更新

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

@@ -0,0 +1,49 @@
+import { isNodePattern } from '@jimp/utils';
+
+/**
+ * Creates a circle out of an image.
+ * @param {function(Error, Jimp)} options (optional) radius, x, y
+ * @param {function(Error, Jimp)} cb (optional) a callback for when complete
+ * @returns {Jimp} this for chaining of methods
+ */
+export default () => ({
+  circle(options = {}, cb) {
+    if (typeof options === 'function') {
+      cb = options;
+      options = {};
+    }
+
+    const radius =
+      options.radius ||
+      (this.bitmap.width > this.bitmap.height
+        ? this.bitmap.height
+        : this.bitmap.width) / 2;
+
+    const center = {
+      x: typeof options.x === 'number' ? options.x : this.bitmap.width / 2,
+      y: typeof options.y === 'number' ? options.y : this.bitmap.height / 2
+    };
+
+    this.scanQuiet(0, 0, this.bitmap.width, this.bitmap.height, function(
+      x,
+      y,
+      idx
+    ) {
+      const curR = Math.sqrt(
+        Math.pow(x - center.x, 2) + Math.pow(y - center.y, 2)
+      );
+
+      if (radius - curR <= 0.0) {
+        this.bitmap.data[idx + 3] = 0;
+      } else if (radius - curR < 1.0) {
+        this.bitmap.data[idx + 3] = 255 * (radius - curR);
+      }
+    });
+
+    if (isNodePattern(cb)) {
+      cb.call(this, null, this);
+    }
+
+    return this;
+  }
+});