Optimize static wait presentation

engine/Age.Engine.Tests/GfxAnimationTests.cs

@@ -39,6 +39,33 @@ public class GfxAnimationTests
         Assert.True(o.RotationEnabled);
     }
 
+    [Fact]
+    public void ActiveVisualPresentation_ExcludesStaticWaits_ButIncludesAmbientChannels()
+    {
+        static GfxState VisibleObject()
+        {
+            var state = new GfxState();
+            state.SetSurface(1, 5, -1);
+            state.BindDraw(7, 1, 0, 0, 64, 64, 0, 0);
+            return state;
+        }
+
+        var unchanged = VisibleObject();
+        Assert.False(unchanged.HasActiveVisualPresentation(1000));
+
+        var spritesheet = VisibleObject();
+        spritesheet.SetSrcRect(7, 4, 1, 0, 800);
+        Assert.True(spritesheet.HasActiveVisualPresentation(1000));
+
+        var color = VisibleObject();
+        color.SetColorAnim(7, 1000, GfxState.PackColor(0x80, 0xff0000));
+        Assert.True(color.HasActiveVisualPresentation(1000));
+
+        var rotation = VisibleObject();
+        rotation.SetRotationCycle(7, 1000, (0, 0, 1));
+        Assert.True(rotation.HasActiveVisualPresentation(1000));
+    }
+
     [Fact]
     public void OneShotRotation_SharesMatrixClockAndMatchesNativeSample()
     {

engine/Age.Engine/Model/GfxState.cs

@@ -352,6 +352,21 @@ public sealed class GfxState
                                              o.RotationChannelEnabled || o.TranslationEnabled));
     }
 
+    /// <summary>Whether sampling the retained scene at a later frame can change its pixels without another
+    /// VM mutation. Includes finite presentation work plus the ambient channels that may remain active while
+    /// the interpreter is parked at an input wait. Static waits themselves are deliberately not animation.</summary>
+    public bool HasActiveVisualPresentation(long nowMs)
+    {
+        lock (_lock)
+            return _surfaceTransitions.Values.Any(t => TransitionProgress(t, nowMs) < 1.0) ||
+                   _objects.Values.Any(o => o.Visible &&
+                       (o.OneShotColorEnabled || o.ScaleEnabled || o.RotationChannelEnabled ||
+                        o.TranslationEnabled ||
+                        (o.SrcAnim && o.SrcPeriod > 0) ||
+                        (o.ColorAnim && o.ColorPeriod > 0) ||
+                        (o.RotationEnabled && o.RotationPeriodMs > 0)));
+    }
+
     /// <summary>Click completion affects only type-0 foreground transitions, never ambient object channels.</summary>
     public int CompleteForegroundTransitions(long nowMs)
     {