Add support for plane-alpha in HWC

Change-Id: I218e7dd5f23de535aabce61e993002ab6cb46cdd

4 files changed, 31 insertions, 20 deletions

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 3bb9ec4..8e73467 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -782,9 +782,10 @@ private:
  * This implements the HWCLayer side of HWCIterableLayer.
  */
 class HWCLayerVersion1 : public Iterable<HWCLayerVersion1, hwc_layer_1_t> {
+    struct hwc_composer_device_1* mHwc;
 public:
-    HWCLayerVersion1(hwc_layer_1_t* layer)
-        : Iterable<HWCLayerVersion1, hwc_layer_1_t>(layer) { }
+    HWCLayerVersion1(struct hwc_composer_device_1* hwc, hwc_layer_1_t* layer)
+        : Iterable<HWCLayerVersion1, hwc_layer_1_t>(layer), mHwc(hwc) { }
 
     virtual int32_t getCompositionType() const {
         return getLayer()->compositionType;
@@ -800,17 +801,29 @@ public:
     virtual void setAcquireFenceFd(int fenceFd) {
         getLayer()->acquireFenceFd = fenceFd;
     }
+    virtual void setPerFrameDefaultState() {
+        //getLayer()->compositionType = HWC_FRAMEBUFFER;
+    }
+    virtual void setPlaneAlpha(uint8_t alpha) {
+        if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_2)) {
+            getLayer()->planeAlpha = alpha;
+        } else {
+            getLayer()->flags |= HWC_SKIP_LAYER;
+        }
+    }
     virtual void setDefaultState() {
-        getLayer()->compositionType = HWC_FRAMEBUFFER;
-        getLayer()->hints = 0;
-        getLayer()->flags = HWC_SKIP_LAYER;
-        getLayer()->handle = 0;
-        getLayer()->transform = 0;
-        getLayer()->blending = HWC_BLENDING_NONE;
-        getLayer()->visibleRegionScreen.numRects = 0;
-        getLayer()->visibleRegionScreen.rects = NULL;
-        getLayer()->acquireFenceFd = -1;
-        getLayer()->releaseFenceFd = -1;
+        hwc_layer_1_t* const l = getLayer();
+        l->compositionType = HWC_FRAMEBUFFER;
+        l->hints = 0;
+        l->flags = HWC_SKIP_LAYER;
+        l->handle = 0;
+        l->transform = 0;
+        l->blending = HWC_BLENDING_NONE;
+        l->visibleRegionScreen.numRects = 0;
+        l->visibleRegionScreen.rects = NULL;
+        l->acquireFenceFd = -1;
+        l->releaseFenceFd = -1;
+        l->planeAlpha = 0xFF;
     }
     virtual void setSkip(bool skip) {
         if (skip) {
@@ -873,7 +886,7 @@ HWComposer::LayerListIterator HWComposer::getLayerIterator(int32_t id, size_t in
     if (!mHwc || !disp.list || index > disp.list->numHwLayers) {
         return LayerListIterator();
     }
-    return LayerListIterator(new HWCLayerVersion1(disp.list->hwLayers), index);
+    return LayerListIterator(new HWCLayerVersion1(mHwc, disp.list->hwLayers), index);
 }
 
 /*
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 1e7ec21..05f7784 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -152,6 +152,7 @@ public:
         virtual void setVisibleRegionScreen(const Region& reg) = 0;
         virtual void setBuffer(const sp<GraphicBuffer>& buffer) = 0;
         virtual void setAcquireFenceFd(int fenceFd) = 0;
+        virtual void setPlaneAlpha(uint8_t alpha) = 0;
         virtual void onDisplayed() = 0;
     };
 
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index f94a9ba..95a5e02 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -251,16 +251,13 @@ void Layer::setGeometry(
     // enable this layer
     layer.setSkip(false);
 
-    // we can't do alpha-fade with the hwc HAL
-    const State& s(drawingState());
-    if (s.alpha < 0xFF) {
-        layer.setSkip(true);
-    }
-
     if (isSecure() && !hw->isSecure()) {
         layer.setSkip(true);
     }
 
+    const State& s(drawingState());
+    layer.setPlaneAlpha(s.alpha);
+
     /*
      * Transformations are applied in this order:
      * 1) buffer orientation/flip/mirror
diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index f129607..54c51bb 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -283,7 +283,7 @@ void LayerBase::setGeometry(
         layer.setTransform(finalTransform);
     }
 
-    if (!isOpaque()) {
+    if (!isOpaque() || s.alpha != 0xFF) {
         layer.setBlending(mPremultipliedAlpha ?
                 HWC_BLENDING_PREMULT :
                 HWC_BLENDING_COVERAGE);