更新

TongjiUniApp/node_modules/@jimp/plugin-displace/src/index.js

@@ -0,0 +1,41 @@
+import { isNodePattern, throwError } from '@jimp/utils';
+
+/**
+ * Displaces the image based on the provided displacement map
+ * @param {object} map the source Jimp instance
+ * @param {number} offset the maximum displacement value
+ * @param {function(Error, Jimp)} cb (optional) a callback for when complete
+ * @returns {Jimp} this for chaining of methods
+ */
+export default () => ({
+  displace(map, offset, cb) {
+    if (typeof map !== 'object' || map.constructor !== this.constructor) {
+      return throwError.call(this, 'The source must be a Jimp image', cb);
+    }
+
+    if (typeof offset !== 'number') {
+      return throwError.call(this, 'factor must be a number', cb);
+    }
+
+    const source = this.cloneQuiet();
+    this.scanQuiet(0, 0, this.bitmap.width, this.bitmap.height, function(
+      x,
+      y,
+      idx
+    ) {
+      let displacement = (map.bitmap.data[idx] / 256) * offset;
+      displacement = Math.round(displacement);
+
+      const ids = this.getPixelIndex(x + displacement, y);
+      this.bitmap.data[ids] = source.bitmap.data[idx];
+      this.bitmap.data[ids + 1] = source.bitmap.data[idx + 1];
+      this.bitmap.data[ids + 2] = source.bitmap.data[idx + 2];
+    });
+
+    if (isNodePattern(cb)) {
+      cb.call(this, null, this);
+    }
+
+    return this;
+  }
+});