private void WithExtraCanvas(Rectangle rect, Action <X11Canvas> action)
{
using (X11Image tempImage = X11Image.Create(display, visual, drawableId, rect.Width, rect.Height))
{
var gcValues = new XGCValues();
gcValues.foreground = ToPArgb(Color.Transparent);
var gcValueMask = XGCValueMask.GCForeground;
var gc = LibX11.XCreateGC(display, drawableId, gcValueMask, ref gcValues);
try
{
// todo: check int -> uint conversion
LibX11.XFillRectangle(display, tempImage.PixmapId, gc, 0, 0, (uint)rect.Width, (uint)rect.Height);
}
finally
{
LibX11.XFreeGC(display, gc);
}
using (var innerCanvas = X11Canvas.CreateForDrawable(display, screenNum, objectCache, visual, colormap, pictFormatPtr, tempImage.PixmapId))
{
action(innerCanvas);
DrawImage(tempImage, rect.X + origin.X, rect.Y + origin.Y);
}
}
}