Mark empty EffectLayer as skipContentDraw

An effect layer that only draws a shadow or blurs shouldn't draw a
color. We should skip drawing its contents altogether.

Bug: 189207458
Test: manual
Change-Id: I01bb066d4a02f6111a6974dd241f9530c4979420

2 files changed, 5 insertions, 3 deletions

diff --git a/services/surfaceflinger/EffectLayer.cpp b/services/surfaceflinger/EffectLayer.cpp
index fd18c3bf31..0cc5f33d73 100644
--- a/services/surfaceflinger/EffectLayer.cpp
+++ b/services/surfaceflinger/EffectLayer.cpp
@@ -66,6 +66,7 @@ std::vector<compositionengine::LayerFE::LayerSettings> EffectLayer::prepareClien
         layerSettings->source.solidColor = getColor().rgb;
         results.push_back(*layerSettings);
     } else if (hasBlur() || drawShadows()) {
+        layerSettings->skipContentDraw = true;
         results.push_back(*layerSettings);
     }
 
@@ -126,7 +127,7 @@ const compositionengine::LayerFECompositionState* EffectLayer::getCompositionSta
 bool EffectLayer::isOpaque(const Layer::State& s) const {
     // Consider the layer to be opaque if its opaque flag is set or its effective
     // alpha (considering the alpha of its parents as well) is 1.0;
-    return (s.flags & layer_state_t::eLayerOpaque) != 0 || getAlpha() == 1.0_hf;
+    return (s.flags & layer_state_t::eLayerOpaque) != 0 || (fillsColor() && getAlpha() == 1.0_hf);
 }
 
 ui::Dataspace EffectLayer::getDataSpace() const {
@@ -147,7 +148,7 @@ bool EffectLayer::fillsColor() const {
 }
 
 bool EffectLayer::hasBlur() const {
-    return getBackgroundBlurRadius() > 0;
+    return getBackgroundBlurRadius() > 0 || getDrawingState().blurRegions.size() > 0;
 }
 
 } // namespace android
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index a7c870483b..690fda66a6 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -574,7 +574,8 @@ std::optional<compositionengine::LayerFE::LayerSettings> Layer::prepareClientCom
     layerSettings.geometry.positionTransform = getTransform().asMatrix4();
 
     // skip drawing content if the targetSettings indicate the content will be occluded
-    layerSettings.skipContentDraw = !targetSettings.realContentIsVisible;
+    layerSettings.skipContentDraw =
+            layerSettings.skipContentDraw || !targetSettings.realContentIsVisible;
 
     if (hasColorTransform()) {
         layerSettings.colorTransform = getColorTransform();