vertex_pulling.h | Explore in Territory

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#ifndef SRC_TINT_LANG_WGSL_AST_TRANSFORM_VERTEX_PULLING_H_
#define SRC_TINT_LANG_WGSL_AST_TRANSFORM_VERTEX_PULLING_H_

#include <memory>
#include <string>
#include <unordered_map>
#include <vector>

#include "src/tint/lang/wgsl/ast/transform/transform.h"
#include "src/tint/utils/reflection/reflection.h"

namespace tint::ast::transform {

/// Describes the format of data in a vertex buffer
enum class VertexFormat { … };

/// Describes if a vertex attributes increments with vertex index or instance
/// index
enum class VertexStepMode { … };

/// Describes a vertex attribute within a buffer
struct VertexAttributeDescriptor { … };

/// Describes a buffer containing multiple vertex attributes
struct VertexBufferLayoutDescriptor { … };

/// Describes vertex state, which consists of many buffers containing vertex
/// attributes
VertexStateDescriptor;

/// Converts a program to use vertex pulling
///
/// Variables which accept vertex input are var<in> with a location attribute.
/// This transform will convert those to be assigned from storage buffers
/// instead. The intention is to allow vertex input to rely on a storage buffer
/// clamping pass for out of bounds reads. We bind the storage buffers as arrays
/// of u32, so any read to byte position `p` will actually need to read position
/// `p / 4`, since `sizeof(u32) == 4`.
///
/// `VertexFormat` represents the input type of the attribute. This isn't
/// related to the type of the variable in the shader. For example,
/// `VertexFormat::kVec2F16` tells us that the buffer will contain `f16`
/// elements, to be read as vec2. In the shader, a user would make a `vec2<f32>`
/// to be able to use them. The conversion between `f16` and `f32` will need to
/// be handled by us (using unpack functions).
///
/// To be clear, there won't be types such as `f16` or `u8` anywhere in WGSL
/// code, but these are types that the data may arrive as. We need to convert
/// these smaller types into the base types such as `f32` and `u32` for the
/// shader to use.
///
/// The SingleEntryPoint transform must have run before VertexPulling.
class VertexPulling final : public Castable<VertexPulling, Transform> { … };

}  // namespace tint::ast::transform

tint  // namespace tint

#endif  // SRC_TINT_LANG_WGSL_AST_TRANSFORM_VERTEX_PULLING_H_
chromium/third_party/dawn/src/tint/lang/wgsl/ast/transform/vertex_pulling.h
