5 files changed, 14 insertions, 7 deletions
diff --git a/src/com/android/gallery3d/ui/AnimationTime.java b/src/com/android/gallery3d/ui/AnimationTime.java
index 793e8b607..64ee27c7b 100644
--- a/src/com/android/gallery3d/ui/AnimationTime.java
+++ b/src/com/android/gallery3d/ui/AnimationTime.java
@@ -18,11 +18,17 @@ package com.android.gallery3d.ui;
 
 import android.os.SystemClock;
 
+//
+// The animation time should ideally be the vsync time the frame will be
+// displayed, but that is an unknown time in the future. So we use the system
+// time just after eglSwapBuffers (when GLSurfaceView.onDrawFrame is called)
+// as a approximation.
+//
 public class AnimationTime {
     private static volatile long sTime;
 
     // Sets current time as the animation time.
-    public static void setNow() {
+    public static void update() {
         sTime = SystemClock.uptimeMillis();
     }
 
diff --git a/src/com/android/gallery3d/ui/FadeInTexture.java b/src/com/android/gallery3d/ui/FadeInTexture.java
index 1c44b5aed..f351e34f3 100644
--- a/src/com/android/gallery3d/ui/FadeInTexture.java
+++ b/src/com/android/gallery3d/ui/FadeInTexture.java
@@ -85,6 +85,6 @@ public class FadeInTexture implements Texture {
     }
 
     private long now() {
-        return SystemClock.uptimeMillis();
+        return AnimationTime.get();
     }
 }
diff --git a/src/com/android/gallery3d/ui/GLRootView.java b/src/com/android/gallery3d/ui/GLRootView.java
index 6429d5a0a..62fc4f372 100644
--- a/src/com/android/gallery3d/ui/GLRootView.java
+++ b/src/com/android/gallery3d/ui/GLRootView.java
@@ -104,7 +104,7 @@ public class GLRootView extends GLSurfaceView
         setEGLConfigChooser(mEglConfigChooser);
         setRenderer(this);
         getHolder().setFormat(PixelFormat.RGB_565);
-        AnimationTime.setNow();
+        AnimationTime.update();
 
         // Uncomment this to enable gl error check.
         //setDebugFlags(DEBUG_CHECK_GL_ERROR);
@@ -256,6 +256,7 @@ public class GLRootView extends GLSurfaceView
 
     @Override
     public void onDrawFrame(GL10 gl) {
+        AnimationTime.update();
         long t0;
         if (DEBUG_PROFILE_SLOW_ONLY) {
             Profile.hold();
@@ -305,7 +306,7 @@ public class GLRootView extends GLSurfaceView
             gl.glScissor(clip.left, clip.top, clip.width(), clip.height());
         }
 
-        AnimationTime.setNow();
+
         if (mContentView != null) {
            mContentView.render(mCanvas);
         }
diff --git a/src/com/android/gallery3d/ui/Paper.java b/src/com/android/gallery3d/ui/Paper.java
index 830698c4a..841908fbf 100644
--- a/src/com/android/gallery3d/ui/Paper.java
+++ b/src/com/android/gallery3d/ui/Paper.java
@@ -184,6 +184,6 @@ class EdgeAnimation {
     }
 
     private long now() {
-        return SystemClock.uptimeMillis();
+        return AnimationTime.get();
     }
 }
diff --git a/src/com/android/gallery3d/ui/PositionController.java b/src/com/android/gallery3d/ui/PositionController.java
index 4baa2e0ed..b9efb743e 100644
--- a/src/com/android/gallery3d/ui/PositionController.java
+++ b/src/com/android/gallery3d/ui/PositionController.java
@@ -423,7 +423,7 @@ class PositionController {
             mToY = mImageH / 2;
         }
 
-        mAnimationStartTime = SystemClock.uptimeMillis();
+        mAnimationStartTime = AnimationTime.get();
         if (mAnimationKind != ANIM_KIND_FLING) {
             mAnimationDuration = ANIM_TIME[mAnimationKind];
         }
@@ -438,7 +438,7 @@ class PositionController {
             return;
         }
 
-        long now = SystemClock.uptimeMillis();
+        long now = AnimationTime.get();
         float progress;
         if (mAnimationDuration == 0) {
             progress = 1;