private void WriteColor(Color color, MimTileBlendType blendType, Stream ioStream)
{
if (ColorsHelper.IsBlack(color))
{
ioStream.Seek(3, SeekOrigin.Current);
return;
}
if ((int)blendType < 4)
{
Color oldColor = ColorsHelper.ReadColor(ioStream, _buff3);
color = BlendColor(color, oldColor, blendType);
ioStream.Seek(-3, SeekOrigin.Current);
}
ColorsHelper.WriteBgr(ioStream, color);
}
private static Color BlendColor(Color newColor, Color oldColor, MimTileBlendType blendType)
{
byte nr = newColor.R;
byte ng = newColor.G;
byte nb = newColor.B;
byte or = oldColor.R;
byte og = oldColor.G;
byte ob = oldColor.B;
switch (blendType)
{
case MimTileBlendType.Average:
return(Color.FromArgb(255,
(byte)Math.Min(255, ((nr + or) / 2)),
(byte)Math.Min(255, ((ng + og) / 2)),
(byte)Math.Min(255, ((nb + ob) / 2))));
case MimTileBlendType.Add:
return(Color.FromArgb(255,
(byte)Math.Min(255, (nr + or)),
(byte)Math.Min(255, (ng + og)),
(byte)Math.Min(255, (nb + ob))));
case MimTileBlendType.Sub:
return(Color.FromArgb(255,
(byte)Math.Min(255, (nr - or)),
(byte)Math.Min(255, (ng - og)),
(byte)Math.Min(255, (nb - ob))));
case MimTileBlendType.Mul25:
return(Color.FromArgb(255,
(byte)Math.Min(255, (0.25 * nr + or)),
(byte)Math.Min(255, (0.25 * ng + og)),
(byte)Math.Min(255, (0.25 * nb + ob))));
default:
throw new NotSupportedException();
}
}
