src/dawn/native/ImmediateConstantsLayout.h

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#ifndef SRC_DAWN_NATIVE_IMMEDIATECONSTANTSLAYOUT_H_
#define SRC_DAWN_NATIVE_IMMEDIATECONSTANTSLAYOUT_H_

#include <unordered_map>

#include "dawn/common/ityp_bitset.h"
#include "dawn/native/IntegerTypes.h"

namespace dawn::native {

// Define common immediate data layout. Append members to expand layouts.
// NOTE: 'offsetof' doesn't support non-standard-layout structs. So use
// aggregate instead of inheritance for RenderImmediateConstants and
// ComputeImmediateConstants.
struct UserImmediateConstants {
    uint32_t userImmediateData[kMaxExternalImmediateConstantsPerPipeline];
};

struct ClampFragDepthArgs {
    float minClampFragDepth;
    float maxClampFragDepth;
};

// Define render pipeline immediate data layout. Append members to
// expand the layout.
struct RenderImmediateConstants {
    UserImmediateConstants userConstants;

    ClampFragDepthArgs clampFragDepth;

    // first index offset
    uint32_t firstVertex;
    uint32_t firstInstance;
};
static_assert(sizeof(RenderImmediateConstants) == 32u);

struct NumWorkgroupsDimensions {
    uint32_t numWorkgroupsX;
    uint32_t numWorkgroupsY;
    uint32_t numWorkgroupsZ;
};

// Define compute pipeline immediate data layout. Append members to
// expand the layout.
struct ComputeImmediateConstants {
    UserImmediateConstants userConstants;

    NumWorkgroupsDimensions numWorkgroups;
};
static_assert(sizeof(ComputeImmediateConstants) == 28u);

// Convert byte sizes and offsets into immediate constant indices and offsets
// (dividing everything by kImmediateConstantElementByteSize)
ImmediateConstantMask GetImmediateConstantBlockBits(size_t byteOffset, size_t byteSize);

}  // namespace dawn::native

#endif  // SRC_DAWN_NATIVE_IMMEDIATECONSTANTSLAYOUT_H_