public override ImageData Read(IBinaryStream stream, ImageMetaData info)
{
using (var reader = new PgdReader(stream, (PgdGeMetaData)info))
{
var pixels = reader.UnpackGE();
return(ImageData.Create(info, reader.Format, null, pixels));
}
}
public override ImageData Read(IBinaryStream stream, ImageMetaData info)
{
var meta = (PgdIncMetaData)info;
string dir_name = VFS.GetDirectoryName(meta.FileName);
string name = VFS.CombinePath(dir_name, meta.BaseName);
PgdGeMetaData base_info;
byte[] image, overlay;
PixelFormat format;
using (var base_file = VFS.OpenBinaryStream(name))
{
base_info = PalFormat.Value.ReadMetaData(base_file) as PgdGeMetaData;
if (null == base_info)
{
throw new InvalidFormatException("Invalid baseline image format");
}
if (meta.OffsetX + meta.Width > base_info.Width ||
meta.OffsetY + meta.Height > base_info.Height)
{
throw new InvalidFormatException("Incompatible baseline image dimensions");
}
base_info.FileName = name;
using (var reader = new PgdReader(base_file, base_info))
{
image = reader.UnpackGE();
format = reader.Format;
}
}
using (var reader = new PgdReader(stream, meta))
overlay = reader.UnpackOverlay();
int overlay_bpp = meta.BPP / 8;
int base_bpp = format.BitsPerPixel / 8;
int dst = (meta.OffsetY * (int)base_info.Width + meta.OffsetX) * base_bpp;
int gap = (int)(base_info.Width - meta.Width) * base_bpp;
int src = 0;
bool apply_alpha = overlay_bpp == 4 && base_bpp == 4;
for (uint y = 0; y < meta.Height; ++y)
{
for (uint x = 0; x < meta.Width; ++x)
{
image[dst] ^= overlay[src];
image[dst + 1] ^= overlay[src + 1];
image[dst + 2] ^= overlay[src + 2];
if (apply_alpha)
{
image[dst + 3] ^= overlay[src + 3];
}
dst += base_bpp;
src += overlay_bpp;
}
dst += gap;
}
base_info.FileName = meta.FileName;
return(ImageData.Create(base_info, format, null, image));
}