谷歌地图的html2canvas图像 - 由地图图块边缘修剪的多边形

Question

保存从包含多边形的Google地图创建的画布时，正在裁剪多边形的位置 - Example。

多边形线和折线正在被剪裁，这个问题在地图中看不到，只是在通过html2canvas保存图像时。

// Setup vars
var $this = $(this),
    $mapContainer = $('#area-map .gm-style div:first'),
    $input = $('input[name="map_image_data"]')

// Run HTML2Canvas to convert map to data image
html2canvas($mapContainer, {
    proxy : 'html2canvasproxy.php',
    useCORS : false,
    logging : true,
    onrendered: function(canvas) {
        var dataURL = canvas.toDataURL();
        $input.val(dataURL);
    }
});

html2canvas日志输出：

html2canvas: Preload starts: finding background-images
html2canvas: Preload: Finding images 
html2canvas: Preload: Done.
html2canvas: start: images: 1 / 9 (failed: 0)
html2canvas: start: images: 2 / 9 (failed: 0)
html2canvas: start: images: 3 / 9 (failed: 0)
html2canvas: start: images: 4 / 9 (failed: 0)
html2canvas: start: images: 5 / 9 (failed: 0)
html2canvas: start: images: 6 / 9 (failed: 0)
html2canvas: start: images: 7 / 9 (failed: 0)
html2canvas: start: images: 8 / 9 (failed: 0)
html2canvas: start: images: 9 / 9 (failed: 0)
Finished loading images: # 9 (failed: 0)
html2canvas: Renderer: Canvas renderer done - returning canvas obj

我一直试图将多边形移动到另一个地图窗格，但没有任何运气。