void rgbcx__encode_bc1( uint32_t level, void* pDst, const uint8_t* pPixels, int allow_3color, int use_transparent_texels_for_black );
void rgbcx__encode_bc3( uint32_t level, void* pDst, const uint8_t* pPixels );
void rgbcx__encode_bc1( uint32_t level, void* pDst, const uint8_t* pPixels, int allow_3color, int use_transparent_texels_for_black );
void rgbcx__encode_bc3( uint32_t level, void* pDst, const uint8_t* pPixels );