public override void AttachToBackBuffer(DrawboardBuffer backbuffer)
{
#if DEBUG
if (dbugSwitchCount > 0)
{
}
dbugSwitchCount++;
#endif
//save prev context
SaveContext prevContext = new SaveContext();
prevContext.prevClipRect = _currentClipRect;
prevContext.prevCanvasOrgX = _canvasOriginX;
prevContext.prevCanvasOrgY = _canvasOriginY;
prevContext.prevGLRenderSurface = _gpuPainter.PainterContext.CurrentRenderSurface;
_saveContexts.Push(prevContext);
//_prevClipRect = _currentClipRect;
_currentClipRect = new Rectangle(0, 0, backbuffer.Width, backbuffer.Height);
MyGLBackbuffer glBackBuffer = (MyGLBackbuffer)backbuffer;
_gpuPainter.PainterContext.AttachToRenderSurface(glBackBuffer.RenderSurface);
_gpuPainter.PainterContext.OriginKind = RenderSurfaceOrientation.LeftTop;
_gpuPainter.UpdatePainterContext();
_left = 0;
_top = 0;
_width = _gpuPainter.Width;
_height = _gpuPainter.Height;
//_prevCanvasOrgX = _canvasOriginX;
//_prevCanvasOrgY = _canvasOriginY;
_canvasOriginX = 0;
_canvasOriginY = 0;
_gpuPainter.SetOrigin(0, 0);
SetClipRect(_currentClipRect);
}