public static Bitmap ReadLZ77Image(BinaryReader reader, int bytesPerPixel)
{
byte[] bufferPalette = reader.ReadBytes(256 * sizeof(UInt32));
Int32 sizeUncompressed = reader.ReadInt32();
// TODO(adm244): check compressed size; or read buffer first and then decode
Int32 sizeCompressed = reader.ReadInt32();
byte[] bufferPixels = AGSCompression.ReadLZ77(reader, sizeUncompressed, bytesPerPixel, out int width, out int height);
PixelFormat format = PixelFormatExtension.FromBytesPerPixel(bytesPerPixel);
// CHECK(adm244): palette format in room files
//PixelFormat paletteFormat = PixelFormat.Argb32;
//if (format == PixelFormat.Indexed)
PixelFormat paletteFormat = PixelFormat.Argb6666;
Palette palette = Palette.FromBuffer(bufferPalette, paletteFormat);
if (format == PixelFormat.Indexed)
{
return(new Bitmap(width, height, bufferPixels, format, palette));
}
Bitmap bitmap = new Bitmap(width, height, bufferPixels, format);
// NOTE(adm244): removes null-alpha; see AGSGraphics.ReadSprite
if (bitmap.Format == PixelFormat.Argb32)
{
bitmap = bitmap.Convert(PixelFormat.Rgb24);
}
return(bitmap);
}
public static void WriteLZ77Image(BinaryWriter writer, Bitmap image, int bytesPerPixel)
{
// CHECK(adm244): palette format in room files
//PixelFormat paletteFormat = PixelFormat.Argb32;
// CHECK(adm244): 2.54 crashes if palette is not 6-bits in some cases (if some >0x3F values are present)
// maybe we don't care for 8-bits palette then? double check that
//if (image.Format == PixelFormat.Indexed)
PixelFormat paletteFormat = PixelFormat.Argb6666;
Palette palette = image.Palette.HasValue ? image.Palette.Value : AGSSpriteSet.DefaultPalette;
byte[] paletteBuffer = palette.ToBuffer(paletteFormat);
writer.Write((byte[])paletteBuffer);
//NOTE(adm244): convert bitmap to match requested bytesPerPixel
PixelFormat targetFormat = PixelFormatExtension.FromBytesPerPixel(bytesPerPixel);
if (image.Format != targetFormat)
{
image = image.Convert(targetFormat, discardAlpha: true);
}
byte[] pixels = image.GetPixels();
Debug.Assert(pixels.Length == (image.Width * image.Height * bytesPerPixel));
byte[] buffer = PreAppendImageSize(image.Width, image.Height, bytesPerPixel, pixels);
byte[] bufferCompressed = AGSCompression.LZ77Compress(buffer);
writer.Write((UInt32)buffer.Length);
writer.Write((UInt32)bufferCompressed.Length);
writer.Write((byte[])bufferCompressed);
}
private static Bitmap ReadSprite(BinaryReader reader, SpriteSetHeader header)
{
// TODO(adm244): maybe return PixelFormat instead of bytesPerPixel?
byte[] buffer = ReadSprite(reader, header, out int width, out int height, out int bytesPerPixel);
if (buffer == null)
{
return(null);
}
PixelFormat format = PixelFormatExtension.FromBytesPerPixel(bytesPerPixel);
if (format == PixelFormat.Indexed)
{
return(new Bitmap(width, height, buffer, format, header.Palette));
}
Bitmap bitmap = new Bitmap(width, height, buffer, format);
// NOTE(adm244): since AGS doesn't support 24bpp RLE images it converts them to 32bpp
// (even if it won't be compressed, you know, 'just in case' case...)
// in the process alpha channel gets set to 0 (transparent) instead of 255 (opaque)
// which leads to a problem of fully transparent images (and "features" in GDI decoders)
//
// to resolve this issue, we check if alpha channel is used and if not discard it
if (format == PixelFormat.Argb32 && !IsAlphaChannelUsed(buffer))
{
bitmap = bitmap.Convert(PixelFormat.Rgb24);
}
return(bitmap);
}
public static Bitmap ReadAllegroImage(BinaryReader reader)
{
Int16 bytesPerPixel = 1;
Int16 width = reader.ReadInt16();
Int16 height = reader.ReadInt16();
byte[] buffer = AGSCompression.ReadAllegro(reader, width, height);
Debug.Assert(buffer.Length == (width * height * bytesPerPixel));
PixelFormat format = PixelFormatExtension.FromBytesPerPixel(bytesPerPixel);
// NOTE(adm244): in this case palette is always(?) rgb666
Palette palette = ReadPalette(reader, PixelFormat.Rgb666);
return(new Bitmap(width, height, buffer, format, palette));
}
