/// <summary>
/// This is the event handler for the Paint Event, try to draw as little as possible!
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void SurfacePaint(object sender, PaintEventArgs e)
{
Graphics targetGraphics = e.Graphics;
Rectangle clipRectangle = e.ClipRectangle;
if (Rectangle.Empty.Equals(clipRectangle))
{
LOG.Debug("Empty cliprectangle??");
return;
}
if (elements.hasIntersectingFilters(clipRectangle))
{
if (buffer != null)
{
if (buffer.Width != Image.Width || buffer.Height != Image.Height || buffer.PixelFormat != Image.PixelFormat)
{
buffer.Dispose();
buffer = null;
}
}
if (buffer == null)
{
buffer = new Bitmap(Image.Width, Image.Height, Image.PixelFormat);
}
// Elements might need the bitmap, so we copy the part we need
using (Graphics graphics = Graphics.FromImage(buffer)) {
graphics.DrawImage(Image, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
graphics.SetClip(targetGraphics);
elements.Draw(graphics, buffer, RenderMode.EDIT, clipRectangle);
}
targetGraphics.DrawImage(buffer, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
}
else
{
// Only "simple" elements need to be redrawn, as the image is already drawn before getting the event we don't need the next line:
//targetGraphics.DrawImage(Image, clipRectangle, clipRectangle, GraphicsUnit.Pixel);
elements.Draw(targetGraphics, null, RenderMode.EDIT, clipRectangle);
}
}
