Cache calls to set custom clipping rectangles on a CanvasItem

[rraallvv]

For instance in this snipped of code:

void MyCustomItem::_notification(int p_what) {

	case NOTIFICATION_DRAW: {
		// Enable clipping
		VisualServer::get_singleton()->canvas_item_set_clip(get_canvas_item(), true);

		draw_background();

		// Clip to margins
		VisualServer::get_singleton()->canvas_item_set_custom_rect(get_canvas_item(), true, Rect2(
			Point2(
			 margin_left,
			 margin_top
			),
			Size2(
			 width - margin_left - margin_right,
			 height - margin_top - margin_bottom
			)
		));

		draw_stuff();
		break;
	}
}

I need draw_background() to paint something within the CanvasItem clipping area and draw_stuff() to draw everything else within some margin. Such thing would be possible if calls to canvas_item_set_clip() and canvas_item_set_custom_rect() were cached.

[akien-mga]

Is this issue still relevant in the current master branch?

If so, could you provide an example project that shows what happens currently, and describe what you'd expect?

[rraallvv]

@akien-mga I'm not sure, I'll try to reproduce it with the current master branch and report back.

[tom-jk]

The issue as I understand it is as follows: we want to clip drawing to some area A, and draw some things X, then clip it to some area B, and draw some other things Y. The draw commands are queued up to be drawn but the clip setting commands are performed immediately(?); the result is that both X and Y are drawn clipped to area B (the last clip we set).

Tested in 2.1.4, 3.0, 3.2.3.rc3
Can reproduce issue in all

Tested with a control with this script:

extends Control


func _notification(what):
	
	if what == NOTIFICATION_DRAW:
		# Enable clipping
		VisualServer.canvas_item_set_clip(get_canvas_item(), true)
		
		# clip to size area A
		if true:
			VisualServer.canvas_item_set_custom_rect(get_canvas_item(), true,
			Rect2(Vector2(0, 0), Vector2(128, 128)));
		
		# draw some X
		draw_circle(get_local_mouse_position(), 128, Color(0,1,0,1))
		
		# clip to size area B
		if true:
			VisualServer.canvas_item_set_custom_rect(get_canvas_item(), true,
			Rect2(Vector2(32, 32), Vector2(64, 64)));
		
		# draw some Y
		draw_circle(get_local_mouse_position(),  80, Color(1,0,0,1))


func _physics_process(delta):
	update()

Expected (left): a large green circle clipped by a large square area, and a small red circle clipped by a smaller square area. (Both circles are drawn at the mouse position.)

Result (right): large green circle and small red circle both clipped by the smaller square area.