// Update the dimmed bitmap. If the intensity is < 1 and we're using a bitmap, dim it.
public void UpdateDimmedBitmap()
{
if (dimmedBitmap != null)
{
dimmedBitmap.Dispose();
}
dimmedBitmap = null;
// Only dim bitmap if size isn't too large. Otherwise takes too much memory.
if ((mapType == MapType.Bitmap || mapType == MapType.PDF) && mapIntensity < 0.99F && (bitmap.PixelWidth * bitmap.PixelHeight) < 36000000)
{
Bitmap dimmed = null;
try {
dimmed = new Bitmap(bitmap.PixelWidth, bitmap.PixelHeight);
}
catch (Exception) {
return; // typically because not enough memory. Uses alternate dimming method.
}
Graphics g = Graphics.FromImage(dimmed);
ImageAttributes imageAttributes = new ImageAttributes();
imageAttributes.SetColorMatrix(ComputeColorMatrix());
g.DrawImage(((GDIPlus_Bitmap)bitmap).Bitmap, new Rectangle(0, 0, bitmap.PixelWidth, bitmap.PixelHeight), 0, 0, bitmap.PixelWidth, bitmap.PixelHeight, GraphicsUnit.Pixel, imageAttributes);
g.Dispose();
dimmedBitmap = new GDIPlus_Bitmap(dimmed);
}
else
{
dimmedBitmap = null;
}
}
