Merge "Stop using transparent region for computing visible regions (DO NOT MERGE)"

3 files changed, 29 insertions, 3 deletions

diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index 16bac8f79c..a4da92f2c4 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -196,6 +196,12 @@ void LayerBase::setCoveredRegion(const Region& coveredRegion) {
     coveredRegionScreen = coveredRegion;
 }
 
+void LayerBase::setVisibleNonTransparentRegion(const Region&
+        visibleNonTransparentRegion) {
+    // always called from main thread
+    this->visibleNonTransparentRegion = visibleNonTransparentRegion;
+}
+
 uint32_t LayerBase::doTransaction(uint32_t flags)
 {
     const Layer::State& front(drawingState());
diff --git a/services/surfaceflinger/LayerBase.h b/services/surfaceflinger/LayerBase.h
index c547a40725..94d074abf7 100644
--- a/services/surfaceflinger/LayerBase.h
+++ b/services/surfaceflinger/LayerBase.h
@@ -63,6 +63,7 @@ public:
             Region      visibleRegionScreen;
             Region      transparentRegionScreen;
             Region      coveredRegionScreen;
+            Region      visibleNonTransparentRegion;
             int32_t     sequence;
             
             struct Geometry {
@@ -98,7 +99,7 @@ public:
             bool setSize(uint32_t w, uint32_t h);
             bool setAlpha(uint8_t alpha);
             bool setMatrix(const layer_state_t::matrix22_t& matrix);
-            bool setTransparentRegionHint(const Region& opaque);
+            bool setTransparentRegionHint(const Region& transparent);
             bool setFlags(uint8_t flags, uint8_t mask);
             bool setCrop(const Rect& crop);
             
@@ -159,6 +160,13 @@ public:
     virtual void setCoveredRegion(const Region& coveredRegion);
 
     /**
+     * setVisibleNonTransparentRegion - called when the visible and
+     * non-transparent region changes.
+     */
+    virtual void setVisibleNonTransparentRegion(const Region&
+            visibleNonTransparentRegion);
+
+    /**
      * validateVisibility - cache a bunch of things
      */
     virtual void validateVisibility(const Transform& globalTransform);
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 51fcce43e6..859db58bcb 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -620,6 +620,16 @@ void SurfaceFlinger::computeVisibleRegions(
          */
         Region coveredRegion;
 
+        /*
+         * transparentRegion: area of a surface that is hinted to be completely
+         * transparent. This is only used to tell when the layer has no visible
+         * non-transparent regions and can be removed from the layer list. It
+         * does not affect the visibleRegion of this layer or any layers
+         * beneath it. The hint may not be correct if apps don't respect the
+         * SurfaceView restrictions (which, sadly, some don't).
+         */
+        Region transparentRegion;
+
 
         // handle hidden surfaces by setting the visible region to empty
         if (CC_LIKELY(!(s.flags & ISurfaceComposer::eLayerHidden) && s.alpha)) {
@@ -630,7 +640,7 @@ void SurfaceFlinger::computeVisibleRegions(
             if (!visibleRegion.isEmpty()) {
                 // Remove the transparent area from the visible region
                 if (translucent) {
-                    visibleRegion.subtractSelf(layer->transparentRegionScreen);
+                    transparentRegion = layer->transparentRegionScreen;
                 }
 
                 // compute the opaque region
@@ -689,6 +699,8 @@ void SurfaceFlinger::computeVisibleRegions(
         // Store the visible region is screen space
         layer->setVisibleRegion(visibleRegion);
         layer->setCoveredRegion(coveredRegion);
+        layer->setVisibleNonTransparentRegion(
+                visibleRegion.subtract(transparentRegion));
 
         // If a secure layer is partially visible, lock-down the screen!
         if (layer->isSecure() && !visibleRegion.isEmpty()) {
@@ -740,7 +752,7 @@ void SurfaceFlinger::handlePageFlip()
             mVisibleLayersSortedByZ.clear();
             mVisibleLayersSortedByZ.setCapacity(count);
             for (size_t i=0 ; i<count ; i++) {
-                if (!currentLayers[i]->visibleRegionScreen.isEmpty())
+                if (!currentLayers[i]->visibleNonTransparentRegion.isEmpty())
                     mVisibleLayersSortedByZ.add(currentLayers[i]);
             }