set correct crop rectangle in LayerBase::setCrop

The crop always had left=top=0, because the crop position
and the layer's transform were merged together in
computeBounds() (which really used to compute the
bounds in screen space, which we usually call the
"frame" elsewhere in the code)

Note: in practice this crop value is not used by
hwc, because it's overridden in Layer::setGeometry(), which
is why this bug was never apparent.

Change-Id: I1ec6400a8fc8314408e4252708f43ea98c2fe64e

2 files changed, 11 insertions, 8 deletions

diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index dfdbf30..24b122a 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -259,7 +259,7 @@ Rect LayerBase::computeBounds() const {
     if (!s.active.crop.isEmpty()) {
         win.intersect(s.active.crop, &win);
     }
-    return s.transform.transform(win);
+    return win;
 }
 
 Region LayerBase::latchBuffer(bool& recomputeVisibleRegions) {
@@ -289,13 +289,16 @@ void LayerBase::setGeometry(
                 HWC_BLENDING_COVERAGE);
     }
 
-    const Transform& tr = hw->getTransform();
-    Rect transformedBounds(computeBounds());
-    transformedBounds = tr.transform(transformedBounds);
 
-    // scaling is already applied in transformedBounds
-    layer.setFrame(transformedBounds);
-    layer.setCrop(transformedBounds.getBounds());
+    Rect bounds(computeBounds());
+
+    // apply the layer's transform, followed by the display's global transform
+    // here we're guaranteed that the layer's transform preserves rects
+
+    const Transform& tr = hw->getTransform();
+    Rect frame(tr.transform(s.transform.transform(bounds)));
+    layer.setFrame(frame);
+    layer.setCrop(bounds);
 }
 
 void LayerBase::setPerFrameData(const sp<const DisplayDevice>& hw,
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index ee3e93b..bdeffdf 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1384,7 +1384,7 @@ void SurfaceFlinger::computeVisibleRegions(
         // handle hidden surfaces by setting the visible region to empty
         if (CC_LIKELY(layer->isVisible())) {
             const bool translucent = !layer->isOpaque();
-            Rect bounds(layer->computeBounds());
+            Rect bounds(s.transform.transform(layer->computeBounds()));
             visibleRegion.set(bounds);
             if (!visibleRegion.isEmpty()) {
                 // Remove the transparent area from the visible region