Track canvas clearing for swap buffers logic.

A previous fix made it necessary for a frame to render something to GL
in order to cause a call to eglSwapBuffers(). Besides the calls being
tracked as part of issuing a DisplayList, there is also a potential call
to clear the canvas (via glClear()) on non-opaque surfaces. This call is also
good to track, since a surface that gets cleared without any other drawing operations
is worth flipping to the screen (to erase old contents on that surface).

This fix tracks the status of the pre-draw operations to find out whether
glClear() was called and then sets the drawing status appropriately.

Issue #6606422 QuickContact dismissal is janky again (Tracking)

Change-Id: I5fcaccfdc9293dd46b83f2fc279730a5d2740ebf

6 files changed, 15 insertions, 11 deletions

diff --git a/libs/hwui/DisplayListRenderer.cpp b/libs/hwui/DisplayListRenderer.cpp
index 88d2209..d376e3a 100644
--- a/libs/hwui/DisplayListRenderer.cpp
+++ b/libs/hwui/DisplayListRenderer.cpp
@@ -1368,13 +1368,14 @@ void DisplayListRenderer::setViewport(int width, int height) {
     mHeight = height;
 }
 
-void DisplayListRenderer::prepareDirty(float left, float top,
+int DisplayListRenderer::prepareDirty(float left, float top,
         float right, float bottom, bool opaque) {
     mSnapshot = new Snapshot(mFirstSnapshot,
             SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
     mSaveCount = 1;
     mSnapshot->setClip(0.0f, 0.0f, mWidth, mHeight);
     mRestoreSaveCount = -1;
+    return DrawGlInfo::kStatusDone; // No invalidate needed at record-time
 }
 
 void DisplayListRenderer::finish() {
diff --git a/libs/hwui/DisplayListRenderer.h b/libs/hwui/DisplayListRenderer.h
index 4fa1baa..6b4c6b2 100644
--- a/libs/hwui/DisplayListRenderer.h
+++ b/libs/hwui/DisplayListRenderer.h
@@ -547,7 +547,7 @@ public:
     virtual bool isDeferred();
 
     virtual void setViewport(int width, int height);
-    virtual void prepareDirty(float left, float top, float right, float bottom, bool opaque);
+    virtual int prepareDirty(float left, float top, float right, float bottom, bool opaque);
     virtual void finish();
 
     virtual status_t callDrawGLFunction(Functor *functor, Rect& dirty);
diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index 2a4e72b..65f8c7c 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -37,7 +37,7 @@ LayerRenderer::LayerRenderer(Layer* layer): mLayer(layer) {
 LayerRenderer::~LayerRenderer() {
 }
 
-void LayerRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
+int LayerRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
     LAYER_RENDERER_LOGD("Rendering into layer, fbo = %d", mLayer->getFbo());
 
     glBindFramebuffer(GL_FRAMEBUFFER, mLayer->getFbo());
@@ -57,9 +57,9 @@ void LayerRenderer::prepareDirty(float left, float top, float right, float botto
         mLayer->region.subtractSelf(r);
     }
 
-    OpenGLRenderer::prepareDirty(dirty.left, dirty.top, dirty.right, dirty.bottom, opaque);
+    return OpenGLRenderer::prepareDirty(dirty.left, dirty.top, dirty.right, dirty.bottom, opaque);
 #else
-    OpenGLRenderer::prepareDirty(0.0f, 0.0f, width, height, opaque);
+    return OpenGLRenderer::prepareDirty(0.0f, 0.0f, width, height, opaque);
 #endif
 }
 
diff --git a/libs/hwui/LayerRenderer.h b/libs/hwui/LayerRenderer.h
index c461ea7..8f3a0a3 100644
--- a/libs/hwui/LayerRenderer.h
+++ b/libs/hwui/LayerRenderer.h
@@ -47,7 +47,7 @@ public:
     ANDROID_API LayerRenderer(Layer* layer);
     virtual ~LayerRenderer();
 
-    virtual void prepareDirty(float left, float top, float right, float bottom, bool opaque);
+    virtual int prepareDirty(float left, float top, float right, float bottom, bool opaque);
     virtual void finish();
 
     virtual bool hasLayer();
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 2dc9726..0d857bf 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -164,11 +164,11 @@ void OpenGLRenderer::setViewport(int width, int height) {
     glEnableVertexAttribArray(Program::kBindingPosition);
 }
 
-void OpenGLRenderer::prepare(bool opaque) {
-    prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
+int OpenGLRenderer::prepare(bool opaque) {
+    return prepareDirty(0.0f, 0.0f, mWidth, mHeight, opaque);
 }
 
-void OpenGLRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
+int OpenGLRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
     mCaches.clearGarbage();
 
     mSnapshot = new Snapshot(mFirstSnapshot,
@@ -184,9 +184,12 @@ void OpenGLRenderer::prepareDirty(float left, float top, float right, float bott
     if (!opaque) {
         mCaches.setScissor(left, mSnapshot->height - bottom, right - left, bottom - top);
         glClear(GL_COLOR_BUFFER_BIT);
+        return DrawGlInfo::kStatusDrew;
     } else {
         mCaches.resetScissor();
     }
+
+    return DrawGlInfo::kStatusDone;
 }
 
 void OpenGLRenderer::syncState() {
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index 7703e80..b342f50 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -67,8 +67,8 @@ public:
 
     virtual void setViewport(int width, int height);
 
-    ANDROID_API void prepare(bool opaque);
-    virtual void prepareDirty(float left, float top, float right, float bottom, bool opaque);
+    ANDROID_API int prepare(bool opaque);
+    virtual int prepareDirty(float left, float top, float right, float bottom, bool opaque);
     virtual void finish();
 
     // These two calls must not be recorded in display lists