static ThumbnailHeader LoadHeader(BinaryReader reader)
{
var header = new ThumbnailHeader();
header.Type = ScummHelper.SwapBytes(reader.ReadUInt32());
// We also accept the bad 'BMHT' header here, for the sake of compatibility
// with some older savegames which were written incorrectly due to a bug in
// ScummVM which wrote the thumb header type incorrectly on LE systems.
if (header.Type != ScummHelper.MakeTag('T', 'H', 'M', 'B') && header.Type != ScummHelper.MakeTag('B', 'M', 'H', 'T'))
{
//if (outputWarnings)
// warning("couldn't find thumbnail header type");
return null;
}
header.Size = ScummHelper.SwapBytes(reader.ReadUInt32());
header.Version = reader.ReadByte();
if (header.Version > TumbnailVersion)
{
//if (outputWarnings)
// warning("trying to load a newer thumbnail version: %d instead of %d", header.version, THMB_VERSION);
return null;
}
header.Width = ScummHelper.SwapBytes(reader.ReadUInt16());
header.Height = ScummHelper.SwapBytes(reader.ReadUInt16());
header.Bpp = reader.ReadByte();
return header;
}
void SaveThumbnail(BinaryWriter output, Surface thumb)
{
var bpp = Surface.GetBytesPerPixel(thumb.PixelFormat);
if (bpp != 2 && bpp != 4)
{
// TODO: warning("trying to save thumbnail with bpp %u", bpp);
return;
}
ThumbnailHeader header = new ThumbnailHeader();
header.Type = ScummHelper.MakeTag('T', 'H', 'M', 'B');
header.Size = (uint)(ThumbnailHeaderSize + thumb.Width * thumb.Height * bpp);
header.Version = THMB_VERSION;
header.Width = (ushort)thumb.Width;
header.Height = (ushort)thumb.Height;
output.WriteUInt32BigEndian(header.Type);
output.WriteUInt32BigEndian(header.Size);
output.WriteByte(header.Version);
output.WriteUInt16BigEndian(header.Width);
output.WriteUInt16BigEndian(header.Height);
// Serialize the PixelFormat
output.WriteByte(bpp);
output.WriteByte(3);
output.WriteByte(2);
output.WriteByte(3);
output.WriteByte(8);
output.WriteByte(11);
output.WriteByte(5);
output.WriteByte(0);
output.WriteByte(0);
// Serialize the pixel data
for (uint y = 0; y < thumb.Height; ++y)
{
switch (bpp)
{
case 2:
{
var pixels = new UShortAccess(thumb.Pixels, (int)(y * thumb.Width * 2));
for (uint x = 0; x < thumb.Width; ++x)
{
output.WriteUInt16BigEndian(pixels[0]);
pixels.Offset += 2;
}
}
break;
case 4:
{
var pixels = new UIntAccess(thumb.Pixels, (int)(y * thumb.Width * 4));
for (var x = 0; x < thumb.Width; ++x)
{
output.WriteUInt32BigEndian(pixels[0]);
pixels.Offset += 4;
}
}
break;
default:
throw new NotSupportedException();
}
}
}
