Function egDecodePNG

Protocols/AppleImageCodec/picopng.c:1313–1353

EG_IMAGE * egDecodePNG(IN UINT8 *FileData, IN UINTN FileDataLength, IN BOOLEAN WantAlpha)
{
  EG_IMAGE            *NewImage;
  PNG_INFO            *info;
  EFI_UGA_PIXEL       *Pixel;
  UINT8               *Data;
  INTN                x, y;

  // read and check header
  info = PNG_decode(FileData, (UINT32)FileDataLength);
  if (info == NULL) {
    return NULL;
  }

  NewImage = egCreateImage((INTN)info->width, (INTN)info->height, WantAlpha);
  if (NewImage == NULL) {
    return NULL;
  }

  //CopyMem(NewImage->PixelData, info->image->data, info->image->size);
  Data = (UINT8*)info->image->data;
  Pixel = (EFI_UGA_PIXEL*)NewImage->PixelData;
  for (y = 0; y < NewImage->Height; y++) {
    for (x = 0; x < NewImage->Width; x++) {
     /*  UINT8	Temp;
       Temp = Pixel->Blue;
       Pixel->Blue = Pixel->Red;
       Pixel->Red = Temp; */
       // It seems 0 is opaque and 255 is fully transparent
      // Pixel->Reserved = 255 - Pixel->Reserved; */
      Pixel->Red = *Data++;
      Pixel->Green = *Data++;
      Pixel->Blue = *Data++;
      Pixel->Reserved = 255 - *Data++;
      Pixel++;
    //  PixelD++;
    }
  }
  png_alloc_free_all();
  return NewImage;
}