add GPUImageFilterGroup setBackground and fix bug for cats-oss#395

build.gradle

@@ -7,7 +7,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.2.0-beta04'
+        classpath 'com.android.tools.build:gradle:3.4.2'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
 // TODO: Close JCenter on May 1st https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https://services.gradle.org/distributions/gradle-6.7.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

library/build.gradle

@@ -53,4 +53,4 @@ ext {
 // apply from: 'https://gist.githubusercontent.com/wasabeef/cf14805bee509baf7461974582f17d26/raw/bintray-v1.gradle'
 // apply from: 'https://gist.githubusercontent.com/wasabeef/cf14805bee509baf7461974582f17d26/raw/install-v1.gradle'
 
-apply from: 'https://gist.githubusercontent.com/wasabeef/2f2ae8d97b429e7d967128125dc47854/raw/maven-central-v1.gradle'
+//apply from: 'https://gist.githubusercontent.com/wasabeef/2f2ae8d97b429e7d967128125dc47854/raw/maven-central-v1.gradle'

library/src/main/java/jp/co/cyberagent/android/gpuimage/filter/GPUImageFilterGroup.java

@@ -46,6 +46,10 @@ public class GPUImageFilterGroup extends GPUImageFilter {
     private final FloatBuffer glTextureBuffer;
     private final FloatBuffer glTextureFlipBuffer;
 
+    private float mBackgroundRed;
+    private float mBackgroundGreen;
+    private float mBackgroundBlue;
+
     /**
      * Instantiates a new GPUImageFilterGroup with no filters.
      */
@@ -196,12 +200,12 @@ public void onDraw(final int textureId, final FloatBuffer cubeBuffer,
                 boolean isNotLast = i < size - 1;
                 if (isNotLast) {
                     GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, frameBuffers[i]);
-                    GLES20.glClearColor(0, 0, 0, 0);
+                    GLES20.glClearColor(mBackgroundRed, mBackgroundGreen, mBackgroundBlue, 1);
                 }
 
-                if (i == 0) {
+                if (i == size - 1) {
                     filter.onDraw(previousTexture, cubeBuffer, textureBuffer);
-                } else if (i == size - 1) {
+                } else if (i == 0) {
                     filter.onDraw(previousTexture, glCubeBuffer, (size % 2 == 0) ? glTextureFlipBuffer : glTextureBuffer);
                 } else {
                     filter.onDraw(previousTexture, glCubeBuffer, glTextureBuffer);
@@ -252,4 +256,10 @@ public void updateMergedFilters() {
             mergedFilters.add(filter);
         }
     }
+
+    public void setBackgroundColor(float red, float green, float blue) {
+        mBackgroundRed = red;
+        mBackgroundGreen = green;
+        mBackgroundBlue = blue;
+    }
 }

sample/src/main/AndroidManifest.xml

@@ -35,6 +35,10 @@
             android:name=".activity.CameraActivity"
             android:screenOrientation="portrait"
             android:theme="@style/AppTheme.NoActionBar" />
+        <activity
+            android:name=".activity.ImageActivity"
+            android:screenOrientation="portrait"
+            android:theme="@style/AppTheme.NoActionBar" />
     </application>
 
 </manifest>

sample/src/main/java/jp/co/cyberagent/android/gpuimage/sample/activity/GalleryActivity.kt

@@ -23,6 +23,7 @@ import android.widget.SeekBar
 import android.widget.SeekBar.OnSeekBarChangeListener
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
+import jp.co.cyberagent.android.gpuimage.GPUImage
 import jp.co.cyberagent.android.gpuimage.GPUImageView
 import jp.co.cyberagent.android.gpuimage.filter.GPUImageFilter
 import jp.co.cyberagent.android.gpuimage.sample.GPUImageFilterTools
@@ -39,6 +40,8 @@ class GalleryActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_gallery)
 
+        gpuImageView.setScaleType(GPUImage.ScaleType.CENTER_INSIDE)
+
         seekBar.setOnSeekBarChangeListener(object : OnSeekBarChangeListener {
             override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
                 filterAdjuster?.adjust(progress)

sample/src/main/java/jp/co/cyberagent/android/gpuimage/sample/activity/ImageActivity.kt

@@ -0,0 +1,43 @@
+package jp.co.cyberagent.android.gpuimage.sample.activity
+
+import android.graphics.BitmapFactory
+import android.net.Uri
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import jp.co.cyberagent.android.gpuimage.GPUImage
+import jp.co.cyberagent.android.gpuimage.GPUImageView
+import jp.co.cyberagent.android.gpuimage.filter.*
+import jp.co.cyberagent.android.gpuimage.sample.R
+
+/*
+ * Copyright (C) 2018 CyberAgent, Inc.
+ *
+ * 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.
+ */
+class ImageActivity : AppCompatActivity() {
+
+    private val gpuImage: GPUImageView by lazy { findViewById<GPUImageView>(R.id.gpu_image) }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_image)
+        gpuImage.setScaleType(GPUImage.ScaleType.CENTER_INSIDE)
+        gpuImage.filter = GPUImageFilterGroup(listOf(GPUImageBrightnessFilter(),
+            GPUImageSaturationFilter(),
+            GPUImageWhiteBalanceFilter(),
+            GPUImageSharpenFilter())).apply {
+            setBackgroundColor(0.27f, 0.27f, 0.27f)
+        }
+        gpuImage.setImage(Uri.parse("file:///android_asset/image.png"))
+    }
+}

sample/src/main/java/jp/co/cyberagent/android/gpuimage/sample/activity/MainActivity.kt

@@ -35,6 +35,11 @@ class MainActivity : AppCompatActivity() {
         findViewById<View>(R.id.button_gallery).setOnClickListener {
             startActivity(Intent(this, GalleryActivity::class.java))
         }
+
+        findViewById<View>(R.id.button_image).setOnClickListener {
+            startActivity(Intent(this,ImageActivity::class.java))
+        }
+
         findViewById<View>(R.id.button_camera).setOnClickListener {
             if (!hasCameraPermission() || !hasStoragePermission()) {
                 ActivityCompat.requestPermissions(

sample/src/main/res/layout/activity_image.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <jp.co.cyberagent.android.gpuimage.GPUImageView
+        android:id="@+id/gpu_image"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        />
+</LinearLayout>

sample/src/main/res/layout/activity_main.xml

@@ -10,6 +10,15 @@
         android:gravity="center"
         android:orientation="vertical">
 
+        <Button
+            android:id="@+id/button_image"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginBottom="10dp"
+            android:drawableTop="@android:drawable/ic_menu_gallery"
+            android:text="ImageGroupFilter"
+            tools:ignore="HardcodedText" />
+
         <Button
             android:id="@+id/button_gallery"
             android:layout_width="wrap_content"