BitmapSource ReadBitmapSource(IBinaryStream file, GdtMetaData info)
{
using (var bmp = new StreamRegion(file.AsStream, info.BitmapOffset, true))
{
var decoder = new BmpBitmapDecoder(bmp,
BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
return(decoder.Frames[0]);
}
}
BitmapSource BlendBaseLine(BitmapSource overlay, GdtMetaData meta)
{
string base_name = VFS.ChangeFileName(meta.FileName, meta.BaseLine);
if (!VFS.FileExists(base_name))
{
base_name += ".gdt";
if (!VFS.FileExists(base_name))
{
return(overlay);
}
}
using (var base_file = VFS.OpenBinaryStream(base_name))
{
var base_info = ReadMetaData(base_file) as GdtMetaData;
if (null == base_info)
{
return(overlay);
}
var base_image = ReadBitmapSource(base_file, base_info);
if (base_image.Format.BitsPerPixel < 24)
{
base_image = new FormatConvertedBitmap(base_image, PixelFormats.Bgr32, null, 0);
}
var canvas = new WriteableBitmap(base_image);
int canvas_bpp = canvas.Format.BitsPerPixel;
if (canvas_bpp != overlay.Format.BitsPerPixel)
{
overlay = new FormatConvertedBitmap(overlay, canvas.Format, null, 0);
}
canvas.Lock();
unsafe
{
byte *buffer = (byte *)canvas.BackBuffer;
int canvas_stride = canvas.BackBufferStride;
int canvas_size = canvas_stride * canvas.PixelHeight;
int overlay_stride = (overlay.PixelWidth * canvas_bpp + 7) / 8;
int overlay_size = overlay_stride * overlay.PixelHeight;
int pos = meta.OffsetY * canvas_stride + meta.OffsetX * canvas_bpp / 8;
overlay.CopyPixels(Int32Rect.Empty, (IntPtr)(buffer + pos), canvas_size - pos, canvas_stride);
}
var rect = new Int32Rect(meta.OffsetX, meta.OffsetY, overlay.PixelWidth, overlay.PixelHeight);
canvas.AddDirtyRect(rect);
canvas.Unlock();
return(canvas);
}
}
