Update canvas-helper.js

Author: Shinerising

src/lib/canvas-helper.js

@@ -54,6 +54,48 @@ export default {
  callback(data);
  }
  },
+ 
+ /**
+ * init image for reset size and rotation
+ **/
+ init(src, callback) {
+ console.log(src);
+ let image = new Image();
+ image.src = src;
+ var self = this;
+ image.onload = function() {
+ var mimeType = self._getImageType(image.src);
+ var cvs = self._getCanvas(image.naturalWidth, image.naturalHeight);
+ var ctx = cvs.getContext("2d");
+ ctx.drawImage(image, 0, 0);
+ var newImageData = cvs.toDataURL(mimeType, 100);
+ callback(newImageData);
+ }
+ },
+
+ /**
+ * rotate image via canvas
+ **/
+ rotate(imageData, direction, callback) {
+ let image = new Image();
+ image.src = imageData.src;
+ var self = this;
+ image.onload = function() {
+ var mimeType = self._getImageType(image.src);
+ var cvs = self._getCanvas(image.naturalHeight, image.naturalWidth);
+ var ctx = cvs.getContext("2d");
+ if (direction == 1) { 
+ ctx.rotate(90 * Math.PI / 180);
+ ctx.translate(0, -cvs.width);
+ } else {
+ ctx.rotate(-90 * Math.PI / 180);
+ ctx.translate(-cvs.height, 0);
+ }
+ ctx.drawImage(image, 0, 0);
+ var newImageData = cvs.toDataURL(mimeType, 100);
+ callback(newImageData);
+ }
+ },
 
  resize(image, options, callback) {
  const checkNumber = function(num) {