diff --git a/services/core/java/com/android/server/wm/Dimmer.java b/services/core/java/com/android/server/wm/Dimmer.java
index 537ca08f49fcc..5efc9241a494b 100644
--- a/services/core/java/com/android/server/wm/Dimmer.java
+++ b/services/core/java/com/android/server/wm/Dimmer.java
@@ -382,8 +382,8 @@ class Dimmer {
 
         @Override
         public void apply(SurfaceControl.Transaction t, SurfaceControl sc, long currentPlayTime) {
-            float alpha = ((float) currentPlayTime / getDuration()) * (mToAlpha - mFromAlpha)
-                    + mFromAlpha;
+            final float fraction = getFraction(currentPlayTime);
+            final float alpha = fraction * (mToAlpha - mFromAlpha) + mFromAlpha;
             t.setAlpha(sc, alpha);
         }
 
diff --git a/services/core/java/com/android/server/wm/LocalAnimationAdapter.java b/services/core/java/com/android/server/wm/LocalAnimationAdapter.java
index 7c1a6161236af..f0629fa953fc1 100644
--- a/services/core/java/com/android/server/wm/LocalAnimationAdapter.java
+++ b/services/core/java/com/android/server/wm/LocalAnimationAdapter.java
@@ -130,6 +130,16 @@ class LocalAnimationAdapter implements AnimationAdapter {
          */
         default boolean needsEarlyWakeup() { return false; }
 
+        /**
+         * @return The fraction of the animation, returns 1 if duration is 0.
+         *
+         * @param currentPlayTime The current play time.
+         */
+        default float getFraction(float currentPlayTime) {
+            final float duration = getDuration();
+            return duration > 0 ? currentPlayTime / duration : 1.0f;
+        }
+
         void dump(PrintWriter pw, String prefix);
 
         default void dumpDebug(ProtoOutputStream proto, long fieldId) {
diff --git a/services/core/java/com/android/server/wm/ScreenRotationAnimation.java b/services/core/java/com/android/server/wm/ScreenRotationAnimation.java
index 86e0818545978..90936efe67157 100644
--- a/services/core/java/com/android/server/wm/ScreenRotationAnimation.java
+++ b/services/core/java/com/android/server/wm/ScreenRotationAnimation.java
@@ -646,8 +646,8 @@ class ScreenRotationAnimation {
                     @Override
                     public void apply(SurfaceControl.Transaction t, SurfaceControl leash,
                         long currentPlayTime) {
-                        float fraction = (float)currentPlayTime / (float)getDuration();
-                        int color = (Integer) va.evaluate(fraction, startColor, endColor);
+                        final float fraction = getFraction(currentPlayTime);
+                        final int color = (Integer) va.evaluate(fraction, startColor, endColor);
                         Color middleColor = Color.valueOf(color);
                         rgbTmpFloat[0] = middleColor.red();
                         rgbTmpFloat[1] = middleColor.green();
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 706dcba31cfeb..912fdbf0a4cac 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -5595,7 +5595,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
 
         @Override
         public void apply(Transaction t, SurfaceControl leash, long currentPlayTime) {
-            final float fraction = (float) currentPlayTime / getDuration();
+            final float fraction = getFraction(currentPlayTime);
             final float v = mInterpolator.getInterpolation(fraction);
             t.setPosition(leash, mFrom.x + (mTo.x - mFrom.x) * v,
                     mFrom.y + (mTo.y - mFrom.y) * v);