
		}

		return totalMarked();
	}

	canvas.onmousemove = function() {
		const h = Math.floor((reverse ? event.offsetY : (canvasHeight - event.offsetY)) / 16);
		if (h >= 0 && h < levels.length) {
			const f = findFrame(levels[h], event.offsetX / px + root.left);
			if (f) {
				hl.style.left = (Math.max(f.left - root.left, 0) * px + canvas.offsetLeft) + 'px';
				hl.style.width = (Math.min(f.width, root.width) * px) + 'px';
				hl.style.top = ((reverse ? h * 16 : canvasHeight - (h + 1) * 16) + canvas.offsetT