 canvasRect.left;
    const left = Math.max(0, elemRect.left - canvasRect.left);
    const bottom = Math.min(elemRect.bottom, canvasRect.bottom) - canvasRect.top;
    const top = Math.max(0, elemRect.top - canvasRect.top);

    const width = Math.min(canvasRect.width, right - left);
    const height = Math.min(canvasRect.height, bottom - top);

    // setup the scissor to only render to that part of the canvas
    const positiveYUpBottom = canvasRect.height - bottom;
    renderer.setScissor(left, positiveYU