XBOX Texture Compressor (XBTC) 封存檔案規格

    struct XBTC_ARCHIVE_HEADER
    {
        uint32_t    Identifier;             // File identifier; "XBTC" as char[].
        uint32_t    Version         : 8;    // Archive format version.
        uint32_t    TextureCount    : 24;   // Number of individual textures in archive.
        uint64_t    DataOffset      : 24;   // Header + Index size in bytes.
        uint64_t    DataSize        : 40;   // Size of all data streams in bytes.
    };

    enum XBTC_TEX_DIMENSION
    {
        XBTC_TEX_DIMENSION_1D,              // 1D Texture or Buffer.
        XBTC_TEX_DIMENSION_2D,              // 2D Texture or Texture Array.
        XBTC_TEX_DIMENSION_3D,              // 3D (Volume) Texture.
        XBTC_TEX_DIMENSION_CUBE             // Cubemap or Cubemap Array.
    };

    enum XBTC_TILING_MODE
    {
        XBTC_TILING_SCARLETT_LINEAR,        // Texel elements are arranged in row major order, mips are 256-byte-aligned.
        XBTC_TILING_SCARLETT_256B,          // Tiles are 256 bytes (NO mip tail).
        XBTC_TILING_SCARLETT_4KB,           // Tiles are 4 KB (4 KB mip tail).
        XBTC_TILING_SCARLETT_64KB,          // Tiles are 64 KB (64 KB mip tail).
        XBTC_TILING_SCARLETT_64KB_PRT,      // Tiles are 64 KB, compressed individually for partial residency.
        XBTC_TILING_STANDARD_SWIZZLE        // D3D Standard Swizzle (64 KB tiles).
    };

    struct XBTC_TEXTURE_INFO
    {
        uint64_t    Format          : 8;    // DXGI_FORMAT
        uint64_t    Dimension       : 2;    // XBTC_TEX_DIMENSION
        uint64_t    Width           : 14;   // Width in pixels of mip 0 (minus 1).
        uint64_t    Height          : 14;   // Height in pixels of mip 0 (minus 1).
        uint64_t    Depth           : 11;   // Depth or array count (minus 1).
        uint64_t    TileMode        : 3;    // XBTC_TILING_MODE
        uint64_t    MipCount        : 4;    // Total number of LODs.
        uint64_t    MipStreams      : 4;    // Number of streamable LODs (excluding base).
        uint64_t    Reserved        : 4;
    };

    struct XBTC_OFFSET_AND_INDEX
    {
        uint64_t    BaseOffset      : 40;   // Base offset into data chunk.
        uint64_t    NextIndex       : 24;   // Base stream index of *next* resource.
    };

    struct XBTC_STREAM_INFO
    {
        uint32_t RelativeOffset             // Stream start offset (relative to base).
        uint32_t CompressedSize;            // Length of compressed stream.
        uint32_t InflatedSize;              // Size of stream before Deflate.
        uint32_t UncompressedSize;          // Uncompressed stream size.
    };