Add RenderEffect support for Shaders as inputs

Added RenderEffect.createShader to handle creation
of RenderEffects using shaders as inputs that can be
chained with other RenderEffects

Fixes: 178536866
Test: Added example in HwAccelerationTest activity
Change-Id: I4d9791ad63f3057ffa528918ce2cd083986089e5

5 files changed, 149 insertions, 6 deletions

diff --git a/core/api/current.txt b/core/api/current.txt
index f5c67c170931..2c4a36500531 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -15795,6 +15795,7 @@ package android.graphics {
     method @NonNull public static android.graphics.RenderEffect createColorFilterEffect(@NonNull android.graphics.ColorFilter);
     method @NonNull public static android.graphics.RenderEffect createOffsetEffect(float, float);
     method @NonNull public static android.graphics.RenderEffect createOffsetEffect(float, float, @NonNull android.graphics.RenderEffect);
+    method @NonNull public static android.graphics.RenderEffect createShaderEffect(@NonNull android.graphics.Shader);
   }
 
   public final class RenderNode {
diff --git a/graphics/java/android/graphics/RenderEffect.java b/graphics/java/android/graphics/RenderEffect.java
index 496e4707dbff..ad4c3fe86175 100644
--- a/graphics/java/android/graphics/RenderEffect.java
+++ b/graphics/java/android/graphics/RenderEffect.java
@@ -190,7 +190,7 @@ public final class RenderEffect {
     }
 
     /**
-     * Create a filter that applies the color filter to the provided RenderEffect
+     * Create a {@link RenderEffect} that applies the color filter to the provided RenderEffect
      *
      * @param colorFilter ColorFilter applied to the content in the input RenderEffect
      * @param renderEffect Source to be transformed by the specified {@link ColorFilter}
@@ -209,7 +209,7 @@ public final class RenderEffect {
     }
 
     /**
-     * Create a filter that applies the color filter to the contents of the
+     * Create a {@link RenderEffect} that applies the color filter to the contents of the
      * {@link android.graphics.RenderNode} that this RenderEffect is installed on
      * @param colorFilter ColorFilter applied to the content in the input RenderEffect
      */
@@ -224,7 +224,7 @@ public final class RenderEffect {
     }
 
     /**
-     * {@link RenderEffect} that is a composition of 2 other {@link RenderEffect} instances
+     * Create a {@link RenderEffect} that is a composition of 2 other {@link RenderEffect} instances
      * combined by the specified {@link BlendMode}
      *
      * @param dst The Dst pixels used in blending
@@ -248,8 +248,8 @@ public final class RenderEffect {
     }
 
     /**
-     * Create a filter that composes 'inner' with 'outer', such that the results of 'inner' are
-     * treated as the source bitmap passed to 'outer', i.e.
+     * Create a {@link RenderEffect} that composes 'inner' with 'outer', such that the results of
+     * 'inner' are treated as the source bitmap passed to 'outer', i.e.
      *
      * <pre>
      * {@code
@@ -278,6 +278,18 @@ public final class RenderEffect {
             );
     }
 
+    /**
+     * Create a {@link RenderEffect} that renders the contents of the input {@link Shader}.
+     * This is useful to create an input for other {@link RenderEffect} types such as
+     * {@link RenderEffect#createBlurEffect(float, float, RenderEffect, TileMode)}
+     * {@link RenderEffect#createBlurEffect(float, float, RenderEffect, TileMode)} or
+     * {@link RenderEffect#createColorFilterEffect(ColorFilter, RenderEffect)}.
+     */
+    @NonNull
+    public static RenderEffect createShaderEffect(@NonNull Shader shader) {
+        return new RenderEffect(nativeCreateShaderEffect(shader.getNativeInstance()));
+    }
+
     private final long mNativeRenderEffect;
 
     /* only constructed from static factory methods */
@@ -305,5 +317,6 @@ public final class RenderEffect {
     private static native long nativeCreateColorFilterEffect(long colorFilter, long nativeInput);
     private static native long nativeCreateBlendModeEffect(long dst, long src, int blendmode);
     private static native long nativeCreateChainEffect(long outer, long inner);
+    private static native long nativeCreateShaderEffect(long shader);
     private static native long nativeGetFinalizer();
 }
diff --git a/libs/hwui/jni/RenderEffect.cpp b/libs/hwui/jni/RenderEffect.cpp
index 97c40d695f97..fa1752cc47d6 100644
--- a/libs/hwui/jni/RenderEffect.cpp
+++ b/libs/hwui/jni/RenderEffect.cpp
@@ -115,6 +115,18 @@ static jlong createChainEffect(
     return reinterpret_cast<jlong>(composeFilter.release());
 }
 
+static jlong createShaderEffect(
+    JNIEnv* env,
+    jobject,
+    jlong shaderHandle
+) {
+    auto* shader = reinterpret_cast<const SkShader*>(shaderHandle);
+    sk_sp<SkImageFilter> shaderFilter = SkImageFilters::Shader(
+          sk_ref_sp(shader), nullptr
+    );
+    return reinterpret_cast<jlong>(shaderFilter.release());
+}
+
 static void RenderEffect_safeUnref(SkImageFilter* filter) {
     SkSafeUnref(filter);
 }
@@ -130,7 +142,8 @@ static const JNINativeMethod gRenderEffectMethods[] = {
     {"nativeCreateBitmapEffect", "(JFFFFFFFF)J", (void*)createBitmapEffect},
     {"nativeCreateColorFilterEffect", "(JJ)J", (void*)createColorFilterEffect},
     {"nativeCreateBlendModeEffect", "(JJI)J", (void*)createBlendModeEffect},
-    {"nativeCreateChainEffect", "(JJ)J", (void*)createChainEffect}
+    {"nativeCreateChainEffect", "(JJ)J", (void*)createChainEffect},
+    {"nativeCreateShaderEffect", "(J)J", (void*)createShaderEffect}
 };
 
 int register_android_graphics_RenderEffect(JNIEnv* env) {
diff --git a/tests/HwAccelerationTest/AndroidManifest.xml b/tests/HwAccelerationTest/AndroidManifest.xml
index 1a940c75cfa4..c6c67feeed72 100644
--- a/tests/HwAccelerationTest/AndroidManifest.xml
+++ b/tests/HwAccelerationTest/AndroidManifest.xml
@@ -753,6 +753,15 @@
             </intent-filter>
         </activity>
 
+        <activity android:name="RenderEffectShaderActivity"
+                  android:label="RenderEffect/Shader"
+                  android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="com.android.test.hwui.TEST"/>
+            </intent-filter>
+        </activity>
+
         <activity android:name="TextActivity"
              android:label="Text/Simple Text"
              android:theme="@android:style/Theme.NoTitleBar"
diff --git a/tests/HwAccelerationTest/src/com/android/test/hwui/RenderEffectShaderActivity.java b/tests/HwAccelerationTest/src/com/android/test/hwui/RenderEffectShaderActivity.java
new file mode 100644
index 000000000000..661d48a84768
--- /dev/null
+++ b/tests/HwAccelerationTest/src/com/android/test/hwui/RenderEffectShaderActivity.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.test.hwui;
+
+import android.app.Activity;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.LinearGradient;
+import android.graphics.Paint;
+import android.graphics.RenderEffect;
+import android.graphics.RenderNode;
+import android.graphics.Shader;
+import android.os.Bundle;
+import android.view.Gravity;
+import android.view.View;
+import android.widget.LinearLayout;
+
+@SuppressWarnings({"UnusedDeclaration"})
+public class RenderEffectShaderActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        LinearLayout layout = new LinearLayout(this);
+        layout.setClipChildren(false);
+        layout.setGravity(Gravity.CENTER);
+        layout.setOrientation(LinearLayout.VERTICAL);
+
+
+        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(500, 500);
+        params.bottomMargin = 100;
+
+        layout.addView(new ShaderRenderEffectView(this), params);
+
+        setContentView(layout);
+    }
+
+    public static class ShaderRenderEffectView extends View {
+
+        private final Paint mPaint;
+        private final RenderNode mRenderNode;
+
+        public ShaderRenderEffectView(Context c) {
+            super(c);
+
+            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+            mRenderNode = new RenderNode("blurNode");
+
+        }
+
+        @Override
+        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+            if (changed) {
+                LinearGradient gradient = new LinearGradient(
+                        0f, 0f,
+                        0f, bottom - top,
+                        new int[]{Color.CYAN, Color.MAGENTA},
+                        null,
+                        Shader.TileMode.CLAMP
+                );
+                mRenderNode.setRenderEffect(
+                        RenderEffect.createShaderEffect(gradient)
+                );
+
+                int width = right - left;
+                int height = bottom - top;
+                mRenderNode.setPosition(0, 0, width, height);
+                Canvas canvas = mRenderNode.beginRecording(width, height);
+                mPaint.setColor(Color.BLUE);
+
+                canvas.drawRect(
+                        0,
+                        0,
+                        width,
+                        height,
+                        mPaint
+                );
+
+                mPaint.setColor(Color.RED);
+                canvas.drawCircle((right - left) / 2f, (bottom - top) / 2f, 50f, mPaint);
+
+                mRenderNode.endRecording();
+            }
+        }
+
+        @Override
+        protected void onDraw(Canvas canvas) {
+            super.onDraw(canvas);
+            canvas.drawRenderNode(mRenderNode);
+        }
+    }
+}