Fix missing dirty rectangles for animations

Author: xoofx

src/XenoAtom.Terminal.UI.Tests/SpinnerTests.cs

@@ -56,6 +56,44 @@ public void Spinner_Bound_IsActive_Starts_Animating_When_Switched_To_True()
         StringAssert.Contains(after, "b");
     }
 
+    [TestMethod]
+    public void Spinner_Animation_Redraws_When_Same_Frame_Uses_Partial_Repaint()
+    {
+        var marker = new Spinner("Marker")
+            .IsActive(false);
+        marker.Style(new SpinnerStyle("Test", TimeSpan.FromMilliseconds(10), "x", "y")
+        {
+            TextStyle = TextStyle.None,
+        });
+        var spinner = new Spinner("Loading");
+        spinner.Style(new SpinnerStyle("Test", TimeSpan.FromMilliseconds(10), "a", "b")
+        {
+            TextStyle = TextStyle.None,
+        });
+
+        var root = new VStack(
+            marker,
+            new HStack(
+                "Depth:",
+                new VStack(
+                    new HStack(
+                        "Node",
+                        spinner).Spacing(1))).Spacing(1));
+
+        using var driver = new TerminalAppTestDriver(root, TerminalHostKind.Fullscreen, new TerminalSize(30, 5));
+        driver.Tick();
+
+        marker.Tone = ControlTone.Success;
+        driver.Tick();
+
+        var screen = new AnsiTestScreen(30, 5);
+        screen.Apply(driver.Backend.GetOutText());
+        var rendered = screen.GetText();
+
+        StringAssert.Contains(rendered, "x Marker");
+        StringAssert.Contains(rendered, "b Loading");
+    }
+
     [TestMethod]
     public void SpinnerStyle_Computes_MaxWidth_For_Different_FrameWidths()
     {
@@ -75,4 +113,5 @@ public void SpinnerStyle_Uses_MaxFrameWidth_For_WideRuneProfiles()
         Assert.AreEqual(2, style.GetFrameWidth(TerminalWideRuneResolvers.NerdFontDoubleWidth));
         Assert.AreEqual(1, style.GetFrameWidth(TerminalWideRuneResolvers.NerdFontMono));
     }
+
 }

src/XenoAtom.Terminal.UI/TerminalApp.cs

@@ -1297,7 +1297,19 @@ private void AdvanceAnimations(long? timestamp = null)
             var visual = _animatedVisuals[i];
             if (now >= visual.NextAnimationTick)
             {
-                changed |= visual.AdvanceAnimation(now);
+                var visualChanged = visual.AdvanceAnimation(now);
+                changed |= visualChanged;
+                if (visualChanged)
+                {
+                    if (visual is Visual renderVisual)
+                    {
+                        AddRenderDirtyRect(renderVisual);
+                    }
+                    else
+                    {
+                        _pendingRenderDirtyRectValid = false;
+                    }
+                }
             }
 
             next = Math.Min(next, visual.NextAnimationTick);
@@ -1413,27 +1425,7 @@ private void ProcessBindingWrites()
             {
                 foreach (var v in renderVisuals)
                 {
-                    var bounds = v.Bounds;
-                    if (bounds.Width <= 0 || bounds.Height <= 0)
-                    {
-                        continue;
-                    }
-
-                    // Expand by 1 cell horizontally to reduce artifacts with wide glyphs clipped at region boundaries.
-                    var x = Math.Max(0, bounds.X - 1);
-                    var right = Math.Min(LayoutConstants.MaxFinite, bounds.Right + 1);
-                    var expanded = new Rectangle(x, bounds.Y, Math.Max(0, right - x), bounds.Height);
-                    metrics?.AddDirtyRect(expanded);
-
-                    if (!_pendingRenderDirtyRectValid)
-                    {
-                        _pendingRenderDirtyRect = expanded;
-                        _pendingRenderDirtyRectValid = true;
-                    }
-                    else
-                    {
-                        _pendingRenderDirtyRect = Rectangle.Union(_pendingRenderDirtyRect, expanded);
-                    }
+                    AddRenderDirtyRect(v);
                 }
             }
         }
@@ -1442,6 +1434,32 @@ private void ProcessBindingWrites()
         _renderRequested = true;
     }
 
+    private void AddRenderDirtyRect(Visual visual)
+    {
+        var bounds = visual.Bounds;
+        if (bounds.Width <= 0 || bounds.Height <= 0)
+        {
+            return;
+        }
+
+        // Expand by 1 cell horizontally to reduce artifacts with wide glyphs clipped at region boundaries.
+        var x = Math.Max(0, bounds.X - 1);
+        var right = Math.Min(LayoutConstants.MaxFinite, bounds.Right + 1);
+        var expanded = new Rectangle(x, bounds.Y, Math.Max(0, right - x), bounds.Height);
+
+        _debugOverlayMetrics?.AddDirtyRect(expanded);
+
+        if (!_pendingRenderDirtyRectValid)
+        {
+            _pendingRenderDirtyRect = expanded;
+            _pendingRenderDirtyRectValid = true;
+        }
+        else
+        {
+            _pendingRenderDirtyRect = Rectangle.Union(_pendingRenderDirtyRect, expanded);
+        }
+    }
+
     private void Render()
     {
         EnsureFocusInScope();