Javascript Save canvas to image

// saveImage.js

const dataURLtoBlob = (dataurl) => {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], {type:mime});
}

const saveImage = (canvas, filename) => {

	var link = document.createElement("a");
	var imgData = canvas.toDataURL({    
		format: 'png',
		multiplier: 4});

	var blob = dataURLtoBlob(imgData);
	var objurl = URL.createObjectURL(blob);

	link.download = `${filename}.png`;

	link.href = objurl;

	link.click();
};


export { saveImage };

When initialize the canvas, if using WebGL need to set preserveDrawingBuffer to true.