void update_refresh(VideoDevice *device, VFrame *output_frame);
// Redraws the refresh_frame
virtual void draw_refresh(int flush = 1) {};
void update_refresh(VideoDevice *device, VFrame *output_frame);
// Redraws the refresh_frame
virtual void draw_refresh(int flush = 1) {};
// Get top left offset of canvas relative to output.
// Normally negative. Can be positive if output is smaller than canvas.
// Get top left offset of canvas relative to output.
// Normally negative. Can be positive if output is smaller than canvas.