SurfaceFlinger: fix a layer occlusion bug
This change fixes a bug where the window visibility would be computed
before any buffers were available, causing the window to be treated as
non-opaque. When the first buffer arrived, if both mCurrentOpacity and
the opacity determined by the buffer's format were 'opaque', a
recomputation of the opacity would not be done, and the window would
continue to be treated as non-opaque. SurfaceFlinger could then
unnecessarily draw fully occluded layers.
Change-Id: I2b95da2f4b50e68d50fc5afd8b772e26e62f58d6
Bug: 5057122
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 7d6a14d..63062cc 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -326,8 +326,9 @@
{
// if we don't have a buffer yet, we're translucent regardless of the
// layer's opaque flag.
- if (mActiveBuffer == 0)
+ if (mActiveBuffer == 0) {
return false;
+ }
// if the layer has the opaque flag, then we're always opaque,
// otherwise we use the current buffer's format.
@@ -411,6 +412,8 @@
void Layer::lockPageFlip(bool& recomputeVisibleRegions)
{
if (mQueuedFrames > 0) {
+ const bool oldOpacity = isOpaque();
+
// signal another event if we have more frames pending
if (android_atomic_dec(&mQueuedFrames) > 1) {
mFlinger->signalEvent();
@@ -438,9 +441,8 @@
mFlinger->invalidateHwcGeometry();
}
- const bool opacity(getOpacityForFormat(mActiveBuffer->format));
- if (opacity != mCurrentOpacity) {
- mCurrentOpacity = opacity;
+ mCurrentOpacity = getOpacityForFormat(mActiveBuffer->format);
+ if (oldOpacity != isOpaque()) {
recomputeVisibleRegions = true;
}