//--------------------------------------------------------------------------------------
// dds.h
//
// This header defines constants and structures that are useful when parsing
// DDS files.  DDS files were originally designed to use several structures
// and constants that are native to DirectDraw and are defined in ddraw.h,
// such as DDSURFACEDESC2 and DDSCAPS2.  This file defines similar
// (compatible) constants and structures so that one can use DDS files
// without needing to include ddraw.h.
//--------------------------------------------------------------------------------------

#ifndef _DDS_H_
#define _DDS_H_

#pragma pack(push,1)

#define DDS_MAGIC 0x20534444 // "DDS "

#define MAKEFOURCC(ch0, ch1, ch2, ch3)  \
    ((unsigned int)(unsigned char)(ch0) | ((unsigned int)(unsigned char)(ch1) << 8) |  \
    ((unsigned int)(unsigned char)(ch2) << 16) | ((unsigned int)(unsigned char)(ch3) << 24 ))

struct DDS_PIXELFORMAT
{
    unsigned int dwSize;
    unsigned int dwFlags;
    unsigned int dwFourCC;
    unsigned int dwRGBBitCount;
    unsigned int dwRBitMask;
    unsigned int dwGBitMask;
    unsigned int dwBBitMask;
    unsigned int dwABitMask;
};

#define DDS_FOURCC      0x00000004  // DDPF_FOURCC
#define DDS_RGB         0x00000040  // DDPF_RGB
#define DDS_RGBA        0x00000041  // DDPF_RGB | DDPF_ALPHAPIXELS
#define DDS_LUMINANCE   0x00020000  // DDPF_LUMINANCE
#define DDS_ALPHA       0x00000002  // DDPF_ALPHA

const DDS_PIXELFORMAT DDSPF_DXT1 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','T','1'), 0, 0, 0, 0, 0 };

const DDS_PIXELFORMAT DDSPF_DXT2 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','T','2'), 0, 0, 0, 0, 0 };

const DDS_PIXELFORMAT DDSPF_DXT3 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','T','3'), 0, 0, 0, 0, 0 };

const DDS_PIXELFORMAT DDSPF_DXT4 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','T','4'), 0, 0, 0, 0, 0 };

const DDS_PIXELFORMAT DDSPF_DXT5 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','T','5'), 0, 0, 0, 0, 0 };

const DDS_PIXELFORMAT DDSPF_A8R8G8B8 =
    { sizeof(DDS_PIXELFORMAT), DDS_RGBA, 0, 32, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000 };

const DDS_PIXELFORMAT DDSPF_A1R5G5B5 =
    { sizeof(DDS_PIXELFORMAT), DDS_RGBA, 0, 16, 0x00007c00, 0x000003e0, 0x0000001f, 0x00008000 };

const DDS_PIXELFORMAT DDSPF_A4R4G4B4 =
    { sizeof(DDS_PIXELFORMAT), DDS_RGBA, 0, 16, 0x00000f00, 0x000000f0, 0x0000000f, 0x0000f000 };

const DDS_PIXELFORMAT DDSPF_R8G8B8 =
    { sizeof(DDS_PIXELFORMAT), DDS_RGB, 0, 24, 0x00ff0000, 0x0000ff00, 0x000000ff, 0x00000000 };

const DDS_PIXELFORMAT DDSPF_R5G6B5 =
    { sizeof(DDS_PIXELFORMAT), DDS_RGB, 0, 16, 0x0000f800, 0x000007e0, 0x0000001f, 0x00000000 };

// This indicates the DDS_HEADER_DXT10 extension is present (the format is in dxgiFormat)
const DDS_PIXELFORMAT DDSPF_DX10 =
    { sizeof(DDS_PIXELFORMAT), DDS_FOURCC, MAKEFOURCC('D','X','1','0'), 0, 0, 0, 0, 0 };

#define DDS_HEADER_FLAGS_TEXTURE        0x00001007  // DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_PIXELFORMAT
#define DDS_HEADER_FLAGS_MIPMAP         0x00020000  // DDSD_MIPMAPCOUNT
#define DDS_HEADER_FLAGS_VOLUME         0x00800000  // DDSD_DEPTH
#define DDS_HEADER_FLAGS_PITCH          0x00000008  // DDSD_PITCH
#define DDS_HEADER_FLAGS_LINEARSIZE     0x00080000  // DDSD_LINEARSIZE

#define DDS_SURFACE_FLAGS_TEXTURE 0x00001000 // DDSCAPS_TEXTURE
#define DDS_SURFACE_FLAGS_MIPMAP  0x00400008 // DDSCAPS_COMPLEX | DDSCAPS_MIPMAP
#define DDS_SURFACE_FLAGS_CUBEMAP 0x00000008 // DDSCAPS_COMPLEX

#define DDS_CUBEMAP_POSITIVEX 0x00000600 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEX
#define DDS_CUBEMAP_NEGATIVEX 0x00000a00 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEX
#define DDS_CUBEMAP_POSITIVEY 0x00001200 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEY
#define DDS_CUBEMAP_NEGATIVEY 0x00002200 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEY
#define DDS_CUBEMAP_POSITIVEZ 0x00004200 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEZ
#define DDS_CUBEMAP_NEGATIVEZ 0x00008200 // DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEZ

#define DDS_CUBEMAP_ALLFACES ( DDS_CUBEMAP_POSITIVEX | DDS_CUBEMAP_NEGATIVEX |\
                               DDS_CUBEMAP_POSITIVEY | DDS_CUBEMAP_NEGATIVEY |\
                               DDS_CUBEMAP_POSITIVEZ | DDS_CUBEMAP_NEGATIVEZ )

#define DDS_FLAGS_VOLUME 0x00200000 // DDSCAPS2_VOLUME

typedef struct
{
    unsigned int dwSize;
    unsigned int dwHeaderFlags;
    unsigned int dwHeight;
    unsigned int dwWidth;
    unsigned int dwPitchOrLinearSize;
    unsigned int dwDepth; // only if DDS_HEADER_FLAGS_VOLUME is set in dwHeaderFlags
    unsigned int dwMipMapCount;
    unsigned int dwReserved1[11];
    DDS_PIXELFORMAT ddspf;
    unsigned int dwSurfaceFlags;
    unsigned int dwCubemapFlags;
    unsigned int dwReserved2[3];
} DDS_HEADER;

/*
typedef struct
{
    DXGI_FORMAT dxgiFormat;
    D3D10_RESOURCE_DIMENSION resourceDimension;
    unsigned int miscFlag;
    unsigned int arraySize;
    unsigned int reserved;
} DDS_HEADER_DXT10;
*/

#pragma pack(pop)

#endif // _DDS_H