s.getBoundingClientRect();
			points_for_interpolation[interpolation_i] = [e.clientX - canvas_rect.left, e.clientY - canvas_rect.top];
			draw_canvas("interpolation_canvas");
		}
	}, false);

	canvas.addEventListener('pointerup', function(e){
		canvas_rect = canvas.getBoundingClientRect();
		points_for_interpolation[interpolation_i] = [e.clientX - canvas_rect.left, e.clientY - canvas_rect.top];
		draw_canvas("interpolation_canvas");
	}, false);

	draw_canvas("interpolation_canvas");
}

var both_i = 0;
funct