From 73d7468fe62fea979d12b1f33c5f807e62f1a0e0 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Wed, 10 Aug 2022 20:47:59 -0600
Subject: [PATCH] Set rotation layers as opaque initially

The layers should cover the window behind during rotation animation.
So it can be opaque initially to avoid blended composition for one
intermediate frame.

After the animation starts and changes the alpha < 1 to the rotation
layer for fading animation, it can still switch from opaque composition
to blended composition automatically.

Bug: 240568519
Test: atest ChangeAppRotationTest

Change-Id: Ic4173d33c15c35e252315f9cf53127c759e56ece
---
 .../wm/shell/transition/ScreenRotationAnimation.java        | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
index a843b2a0ac39f..45b69f17a861d 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
@@ -162,13 +162,12 @@ class ScreenRotationAnimation {
                     .setParent(mAnimLeash)
                     .setBLASTLayer()
                     .setSecure(screenshotBuffer.containsSecureLayers())
+                    .setOpaque(true)
                     .setCallsite("ShellRotationAnimation")
                     .setName("RotationLayer")
                     .build();
 
             t.setLayer(mAnimLeash, SCREEN_FREEZE_LAYER_BASE);
-            t.setPosition(mAnimLeash, 0, 0);
-            t.setAlpha(mAnimLeash, 1);
             t.show(mAnimLeash);
 
             final ColorSpace colorSpace = screenshotBuffer.getColorSpace();
@@ -181,6 +180,7 @@ class ScreenRotationAnimation {
                 mBackColorSurface = new SurfaceControl.Builder(session)
                         .setParent(rootLeash)
                         .setColorLayer()
+                        .setOpaque(true)
                         .setCallsite("ShellRotationAnimation")
                         .setName("BackColorSurface")
                         .build();
@@ -189,7 +189,6 @@ class ScreenRotationAnimation {
 
                 t.setLayer(mBackColorSurface, -1);
                 t.setColor(mBackColorSurface, new float[]{mStartLuma, mStartLuma, mStartLuma});
-                t.setAlpha(mBackColorSurface, 1);
                 t.show(mBackColorSurface);
             }
 
@@ -242,7 +241,6 @@ class ScreenRotationAnimation {
         t.setMatrix(mScreenshotLayer,
                 mTmpFloats[Matrix.MSCALE_X], mTmpFloats[Matrix.MSKEW_Y],
                 mTmpFloats[Matrix.MSKEW_X], mTmpFloats[Matrix.MSCALE_Y]);
-        t.setAlpha(mScreenshotLayer, (float) 1.0);
     }
 
     /**