chromium/third_party/skia/src/gpu/ganesh/GrEagerVertexAllocator.h

/*
 * Copyright 2020 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrEagerVertexAllocator_DEFINED
#define GrEagerVertexAllocator_DEFINED

#include "include/core/SkRefCnt.h"
#include "include/core/SkTypes.h"
#include "src/gpu/BufferWriter.h"
#include "src/gpu/ganesh/GrThreadSafeCache.h"

#include <cstddef>

class GrBuffer;
class GrMeshDrawTarget;

// This interface is used to allocate and map GPU vertex data before the exact number of required
// vertices is known. Usage pattern:
//
//   1. Call lock(eagerCount) with an upper bound on the number of required vertices.
//   2. Compute and write vertex data to the returned pointer (if not null).
//   3. Call unlock(actualCount) and provide the actual number of vertices written during step #2.
//
// On step #3, the implementation will attempt to shrink the underlying GPU memory slot to fit the
// actual vertex count.
class GrEagerVertexAllocator { … };

// GrEagerVertexAllocator implementation that uses GrMeshDrawTarget::makeVertexSpace and
// GrMeshDrawTarget::putBackVertices.
class GrEagerDynamicVertexAllocator : public GrEagerVertexAllocator { … };

class GrCpuVertexAllocator : public GrEagerVertexAllocator { … };

#endif