Add a sysprop to switch between blur algorithms

Bug: 185365391
Test: adb root && adb shell 'setprop debug.renderengine.blur_algorithm kawase'   && adb shell 'stop; start' && sleep 30 && atest BlurTests
Test: adb root && adb shell 'setprop debug.renderengine.blur_algorithm gaussian' && adb shell 'stop  start' && sleep 30 && atest BlurTests
Test: adb root && adb shell 'setprop debug.renderengine.blur_algorithm ""'       && adb shell 'stop; start' && sleep 30 && atest BlurTests
Merged-In: Ib977e1d54eb08946449d447101a0c65273aa3b40
Change-Id: Ib977e1d54eb08946449d447101a0c65273aa3b40

7 files changed, 57 insertions, 16 deletions

diff --git a/libs/renderengine/include/renderengine/RenderEngine.h b/libs/renderengine/include/renderengine/RenderEngine.h
index 00a621372d..69e7b88bea 100644
--- a/libs/renderengine/include/renderengine/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/RenderEngine.h
@@ -50,6 +50,11 @@
 #define PROPERTY_DEBUG_RENDERENGINE_CAPTURE_FILENAME "debug.renderengine.capture_filename"
 
 /**
+ * Switches the cross-window background blur algorithm.
+ */
+#define PROPERTY_DEBUG_RENDERENGINE_BLUR_ALGORITHM "debug.renderengine.blur_algorithm"
+
+/**
  * Allows recording of Skia drawing commands with systrace.
  */
 #define PROPERTY_SKIA_ATRACE_ENABLED "debug.renderengine.skia_atrace_enabled"
@@ -107,6 +112,12 @@ public:
         GRAPHITE,
     };
 
+    enum class BlurAlgorithm {
+        NONE,
+        GAUSSIAN,
+        KAWASE,
+    };
+
     static std::unique_ptr<RenderEngine> create(const RenderEngineCreationArgs& args);
 
     static bool canSupport(GraphicsApi);
@@ -258,7 +269,7 @@ struct RenderEngineCreationArgs {
     bool useColorManagement;
     bool enableProtectedContext;
     bool precacheToneMapperShaderOnly;
-    bool supportsBackgroundBlur;
+    RenderEngine::BlurAlgorithm blurAlgorithm;
     RenderEngine::ContextPriority contextPriority;
     RenderEngine::Threaded threaded;
     RenderEngine::GraphicsApi graphicsApi;
@@ -270,7 +281,7 @@ private:
     // must be created by Builder via constructor with full argument list
     RenderEngineCreationArgs(int _pixelFormat, uint32_t _imageCacheSize,
                              bool _enableProtectedContext, bool _precacheToneMapperShaderOnly,
-                             bool _supportsBackgroundBlur,
+                             RenderEngine::BlurAlgorithm _blurAlgorithm,
                              RenderEngine::ContextPriority _contextPriority,
                              RenderEngine::Threaded _threaded,
                              RenderEngine::GraphicsApi _graphicsApi,
@@ -279,7 +290,7 @@ private:
             imageCacheSize(_imageCacheSize),
             enableProtectedContext(_enableProtectedContext),
             precacheToneMapperShaderOnly(_precacheToneMapperShaderOnly),
-            supportsBackgroundBlur(_supportsBackgroundBlur),
+            blurAlgorithm(_blurAlgorithm),
             contextPriority(_contextPriority),
             threaded(_threaded),
             graphicsApi(_graphicsApi),
@@ -306,8 +317,8 @@ struct RenderEngineCreationArgs::Builder {
         this->precacheToneMapperShaderOnly = precacheToneMapperShaderOnly;
         return *this;
     }
-    Builder& setSupportsBackgroundBlur(bool supportsBackgroundBlur) {
-        this->supportsBackgroundBlur = supportsBackgroundBlur;
+    Builder& setBlurAlgorithm(RenderEngine::BlurAlgorithm blurAlgorithm) {
+        this->blurAlgorithm = blurAlgorithm;
         return *this;
     }
     Builder& setContextPriority(RenderEngine::ContextPriority contextPriority) {
@@ -328,7 +339,7 @@ struct RenderEngineCreationArgs::Builder {
     }
     RenderEngineCreationArgs build() const {
         return RenderEngineCreationArgs(pixelFormat, imageCacheSize, enableProtectedContext,
-                                        precacheToneMapperShaderOnly, supportsBackgroundBlur,
+                                        precacheToneMapperShaderOnly, blurAlgorithm,
                                         contextPriority, threaded, graphicsApi, skiaBackend);
     }
 
@@ -338,7 +349,7 @@ private:
     uint32_t imageCacheSize = 0;
     bool enableProtectedContext = false;
     bool precacheToneMapperShaderOnly = false;
-    bool supportsBackgroundBlur = false;
+    RenderEngine::BlurAlgorithm blurAlgorithm = RenderEngine::BlurAlgorithm::NONE;
     RenderEngine::ContextPriority contextPriority = RenderEngine::ContextPriority::MEDIUM;
     RenderEngine::Threaded threaded = RenderEngine::Threaded::YES;
     RenderEngine::GraphicsApi graphicsApi = RenderEngine::GraphicsApi::GL;
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index 61369ae764..9d3d98e269 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -271,7 +271,7 @@ SkiaGLRenderEngine::SkiaGLRenderEngine(const RenderEngineCreationArgs& args, EGL
                                        EGLContext ctxt, EGLSurface placeholder,
                                        EGLContext protectedContext, EGLSurface protectedPlaceholder)
       : SkiaRenderEngine(args.threaded, static_cast<PixelFormat>(args.pixelFormat),
-                         args.supportsBackgroundBlur),
+                         args.blurAlgorithm),
         mEGLDisplay(display),
         mEGLContext(ctxt),
         mPlaceholderSurface(placeholder),
diff --git a/libs/renderengine/skia/SkiaRenderEngine.cpp b/libs/renderengine/skia/SkiaRenderEngine.cpp
index 24846509bc..4641cb9f93 100644
--- a/libs/renderengine/skia/SkiaRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaRenderEngine.cpp
@@ -273,12 +273,25 @@ void SkiaRenderEngine::setEnableTracing(bool tracingEnabled) {
 }
 
 SkiaRenderEngine::SkiaRenderEngine(Threaded threaded, PixelFormat pixelFormat,
-                                   bool supportsBackgroundBlur)
+                                   BlurAlgorithm blurAlgorithm)
       : RenderEngine(threaded), mDefaultPixelFormat(pixelFormat) {
-    if (supportsBackgroundBlur) {
-        ALOGD("Background Blurs Enabled");
-        mBlurFilter = new KawaseBlurFilter();
+    switch (blurAlgorithm) {
+        case BlurAlgorithm::GAUSSIAN: {
+            ALOGD("Background Blurs Enabled (Gaussian algorithm)");
+            mBlurFilter = new GaussianBlurFilter();
+            break;
+        }
+        case BlurAlgorithm::KAWASE: {
+            ALOGD("Background Blurs Enabled (Kawase algorithm)");
+            mBlurFilter = new KawaseBlurFilter();
+            break;
+        }
+        default: {
+            mBlurFilter = nullptr;
+            break;
+        }
     }
+
     mCapture = std::make_unique<SkiaCapture>();
 }
 
diff --git a/libs/renderengine/skia/SkiaRenderEngine.h b/libs/renderengine/skia/SkiaRenderEngine.h
index d7b491083d..ed50029cfa 100644
--- a/libs/renderengine/skia/SkiaRenderEngine.h
+++ b/libs/renderengine/skia/SkiaRenderEngine.h
@@ -59,7 +59,7 @@ class BlurFilter;
 class SkiaRenderEngine : public RenderEngine {
 public:
     static std::unique_ptr<SkiaRenderEngine> create(const RenderEngineCreationArgs& args);
-    SkiaRenderEngine(Threaded, PixelFormat pixelFormat, bool supportsBackgroundBlur);
+    SkiaRenderEngine(Threaded, PixelFormat pixelFormat, BlurAlgorithm);
     ~SkiaRenderEngine() override;
 
     std::future<void> primeCache(bool shouldPrimeUltraHDR) override final;
diff --git a/libs/renderengine/skia/SkiaVkRenderEngine.cpp b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
index fd71332089..406fd81487 100644
--- a/libs/renderengine/skia/SkiaVkRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
@@ -85,7 +85,7 @@ using base::StringAppendF;
 
 SkiaVkRenderEngine::SkiaVkRenderEngine(const RenderEngineCreationArgs& args)
       : SkiaRenderEngine(args.threaded, static_cast<PixelFormat>(args.pixelFormat),
-                         args.supportsBackgroundBlur) {}
+                         args.blurAlgorithm) {}
 
 SkiaVkRenderEngine::~SkiaVkRenderEngine() {
     finishRenderingAndAbandonContext();
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index 9f614bdd37..640c434990 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -116,7 +116,7 @@ public:
                         .setImageCacheSize(1)
                         .setEnableProtectedContext(false)
                         .setPrecacheToneMapperShaderOnly(false)
-                        .setSupportsBackgroundBlur(true)
+                        .setBlurAlgorithm(renderengine::RenderEngine::BlurAlgorithm::KAWASE)
                         .setContextPriority(renderengine::RenderEngine::ContextPriority::MEDIUM)
                         .setThreaded(renderengine::RenderEngine::Threaded::NO)
                         .setGraphicsApi(graphicsApi())
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 21f1cb3e4a..b3f83f0799 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -821,6 +821,23 @@ void chooseRenderEngineType(renderengine::RenderEngineCreationArgs::Builder& bui
     }
 }
 
+/**
+ * Choose a suggested blurring algorithm if supportsBlur is true. By default Kawase will be
+ * suggested as it's faster than a full Gaussian blur and looks close enough.
+ */
+renderengine::RenderEngine::BlurAlgorithm chooseBlurAlgorithm(bool supportsBlur) {
+    if (!supportsBlur) {
+        return renderengine::RenderEngine::BlurAlgorithm::NONE;
+    }
+
+    auto const algorithm = base::GetProperty(PROPERTY_DEBUG_RENDERENGINE_BLUR_ALGORITHM, "");
+    if (algorithm == "gaussian") {
+        return renderengine::RenderEngine::BlurAlgorithm::GAUSSIAN;
+    } else {
+        return renderengine::RenderEngine::BlurAlgorithm::KAWASE;
+    }
+}
+
 void SurfaceFlinger::init() FTL_FAKE_GUARD(kMainThreadContext) {
     ATRACE_CALL();
     ALOGI(  "SurfaceFlinger's main thread ready to run. "
@@ -836,7 +853,7 @@ void SurfaceFlinger::init() FTL_FAKE_GUARD(kMainThreadContext) {
                            .setImageCacheSize(maxFrameBufferAcquiredBuffers)
                            .setEnableProtectedContext(enable_protected_contents(false))
                            .setPrecacheToneMapperShaderOnly(false)
-                           .setSupportsBackgroundBlur(mSupportsBlur)
+                           .setBlurAlgorithm(chooseBlurAlgorithm(mSupportsBlur))
                            .setContextPriority(
                                    useContextPriority
                                            ? renderengine::RenderEngine::ContextPriority::REALTIME