Support buildLayer in new pipeline

bug:26561995
bug:27620686

Change-Id: I6c39f9a077e7e6002d3c01b8888238fd17b0f02a
diff --git a/libs/hwui/FrameBuilder.cpp b/libs/hwui/FrameBuilder.cpp
index b18836f..9c46c00 100644
--- a/libs/hwui/FrameBuilder.cpp
+++ b/libs/hwui/FrameBuilder.cpp
@@ -37,7 +37,8 @@
         const LightGeometry& lightGeometry, const Rect &contentDrawBounds, Caches& caches)
         : mCanvasState(*this)
         , mCaches(caches)
-        , mLightRadius(lightGeometry.radius) {
+        , mLightRadius(lightGeometry.radius)
+        , mDrawFbo0(!nodes.empty()) {
     ATRACE_NAME("prepare drawing commands");
 
     mLayerBuilders.reserve(layers.entries().size());
diff --git a/libs/hwui/FrameBuilder.h b/libs/hwui/FrameBuilder.h
index 02c05cb..e418227 100644
--- a/libs/hwui/FrameBuilder.h
+++ b/libs/hwui/FrameBuilder.h
@@ -137,12 +137,14 @@
         }
 
         GL_CHECKPOINT(MODERATE);
-        const LayerBuilder& fbo0 = *(mLayerBuilders[0]);
-        renderer.startFrame(fbo0.width, fbo0.height, fbo0.repaintRect);
-        GL_CHECKPOINT(MODERATE);
-        fbo0.replayBakedOpsImpl((void*)&renderer, unmergedReceivers, mergedReceivers);
-        GL_CHECKPOINT(MODERATE);
-        renderer.endFrame(fbo0.repaintRect);
+        if (CC_LIKELY(mDrawFbo0)) {
+            const LayerBuilder& fbo0 = *(mLayerBuilders[0]);
+            renderer.startFrame(fbo0.width, fbo0.height, fbo0.repaintRect);
+            GL_CHECKPOINT(MODERATE);
+            fbo0.replayBakedOpsImpl((void*)&renderer, unmergedReceivers, mergedReceivers);
+            GL_CHECKPOINT(MODERATE);
+            renderer.endFrame(fbo0.repaintRect);
+        }
     }
 
     void dump() const {
@@ -239,6 +241,8 @@
 
     // contains single-frame objects, such as BakedOpStates, LayerBuilders, Batches
     LinearAllocator mAllocator;
+
+    const bool mDrawFbo0;
 };
 
 }; // namespace uirenderer
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index eee5278..6933b2f 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -86,10 +86,12 @@
     freePrefetechedLayers();
     destroyHardwareResources();
     mAnimationContext->destroy();
+#if !HWUI_NEW_OPS
     if (mCanvas) {
         delete mCanvas;
         mCanvas = nullptr;
     }
+#endif
 }
 
 void CanvasContext::setSurface(Surface* surface) {
@@ -587,9 +589,11 @@
 
 void CanvasContext::buildLayer(RenderNode* node) {
     ATRACE_CALL();
-    if (!mEglManager.hasEglContext() || !mCanvas) {
-        return;
-    }
+    if (!mEglManager.hasEglContext()) return;
+#if !HWUI_NEW_OPS
+    if (!mCanvas) return;
+#endif
+
     // buildLayer() will leave the tree in an unknown state, so we must stop drawing
     stopDrawing();
 
@@ -609,7 +613,15 @@
     node->setPropertyFieldsDirty(RenderNode::GENERIC);
 
 #if HWUI_NEW_OPS
-    // TODO: support buildLayer
+    static const std::vector< sp<RenderNode> > emptyNodeList;
+    auto& caches = Caches::getInstance();
+    FrameBuilder frameBuilder(mLayerUpdateQueue, SkRect::MakeWH(1, 1), 1, 1,
+            emptyNodeList, mLightGeometry, mContentDrawBounds, caches);
+    mLayerUpdateQueue.clear();
+    BakedOpRenderer renderer(caches, mRenderThread.renderState(),
+            mOpaque, mLightInfo);
+    LOG_ALWAYS_FATAL_IF(renderer.didDraw(), "shouldn't draw in buildlayer case");
+    frameBuilder.replayBakedOps<BakedOpDispatcher>(renderer);
 #else
     mCanvas->markLayersAsBuildLayers();
     mCanvas->flushLayerUpdates();
diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index 6706c30..6d0889e 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -196,10 +196,11 @@
     RingBuffer<SwapHistory, 3> mSwapHistory;
 
     bool mOpaque;
-    OpenGLRenderer* mCanvas = nullptr;
 #if HWUI_NEW_OPS
     BakedOpRenderer::LightInfo mLightInfo;
     FrameBuilder::LightGeometry mLightGeometry = { {0, 0, 0}, 0 };
+#else
+    OpenGLRenderer* mCanvas = nullptr;
 #endif
 
     bool mHaveNewSurface = false;
diff --git a/libs/hwui/tests/unit/FrameBuilderTests.cpp b/libs/hwui/tests/unit/FrameBuilderTests.cpp
index ba22f91..7dfafb9 100644
--- a/libs/hwui/tests/unit/FrameBuilderTests.cpp
+++ b/libs/hwui/tests/unit/FrameBuilderTests.cpp
@@ -30,6 +30,7 @@
 namespace uirenderer {
 
 const LayerUpdateQueue sEmptyLayerUpdateQueue;
+const std::vector< sp<RenderNode> > sEmptyNodeList;
 const FrameBuilder::LightGeometry sLightGeometry = { {100, 100, 100}, 50};
 
 
@@ -216,6 +217,49 @@
             << "Expect number of ops = 2 * loop count";
 }
 
+RENDERTHREAD_TEST(FrameBuilder, empty_noFbo0) {
+    class EmptyNoFbo0TestRenderer : public TestRendererBase {
+    public:
+        void startFrame(uint32_t width, uint32_t height, const Rect& repaintRect) override {
+            ADD_FAILURE() << "Primary frame draw not expected in this test";
+        }
+        void endFrame(const Rect& repaintRect) override {
+            ADD_FAILURE() << "Primary frame draw not expected in this test";
+        }
+    };
+
+    // Pass empty node list, so no work is enqueued for Fbo0
+    FrameBuilder frameBuilder(sEmptyLayerUpdateQueue, SkRect::MakeWH(200, 200), 200, 200,
+            sEmptyNodeList, sLightGeometry, Caches::getInstance());
+    EmptyNoFbo0TestRenderer renderer;
+    frameBuilder.replayBakedOps<TestDispatcher>(renderer);
+}
+
+RENDERTHREAD_TEST(FrameBuilder, empty_withFbo0) {
+    class EmptyWithFbo0TestRenderer : public TestRendererBase {
+    public:
+        void startFrame(uint32_t width, uint32_t height, const Rect& repaintRect) override {
+            EXPECT_EQ(0, mIndex++);
+        }
+        void endFrame(const Rect& repaintRect) override {
+            EXPECT_EQ(1, mIndex++);
+        }
+    };
+    auto node = TestUtils::createNode(10, 10, 110, 110,
+            [](RenderProperties& props, RecordingCanvas& canvas) {
+        // no drawn content
+    });
+    auto syncedNodeList = TestUtils::createSyncedNodeList(node);
+
+    // Draw, but pass empty node list, so no work is done for primary frame
+    FrameBuilder frameBuilder(sEmptyLayerUpdateQueue, SkRect::MakeWH(200, 200), 200, 200,
+            syncedNodeList, sLightGeometry, Caches::getInstance());
+    EmptyWithFbo0TestRenderer renderer;
+    frameBuilder.replayBakedOps<TestDispatcher>(renderer);
+    EXPECT_EQ(2, renderer.getIndex()) << "No drawing content produced,"
+            " but fbo0 update lifecycle should still be observed";
+}
+
 RENDERTHREAD_TEST(FrameBuilder, avoidOverdraw_rects) {
     class AvoidOverdrawRectsTestRenderer : public TestRendererBase {
     public:
@@ -1152,6 +1196,64 @@
     *(parent->getLayerHandle()) = nullptr;
 }
 
+
+RENDERTHREAD_TEST(FrameBuilder, buildLayer) {
+    class BuildLayerTestRenderer : public TestRendererBase {
+    public:
+        void startRepaintLayer(OffscreenBuffer* offscreenBuffer, const Rect& repaintRect) override {
+            EXPECT_EQ(0, mIndex++);
+            EXPECT_EQ(100u, offscreenBuffer->viewportWidth);
+            EXPECT_EQ(100u, offscreenBuffer->viewportHeight);
+            EXPECT_EQ(Rect(25, 25, 75, 75), repaintRect);
+        }
+        void onColorOp(const ColorOp& op, const BakedOpState& state) override {
+            EXPECT_EQ(1, mIndex++);
+
+            EXPECT_TRUE(state.computedState.transform.isIdentity())
+                    << "Transform should be reset within layer";
+
+            EXPECT_EQ(Rect(25, 25, 75, 75), state.computedState.clipRect())
+                    << "Damage rect should be used to clip layer content";
+        }
+        void endLayer() override {
+            EXPECT_EQ(2, mIndex++);
+        }
+        void startFrame(uint32_t width, uint32_t height, const Rect& repaintRect) override {
+            ADD_FAILURE() << "Primary frame draw not expected in this test";
+        }
+        void endFrame(const Rect& repaintRect) override {
+            ADD_FAILURE() << "Primary frame draw not expected in this test";
+        }
+    };
+
+    auto node = TestUtils::createNode(10, 10, 110, 110,
+            [](RenderProperties& props, RecordingCanvas& canvas) {
+        props.mutateLayerProperties().setType(LayerType::RenderLayer);
+        canvas.drawColor(SK_ColorWHITE, SkXfermode::Mode::kSrcOver_Mode);
+    });
+    OffscreenBuffer** layerHandle = node->getLayerHandle();
+
+    // create RenderNode's layer here in same way prepareTree would
+    OffscreenBuffer layer(renderThread.renderState(), Caches::getInstance(), 100, 100);
+    *layerHandle = &layer;
+
+    auto syncedNodeList = TestUtils::createSyncedNodeList(node);
+
+    // only enqueue partial damage
+    LayerUpdateQueue layerUpdateQueue; // Note: enqueue damage post-sync, so bounds are valid
+    layerUpdateQueue.enqueueLayerWithDamage(node.get(), Rect(25, 25, 75, 75));
+
+    // Draw, but pass empty node list, so no work is done for primary frame
+    FrameBuilder frameBuilder(layerUpdateQueue, SkRect::MakeWH(1, 1), 1, 1,
+            sEmptyNodeList, sLightGeometry, Caches::getInstance());
+    BuildLayerTestRenderer renderer;
+    frameBuilder.replayBakedOps<TestDispatcher>(renderer);
+    EXPECT_EQ(3, renderer.getIndex());
+
+    // clean up layer pointer, so we can safely destruct RenderNode
+    *layerHandle = nullptr;
+}
+
 static void drawOrderedRect(RecordingCanvas* canvas, uint8_t expectedDrawOrder) {
     SkPaint paint;
     paint.setColor(SkColorSetARGB(256, 0, 0, expectedDrawOrder)); // order put in blue channel