#include "dds.h"

#include <stdint.h>

#include <stdio.h>

#include <string.h>

#pragma pack( push, 1 )

struct DDS_PIXELFORMAT

{

uint32_t dwSize;

uint32_t dwFlags;

uint32_t dwFourCC;

uint32_t dwRGBBitCount;

uint32_t dwRBitMask;

uint32_t dwGBitMask;

uint32_t dwBBitMask;

uint32_t dwABitMask;

};

struct DDS_HEADER

{

uint32_t dwSize;

uint32_t dwFlags;

uint32_t dwHeight;

uint32_t dwWidth;

uint32_t dwPitchOrLinearSize;

uint32_t dwDepth;

uint32_t dwMipMapCount;

uint32_t dwReserved1[ 11 ];

DDS_PIXELFORMAT ddspf;

uint32_t dwCaps;

uint32_t dwCaps2;

uint32_t dwCaps3;

uint32_t dwCaps4;

uint32_t dwReserved2;

};

struct DDS_HEADER_DXT10

{

uint32_t dxgiFormat;

uint32_t resourceDimension;

uint32_t miscFlag;

uint32_t arraySize;

uint32_t miscFlags2;

};

#pragma pack( pop )

DDS_PIXELFORMAT const DDSPF_DX10 = { sizeof(DDS_PIXELFORMAT), 0x00000004, 0x30315844, 0, 0, 0, 0, 0 };

uint32_t const DDS_MAGIC = 0x20534444; // "DDS "

uint32_t const DDS_HEADER_FLAGS_TEXTURE = 0x00001007; // DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_PIXELFORMAT

uint32_t const DDS_HEADER_FLAGS_PITCH = 0x00000008;

uint32_t const DDS_SURFACE_FLAGS_TEXTURE = 0x00001000; // DDSCAPS_TEXTURE

uint32_t const DDS_RESOURCE_DIMENSION_TEXTURE2D = 3;

bool SaveDDS( char const* path, unsigned format, unsigned texelSizeInBytes, unsigned width, unsigned height, void const* data )

{

FILE* f = fopen( path, "wb" );

if ( !f )

{

return false;

}

fwrite( &DDS_MAGIC, sizeof( DDS_MAGIC ), 1, f );

DDS_HEADER hdr;

memset( &hdr, 0, sizeof( hdr ) );

hdr.dwSize = sizeof( hdr );

hdr.dwFlags = DDS_HEADER_FLAGS_TEXTURE | DDS_HEADER_FLAGS_PITCH;

hdr.dwHeight = height;

hdr.dwWidth = width;

hdr.dwDepth = 1;

hdr.dwMipMapCount = 1;

hdr.dwPitchOrLinearSize = width * texelSizeInBytes;

hdr.ddspf = DDSPF_DX10;

hdr.dwCaps = DDS_SURFACE_FLAGS_TEXTURE;

fwrite( &hdr, sizeof( hdr ), 1, f );

DDS_HEADER_DXT10 hdrDX10;

memset( &hdrDX10, 0, sizeof( hdrDX10 ) );

hdrDX10.dxgiFormat = format;

hdrDX10.resourceDimension = DDS_RESOURCE_DIMENSION_TEXTURE2D;

hdrDX10.arraySize = 1;

fwrite( &hdrDX10, sizeof( hdrDX10 ), 1, f );

fwrite( data, width * height * texelSizeInBytes, 1, f );

fclose( f );

return true;

}