Create a function to round image into an ellipse

imagepipeline/src/main/java/com/facebook/imagepipeline/filter/InPlaceEllipseRoundFilter.java

@@ -0,0 +1,45 @@
+package com.facebook.imagepipeline.filter;
+
+import android.graphics.Bitmap;
+import com.facebook.common.internal.Preconditions;
+import com.facebook.imageutils.BitmapUtil;
+
+/**
+ * Filter for rounding to ellipse.
+ */
+public final class InPlaceEllipseRoundFilter {
+
+    private InPlaceEllipseRoundFilter() {}
+
+    /**
+     * An implementation for rounding a given bitmap to an ellipse shape.
+     *
+     * @param bitmap The input {@link Bitmap}
+     */
+    public static void roundEllipseBitmapInPlace(Bitmap bitmap) {
+        Preconditions.checkNotNull(bitmap);
+        final int w = bitmap.getWidth();
+        final int h = bitmap.getHeight();
+
+        final int[] transparentColor = new int[w];
+
+        final int[] pixels = new int[w*h];
+        bitmap.getPixels(pixels, 0, w, 0, 0, w, h);
+
+        for (int y = -1*h/2; y < h/2; y++) {
+            int x = -1*w/2;
+            while ( ((float) 4*x*x)/(w*w) + ((float) 4*y*y)/(h*h) > 1 ) {
+                x++;
+            }
+
+            int pixelsToHide = Math.max(0, x + w/2 - 1);
+
+            System.arraycopy(transparentColor, 0, pixels, (y + h/2)*w, pixelsToHide);
+
+            System.arraycopy(transparentColor, 0, pixels, (y + h/2)*w + w - pixelsToHide, pixelsToHide);
+        }
+
+        bitmap.setPixels(pixels, 0, w, 0, 0, w, h);
+    }
+}
+

imagepipeline/src/main/java/com/facebook/imagepipeline/postprocessors/EllipsePostprocessor.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.imagepipeline.postprocessors;
+
+import android.graphics.Bitmap;
+import com.facebook.cache.common.CacheKey;
+import com.facebook.cache.common.SimpleCacheKey;
+import com.facebook.imagepipeline.filter.InPlaceEllipseRoundFilter;
+import com.facebook.imagepipeline.request.BasePostprocessor;
+import javax.annotation.Nullable;
+
+/** Postprocessor that rounds a given image as a ellipse using non-native code. */
+public class EllipsePostprocessor extends BasePostprocessor {
+
+    private @Nullable CacheKey mCacheKey;
+
+    public EllipsePostprocessor() {;}
+
+    @Override
+    public void process(Bitmap bitmap) {
+        InPlaceEllipseRoundFilter.roundEllipseBitmapInPlace(bitmap);
+    }
+
+    @Nullable
+    @Override
+    public CacheKey getPostprocessorCacheKey() {
+        if (mCacheKey == null) {
+            mCacheKey = new SimpleCacheKey("InPlaceEllipseRoundFilter");
+        }
+        return mCacheKey;
+    }
+}

samples/showcase/src/main/java/com/facebook/fresco/samples/showcase/imagepipeline/ImagePipelinePostProcessorFragment.java

@@ -34,6 +34,7 @@
 import com.facebook.fresco.samples.showcase.postprocessor.SlowGreyScalePostprocessor;
 import com.facebook.fresco.samples.showcase.postprocessor.WatermarkPostprocessor;
 import com.facebook.imagepipeline.postprocessors.BlurPostProcessor;
+import com.facebook.imagepipeline.postprocessors.EllipsePostprocessor;
 import com.facebook.imagepipeline.postprocessors.IterativeBoxBlurPostProcessor;
 import com.facebook.imagepipeline.postprocessors.RoundAsCirclePostprocessor;
 import com.facebook.imagepipeline.postprocessors.RoundPostprocessor;
@@ -212,6 +213,10 @@ this, new RoundAsCirclePostprocessor(true))),
             R.string.imagepipeline_postprocessor_set_rounded_corners,
             new BenchmarkPostprocessorForDuplicatedBitmapInPlace(
                 this, new RoundedCornersPostprocessor())),
+        new Entry(
+            R.string.imagepipeline_postprocessor_set_ellipse,
+            new BenchmarkPostprocessorForDuplicatedBitmapInPlace(
+               this, new EllipsePostprocessor())),
         new Entry(
             R.string.imagepipeline_postprocessor_set_round_as_circle,
             new BenchmarkPostprocessorForDuplicatedBitmap(this, new RoundPostprocessor())));

samples/showcase/src/main/res/values/strings.xml

@@ -74,6 +74,7 @@
   <string name="imagepipeline_postprocessor_set_round_as_circle">Round As Circle Post-Processor</string>
   <string name="imagepipeline_postprocessor_set_round_as_aa_circle">Antialiased Circle Post-Processor</string>
   <string name="imagepipeline_postprocessor_set_rounded_corners">Rounded Corners Post-Processor</string>
+  <string name="imagepipeline_postprocessor_set_ellipse">Ellipse Post-Processor</string>
   <string name="imagepipeline_postprocessor_refresh">Refresh</string>
 
   <string name="imagepipeline_prefetch_title">Prefetch</string>