Function atitc_decode

core/base/atitc.cpp:154–197

Decode ATITC encode data to RGB32

// Decode ATITC encode data to RGB32
void atitc_decode(uint8_t* encodeData,  // in_data
                  uint8_t* decodeData,  // out_data
                  const int pixelsWidth,
                  const int pixelsHeight,
                  ATITCDecodeFlag decodeFlag)
{
    uint32_t* decodeBlockData = (uint32_t*)decodeData;

    for (int block_y = 0; block_y < pixelsHeight / 4; ++block_y, decodeBlockData += 3 * pixelsWidth)  // stride =
                                                                                                      // 3*width
    {
        for (int block_x = 0; block_x < pixelsWidth / 4; ++block_x, decodeBlockData += 4)  // skip 4 pixels
        {
            uint64_t blockAlpha = 0;

            switch (decodeFlag)
            {
            case ATITCDecodeFlag::ATC_RGB:
            {
                atitc_decode_block(&encodeData, decodeBlockData, pixelsWidth, 0, 0LL, ATITCDecodeFlag::ATC_RGB);
            }
            break;
            case ATITCDecodeFlag::ATC_EXPLICIT_ALPHA:
            {
                memcpy((void*)&blockAlpha, encodeData, 8);
                encodeData += 8;
                atitc_decode_block(&encodeData, decodeBlockData, pixelsWidth, 1, blockAlpha,
                                   ATITCDecodeFlag::ATC_EXPLICIT_ALPHA);
            }
            break;
            case ATITCDecodeFlag::ATC_INTERPOLATED_ALPHA:
            {
                memcpy((void*)&blockAlpha, encodeData, 8);
                encodeData += 8;
                atitc_decode_block(&encodeData, decodeBlockData, pixelsWidth, 1, blockAlpha,
                                   ATITCDecodeFlag::ATC_INTERPOLATED_ALPHA);
            }
            break;
            default:
                break;
            }  // switch
        }      // for block_x
    }          // for block_y
}