Move rotation flags to SF

The rotation flags are typically only used for a camera preview, which
wants to avoid changing its orientation and flicker during rotation.
Prior to this CL, the rotation flags were tied to the primary display,
meaning that if the camera preview was on another display, the rotation
flags may not be up to date. For example, if the primary display is off,
its flags will not be updated on rotation.

Ideally, the flags should be based on the display where the preview will
be shown, but this is a much larger architectural change, tracked in
b/259407931.

As a temporary workaround, associate the flags with the active display.
Store the flags in SurfaceFlinger, which knows when the active display
changes. Update when the active display switches to a different display
or when the active display rotates, matching the behavior of
mActiveDisplayTransformHint, which seems similar but is different. Store
the flags as a static variable so that LayerFE can access it. LayerFE
does not have a way to access the actual SurfaceFlinger object, and it
should not.

Access to the new flags is safe because it is only read or written from
the main thread.

Bug: 269685949
Bug: 259407931
Test: ActiveDisplayRotationFlagsTest
Change-Id: I5532e140a603be222cb3ea1ae563638317c1d745

1 files changed, 6 insertions, 1 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index de0280cf96..0dff2579ce 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -356,6 +356,8 @@ bool callingThreadHasPermission(const String16& permission) {
             PermissionCache::checkPermission(permission, pid, uid);
 }
 
+ui::Transform::RotationFlags SurfaceFlinger::sActiveDisplayRotationFlags = ui::Transform::ROT_0;
+
 SurfaceFlinger::SurfaceFlinger(Factory& factory, SkipInitializationTag)
       : mFactory(factory),
         mPid(getpid()),
@@ -2531,7 +2533,7 @@ CompositeResult SurfaceFlinger::composite(scheduler::FrameTargeter& pacesetterFr
 
     refreshArgs.updatingOutputGeometryThisFrame = mVisibleRegionsDirty;
     refreshArgs.updatingGeometryThisFrame = mGeometryDirty.exchange(false) || mVisibleRegionsDirty;
-    refreshArgs.internalDisplayRotationFlags = DisplayDevice::getPrimaryDisplayRotationFlags();
+    refreshArgs.internalDisplayRotationFlags = getActiveDisplayRotationFlags();
 
     if (CC_UNLIKELY(mDrawingState.colorMatrixChanged)) {
         refreshArgs.colorTransformMatrix = mDrawingState.colorMatrix;
@@ -3475,6 +3477,8 @@ void SurfaceFlinger::processDisplayChanged(const wp<IBinder>& displayToken,
                                    currentState.orientedDisplaySpaceRect);
             if (display->getId() == mActiveDisplayId) {
                 mActiveDisplayTransformHint = display->getTransformHint();
+                sActiveDisplayRotationFlags =
+                        ui::Transform::toRotationFlags(display->getOrientation());
             }
         }
         if (currentState.width != drawingState.width ||
@@ -7875,6 +7879,7 @@ void SurfaceFlinger::onActiveDisplayChangedLocked(const DisplayDevice* inactiveD
 
     onActiveDisplaySizeChanged(activeDisplay);
     mActiveDisplayTransformHint = activeDisplay.getTransformHint();
+    sActiveDisplayRotationFlags = ui::Transform::toRotationFlags(activeDisplay.getOrientation());
 
     // The policy of the new active/pacesetter display may have changed while it was inactive. In
     // that case, its preferred mode has not been propagated to HWC (via setDesiredActiveMode). In