requires allocating a new memory block, the library
tries not to exceed the budget automatically. If a block with default recommended size
(e.g. 256 MB) would go over budget, a smaller block is allocated, possibly even
dedicated memory for just this resource.

If the size of the requested resource plus current memory usage is more than the
budget, by default the library still tries to create it, leaving it to the Vulkan
implementation whether the allocation succeeds or fails. You can change this behavior
by using #VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT flag. With it, the allocation is
not made if it would exceed the budget or if the budget is already exceeded.
VMA then tries to make the allocation from the next eligible Vulkan memory type.
The all of them fail, the call then fails with `VK_ERROR_OUT_OF_DEVICE_MEMORY`.
Example usage pattern may be to pass the #VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT flag
when creating resources that are not essential for the application (e.g. the texture
of a specific object) and not to pass it when creating critically important resources
(e.g. render targets).

On AMD graphics cards there is a custom vendor extension available: <b>VK_AMD_memory_overallocation_behavior</b>
that allows to control the behavior of the Vulkan implementation in out-of-memory cases -
whether it should fail with an error code or still allow the allocation.
Usage of this extension involves only passing extra structure on Vulkan device creation,
so it is out of scope of this library.

Finally, you can also use #VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT flag to make sure
a new allocation is created only when it fits inside one of the existing memory blocks.
If it would require to allocate a new block, if fails instead with `VK_ERROR_OUT_OF_DEVICE_MEMORY`.
This also ensures that the function call is very fast because it never goes to Vulkan
to obtain a new block.

\note Creating \ref custom_memory_pools with VmaPoolCreateInfo::minBlockCount
set to more than 0 will currently try to allocate memory blocks without checking whether they
fit within budget.


\page resource_aliasing Resource aliasing (overlap)

New explicit graphics APIs (Vulkan and Direct3D 12), thanks to manual memory
management, give an opportunity to alias (overlap) multiple resources in the
same region of memory - a feature not available in the old APIs (Direct3D 11, OpenGL).
It can be useful to save video memory, but it must be used with caution.

For example, if you know the flow of your whole render frame in advance, you
are going to use some intermediate textures or buffers only during a small range of render passes,
and you know these ranges don't overlap in time, you can bind these resources to
the same place in memory, even if they have completely different parameters (width, height, format etc.).

![Resource aliasing (overlap)](../gfx/Aliasing.png)

Such scenario is possible using VMA, but you need to create your images manually.
Then you need to calculate parameters of an allocation to be made using formula:

- allocation size = max(size of each image)
- allocation alignment = max(alignment of each image)
- allocation memoryTypeBits = bitwise AND(memoryTypeBits of each image)

Following example shows two different images bound to the same place in memory,
allocated to fit largest of them.

\code
// A 512x512 texture to be sampled.
VkImageCreateInfo img1CreateInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO };
img1CreateInfo.imageType = VK_IMAGE_TYPE_2D;
img1CreateInfo.extent.width = 512;
img1CreateInfo.extent.height = 512;
img1CreateInfo.extent.depth = 1;
img1CreateInfo.mipLevels = 10;
img1CreateInfo.arrayLayers = 1;
img1CreateInfo.format = VK_FORMAT_R8G8B8A8_SRGB;
img1CreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
img1CreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
img1CreateInfo.usage = VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
img1CreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;

// A full screen texture to be used as color attachment.
VkImageCreateInfo img2CreateInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO };
img2CreateInfo.imageType = VK_IMAGE_TYPE_2D;
img2CreateInfo.extent.width = 1920;
img2CreateInfo.extent.height = 1080;
img2CreateInfo.extent.depth = 1;
img2CreateInfo.mipLevels = 1;
img2CreateInfo.arrayLayers = 1;
img2CreateInfo.format = VK_FORMAT_R8G8B8A8_UNORM;
img2CreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
img2CreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
img2CreateInfo.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
img2CreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;

VkImage img1;
res = vkCreateImage(device, &img1CreateInfo, nullptr, &img1);
VkImage img2;
res = vkCreateImage(device, &img2CreateInfo, nullptr, &img2);

VkMemoryRequirements img1MemReq;
vkGetImageMemoryRequirements(device, img1, &img1MemReq);
VkMemoryRequirements img2MemReq;
vkGetImageMemoryRequirements(device, img2, &img2MemReq);

VkMemoryRequirements finalMemReq = {};
finalMemReq.size = std::max(img1MemReq.size, img2MemReq.size);
finalMemReq.alignment = std::max(img1MemReq.alignment, img2MemReq.alignment);
finalMemReq.memoryTypeBits = img1MemReq.memoryTypeBits & img2MemReq.memoryTypeBits;
// Validate if(finalMemReq.memoryTypeBits != 0)

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.preferredFlags = VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;

VmaAllocation alloc;
res = vmaAllocateMemory(allocator, &finalMemReq, &allocCreateInfo, &alloc, nullptr);

res = vmaBindImageMemory(allocator, alloc, img1);
res = vmaBindImageMemory(allocator, alloc, img2);

// You can use img1, img2 here, but not at the same time!

vmaFreeMemory(allocator, alloc);
vkDestroyImage(allocator, img2, nullptr);
vkDestroyImage(allocator, img1, nullptr);
\endcode

VMA also provides convenience functions that create a buffer or image and bind it to memory
represented by an existing #VmaAllocation:
vmaCreateAliasingBuffer(), vmaCreateAliasingBuffer2(),
vmaCreateAliasingImage(), vmaCreateAliasingImage2().
Versions with "2" offer additional parameter `allocationLocalOffset`.

Remember that using resources that alias in memory requires proper synchronization.
You need to issue a memory barrier to make sure commands that use `img1` and `img2`
don't overlap on GPU timeline.
You also need to treat a resource after aliasing as uninitialized - containing garbage data.
For example, if you use `img1` and then want to use `img2`, you need to issue
an image memory barrier for `img2` with `oldLayout` = `VK_IMAGE_LAYOUT_UNDEFINED`.

Additional considerations:

- Vulkan also allows to interpret contents of memory between aliasing resources consistently in some cases.
See chapter 11.8. "Memory Aliasing" of Vulkan specification or `VK_IMAGE_CREATE_ALIAS_BIT` flag.
- You can create more complex layout where different images and buffers are bound
at different offsets inside one large allocation. For example, one can imagine
a big texture used in some render passes, aliasing with a set of many small buffers
used between in some further passes. To bind a resource at non-zero offset in an allocation,
use vmaBindBufferMemory2() / vmaBindImageMemory2().
- Before allocating memory for the resources you want to alias, check `memoryTypeBits`
returned in memory requirements of each resource to make sure the bits overlap.
Some GPUs may expose multiple memory types suitable e.g. only for buffers or
images with `COLOR_ATTACHMENT` usage, so the sets of memory types supported by your
resources may be disjoint. Aliasing them is not possible in that case.


\page custom_memory_pools Custom memory pools

A memory pool contains a number of `VkDeviceMemory` blocks.
The library automatically creates and manages default pool for each memory type available on the device.
Default memory pool automatically grows in size.
Size of allocated blocks is also variable and managed automatically.
You are using default pools whenever you leave VmaAllocationCreateInfo::pool = null.

You can create custom pool and allocate memory out of it.
It can be useful if you want to:

- Keep certain kind of allocations separate from others.
- Enforce particular, fixed size of Vulkan memory blocks.
- Limit maximum amount of Vulkan memory allocated for that pool.
- Reserve minimum or fixed amount of Vulkan memory always preallocated for that pool.
- Use extra parameters for a set of your allocations that are available in #VmaPoolCreateInfo but not in
  #VmaAllocationCreateInfo - e.g., custom minimum alignment, custom `pNext` chain.
- Perform defragmentation on a specific subset of your allocations.

To use custom memory pools:

-# Fill VmaPoolCreateInfo structure.
-# Call vmaCreatePool() to obtain #VmaPool handle.
-# When making an allocation, set VmaAllocationCreateInfo::pool to this handle.
   You don't need to specify any other parameters of this structure, like `usage`.

Example:

\code
// Find memoryTypeIndex for the pool.
VkBufferCreateInfo sampleBufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
sampleBufCreateInfo.size = 0x10000; // Doesn't matter.
sampleBufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo sampleAllocCreateInfo = {};
sampleAllocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;

uint32_t memTypeIndex;
VkResult res = vmaFindMemoryTypeIndexForBufferInfo(allocator,
    &sampleBufCreateInfo, &sampleAllocCreateInfo, &memTypeIndex);
// Check res...

// Create a pool that can have at most 2 blocks, 128 MiB each.
VmaPoolCreateInfo poolCreateInfo = {};
poolCreateInfo.memoryTypeIndex = memTypeIndex;
poolCreateInfo.blockSize = 128ull * 1024 * 1024;
poolCreateInfo.maxBlockCount = 2;

VmaPool pool;
res = vmaCreatePool(allocator, &poolCreateInfo, &pool);
// Check res...

// Allocate a buffer out of it.
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = 1024;
bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.pool = pool;

VkBuffer buf;
VmaAllocation alloc;
res = vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, nullptr);
// Check res...
\endcode

You have to free all allocations made from this pool before destroying it.

\code
vmaDestroyBuffer(allocator, buf, alloc);
vmaDestroyPool(allocator, pool);
\endcode

New versions of this library support creating dedicated allocations in custom pools.
It is supported only when VmaPoolCreateInfo::blockSize = 0.
To use this feature, set VmaAllocationCreateInfo::pool to the pointer to your custom pool and
VmaAllocationCreateInfo::flags to #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.


\section custom_memory_pools_MemTypeIndex Choosing memory type index

When creating a pool, you must explicitly specify memory type index.
To find the one suitable for your buffers or images, you can use helper functions
vmaFindMemoryTypeIndexForBufferInfo(), vmaFindMemoryTypeIndexForImageInfo().
You need to provide structures with example parameters of buffers or images
that you are going to create in that pool.

\code
VkBufferCreateInfo exampleBufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
exampleBufCreateInfo.size = 1024; // Doesn't matter
exampleBufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;

uint32_t memTypeIndex;
vmaFindMemoryTypeIndexForBufferInfo(allocator, &exampleBufCreateInfo, &allocCreateInfo, &memTypeIndex);

VmaPoolCreateInfo poolCreateInfo = {};
poolCreateInfo.memoryTypeIndex = memTypeIndex;
// ...
\endcode

When creating buffers/images allocated in that pool, provide following parameters:

- `VkBufferCreateInfo`: Prefer to pass same parameters as above.
  Otherwise you risk creating resources in a memory type that is not suitable for them, which may result in undefined behavior.
  Using different `VK_BUFFER_USAGE_` flags may work, but you shouldn't create images in a pool intended for buffers
  or the other way around.
- VmaAllocationCreateInfo: You don't need to pass same parameters. Fill only `pool` member.
  Other members are ignored anyway.


\section custom_memory_pools_when_not_use When not to use custom pools

Custom pools are commonly overused by VMA users.
While it may feel natural to keep some logical groups of resources separate in memory,
in most cases it does more harm than good.
Using custom pool shouldn't be your first choice.
Instead, please make all allocations from default pools first and only use custom pools
if you can prove and measure that it is beneficial in some way,
e.g. it results in lower memory usage, better performance, etc.

Using custom pools has disadvantages:

- Each pool has its own collection of `VkDeviceMemory` blocks.
  Some of them may be partially or even completely empty.
  Spreading allocations across multiple pools increases the amount of wasted (allocated but unbound) memory.
- You must manually choose specific memory type to be used by a custom pool (set as VmaPoolCreateInfo::memoryTypeIndex).
  When using default pools, best memory type for each of your allocations can be selected automatically
  using a carefully design algorithm that works across all kinds of GPUs.
- If an allocation from a custom pool at specific memory type fails, entire allocation operation returns failure.
  When using default pools, VMA tries another compatible memory type.
- If you set VmaPoolCreateInfo::blockSize != 0, each memory block has the same size,
  while default pools start from small blocks and only allocate next blocks larger and larger
  up to the preferred block size.

Many of the common concerns can be addressed in a different way than using custom pools:

- If you want to keep your allocations of certain size (small versus large) or certain lifetime (transient versus long lived)
  separate, you likely don't need to.
  VMA uses a high quality allocation algorithm that manages memory well in various cases.
  Please measure and check if using custom pools provides a benefit.
- If you want to keep your images and buffers separate, you don't need to.
  VMA respects `bufferImageGranularity` limit automatically.
- If you want to keep your mapped and not mapped allocations separate, you don't need to.
  VMA respects `nonCoherentAtomSize` limit automatically.
  It also maps only those `VkDeviceMemory` blocks that need to map any allocation.
  It even tries to keep mappable and non-mappable allocations in separate blocks to minimize the amount of mapped memory.
- If you want to choose a custom size for the default memory block, you can set it globally instead
  using VmaAllocatorCreateInfo::preferredLargeHeapBlockSize.
- If you want to select specific memory type for your allocation,
  you can set VmaAllocationCreateInfo::memoryTypeBits to `(1u << myMemoryTypeIndex)` instead.
- If you need to create a buffer with certain minimum alignment, you can still do it
  using default pools with dedicated function vmaCreateBufferWithAlignment().


\section linear_algorithm Linear allocation algorithm

Each Vulkan memory block managed by this library has accompanying metadata that
keeps track of used and unused regions. By default, the metadata structure and
algorithm tries to find best place for new allocations among free regions to
optimize memory usage. This way you can allocate and free objects in any order.

![Default allocation algorithm](../gfx/Linear_allocator_1_algo_default.png)

Sometimes there is a need to use simpler, linear allocation algorithm. You can
create custom pool that uses such algorithm by adding flag
#VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT to VmaPoolCreateInfo::flags while creating
#VmaPool object. Then an alternative metadata management is used. It always
creates new allocations after last one and doesn't reuse free regions after
allocations freed in the middle. It results in better allocation performance and
less memory consumed by metadata.

![Linear allocation algorithm](../gfx/Linear_allocator_2_algo_linear.png)

With this one flag, you can create a custom pool that can be used in many ways:
free-at-once, stack, double stack, and ring buffer. See below for details.
You don't need to specify explicitly which of these options you are going to use - it is detected automatically.

\subsection linear_algorithm_free_at_once Free-at-once

In a pool that uses linear algorithm, you still need to free all the allocations
individually, e.g. by using vmaFreeMemory() or vmaDestroyBuffer(). You can free
them in any order. New allocations are always made after last one - free space
in the middle is not reused. However, when you release all the allocation and
the pool becomes empty, allocation starts from the beginning again. This way you
can use linear algorithm to speed up creation of allocations that you are going
to release all at once.

![Free-at-once](../gfx/Linear_allocator_3_free_at_once.png)

This mode is also available for pools created with VmaPoolCreateInfo::maxBlockCount
value that allows multiple memory blocks.

\subsection linear_algorithm_stack Stack

When you free an allocation that was created last, its space can be reused.
Thanks to this, if you always release allocations in the order opposite to their
creation (LIFO - Last In First Out), you can achieve behavior of a stack.

![Stack](../gfx/Linear_allocator_4_stack.png)

This mode is also available for pools created with VmaPoolCreateInfo::maxBlockCount
value that allows multiple memory blocks.

\subsection linear_algorithm_double_stack Double stack

The space reserved by a custom pool with linear algorithm may be used by two
stacks:

- First, default one, growing up from offset 0.
- Second, "upper" one, growing down from the end towards lower offsets.

To make allocation from the upper stack, add flag #VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT
to VmaAllocationCreateInfo::flags.

![Double stack](../gfx/Linear_allocator_7_double_stack.png)

Double stack is available only in pools with one memory block -
VmaPoolCreateInfo::maxBlockCount must be 1. Otherwise behavior is undefined.

When the two stacks' ends meet so there is not enough space between them for a
new allocation, such allocation fails with usual
`VK_ERROR_OUT_OF_DEVICE_MEMORY` error.

\subsection linear_algorithm_ring_buffer Ring buffer

When you free some allocations from the beginning and there is not enough free space
for a new one at the end of a pool, allocator's "cursor" wraps around to the
beginning and starts allocation there. Thanks to this, if you always release
allocations in the same order as you created them (FIFO - First In First Out),
you can achieve behavior of a ring buffer / queue.

![Ring buffer](../gfx/Linear_allocator_5_ring_buffer.png)

Ring buffer is available only in pools with one memory block -
VmaPoolCreateInfo::maxBlockCount must be 1. Otherwise behavior is undefined.

\note \ref defragmentation is not supported in custom pools created with #VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT.


\page defragmentation Defragmentation

Interleaved allocations and deallocations of many objects of varying size can
cause fragmentation over time, which can lead to a situation where the library is unable
to find a continuous range of free memory for a new allocation despite there is
enough free space, just scattered across many small free ranges between existing
allocations.

To mitigate this problem, you can use defragmentation feature.
It doesn't happen automatically though and needs your cooperation,
because VMA is a low level library that only allocates memory.
It cannot recreate buffers and images in a new place as it doesn't remember the contents of `VkBufferCreateInfo` / `VkImageCreateInfo` structures.
It cannot copy their contents as it doesn't record any commands to a command buffer.

Example:

\code
VmaDefragmentationInfo defragInfo = {};
defragInfo.pool = myPool;
defragInfo.flags = VMA_DEFRAGMENTATION_FLAG_ALGORITHM_FAST_BIT;

VmaDefragmentationContext defragCtx;
VkResult res = vmaBeginDefragmentation(allocator, &defragInfo, &defragCtx);
// Check res...

for(;;)
{
    VmaDefragmentationPassMoveInfo pass;
    res = vmaBeginDefragmentationPass(allocator, defragCtx, &pass);
    if(res == VK_SUCCESS)
        break;
    else if(res != VK_INCOMPLETE)
        // Handle error...

    for(uint32_t i = 0; i < pass.moveCount; ++i)
    {
        // Inspect pass.pMoves[i].srcAllocation, identify what buffer/image it represents.
        VmaAllocationInfo allocInfo;
        vmaGetAllocationInfo(allocator, pass.pMoves[i].srcAllocation, &allocInfo);
        MyEngineResourceData* resData = (MyEngineResourceData*)allocInfo.pUserData;

        // Recreate and bind this buffer/image at: pass.pMoves[i].dstMemory, pass.pMoves[i].dstOffset.
        VkImageCreateInfo imgCreateInfo = ...
        VkImage newImg;
        res = vkCreateImage(device, &imgCreateInfo, nullptr, &newImg);
        // Check res...
        res = vmaBindImageMemory(allocator, pass.pMoves[i].dstTmpAllocation, newImg);
        // Check res...

        // Issue a vkCmdCopyBuffer/vkCmdCopyImage to copy its content to the new place.
        vkCmdCopyImage(cmdBuf, resData->img, ..., newImg, ...);
    }

    // Make sure the copy commands finished executing.
    vkWaitForFences(...);

    // Destroy old buffers/images bound with pass.pMoves[i].srcAllocation.
    for(uint32_t i = 0; i < pass.moveCount; ++i)
    {
        // ...
        vkDestroyImage(device, resData->img, nullptr);
    }

    // Update appropriate descriptors to point to the new places...

    res = vmaEndDefragmentationPass(allocator, defragCtx, &pass);
    if(res == VK_SUCCESS)
        break;
    else if(res != VK_INCOMPLETE)
        // Handle error...
}

vmaEndDefragmentation(allocator, defragCtx, nullptr);
\endcode

Although functions like vmaCreateBuffer(), vmaCreateImage(), vmaDestroyBuffer(), vmaDestroyImage()
create/destroy an allocation and a buffer/image at once, these are just a shortcut for
creating the resource, allocating memory, and binding them together.
Defragmentation works on memory allocations only. You must handle the rest manually.
Defragmentation is an iterative process that should repreat "passes" as long as related functions
return `VK_INCOMPLETE` not `VK_SUCCESS`.
In each pass:

1. vmaBeginDefragmentationPass() function call:
   - Calculates and returns the list of allocations to be moved in this pass.
     Note this can be a time-consuming process.
   - Reserves destination memory for them by creating temporary destination allocations
     that you can query for their `VkDeviceMemory` + offset using vmaGetAllocationInfo().
2. Inside the pass, **you should**:
   - Inspect the returned list of allocations to be moved.
   - Create new buffers/images and bind them at the returned destination temporary allocations.
   - Copy data from source to destination resources if necessary.
   - Destroy the source buffers/images, but NOT their allocations.
3. vmaEndDefragmentationPass() function call:
   - Frees the source memory reserved for the allocations that are moved.
   - Modifies source #VmaAllocation objects that are moved to point to the destination reserved memory.
   - Frees `VkDeviceMemory` blocks that became empty.

Unlike in previous iterations of the defragmentation API, there is no list of "movable" allocations passed as a parameter.
Defragmentation algorithm tries to move all suitable allocations.
You can, however, refuse to move some of them inside a defragmentation pass, by setting
`pass.pMoves[i].operation` to #VMA_DEFRAGMENTATION_MOVE_OPERATION_IGNORE.
This is not recommended and may result in suboptimal packing of the allocations after defragmentation.
If you cannot ensure any allocation can be moved, it is better to keep movable allocations separate in a custom pool.

Inside a pass, for each allocation that should be moved:

- You should copy its data from the source to the destination place by calling e.g. `vkCmdCopyBuffer()`, `vkCmdCopyImage()`.
  - You need to make sure these commands finished executing before destroying the source buffers/images and before calling vmaEndDefragmentationPass().
- If a resource doesn't contain any meaningful data, e.g. it is a transient color attachment image to be cleared,
  filled, and used temporarily in each rendering frame, you can just recreate this image
  without copying its data.
- If the resource is in `HOST_VISIBLE` and `HOST_CACHED` memory, you can copy its data on the CPU
  using `memcpy()`.
- If you cannot move the allocation, you can set `pass.pMoves[i].operation` to #VMA_DEFRAGMENTATION_MOVE_OPERATION_IGNORE.
  This will cancel the move.
  - vmaEndDefragmentationPass() will then free the destination memory
    not the source memory of the allocation, leaving it unchanged.
- If you decide the allocation is unimportant and can be destroyed instead of moved (e.g. it wasn't used for long time),
  you can set `pass.pMoves[i].operation` to #VMA_DEFRAGMENTATION_MOVE_OPERATION_DESTROY.
  - vmaEndDefragmentationPass() will then free both source and destination memory, and will destroy the source #VmaAllocation object.

You can defragment a specific custom pool by setting VmaDefragmentationInfo::pool
(like in the example above) or all the default pools by setting this member to null.

Defragmentation is always performed in each pool separately.
Allocations are never moved between different Vulkan memory types.
The size of the destination memory reserved for a moved allocation is the same as the original one.
Alignment of an allocation as it was determined using `vkGetBufferMemoryRequirements()` etc. is also respected after defragmentation.
Buffers/images should be recreated with the same `VkBufferCreateInfo` / `VkImageCreateInfo` parameters as the original ones.

You can perform the defragmentation incrementally to limit the number of allocations and bytes to be moved
in each pass, e.g. to call it in sync with render frames and not to experience too big hitches.
See members: VmaDefragmentationInfo::maxBytesPerPass, VmaDefragmentationInfo::maxAllocationsPerPass.

It is also safe to perform the defragmentation asynchronously to render frames and other Vulkan and VMA
usage, possibly from multiple threads, with the exception that allocations
returned in VmaDefragmentationPassMoveInfo::pMoves shouldn't be destroyed until the defragmentation pass is ended.

<b>Mapping</b> is preserved on allocations that are moved during defragmentation.
Whether through #VMA_ALLOCATION_CREATE_MAPPED_BIT or vmaMapMemory(), the allocations
are mapped at their new place. Of course, pointer to the mapped data changes, so it needs to be queried
using VmaAllocationInfo::pMappedData.

\note Defragmentation is not supported in custom pools created with #VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT.


\page statistics Statistics

This library contains several functions that return information about its internal state,
especially the amount of memory allocated from Vulkan.

\section statistics_numeric_statistics Numeric statistics

If you need to obtain basic statistics about memory usage per heap, together with current budget,
you can call function vmaGetHeapBudgets() and inspect structure #VmaBudget.
This is useful to keep track of memory usage and stay within budget
(see also \ref staying_within_budget).
Example:

\code
uint32_t heapIndex = ...

VmaBudget budgets[VK_MAX_MEMORY_HEAPS];
vmaGetHeapBudgets(allocator, budgets);

printf("My heap currently has %u allocations taking %llu B,\n",
    budgets[heapIndex].statistics.allocationCount,
    budgets[heapIndex].statistics.allocationBytes);
printf("allocated out of %u Vulkan device memory blocks taking %llu B,\n",
    budgets[heapIndex].statistics.blockCount,
    budgets[heapIndex].statistics.blockBytes);
printf("Vulkan reports total usage %llu B with budget %llu B.\n",
    budgets[heapIndex].usage,
    budgets[heapIndex].budget);
\endcode

You can query for more detailed statistics per memory heap, type, and totals,
including minimum and maximum allocation size and unused range size,
by calling function vmaCalculateStatistics() and inspecting structure #VmaTotalStatistics.
This function is slower though, as it has to traverse all the internal data structures,
so it should be used only for debugging purposes.

You can query for statistics of a custom pool using function vmaGetPoolStatistics()
or vmaCalculatePoolStatistics().

You can query for information about a specific allocation using function vmaGetAllocationInfo().
It fill structure #VmaAllocationInfo.

\section statistics_json_dump JSON dump

You can dump internal state of the allocator to a string in JSON format using function vmaBuildStatsString().
The result is guaranteed to be correct JSON.
It uses ANSI encoding.
Any strings provided by user (see [Allocation names](@ref allocation_names))
are copied as-is and properly escaped for JSON, so if they use UTF-8, ISO-8859-2 or any other encoding,
this JSON string can be treated as using this encoding.
It must be freed using function vmaFreeStatsString().

The format of this JSON string is not part of official documentation of the library,
but it will not change in backward-incompatible way without increasing library major version number
and appropriate mention in changelog.

The JSON string contains all the data that can be obtained using vmaCalculateStatistics().
It can also contain detailed map of allocated memory blocks and their regions -
free and occupied by allocations.
This allows e.g. to visualize the memory or assess fragmentation.


\page allocation_annotation Allocation names and user data

\section allocation_user_data Allocation user data

You can annotate allocations with your own information, e.g. for debugging purposes.
To do that, fill VmaAllocationCreateInfo::pUserData field when creating
an allocation. It is an opaque `void*` pointer. You can use it e.g. as a pointer,
some handle, index, key, ordinal number or any other value that would associate
the allocation with your custom metadata.
It is useful to identify appropriate data structures in your engine given #VmaAllocation,
e.g. when doing \ref defragmentation.

\code
VkBufferCreateInfo bufCreateInfo = ...

MyBufferMetadata* pMetadata = CreateBufferMetadata();

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.pUserData = pMetadata;

VkBuffer buffer;
VmaAllocation allocation;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buffer, &allocation, nullptr);
\endcode

The pointer may be later retrieved as VmaAllocationInfo::pUserData:

\code
VmaAllocationInfo allocInfo;
vmaGetAllocationInfo(allocator, allocation, &allocInfo);
MyBufferMetadata* pMetadata = (MyBufferMetadata*)allocInfo.pUserData;
\endcode

It can also be changed using function vmaSetAllocationUserData().

Values of (non-zero) allocations' `pUserData` are printed in JSON report created by
vmaBuildStatsString() in hexadecimal form.

\section allocation_names Allocation names

An allocation can also carry a null-terminated string, giving a name to the allocation.
To set it, call vmaSetAllocationName().
The library creates internal copy of the string, so the pointer you pass doesn't need
to be valid for whole lifetime of the allocation. You can free it after the call.

\code
std::string imageName = "Texture: ";
imageName += fileName;
vmaSetAllocationName(allocator, allocation, imageName.c_str());
\endcode

The string can be later retrieved by inspecting VmaAllocationInfo::pName.
It is also printed in JSON report created by vmaBuildStatsString().

\note Setting string name to VMA allocation doesn't automatically set it to the Vulkan buffer or image created with it.
You must do it manually using an extension like VK_EXT_debug_utils, which is independent of this library.


\page virtual_allocator Virtual allocator

As an extra feature, the core allocation algorithm of the library is exposed through a simple and convenient API of "virtual allocator".
It doesn't allocate any real GPU memory. It just keeps track of used and free regions of a "virtual block".
You can use it to allocate your own memory or other objects, even completely unrelated to Vulkan.
A common use case is sub-allocation of pieces of one large GPU buffer.

\section virtual_allocator_creating_virtual_block Creating virtual block

To use this functionality, there is no main "allocator" object.
You don't need to have #VmaAllocator object created.
All you need to do is to create a separate #VmaVirtualBlock object for each block of memory you want to be managed by the allocator:

-# Fill in #VmaVirtualBlockCreateInfo structure.
-# Call vmaCreateVirtualBlock(). Get new #VmaVirtualBlock object.

Example:

\code
VmaVirtualBlockCreateInfo blockCreateInfo = {};
blockCreateInfo.size = 1048576; // 1 MB

VmaVirtualBlock block;
VkResult res = vmaCreateVirtualBlock(&blockCreateInfo, &block);
\endcode

\section virtual_allocator_making_virtual_allocations Making virtual allocations

#VmaVirtualBlock object contains internal data structure that keeps track of free and occupied regions
using the same code as the main Vulkan memory allocator.
Similarly to #VmaAllocation for standard GPU allocations, there is #VmaVirtualAllocation type
that represents an opaque handle to an allocation within the virtual block.

In order to make such allocation:

-# Fill in #VmaVirtualAllocationCreateInfo structure.
-# Call vmaVirtualAllocate(). Get new #VmaVirtualAllocation object that represents the allocation.
   You can also receive `VkDeviceSize offset` that was assigned to the allocation.

Example:

\code
VmaVirtualAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.size = 4096; // 4 KB

VmaVirtualAllocation alloc;
VkDeviceSize offset;
res = vmaVirtualAllocate(block, &allocCreateInfo, &alloc, &offset);
if(res == VK_SUCCESS)
{
    // Use the 4 KB of your memory starting at offset.
}
else
{
    // Allocation failed - no space for it could be found. Handle this error!
}
\endcode

\section virtual_allocator_deallocation Deallocation

When no longer needed, an allocation can be freed by calling vmaVirtualFree().
You can only pass to this function an allocation that was previously returned by vmaVirtualAllocate()
called for the same #VmaVirtualBlock.

When whole block is no longer needed, the block object can be released by calling vmaDestroyVirtualBlock().
All allocations must be freed before the block is destroyed, which is checked internally by an assert.
However, if you don't want to call vmaVirtualFree() for each allocation, you can use vmaClearVirtualBlock() to free them all at once -
a feature not available in normal Vulkan memory allocator. Example:

\code
vmaVirtualFree(block, alloc);
vmaDestroyVirtualBlock(block);
\endcode

\section virtual_allocator_allocation_parameters Allocation parameters

You can attach a custom pointer to each allocation by using vmaSetVirtualAllocationUserData().
Its default value is null.
It can be used to store any data that needs to be associated with that allocation - e.g. an index, a handle, or a pointer to some
larger data structure containing more information. Example:

\code
struct CustomAllocData
{
    std::string m_AllocName;
};
CustomAllocData* allocData = new CustomAllocData();
allocData->m_AllocName = "My allocation 1";
vmaSetVirtualAllocationUserData(block, alloc, allocData);
\endcode

The pointer can later be fetched, along with allocation offset and size, by passing the allocation handle to function
vmaGetVirtualAllocationInfo() and inspecting returned structure #VmaVirtualAllocationInfo.
If you allocated a new object to be used as the custom pointer, don't forget to delete that object before freeing the allocation!
Example:

\code
VmaVirtualAllocationInfo allocInfo;
vmaGetVirtualAllocationInfo(block, alloc, &allocInfo);
delete (CustomAllocData*)allocInfo.pUserData;

vmaVirtualFree(block, alloc);
\endcode

\section virtual_allocator_alignment_and_units Alignment and units

It feels natural to express sizes and offsets in bytes.
If an offset of an allocation needs to be aligned to a multiply of some number (e.g. 4 bytes), you can fill optional member
VmaVirtualAllocationCreateInfo::alignment to request it. Example:

\code
VmaVirtualAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.size = 4096; // 4 KB
allocCreateInfo.alignment = 4; // Returned offset must be a multiply of 4 B

VmaVirtualAllocation alloc;
res = vmaVirtualAllocate(block, &allocCreateInfo, &alloc, nullptr);
\endcode

Alignments of different allocations made from one block may vary.
However, if all alignments and sizes are always multiply of some size e.g. 4 B or `sizeof(MyDataStruct)`,
you can express all sizes, alignments, and offsets in multiples of that size instead of individual bytes.
It might be more convenient, but you need to make sure to use this new unit consistently in all the places:

- VmaVirtualBlockCreateInfo::size
- VmaVirtualAllocationCreateInfo::size and VmaVirtualAllocationCreateInfo::alignment
- Using offset returned by vmaVirtualAllocate() or in VmaVirtualAllocationInfo::offset

\section virtual_allocator_statistics Statistics

You can obtain statistics of a virtual block using vmaGetVirtualBlockStatistics()
(to get brief statistics that are fast to calculate)
or vmaCalculateVirtualBlockStatistics() (to get more detailed statistics, slower to calculate).
The functions fill structures #VmaStatistics, #VmaDetailedStatistics respectively - same as used by the normal Vulkan memory allocator.
Example:

\code
VmaStatistics stats;
vmaGetVirtualBlockStatistics(block, &stats);
printf("My virtual block has %llu bytes used by %u virtual allocations\n",
    stats.allocationBytes, stats.allocationCount);
\endcode

You can also request a full list of allocations and free regions as a string in JSON format by calling
vmaBuildVirtualBlockStatsString().
Returned string must be later freed using vmaFreeVirtualBlockStatsString().
The format of this string differs from the one returned by the main Vulkan allocator, but it is similar.

\section virtual_allocator_additional_considerations Additional considerations

The "virtual allocator" functionality is implemented on a level of individual memory blocks.
Keeping track of a whole collection of blocks, allocating new ones when out of free space,
deleting empty ones, and deciding which one to try first for a new allocation must be implemented by the user.

Alternative allocation algorithms are supported, just like in custom pools of the real GPU memory.
See enum #VmaVirtualBlockCreateFlagBits to learn how to specify them (e.g. #VMA_VIRTUAL_BLOCK_CREATE_LINEAR_ALGORITHM_BIT).
You can find their description in chapter \ref custom_memory_pools.
Allocation strategies are also supported.
See enum #VmaVirtualAllocationCreateFlagBits to learn how to specify them (e.g. #VMA_VIRTUAL_ALLOCATION_CREATE_STRATEGY_MIN_TIME_BIT).

Following features are supported only by the allocator of the real GPU memory and not by virtual allocations:
buffer-image granularity, `VMA_DEBUG_MARGIN`, `VMA_MIN_ALIGNMENT`.


\page debugging_memory_usage Debugging incorrect memory usage

If you suspect a bug with memory usage, like usage of uninitialized memory or
memory being overwritten out of bounds of an allocation,
you can use debug features of this library to verify this.

\section debugging_memory_usage_initialization Memory initialization

If you experience a bug with incorrect and nondeterministic data in your program and you suspect uninitialized memory to be used,
you can enable automatic memory initialization to verify this.
To do it, define macro `VMA_DEBUG_INITIALIZE_ALLOCATIONS` to 1.

\code
#define VMA_DEBUG_INITIALIZE_ALLOCATIONS 1
#include "vk_mem_alloc.h"
\endcode

It makes memory of new allocations initialized to bit pattern `0xDCDCDCDC`.
Before an allocation is destroyed, its memory is filled with bit pattern `0xEFEFEFEF`.
Memory is automatically mapped and unmapped if necessary.

If you find these values while debugging your program, good chances are that you incorrectly
read Vulkan memory that is allocated but not initialized, or already freed, respectively.

Memory initialization works only with memory types that are `HOST_VISIBLE` and with allocations that can be mapped.
It works also with dedicated allocations.

\section debugging_memory_usage_margins Margins

By default, allocations are laid out in memory blocks next to each other if possible
(considering required alignment, `bufferImageGranularity`, and `nonCoherentAtomSize`).

![Allocations without margin](../gfx/Margins_1.png)

Define macro `VMA_DEBUG_MARGIN` to some non-zero value (e.g. 16) to enforce specified
number of bytes as a margin after every allocation.

\code
#define VMA_DEBUG_MARGIN 16
#include "vk_mem_alloc.h"
\endcode

![Allocations with margin](../gfx/Margins_2.png)

If your bug goes away after enabling margins, it means it may be caused by memory
being overwritten outside of allocation boundaries. It is not 100% certain though.
Change in application behavior may also be caused by different order and distribution
of allocations across memory blocks after margins are applied.

Margins work with all types of memory.

Margin is applied only to allocations made out of memory blocks and not to dedicated
allocations, which have their own memory block of specific size.
It is thus not applied to allocations made using #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT flag
or those automatically decided to put into dedicated allocations, e.g. due to its
large size or recommended by VK_KHR_dedicated_allocation extension.

Margins appear in [JSON dump](@ref statistics_json_dump) as part of free space.

Note that enabling margins increases memory usage and fragmentation.

Margins do not apply to \ref virtual_allocator.

\section debugging_memory_usage_corruption_detection Corruption detection

You can additionally define macro `VMA_DEBUG_DETECT_CORRUPTION` to 1 to enable validation
of contents of the margins.

\code
#define VMA_DEBUG_MARGIN 16
#define VMA_DEBUG_DETECT_CORRUPTION 1
#include "vk_mem_alloc.h"
\endcode

When this feature is enabled, number of bytes specified as `VMA_DEBUG_MARGIN`
(it must be multiply of 4) after every allocation is filled with a magic number.
This idea is also know as "canary".
Memory is automatically mapped and unmapped if necessary.

This number is validated automatically when the allocation is destroyed.
If it is not equal to the expected value, `VMA_ASSERT()` is executed.
It clearly means that either CPU or GPU overwritten the memory outside of boundaries of the allocation,
which indicates a serious bug.

You can also explicitly request checking margins of all allocations in all memory blocks
that belong to specified memory types by using function vmaCheckCorruption(),
or in memory blocks that belong to specified custom pool, by using function
vmaCheckPoolCorruption().

Margin validation (corruption detection) works only for memory types that are
`HOST_VISIBLE` and `HOST_COHERENT`.


\section debugging_memory_usage_leak_detection Leak detection features

At allocation and allocator destruction time VMA checks for unfreed and unmapped blocks using
`VMA_ASSERT_LEAK()`. This macro defaults to an assertion, triggering a typically fatal error in Debug
builds, and doing nothing in Release builds. You can provide your own definition of `VMA_ASSERT_LEAK()`
to change this behavior.

At memory block destruction time VMA lists out all unfreed allocations using the `VMA_LEAK_LOG_FORMAT()`
macro, which defaults to `VMA_DEBUG_LOG_FORMAT`, which in turn defaults to a no-op.
If you're having trouble with leaks - for example, the aforementioned assertion triggers, but you don't
quite know \em why -, overriding this macro to print out the the leaking blocks, combined with assigning
individual names to allocations using vmaSetAllocationName(), can greatly aid in fixing them.

\page other_api_interop Interop with other graphics APIs

VMA provides some features that help with interoperability with other graphics APIs, e.g. OpenGL.

\section opengl_interop_exporting_memory Exporting memory

If you want to attach `VkExportMemoryAllocateInfoKHR` or other structure to `pNext` chain of memory allocations made by the library:

You can create \ref custom_memory_pools for such allocations.
Define and fill in your `VkExportMemoryAllocateInfoKHR` structure and attach it to VmaPoolCreateInfo::pMemoryAllocateNext
while creating the custom pool.
Please note that the structure must remain alive and unchanged for the whole lifetime of the #VmaPool,
not only while creating it, as no copy of the structure is made,
but its original pointer is used for each allocation instead.

If you want to export all memory allocated by VMA from certain memory types,
also dedicated allocations or other allocations made from default pools,
an alternative solution is to fill in VmaAllocatorCreateInfo::pTypeExternalMemoryHandleTypes.
It should point to an array with `VkExternalMemoryHandleTypeFlagsKHR` to be automatically passed by the library
through `VkExportMemoryAllocateInfoKHR` on each allocation made from a specific memory type.
Please note that new versions of the library also support dedicated allocations created in custom pools.

You should not mix these two methods in a way that allows to apply both to the same memory type.
Otherwise, `VkExportMemoryAllocateInfoKHR` structure would be attached twice to the `pNext` chain of `VkMemoryAllocateInfo`.


\section opengl_interop_custom_alignment Custom alignment

Buffers or images exported to a different API like OpenGL may require a different alignment,
higher than the one used by the library automatically, queried from functions like `vkGetBufferMemoryRequirements`.
To impose such alignment:

You can create \ref custom_memory_pools for such allocations.
Set VmaPoolCreateInfo::minAllocationAlignment member to the minimum alignment required for each allocation
to be made out of this pool.
The alignment actually used will be the maximum of this member and the alignment returned for the specific buffer or image
from a function like `vkGetBufferMemoryRequirements`, which is called by VMA automatically.

If you want to create a buffer with a specific minimum alignment out of default pools,
use special function vmaCreateBufferWithAlignment(), which takes additional parameter `minAlignment`.

Note the problem of alignment affects only resources placed inside bigger `VkDeviceMemory` blocks and not dedicated
allocations, as these, by definition, always have alignment = 0 because the resource is bound to the beginning of its dedicated block.
You can ensure that an allocation is created as dedicated by using #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.
Contrary to Direct3D 12, Vulkan doesn't have a concept of alignment of the entire memory block passed on its allocation.

\section opengl_interop_extended_allocation_information Extended allocation information

If you want to rely on VMA to allocate your buffers and images inside larger memory blocks,
but you need to know the size of the entire block and whether the allocation was made
with its own dedicated memory, use function vmaGetAllocationInfo2() to retrieve
extended allocation information in structure #VmaAllocationInfo2.



\page usage_patterns Recommended usage patterns

Vulkan gives great flexibility in memory allocation.
This chapter shows the most common patterns.

See also slides from talk:
[Sawicki, Adam. Advanced Graphics Techniques Tutorial: Memory management in Vulkan and DX12. Game Developers Conference, 2018](https://www.gdcvault.com/play/1025458/Advanced-Graphics-Techniques-Tutorial-New)


\section usage_patterns_gpu_only GPU-only resource

<b>When:</b>
Any resources that you frequently write and read on GPU,
e.g. images used as color attachments (aka "render targets"), depth-stencil attachments,
images/buffers used as storage image/buffer (aka "Unordered Access View (UAV)").

<b>What to do:</b>
Let the library select the optimal memory type, which will likely have `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT`.

\code
VkImageCreateInfo imgCreateInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO };
imgCreateInfo.imageType = VK_IMAGE_TYPE_2D;
imgCreateInfo.extent.width = 3840;
imgCreateInfo.extent.height = 2160;
imgCreateInfo.extent.depth = 1;
imgCreateInfo.mipLevels = 1;
imgCreateInfo.arrayLayers = 1;
imgCreateInfo.format = VK_FORMAT_R8G8B8A8_UNORM;
imgCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
imgCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
imgCreateInfo.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
imgCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT;
allocCreateInfo.priority = 1.0f;

VkImage img;
VmaAllocation alloc;
vmaCreateImage(allocator, &imgCreateInfo, &allocCreateInfo, &img, &alloc, nullptr);
\endcode

<b>Also consider:</b>
Consider creating them as dedicated allocations using #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT,
especially if they are large or if you plan to destroy and recreate them with different sizes
e.g. when display resolution changes.
Prefer to create such resources first and all other GPU resources (like textures and vertex buffers) later.
When VK_EXT_memory_priority extension is enabled, it is also worth setting high priority to such allocation
to decrease chances to be evicted to system memory by the operating system.

\section usage_patterns_staging_copy_upload Staging copy for upload

<b>When:</b>
A "staging" buffer than you want to map and fill from CPU code, then use as a source of transfer
to some GPU resource.

<b>What to do:</b>
Use flag #VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT.
Let the library select the optimal memory type, which will always have `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT`.

\code
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = 65536;
bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT |
    VMA_ALLOCATION_CREATE_MAPPED_BIT;

VkBuffer buf;
VmaAllocation alloc;
VmaAllocationInfo allocInfo;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo);

...

memcpy(allocInfo.pMappedData, myData, myDataSize);
\endcode

<b>Also consider:</b>
You can map the allocation using vmaMapMemory() or you can create it as persistenly mapped
using #VMA_ALLOCATION_CREATE_MAPPED_BIT, as in the example above.


\section usage_patterns_readback Readback

<b>When:</b>
Buffers for data written by or transferred from the GPU that you want to read back on the CPU,
e.g. results of some computations.

<b>What to do:</b>
Use flag #VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT.
Let the library select the optimal memory type, which will always have `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT`
and `VK_MEMORY_PROPERTY_HOST_CACHED_BIT`.

\code
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = 65536;
bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT |
    VMA_ALLOCATION_CREATE_MAPPED_BIT;

VkBuffer buf;
VmaAllocation alloc;
VmaAllocationInfo allocInfo;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo);

...

const float* downloadedData = (const float*)allocInfo.pMappedData;
\endcode


\section usage_patterns_advanced_data_uploading Advanced data uploading

For resources that you frequently write on CPU via mapped pointer and
frequently read on GPU e.g. as a uniform buffer (also called "dynamic"), multiple options are possible:

-# Easiest solution is to have one copy of the resource in `HOST_VISIBLE` memory,
   even if it means system RAM (not `DEVICE_LOCAL`) on systems with a discrete graphics card,
   and make the device reach out to that resource directly.
   - Reads performed by the device will then go through PCI Express bus.
     The performance of this access may be limited, but it may be fine depending on the size
     of this resource (whether it is small enough to quickly end up in GPU cache) and the sparsity
     of access.
-# On systems with unified memory (e.g. AMD APU or Intel integrated graphics, mobile chips),
   a memory type may be available that is both `HOST_VISIBLE` (available for mapping) and `DEVICE_LOCAL`
   (fast to access from the GPU). Then, it is likely the best choice for such type of resource.
-# Systems with a discrete graphics card and separate video memory may or may not expose
   a memory type that is both `HOST_VISIBLE` and `DEVICE_LOCAL`, also known as Base Address Register (BAR).
   If they do, it represents a piece of VRAM (or entire VRAM, if ReBAR is enabled in the motherboard BIOS)
   that is available to CPU for mapping.
   - Writes performed by the host to that memory go through PCI Express bus.
     The performance of these writes may be limited, but it may be fine, especially on PCIe 4.0,
     as long as rules of using uncached and write-combined memory are followed - only sequential writes and no reads.
-# Finally, you may need or prefer to create a separate copy of the resource in `DEVICE_LOCAL` memory,
   a separate "staging" copy in `HOST_VISIBLE` memory and perform an explicit transfer command between them.

Thankfully, VMA offers an aid to create and use such resources in the the way optimal
for the current Vulkan device. To help the library make the best choice,
use flag #VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT together with
#VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT.
It will then prefer a memory type that is both `DEVICE_LOCAL` and `HOST_VISIBLE` (integrated memory or BAR),
but if no such memory type is available or allocation from it fails
(PC graphics cards have only 256 MB of BAR by default, unless ReBAR is supported and enabled in BIOS),
it will fall back to `DEVICE_LOCAL` memory for fast GPU access.
It is then up to you to detect that the allocation ended up in a memory type that is not `HOST_VISIBLE`,
so you need to create another "staging" allocation and perform explicit transfers.

\code
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = 65536;
bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT |
    VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT |
    VMA_ALLOCATION_CREATE_MAPPED_BIT;

VkBuffer buf;
VmaAllocation alloc;
VmaAllocationInfo allocInfo;
vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo);

VkMemoryPropertyFlags memPropFlags;
vmaGetAllocationMemoryProperties(allocator, alloc, &memPropFlags);

if(memPropFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT)
{
    // Allocation ended up in a mappable memory and is already mapped - write to it directly.

    // [Executed in runtime]:
    memcpy(allocInfo.pMappedData, myData, myDataSize);
}
else
{
    // Allocation ended up in a non-mappable memory - need to transfer.
    VkBufferCreateInfo stagingBufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
    stagingBufCreateInfo.size = 65536;
    stagingBufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

    VmaAllocationCreateInfo stagingAllocCreateInfo = {};
    stagingAllocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
    stagingAllocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT |
        VMA_ALLOCATION_CREATE_MAPPED_BIT;

    VkBuffer stagingBuf;
    VmaAllocation stagingAlloc;
    VmaAllocationInfo stagingAllocInfo;
    vmaCreateBuffer(allocator, &stagingBufCreateInfo, &stagingAllocCreateInfo,
        &stagingBuf, &stagingAlloc, stagingAllocInfo);

    // [Executed in runtime]:
    memcpy(stagingAllocInfo.pMappedData, myData, myDataSize);
    vmaFlushAllocation(allocator, stagingAlloc, 0, VK_WHOLE_SIZE);
    //vkCmdPipelineBarrier: VK_ACCESS_HOST_WRITE_BIT --> VK_ACCESS_TRANSFER_READ_BIT
    VkBufferCopy bufCopy = {
        0, // srcOffset
        0, // dstOffset,
        myDataSize); // size
    vkCmdCopyBuffer(cmdBuf, stagingBuf, buf, 1, &bufCopy);
}
\endcode

\section usage_patterns_other_use_cases Other use cases

Here are some other, less obvious use cases and their recommended settings:

- An image that is used only as transfer source and destination, but it should stay on the device,
  as it is used to temporarily store a copy of some texture, e.g. from the current to the next frame,
  for temporal antialiasing or other temporal effects.
  - Use `VkImageCreateInfo::usage = VK_IMAGE_USAGE_TRANSFER_SRC_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT`
  - Use VmaAllocationCreateInfo::usage = #VMA_MEMORY_USAGE_AUTO
- An image that is used only as transfer source and destination, but it should be placed
  in the system RAM despite it doesn't need to be mapped, because it serves as a "swap" copy to evict
  least recently used textures from VRAM.
  - Use `VkImageCreateInfo::usage = VK_IMAGE_USAGE_TRANSFER_SRC_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT`
  - Use VmaAllocationCreateInfo::usage = #VMA_MEMORY_USAGE_AUTO_PREFER_HOST,
    as VMA needs a hint here to differentiate from the previous case.
- A buffer that you want to map and write from the CPU, directly read from the GPU
  (e.g. as a uniform or vertex buffer), but you have a clear preference to place it in device or
  host memory due to its large size.
  - Use `VkBufferCreateInfo::usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT`
  - Use VmaAllocationCreateInfo::usage = #VMA_MEMORY_USAGE_AUTO_PREFER_DEVICE or #VMA_MEMORY_USAGE_AUTO_PREFER_HOST
  - Use VmaAllocationCreateInfo::flags = #VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT


\page configuration Configuration

Please check "CONFIGURATION SECTION" in the code to find macros that you can define
before each include of this file or change directly in this file to provide
your own implementation of basic facilities like assert, `min()` and `max()` functions,
mutex, atomic etc.
The library uses its own implementation of containers by default, but you can switch to using
STL containers instead.

For example, define `VMA_ASSERT(expr)` before including the library to provide
custom implementation of the assertion, compatible with your project.
By default it is defined to standard C `assert(expr)` in `_DEBUG` configuration
and empty otherwise.

\section config_Vulkan_functions Pointers to Vulkan functions

There are multiple ways to import pointers to Vulkan functions in the library.
In the simplest case you don't need to do anything.
If the compilation or linking of your program or the initialization of the #VmaAllocator
doesn't work for you, you can try to reconfigure it.

First, the allocator tries to fetch pointers to Vulkan functions linked statically,
like this:

\code
m_VulkanFunctions.vkAllocateMemory = (PFN_vkAllocateMemory)vkAllocateMemory;
\endcode

If you want to disable this feature, set configuration macro: `#define VMA_STATIC_VULKAN_FUNCTIONS 0`.

Second, you can provide the pointers yourself by setting member VmaAllocatorCreateInfo::pVulkanFunctions.
You can fetch them e.g. using functions `vkGetInstanceProcAddr` and `vkGetDeviceProcAddr` or
by using a helper library like [volk](https://github.com/zeux/volk).

Third, VMA tries to fetch remaining pointers that are still null by calling
`vkGetInstanceProcAddr` and `vkGetDeviceProcAddr` on its own.
You need to only fill in VmaVulkanFunctions::vkGetInstanceProcAddr and VmaVulkanFunctions::vkGetDeviceProcAddr.
Other pointers will be fetched automatically.
If you want to disable this feature, set configuration macro: `#define VMA_DYNAMIC_VULKAN_FUNCTIONS 0`.

Finally, all the function pointers required by the library (considering selected
Vulkan version and enabled extensions) are checked with `VMA_ASSERT` if they are not null.


\section custom_memory_allocator Custom host memory allocator

If you use custom allocator for CPU memory rather than default operator `new`
and `delete` from C++, you can make this library using your allocator as well
by filling optional member VmaAllocatorCreateInfo::pAllocationCallbacks. These
functions will be passed to Vulkan, as well as used by the library itself to
make any CPU-side allocations.

\section allocation_callbacks Device memory allocation callbacks

The library makes calls to `vkAllocateMemory()` and `vkFreeMemory()` internally.
You can setup callbacks to be informed about these calls, e.g. for the purpose
of gathering some statistics. To do it, fill optional member
VmaAllocatorCreateInfo::pDeviceMemoryCallbacks.

\section heap_memory_limit Device heap memory limit

When device memory of certain heap runs out of free space, new allocations may
fail (returning error code) or they may succeed, silently pushing some existing_
memory blocks from GPU VRAM to system RAM (which degrades performance). This
behavior is implementation-dependent - it depends on GPU vendor and graphics
driver.

On AMD cards it can be controlled while creating Vulkan device object by using
VK_AMD_memory_overallocation_behavior extension, if available.

Alternatively, if you want to test how your program behaves with limited amount of Vulkan device
memory available without switching your graphics card to one that really has
smaller VRAM, you can use a feature of this library intended for this purpose.
To do it, fill optional member VmaAllocatorCreateInfo::pHeapSizeLimit.



\page vk_khr_dedicated_allocation VK_KHR_dedicated_allocation

VK_KHR_dedicated_allocation is a Vulkan extension which can be used to improve
performance on some GPUs. It augments Vulkan API with possibility to query
driver whether it prefers particular buffer or image to have its own, dedicated
allocation (separate `VkDeviceMemory` block) for better efficiency - to be able
to do some internal optimizations. The extension is supported by this library.
It will be used automatically when enabled.

It has been promoted to core Vulkan 1.1, so if you use eligible Vulkan version
and inform VMA about it by setting VmaAllocatorCreateInfo::vulkanApiVersion,
you are all set.

Otherwise, if you want to use it as an extension:

1 . When creating Vulkan device, check if following 2 device extensions are
supported (call `vkEnumerateDeviceExtensionProperties()`).
If yes, enable them (fill `VkDeviceCreateInfo::ppEnabledExtensionNames`).

- VK_KHR_get_memory_requirements2
- VK_KHR_dedicated_allocation

If you enabled these extensions:

2 . Use #VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT flag when creating
your #VmaAllocator to inform the library that you enabled required extensions
and you want the library to use them.

\code
allocatorInfo.flags |= VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT;

vmaCreateAllocator(&allocatorInfo, &allocator);
\endcode

That is all. The extension will be automatically used whenever you create a
buffer using vmaCreateBuffer() or image using vmaCreateImage().

When using the extension together with Vulkan Validation Layer, you will receive
warnings like this:

_vkBindBufferMemory(): Binding memory to buffer 0x33 but vkGetBufferMemoryRequirements() has not been called on that buffer._

It is OK, you should just ignore it. It happens because you use function
`vkGetBufferMemoryRequirements2KHR()` instead of standard
`vkGetBufferMemoryRequirements()`, while the validation layer seems to be
unaware of it.

To learn more about this extension, see:

- [VK_KHR_dedicated_allocation in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap50.html#VK_KHR_dedicated_allocation)
- [VK_KHR_dedicated_allocation unofficial manual](http://asawicki.info/articles/VK_KHR_dedicated_allocation.php5)



\page vk_ext_memory_priority VK_EXT_memory_priority

VK_EXT_memory_priority is a device extension that allows to pass additional "priority"
value to Vulkan memory allocations that the implementation may use prefer certain
buffers and images that are critical for performance to stay in device-local memory
in cases when the memory is over-subscribed, while some others may be moved to the system memory.

VMA offers convenient usage of this extension.
If you enable it, you can pass "priority" parameter when creating allocations or custom pools
and the library automatically passes the value to Vulkan using this extension.

If you want to use this extension in connection with VMA, follow these steps:

\section vk_ext_memory_priority_initialization Initialization

1) Call `vkEnumerateDeviceExtensionProperties` for the physical device.
Check if the extension is supported - if returned array of `VkExtensionProperties` contains "VK_EXT_memory_priority".

2) Call `vkGetPhysicalDeviceFeatures2` for the physical device instead of old `vkGetPhysicalDeviceFeatures`.
Attach additional structure `VkPhysicalDeviceMemoryPriorityFeaturesEXT` to `VkPhysicalDeviceFeatures2::pNext` to be returned.
Check if the device feature is really supported - check if `VkPhysicalDeviceMemoryPriorityFeaturesEXT::memoryPriority` is true.

3) While creating device with `vkCreateDevice`, enable this extension - add "VK_EXT_memory_priority"
to the list passed as `VkDeviceCreateInfo::ppEnabledExtensionNames`.

4) While creating the device, also don't set `VkDeviceCreateInfo::pEnabledFeatures`.
Fill in `VkPhysicalDeviceFeatures2` structure instead and pass it as `VkDeviceCreateInfo::pNext`.
Enable this device feature - attach additional structure `VkPhysicalDeviceMemoryPriorityFeaturesEXT` to
`VkPhysicalDeviceFeatures2::pNext` chain and set its member `memoryPriority` to `VK_TRUE`.

5) While creating #VmaAllocator with vmaCreateAllocator() inform VMA that you
have enabled this extension and feature - add #VMA_ALLOCATOR_CREATE_EXT_MEMORY_PRIORITY_BIT
to VmaAllocatorCreateInfo::flags.

\section vk_ext_memory_priority_usage Usage

When using this extension, you should initialize following member:

- VmaAllocationCreateInfo::priority when creating a dedicated allocation with #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.
- VmaPoolCreateInfo::priority when creating a custom pool.

It should be a floating-point value between `0.0f` and `1.0f`, where recommended default is `0.5f`.
Memory allocated with higher value can be treated by the Vulkan implementation as higher priority
and so it can have lower chances of being pushed out to system memory, experiencing degraded performance.

It might be a good idea to create performance-critical resources like color-attachment or depth-stencil images
as dedicated and set high priority to them. For example:

\code
VkImageCreateInfo imgCreateInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO };
imgCreateInfo.imageType = VK_IMAGE_TYPE_2D;
imgCreateInfo.extent.width = 3840;
imgCreateInfo.extent.height = 2160;
imgCreateInfo.extent.depth = 1;
imgCreateInfo.mipLevels = 1;
imgCreateInfo.arrayLayers = 1;
imgCreateInfo.format = VK_FORMAT_R8G8B8A8_UNORM;
imgCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
imgCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
imgCreateInfo.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
imgCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;

VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT;
allocCreateInfo.priority = 1.0f;

VkImage img;
VmaAllocation alloc;
vmaCreateImage(allocator, &imgCreateInfo, &allocCreateInfo, &img, &alloc, nullptr);
\endcode

`priority` member is ignored in the following situations:

- Allocations created in custom pools: They inherit the priority, along with all other allocation parameters
  from the parameters passed in #VmaPoolCreateInfo when the pool was created.
- Allocations created in default pools: They inherit the priority from the parameters
  VMA used when creating default pools, which means `priority == 0.5f`.


\page vk_amd_device_coherent_memory VK_AMD_device_coherent_memory

VK_AMD_device_coherent_memory is a device extension that enables access to
additional memory types with `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` and
`VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD` flag. It is useful mostly for
allocation of buffers intended for writing "breadcrumb markers" in between passes
or draw calls, which in turn are useful for debugging GPU crash/hang/TDR cases.

When the extension is available but has not been enabled, Vulkan physical device
still exposes those memory types, but their usage is forbidden. VMA automatically
takes care of that - it returns `VK_ERROR_FEATURE_NOT_PRESENT` when an attempt
to allocate memory of such type is made.

If you want to use this extension in connection with VMA, follow these steps:

\section vk_amd_device_coherent_memory_initialization Initialization

1) Call `vkEnumerateDeviceExtensionProperties` for the physical device.
Check if the extension is supported - if returned array of `VkExtensionProperties` contains "VK_AMD_device_coherent_memory".

2) Call `vkGetPhysicalDeviceFeatures2` for the physical device instead of old `vkGetPhysicalDeviceFeatures`.
Attach additional structure `VkPhysicalDeviceCoherentMemoryFeaturesAMD` to `VkPhysicalDeviceFeatures2::pNext` to be returned.
Check if the device feature is really supported - check if `VkPhysicalDeviceCoherentMemoryFeaturesAMD::deviceCoherentMemory` is true.

3) While creating device with `vkCreateDevice`, enable this extension - add "VK_AMD_device_coherent_memory"
to the list passed as `VkDeviceCreateInfo::ppEnabledExtensionNames`.

4) While creating the device, also don't set `VkDeviceCreateInfo::pEnabledFeatures`.
Fill in `VkPhysicalDeviceFeatures2` structure instead and pass it as `VkDeviceCreateInfo::pNext`.
Enable this device feature - attach additional structure `VkPhysicalDeviceCoherentMemoryFeaturesAMD` to
`VkPhysicalDeviceFeatures2::pNext` and set its member `deviceCoherentMemory` to `VK_TRUE`.

5) While creating #VmaAllocator with vmaCreateAllocator() inform VMA that you
have enabled this extension and feature - add #VMA_ALLOCATOR_CREATE_AMD_DEVICE_COHERENT_MEMORY_BIT
to VmaAllocatorCreateInfo::flags.

\section vk_amd_device_coherent_memory_usage Usage

After following steps described above, you can create VMA allocations and custom pools
out of the special `DEVICE_COHERENT` and `DEVICE_UNCACHED` memory types on eligible
devices. There are multiple ways to do it, for example:

- You can request or prefer to allocate out of such memory types by adding
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD` to VmaAllocationCreateInfo::requiredFlags
  or VmaAllocationCreateInfo::preferredFlags. Those flags can be freely mixed with
  other ways of \ref choosing_memory_type, like setting VmaAllocationCreateInfo::usage.
- If you manually found memory type index to use for this purpose, force allocation
  from this specific index by setting VmaAllocationCreateInfo::memoryTypeBits `= 1u << index`.

\section vk_amd_device_coherent_memory_more_information More information

To learn more about this extension, see [VK_AMD_device_coherent_memory in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_AMD_device_coherent_memory.html)

Example use of this extension can be found in the code of the sample and test suite
accompanying this library.


\page enabling_buffer_device_address Enabling buffer device address

Device extension VK_KHR_buffer_device_address
allow to fetch raw GPU pointer to a buffer and pass it for usage in a shader code.
It has been promoted to core Vulkan 1.2.

If you want to use this feature in connection with VMA, follow these steps:

\section enabling_buffer_device_address_initialization Initialization

1) (For Vulkan version < 1.2) Call `vkEnumerateDeviceExtensionProperties` for the physical device.
Check if the extension is supported - if returned array of `VkExtensionProperties` contains
"VK_KHR_buffer_device_address".

2) Call `vkGetPhysicalDeviceFeatures2` for the physical device instead of old `vkGetPhysicalDeviceFeatures`.
Attach additional structure `VkPhysicalDeviceBufferDeviceAddressFeatures*` to `VkPhysicalDeviceFeatures2::pNext` to be returned.
Check if the device feature is really supported - check if `VkPhysicalDeviceBufferDeviceAddressFeatures::bufferDeviceAddress` is true.

3) (For Vulkan version < 1.2) While creating device with `vkCreateDevice`, enable this extension - add
"VK_KHR_buffer_device_address" to the list passed as `VkDeviceCreateInfo::ppEnabledExtensionNames`.

4) While creating the device, also don't set `VkDeviceCreateInfo::pEnabledFeatures`.
Fill in `VkPhysicalDeviceFeatures2` structure instead and pass it as `VkDeviceCreateInfo::pNext`.
Enable this device feature - attach additional structure `VkPhysicalDeviceBufferDeviceAddressFeatures*` to
`VkPhysicalDeviceFeatures2::pNext` and set its member `bufferDeviceAddress` to `VK_TRUE`.

5) While creating #VmaAllocator with vmaCreateAllocator() inform VMA that you
have enabled this feature - add #VMA_ALLOCATOR_CREATE_BUFFER_DEVICE_ADDRESS_BIT
to VmaAllocatorCreateInfo::flags.

\section enabling_buffer_device_address_usage Usage

After following steps described above, you can create buffers with `VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT*` using VMA.
The library automatically adds `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT*` to
allocated memory blocks wherever it might be needed.

Please note that the library supports only `VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT*`.
The second part of this functionality related to "capture and replay" is not supported,
as it is intended for usage in debugging tools like RenderDoc, not in everyday Vulkan usage.

\section enabling_buffer_device_address_more_information More information

To learn more about this extension, see [VK_KHR_buffer_device_address in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap46.html#VK_KHR_buffer_device_address)

Example use of this extension can be found in the code of the sample and test suite
accompanying this library.

\page general_considerations General considerations

\section general_considerations_thread_safety Thread safety

- The library has no global state, so separate #VmaAllocator objects can be used
  independently.
  There should be no need to create multiple such objects though - one per `VkDevice` is enough.
- By default, all calls to functions that take #VmaAllocator as first parameter
  are safe to call from multiple threads simultaneously because they are
  synchronized internally when needed.
  This includes allocation and deallocation from default memory pool, as well as custom #VmaPool.
- When the allocator is created with #VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT
  flag, calls to functions that take such #VmaAllocator object must be
  synchronized externally.
- Access to a #VmaAllocation object must be externally synchronized. For example,
  you must not call vmaGetAllocationInfo() and vmaMapMemory() from different
  threads at the same time if you pass the same #VmaAllocation object to these
  functions.
- #VmaVirtualBlock is not safe to be used from multiple threads simultaneously.

\section general_considerations_versioning_and_compatibility Versioning and compatibility

The library uses [**Semantic Versioning**](https://semver.org/),
which means version numbers follow convention: Major.Minor.Patch (e.g. 2.3.0), where:

- Incremented Patch version means a release is backward- and forward-compatible,
  introducing only some internal improvements, bug fixes, optimizations etc.
  or changes that are out of scope of the official API described in this documentation.
- Incremented Minor version means a release is backward-compatible,
  so existing code that uses the library should continue to work, while some new
  symbols could have been added: new structures, functions, new values in existing
  enums and bit flags, new structure members, but not new function parameters.
- Incrementing Major version means a release could break some backward compatibility.

All changes between official releases are documented in file "CHANGELOG.md".

\warning Backward compatibility is considered on the level of C++ source code, not binary linkage.
Adding new members to existing structures is treated as backward compatible if initializing
the new members to binary zero results in the old behavior.
You should always fully initialize all library structures to zeros and not rely on their
exact binary size.

\section general_considerations_validation_layer_warnings Validation layer warnings

When using this library, you can meet following types of warnings issued by
Vulkan validation layer. They don't necessarily indicate a bug, so you may need
to just ignore them.

- *vkBindBufferMemory(): Binding memory to buffer 0xeb8e4 but vkGetBufferMemoryRequirements() has not been called on that buffer.*
  - It happens when VK_KHR_dedicated_allocation extension is enabled.
    `vkGetBufferMemoryRequirements2KHR` function is used instead, while validation layer seems to be unaware of it.
- *Mapping an image with layout VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL can result in undefined behavior if this memory is used by the device. Only GENERAL or PREINITIALIZED should be used.*
  - It happens when you map a buffer or image, because the library maps entire
    `VkDeviceMemory` block, where different types of images and buffers may end
    up together, especially on GPUs with unified memory like Intel.
- *Non-linear image 0xebc91 is aliased with linear buffer 0xeb8e4 which may indicate a bug.*
  - It may happen when you use [defragmentation](@ref defragmentation).

\section general_considerations_allocation_algorithm Allocation algorithm

The library uses following algorithm for allocation, in order:

-# Try to find free range of memory in existing blocks.
-# If failed, try to create a new block of `VkDeviceMemory`, with preferred block size.
-# If failed, try to create such block with size / 2, size / 4, size / 8.
-# If failed, try to allocate separate `VkDeviceMemory` for this allocation,
   just like when you use #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.
-# If failed, choose other memory type that meets the requirements specified in
   VmaAllocationCreateInfo and go to point 1.
-# If failed, return `VK_ERROR_OUT_OF_DEVICE_MEMORY`.

\section general_considerations_features_not_supported Features not supported

Features deliberately excluded from the scope of this library:

-# **Data transfer.** Uploading (streaming) and downloading data of buffers and images
   between CPU and GPU memory and related synchronization is responsibility of the user.
   Defining some "texture" object that would automatically stream its data from a
   staging copy in CPU memory to GPU memory would rather be a feature of another,
   higher-level library implemented on top of VMA.
   VMA doesn't record any commands to a `VkCommandBuffer`. It just allocates memory.
-# **Recreation of buffers and images.** Although the library has functions for
   buffer and image creation: vmaCreateBuffer(), vmaCreateImage(), you need to
   recreate these objects yourself after defragmentation. That is because the big
   structures `VkBufferCreateInfo`, `VkImageCreateInfo` are not stored in
   #VmaAllocation object.
-# **Handling CPU memory allocation failures.** When dynamically creating small C++
   objects in CPU memory (not Vulkan memory), allocation failures are not checked
   and handled gracefully, because that would complicate code significantly and
   is usually not needed in desktop PC applications anyway.
   Success of an allocation is just checked with an assert.
-# **Code free of any compiler warnings.** Maintaining the library to compile and
   work correctly on so many different platforms is hard enough. Being free of
   any warnings, on any version of any compiler, is simply not feasible.
   There are many preprocessor macros that make some variables unused, function parameters unreferenced,
   or conditional expressions constant in some configurations.
   The code of this library should not be bigger or more complicated just to silence these warnings.
   It is recommended to disable such warnings instead.
-# This is a C++ library with C interface. **Bindings or ports to any other programming languages** are welcome as external projects but
   are not going to be included into this repository.
*/