//实现材质的图片,根据url转成imageData
async function giHttpURLtoImgData(url) {
toTexContext2d.clearRect(0, 0, toTexCanvas.width, toTexCanvas.height);
const image = await createImage(toTexCanvas, url);
toTexContext2d.scale(1, -1);
toTexContext2d.drawImage(image, 0, -image.width);
toTexContext2d.scale(1, -1);
let imageData = toTexContext2d.getImageData(0, 0, image.width, image.height);