ddEventListener('wheel', function(e) {
		const canvas_rect = i_canvas.getBoundingClientRect();
		const sx = e.clientX - canvas_rect.left;
		if(sx >= w)
			return;
		if(e.shiftKey) {
			if(e.deltaY < 0)
				scale_value /= 2;
			else
				scale_value *= 2;
			draw_canvas();
		}
	}, false);

	function redraw() {
		draw_canvas();
		setTimeout(redraw, 20);
	}
	if(i_do_animations)
		redraw();
	else
		draw_canvas();
}

function pretty_print_abcd(a, b, c, d) {
	var text = '';
	if(a < 0)
		text += '-';
	text += Math.