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, 2 insertions, 2 deletions

diff --git a/services/surfaceflinger/LayerFE.cpp b/services/surfaceflinger/LayerFE.cpp
index e713263433..f855f278c3 100644
--- a/services/surfaceflinger/LayerFE.cpp
+++ b/services/surfaceflinger/LayerFE.cpp
@@ -25,8 +25,8 @@
 #include <system/window.h>
 #include <utils/Log.h>
 
-#include "DisplayDevice.h"
 #include "LayerFE.h"
+#include "SurfaceFlinger.h"
 
 namespace android {
 
@@ -260,7 +260,7 @@ void LayerFE::prepareBufferStateClientComposition(
          * the code below applies the primary display's inverse transform to
          * the texture transform
          */
-        uint32_t transform = DisplayDevice::getPrimaryDisplayRotationFlags();
+        uint32_t transform = SurfaceFlinger::getActiveDisplayRotationFlags();
         mat4 tr = inverseOrientation(transform);
 
         /**