src/dawn/native/BlockInfo.h

// Copyright 2025 The Dawn & Tint Authors
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#ifndef SRC_DAWN_NATIVE_BLOCK_INFO_H_
#define SRC_DAWN_NATIVE_BLOCK_INFO_H_

#include "src/dawn/native/Format.h"
#include "src/utils/typed_integer.h"

namespace dawn::native {

// Strong types for texel and block counts.
// These are used to avoid computation errors that occur when using regular integers
// for texel and block values, and mixing them up in computations, particularly for block
// sizes greater than 1x1.
// By using strong types, we cannot mix these two types in computations, and must use
// conversion functions provided in TypedTexelBlockInfo.

// TexelCount and BlockCount are uint64_t, not uint32_t, because as typed
// integers, they do not participate in type promotion to uint64_t, which
// is being relied on for computing buffer offsets and such.
using TexelCount = dawn::TypedInteger<struct TexelCountTag, uint64_t>;
using BlockCount = dawn::TypedInteger<struct BlockCountTag, uint64_t>;

// Strong type version of Origin3D, which is always in texel space
struct TexelOrigin3D {
    TexelCount x{0u};
    TexelCount y{0u};
    TexelCount z{0u};

    // Construct from input values
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TexelOrigin3D(TexelCount x = TexelCount{0u},
                            TexelCount y = TexelCount{0u},
                            TexelCount z = TexelCount{0u})
        : x(x), y(y), z(z) {}

    // Implicitly convert from Origin3D as Origin3D is always in texel space
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TexelOrigin3D(const Origin3D& o) : x(o.x), y(o.y), z(o.z) {}

    // Convert to Origin3D
    // TODO(crbug.com/424536624): Remove once strong types are used everywhere.
    constexpr Origin3D ToOrigin3D() const {
        return {dchecked_cast<uint32_t>(x), dchecked_cast<uint32_t>(y), dchecked_cast<uint32_t>(z)};
    }

    // Comparison operator
    constexpr bool operator==(const TexelOrigin3D&) const = default;
};

// Stores an origin in block space
struct BlockOrigin3D {
    BlockCount x{0u};
    BlockCount y{0u};
    BlockCount z{0u};

    // Construct from input values
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr BlockOrigin3D(BlockCount x = BlockCount{0u},
                            BlockCount y = BlockCount{0u},
                            BlockCount z = BlockCount{0u})
        : x(x), y(y), z(z) {}

    // Comparison operator
    constexpr bool operator==(const BlockOrigin3D&) const = default;
};

// Strong type version of Extent3D.
struct TexelExtent3D {
    TexelCount width{0u};
    TexelCount height{1u};
    TexelCount depthOrArrayLayers{1u};

    // Default constructor
    constexpr TexelExtent3D() = default;

    // Construct from input values
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TexelExtent3D(TexelCount width,
                            TexelCount height = TexelCount{1u},
                            TexelCount depthOrArrayLayers = TexelCount{1u})
        : width(width), height(height), depthOrArrayLayers(depthOrArrayLayers) {}

    // Implicitly convert from Extent3D as Extent3D is always in texel space
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TexelExtent3D(const Extent3D& e)
        : width(e.width), height(e.height), depthOrArrayLayers(e.depthOrArrayLayers) {}

    // Convert to Extent3D
    // TODO(crbug.com/424536624): Remove once strong types are used everywhere.
    constexpr Extent3D ToExtent3D() const {
        return {dchecked_cast<uint32_t>(width), dchecked_cast<uint32_t>(height),
                dchecked_cast<uint32_t>(depthOrArrayLayers)};
    }

    // Comparison operator
    constexpr bool operator==(const TexelExtent3D&) const = default;

    // Returns true if any extent is zero
    bool IsEmpty() const {
        return width == TexelCount{0u} || height == TexelCount{0u} ||
               depthOrArrayLayers == TexelCount{0u};
    }
};

// Stores an extent in block space
struct BlockExtent3D {
    BlockCount width{0u};
    BlockCount height{1u};
    BlockCount depthOrArrayLayers{1u};

    // Default constructor
    constexpr BlockExtent3D() = default;

    // Construct from input values
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr BlockExtent3D(BlockCount width,
                            BlockCount height = BlockCount{1u},
                            BlockCount depthOrArrayLayers = BlockCount{1u})
        : width(width), height(height), depthOrArrayLayers(depthOrArrayLayers) {}

    // Comparison operator
    constexpr bool operator==(const BlockExtent3D&) const = default;

    // Returns true if any extent is zero
    bool IsEmpty() const {
        return width == BlockCount{0u} || height == BlockCount{0u} ||
               depthOrArrayLayers == BlockCount{0u};
    }
};

// Strong type version of TexelBlockInfo that stores the dimensions of the block
// as TexelCounts, and provides conversion functions between texels, blocks, and bytes.
struct TypedTexelBlockInfo {
    uint32_t byteSize = 0;
    TexelCount width{0u};
    TexelCount height{0u};

    // Default constructor
    constexpr TypedTexelBlockInfo() = default;

    // Construct from input values
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TypedTexelBlockInfo(uint32_t byteSize, TexelCount width, TexelCount height)
        : byteSize(byteSize), width(width), height(height) {}

    // Convert from TexelBlockInfo
    // NOLINTNEXTLINE: allow implicit constructor
    constexpr TypedTexelBlockInfo(const TexelBlockInfo& blockInfo)
        : byteSize(blockInfo.byteSize), width(blockInfo.width), height(blockInfo.height) {}

    // Convert to TexelBlockInfo
    // TODO(crbug.com/424536624): Remove once strong types are used everywhere.
    constexpr TexelBlockInfo ToTexelBlockInfo() const {
        return {byteSize, dchecked_cast<uint32_t>(width), dchecked_cast<uint32_t>(height)};
    }

    // Convert blocks to bytes
    constexpr uint64_t ToBytes(BlockCount value) const {
        return static_cast<uint64_t>(value) * byteSize;
    }

    // Convert bytes to blocks
    constexpr BlockCount BytesToBlocks(uint64_t bytes) const {
        DAWN_ASSERT(bytes % byteSize == 0);
        return BlockCount{bytes / byteSize};
    }

    // Convert texel height to block height
    constexpr BlockCount ToBlockHeight(TexelCount value) const {
        DAWN_ASSERT(value % height == TexelCount{0u});
        return BlockCount{static_cast<uint64_t>(value / height)};
    }

    // Convert from texel width to block width
    constexpr BlockCount ToBlockWidth(TexelCount value) const {
        DAWN_ASSERT(value % width == TexelCount{0u});
        return BlockCount{static_cast<uint64_t>(value / width)};
    }

    // Convert from texel depth to block depth
    constexpr BlockCount ToBlockDepth(TexelCount value) const {
        // TODO(amaiorano): When we add block 'depth' for 3D block support, divide this value by
        // 'depth'
        return BlockCount{static_cast<uint64_t>(value)};
    }

    // Convert from block width to texel width
    constexpr TexelCount ToTexelWidth(BlockCount value) const {
        return TexelCount{static_cast<uint64_t>(value)} * width;
    }

    // Convert from block height to texel height
    constexpr TexelCount ToTexelHeight(BlockCount value) const {
        return TexelCount{static_cast<uint64_t>(value)} * height;
    }

    // Convert from block depth to texel depth
    constexpr TexelCount ToTexelDepth(BlockCount value) const {
        // TODO(amaiorano): When we add block 'depth' for 3D block support, multiply this value by
        // 'depth'
        return TexelCount{static_cast<uint64_t>(value)};
    }

    // Convert from TexelOrigin3D to BlockOrigin3D
    constexpr BlockOrigin3D ToBlock(const TexelOrigin3D& origin) const {
        return {ToBlockWidth(origin.x), ToBlockHeight(origin.y), ToBlockDepth(origin.z)};
    }

    // Convert from TexelExtent3D to BlockExtent3D
    constexpr BlockExtent3D ToBlock(const TexelExtent3D& extent) const {
        return {ToBlockWidth(extent.width), ToBlockHeight(extent.height),
                ToBlockDepth(extent.depthOrArrayLayers)};
    }

    // Convert from BlockOrigin3D to TexelOrigin3D
    constexpr TexelOrigin3D ToTexel(const BlockOrigin3D& origin) const {
        return {ToTexelWidth(origin.x), ToTexelHeight(origin.y), ToTexelDepth(origin.z)};
    }

    // Convert from BlockExtent3D to TexelExtent3D
    constexpr TexelExtent3D ToTexel(const BlockExtent3D& extent) const {
        return {ToTexelWidth(extent.width), ToTexelHeight(extent.height),
                ToTexelDepth(extent.depthOrArrayLayers)};
    }
};

}  // namespace dawn::native

#endif  // SRC_DAWN_NATIVE_BLOCK_INFO_H_