Implement the PathFollowEffect

src/Beutl.Engine/Graphics/FilterEffects/PathFollowEffect.cs

@@ -0,0 +1,96 @@
+using System.ComponentModel.DataAnnotations;
+using Beutl.Engine;
+using Beutl.Language;
+using Beutl.Media;
+using SkiaSharp;
+
+namespace Beutl.Graphics.Effects;
+
+public sealed partial class PathFollowEffect : FilterEffect
+{
+    public PathFollowEffect()
+    {
+        ScanProperties<PathFollowEffect>();
+        Geometry.CurrentValue = new PathGeometry();
+    }
+
+    [Display(Name = nameof(Strings.Geometry), ResourceType = typeof(Strings))]
+    public IProperty<Geometry?> Geometry { get; } = Property.Create<Geometry?>();
+
+    [Display(Name = nameof(Strings.Progress), ResourceType = typeof(Strings))]
+    public IProperty<float> Progress { get; } = Property.CreateAnimatable(0f);
+
+    [Display(Name = nameof(Strings.FollowRotation), ResourceType = typeof(Strings))]
+    public IProperty<bool> FollowRotation { get; } = Property.CreateAnimatable(false);
+
+    public override void ApplyTo(FilterEffectContext context, FilterEffect.Resource resource)
+    {
+        var r = (Resource)resource;
+        if (r.Geometry == null)
+            return;
+
+        SKPath skPath = r.Geometry.GetCachedPath();
+        if (skPath.IsEmpty)
+            return;
+
+        float progress = Math.Clamp(r.Progress, 0f, 100f) / 100f;
+
+        using var pathMeasure = new SKPathMeasure(skPath);
+        float totalLength = pathMeasure.Length;
+        if (totalLength <= 0)
+            return;
+
+        float distance = totalLength * progress;
+
+        if (!pathMeasure.GetPositionAndTangent(distance, out SKPoint position, out SKPoint tangent))
+            return;
+
+        if (!pathMeasure.GetPosition(0, out SKPoint startPosition))
+            return;
+
+        float offsetX = position.X - startPosition.X;
+        float offsetY = position.Y - startPosition.Y;
+
+        float rotationAngle = 0f;
+        if (r.FollowRotation)
+        {
+            rotationAngle = MathF.Atan2(tangent.Y, tangent.X);
+        }
+
+        context.CustomEffect((offsetX, offsetY, rotationAngle), static (data, effectContext) =>
+        {
+            effectContext.ForEach((_, target) =>
+            {
+
+                var translate = Matrix.CreateTranslation(data.offsetX, data.offsetY);
+                Matrix m1, m2;
+                if (data.rotationAngle != 0)
+                {
+                    var center = new Vector(target.Bounds.Width / 2, target.Bounds.Height / 2);
+                    var rotate = Matrix.CreateRotation(data.rotationAngle);
+
+                    var offset1 = Matrix.CreateTranslation(center + target.Bounds.Position);
+                    var offset2 = Matrix.CreateTranslation(center);
+                    m1 = -offset1 * rotate * offset1 * translate;
+                    m2 = -offset2 * rotate * offset2 * translate;
+                }
+                else
+                {
+                    m1 = m2 = translate;
+                }
+
+                var newBounds = target.Bounds.TransformToAABB(m1);
+                var newTarget = effectContext.CreateTarget(newBounds);
+                using (var canvas = effectContext.Open(newTarget))
+                using (canvas.PushTransform(Matrix.CreateTranslation(target.Bounds.Position - newTarget.Bounds.Position)))
+                using (canvas.PushTransform(m2))
+                {
+                    target.Draw(canvas);
+                }
+
+                target.Dispose();
+                return newTarget;
+            });
+        });
+    }
+}

src/Beutl.Language/Strings.ja.resx

@@ -1415,4 +1415,16 @@
   <data name="Convert_to_preset" xml:space="preserve">
     <value>プリセットに変換</value>
   </data>
+  <data name="Geometry" xml:space="preserve">
+    <value>ジオメトリ</value>
+  </data>
+  <data name="Progress" xml:space="preserve">
+    <value>進捗</value>
+  </data>
+  <data name="FollowRotation" xml:space="preserve">
+    <value>回転に追従</value>
+  </data>
+  <data name="PathFollowEffect" xml:space="preserve">
+    <value>パス追従</value>
+  </data>
 </root>

src/Beutl.Language/Strings.resx

@@ -1410,4 +1410,16 @@
   <data name="Convert_to_preset" xml:space="preserve">
     <value>Convert to preset</value>
   </data>
+  <data name="Geometry" xml:space="preserve">
+    <value>Geometry</value>
+  </data>
+  <data name="Progress" xml:space="preserve">
+    <value>Progress</value>
+  </data>
+  <data name="FollowRotation" xml:space="preserve">
+    <value>Follow Rotation</value>
+  </data>
+  <data name="PathFollowEffect" xml:space="preserve">
+    <value>Path Follow</value>
+  </data>
 </root>

src/Beutl.Operators/LibraryRegistrar.cs

@@ -145,6 +145,7 @@ public static void RegisterAll()
                 .AddFilterEffect<ColorShift>(Strings.ColorShift)
                 .AddFilterEffect<ShakeEffect>(Strings.ShakeEffect)
                 .AddFilterEffect<DisplacementMapEffect>(Strings.DisplacementMap)
+                .AddFilterEffect<PathFollowEffect>(Strings.PathFollowEffect)
                 .AddFilterEffect<LayerEffect>("Layer")
                 .AddGroup("OpenCV", gg => gg
                     .AddFilterEffect<Graphics.Effects.OpenCv.Blur>("CvBlur")

src/Beutl/Views/Editors/GeometryEditor.axaml

@@ -24,6 +24,9 @@
                     <ui:MenuFlyoutItem Click="SetNullClick"
                                        FontWeight="Normal"
                                        Text="Null" />
+                    <ui:MenuFlyoutItem Click="InitializeClick"
+                                       FontWeight="Normal"
+                                       Text="{x:Static lang:Strings.Initialize}" />
                     <ui:MenuFlyoutItem Click="ImportFromSvgPathClick"
                                        FontWeight="Normal"
                                        Text="{x:Static lang:Strings.ImportSvgPath}" />

src/Beutl/Views/Editors/GeometryEditor.axaml.cs

@@ -60,7 +60,7 @@ private void Tag_Click(object? sender, RoutedEventArgs e)
         else
         {
             _logger.LogInformation("Group is not selected, showing context flyout.");
-            //expandToggle.ContextFlyout?.ShowAt(expandToggle);
+            expandToggle.ContextFlyout?.ShowAt(expandToggle);
         }
     }
 
@@ -113,30 +113,19 @@ private async void ImportFromSvgPathClick(object? sender, RoutedEventArgs e)
         }
     }
 
-    private void AddClick(object? sender, RoutedEventArgs e)
-    {
-        if (DataContext is GeometryEditorViewModel { IsDisposed: false } viewModel
-            && sender is MenuFlyoutItem item
-            && viewModel.IsGroup.Value)
-        {
-            try
-            {
-                _logger.LogInformation("Adding item from menu flyout.");
-                viewModel.AddItem();
-            }
-            catch (Exception ex)
-            {
-                _logger.LogError(ex, "Error occurred while adding item from menu flyout.");
-                NotificationService.ShowError("Error", ex.Message);
-            }
-        }
-    }
-
     private void SetNullClick(object? sender, RoutedEventArgs e)
     {
         if (DataContext is not GeometryEditorViewModel { IsDisposed: false } viewModel) return;
 
         _logger.LogInformation("Setting value to null.");
         viewModel.SetNull();
     }
+
+    private void InitializeClick(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not GeometryEditorViewModel { IsDisposed: false } viewModel) return;
+
+        _logger.LogInformation("Initializing geometry type.");
+        viewModel.ChangeGeometryType(typeof(PathGeometry));
+    }
 }