public void MergeChannels()
{
// no alpha channel
if (AlphaData == null && AlphaBitmap == null && ColorData != null)
{
if (ColorData.StartsWith(Format.Png.Signature) || ColorData.StartsWith(Format.Bmp.Signature))
{
return;
}
}
Decode();
if (ColorBitmap != null && ColorBitmap.PixelFormat != PixelFormat.Format32bppArgb)
{
// make sure cb actually has an alpha channel to copy to
var newColor = new Bitmap(ColorBitmap.Width, ColorBitmap.Height, PixelFormat.Format32bppArgb);
using (var gr = System.Drawing.Graphics.FromImage(newColor)) {
gr.DrawImage(ColorBitmap, new Rectangle(0, 0, ColorBitmap.Width, ColorBitmap.Height));
}
ColorBitmap.Dispose();
ColorBitmap = newColor;
}
BitmapUtils.CopyAlphaChannel(AlphaBitmap, ColorBitmap);
AlphaBitmap?.Dispose();
AlphaBitmap = null;
}
// TODO call dispose
public void Dispose()
{
ColorBitmap?.Dispose();
AlphaBitmap?.Dispose();
GC.SuppressFinalize(this);
}
public bool Encode(AlphaMode am = AlphaMode.Discard, ColorMode cm = ColorMode.MergePng)
{
if (IsEncoded)
{
return(false);
}
Debug.Assert(ColorData == null);
Debug.Assert(AlphaData == null);
if (cm == ColorMode.MergePng || cm == ColorMode.MergeGnp)
{
MergeChannels();
}
// encode color data
var buffer = new MemoryStream();
switch (cm)
{
case ColorMode.MergePng:
case ColorMode.Png:
ColorBitmap.Save(buffer, ImageFormat.Png);
break;
case ColorMode.MergeGnp:
case ColorMode.Gnp:
ColorBitmap.Save(buffer, ImageFormat.Png);
buffer.Seek(0).WriteBytes(Format.Gnp.Signature);
break;
case ColorMode.Bmp:
ColorBitmap.Save(buffer, ImageFormat.Bmp);
break;
}
ColorData = buffer.Length > 0 ? buffer.ToArray() : null;
// encode alpha data
buffer.Seek(0).SetLength(0);
switch (am)
{
case AlphaMode.Png:
ColorBitmap.Save(buffer, ImageFormat.Png);
break;
case AlphaMode.Gnp:
ColorBitmap.Save(buffer, ImageFormat.Png);
buffer.Seek(0).WriteBytes(Format.Gnp.Signature);
break;
case AlphaMode.Bmp:
ColorBitmap.Save(buffer, ImageFormat.Bmp);
break;
}
AlphaData = buffer.Length > 0 ? buffer.ToArray() : null;
ColorBitmap?.Dispose();
AlphaBitmap?.Dispose();
ColorBitmap = null;
AlphaBitmap = null;
return(true);
}
