PipelineBrush and effects refactoring

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/PipelineBrush/PipelineBrushPage.xaml

@@ -21,8 +21,10 @@
             <Border>
                 <Border.Background>
                     <media:PipelineBrush>
-                        <media:PipelineBrush.Effects>
+                        <media:PipelineBrush.Input>
                             <effects:AcrylicEffect/>
+                        </media:PipelineBrush.Input>
+                        <media:PipelineBrush.Effects>
                             <effects:BlendEffect>
                                 <effects:BlendEffect.Input>
                                     <effects:BackdropEffect Source="Backdrop"/>
@@ -39,8 +41,10 @@
             <Border>
                 <Border.Background>
                     <media:PipelineBrush>
-                        <media:PipelineBrush.Effects>
+                        <media:PipelineBrush.Input>
                             <effects:AcrylicEffect/>
+                        </media:PipelineBrush.Input>
+                        <media:PipelineBrush.Effects>
                             <effects:HueRotationEffect/>
                             <effects:BlendEffect>
                                 <effects:BlendEffect.Input>
@@ -59,8 +63,10 @@
             <Border>
                 <Border.Background>
                     <media:PipelineBrush>
-                        <media:PipelineBrush.Effects>
+                        <media:PipelineBrush.Input>
                             <effects:AcrylicEffect/>
+                        </media:PipelineBrush.Input>
+                        <media:PipelineBrush.Effects>
                             <effects:SepiaEffect/>
                             <effects:ShadeEffect/>
                             <effects:BlendEffect>

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/PipelineBrush/PipelineBrushXaml.bind

@@ -21,8 +21,10 @@
               Height="400">
         <Border.Background>
           <brushes:PipelineBrush>
-            <brushes:PipelineBrush.Effects>
+            <brushes:PipelineBrush.Input>
               <effects:BackdropEffect Source="Backdrop"/>
+            </brushes:PipelineBrush.Input>
+            <brushes:PipelineBrush.Effects>
               <effects:LuminanceToAlphaEffect/>
               <effects:OpacityEffect Value="0.4"/>
               <effects:BlendEffect Mode="Multiply">

Microsoft.Toolkit.Uwp.UI.Media/Brushes/PipelineBrush.cs

@@ -2,28 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
-using System.Diagnostics.Contracts;
-using System.Linq;
-using Microsoft.Graphics.Canvas.Effects;
 using Microsoft.Toolkit.Uwp.UI.Media.Base;
 using Microsoft.Toolkit.Uwp.UI.Media.Effects;
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
 using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 using Windows.UI.Xaml.Media;
-using BlendEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.BlendEffect;
-using ExposureEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.ExposureEffect;
-using GrayscaleEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.GrayscaleEffect;
-using HueRotationEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.HueRotationEffect;
-using InvertEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.InvertEffect;
-using LuminanceToAlphaEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.LuminanceToAlphaEffect;
-using OpacityEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.OpacityEffect;
-using SaturationEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.SaturationEffect;
-using SepiaEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.SepiaEffect;
-using TemperatureAndTintEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.TemperatureAndTintEffect;
-using TileEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.TileEffect;
-using TintEffect = Microsoft.Toolkit.Uwp.UI.Media.Effects.TintEffect;
 
 namespace Microsoft.Toolkit.Uwp.UI.Media
 {
@@ -33,100 +16,26 @@ namespace Microsoft.Toolkit.Uwp.UI.Media
     public sealed class PipelineBrush : XamlCompositionEffectBrushBase
     {
         /// <summary>
-        /// Builds a new effects pipeline from the input effects sequence
+        /// Gets or sets the input for the current pipeline
         /// </summary>
-        /// <param name="effects">The input collection of <see cref="IPipelineEffect"/> instance</param>
-        /// <returns>A new <see cref="PipelineBuilder"/> instance with the items in <paramref name="effects"/></returns>
-        [Pure]
-        private static PipelineBuilder Build(IList<IPipelineEffect> effects)
-        {
-            if (effects.Count == 0)
-            {
-                throw new ArgumentException("An effects pipeline can't be empty");
-            }
-
-            return effects.Skip(1).Aggregate(Start(effects[0]), (b, e) => Append(e, b));
-        }
+        public IPipelineInput Input { get; set; }
 
         /// <summary>
-        /// Starts a new composition pipeline from the given effect
+        /// Gets or sets the collection of effects to use in the current pipeline
         /// </summary>
-        /// <param name="effect">The initial <see cref="IPipelineEffect"/> instance</param>
-        /// <returns>A new <see cref="PipelineBuilder"/> instance starting from <paramref name="effect"/></returns>
-        [Pure]
-        private static PipelineBuilder Start(IPipelineEffect effect)
-        {
-            switch (effect)
-            {
-                case BackdropEffect backdrop when backdrop.Source == AcrylicBackgroundSource.Backdrop:
-                    return PipelineBuilder.FromBackdrop();
-                case BackdropEffect backdrop when backdrop.Source == AcrylicBackgroundSource.HostBackdrop:
-                    return PipelineBuilder.FromHostBackdrop();
-                case SolidColorEffect color:
-                    return PipelineBuilder.FromColor(color.Color);
-                case ImageEffect image:
-                    return PipelineBuilder.FromImage(image.Uri, image.DpiMode, image.CacheMode);
-                case TileEffect tile:
-                    return PipelineBuilder.FromTiles(tile.Uri, tile.DpiMode, tile.CacheMode);
-                case AcrylicEffect acrylic when acrylic.Source == AcrylicBackgroundSource.Backdrop:
-                    return PipelineBuilder.FromBackdropAcrylic(acrylic.Tint, (float)acrylic.TintMix, (float)acrylic.BlurAmount, acrylic.TextureUri);
-                case AcrylicEffect acrylic when acrylic.Source == AcrylicBackgroundSource.HostBackdrop:
-                    return PipelineBuilder.FromHostBackdropAcrylic(acrylic.Tint, (float)acrylic.TintMix, acrylic.TextureUri);
-                default:
-                    throw new ArgumentException($"Invalid initial pipeline effect: {effect.GetType()}");
-            }
-        }
+        public IList<IPipelineNode> Effects { get; set; } = new List<IPipelineNode>();
 
-        /// <summary>
-        /// Appends an effect to an existing composition pipeline
-        /// </summary>
-        /// <param name="effect">The <see cref="IPipelineEffect"/> instance to append to the current pipeline</param>
-        /// <param name="builder">The target <see cref="PipelineBuilder"/> instance to modify</param>
-        /// <returns>The target <see cref="PipelineBuilder"/> instance in use</returns>
-        private static PipelineBuilder Append(IPipelineEffect effect, PipelineBuilder builder)
+        /// <inheritdoc/>
+        protected override PipelineBuilder OnBrushRequested()
         {
-            switch (effect)
+            PipelineBuilder builder = Input.StartPipeline();
+
+            foreach (IPipelineNode effect in Effects)
             {
-                case OpacityEffect opacity:
-                    return builder.Opacity((float)opacity.Value);
-                case LuminanceToAlphaEffect _:
-                    return builder.LuminanceToAlpha();
-                case InvertEffect _:
-                    return builder.Invert();
-                case GrayscaleEffect _:
-                    return builder.Grayscale();
-                case ExposureEffect exposure:
-                    return builder.Exposure((float)exposure.Value);
-                case SepiaEffect sepia:
-                    return builder.Sepia((float)sepia.Value);
-                case ShadeEffect shade:
-                    return builder.Shade(shade.Color, (float)shade.Intensity);
-                case HueRotationEffect hueRotation:
-                    return builder.HueRotation((float)hueRotation.Angle);
-                case TintEffect tint:
-                    return builder.Tint(tint.Color);
-                case TemperatureAndTintEffect temperatureAndTint:
-                    return builder.TemperatureAndTint((float)temperatureAndTint.Temperature, (float)temperatureAndTint.Tint);
-                case BlurEffect blur:
-                    return builder.Blur((float)blur.Value);
-                case SaturationEffect saturation:
-                    return builder.Saturation((float)saturation.Value);
-                case BlendEffect blend:
-                    return builder.Blend(Build(blend.Input), (BlendEffectMode)blend.Mode, blend.Placement);
-                default:
-                    throw new ArgumentException($"Invalid pipeline effect: {effect.GetType()}");
+                builder = effect.AppendToPipeline(builder);
             }
-        }
 
-        /// <inheritdoc/>
-        protected override PipelineBuilder OnBrushRequested()
-        {
-            return Build(this.Effects);
+            return builder;
         }
-
-        /// <summary>
-        /// Gets or sets the collection of effects to use in the current pipeline
-        /// </summary>
-        public IList<IPipelineEffect> Effects { get; set; } = new List<IPipelineEffect>();
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/Abstract/ImageEffectBase.cs

@@ -3,14 +3,14 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 
-namespace Microsoft.Toolkit.Uwp.UI.Media.Effects.Abstract
+namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
 {
     /// <summary>
     /// An image based effect that loads an image at the specified location
     /// </summary>
-    public abstract class ImageEffectBase : IPipelineEffect
+    public abstract class ImageEffectBase : IPipelineInput
     {
         /// <summary>
         /// Gets or sets the <see cref="System.Uri"/> for the image to load
@@ -26,5 +26,8 @@ public abstract class ImageEffectBase : IPipelineEffect
         /// Gets or sets the cache mode to use when loading the image (the default is <see cref="Media.CacheMode.Default"/>)
         /// </summary>
         public CacheMode CacheMode { get; set; } = CacheMode.Default;
+
+        /// <inheritdoc/>
+        public abstract PipelineBuilder StartPipeline();
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/Abstract/ValueEffectBase.cs

@@ -2,18 +2,21 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 
-namespace Microsoft.Toolkit.Uwp.UI.Media.Effects.Abstract
+namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
 {
     /// <summary>
     /// A base <see langword="class"/> for an effect that exposes a single <see cref="float"/> parameter
     /// </summary>
-    public abstract class ValueEffectBase : IPipelineEffect
+    public abstract class ValueEffectBase : IPipelineNode
     {
         /// <summary>
         /// Gets or sets the value of the parameter for the current effect
         /// </summary>
         public double Value { get; set; }
+
+        /// <inheritdoc/>
+        public abstract PipelineBuilder AppendToPipeline(PipelineBuilder builder);
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/AcrylicEffect.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 using Windows.UI;
 using Windows.UI.Xaml.Media;
 
@@ -13,7 +13,7 @@ namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
     /// A custom acrylic effect that can be inserted into a pipeline
     /// </summary>
     /// <remarks>This effect mirrors the look of the default <see cref="AcrylicBrush"/> implementation</remarks>
-    public sealed class AcrylicEffect : IPipelineEffect
+    public sealed class AcrylicEffect : IPipelineInput
     {
         /// <summary>
         /// Gets or sets the source mode for the effect
@@ -40,5 +40,16 @@ public sealed class AcrylicEffect : IPipelineEffect
         /// Gets or sets the <see cref="Uri"/> to the texture to use
         /// </summary>
         public Uri TextureUri { get; set; }
+
+        /// <inheritdoc/>
+        public PipelineBuilder StartPipeline()
+        {
+            return Source switch
+            {
+                AcrylicBackgroundSource.Backdrop => PipelineBuilder.FromBackdropAcrylic(Tint, (float)TintMix, (float)BlurAmount, TextureUri),
+                AcrylicBackgroundSource.HostBackdrop => PipelineBuilder.FromHostBackdropAcrylic(Tint, (float)TintMix, TextureUri),
+                _ => throw new ArgumentException($"Invalid source mode for acrylic effect: {Source}")
+            };
+        }
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/BackdropEffect.cs

@@ -2,19 +2,31 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
+using System;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 using Windows.UI.Xaml.Media;
 
 namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
 {
     /// <summary>
     /// A backdrop effect that can sample from a specified source
     /// </summary>
-    public sealed class BackdropEffect : IPipelineEffect
+    public sealed class BackdropEffect : IPipelineInput
     {
         /// <summary>
         /// Gets or sets the backdrop source to use to render the effect
         /// </summary>
         public AcrylicBackgroundSource Source { get; set; }
+
+        /// <inheritdoc/>
+        public PipelineBuilder StartPipeline()
+        {
+            return Source switch
+            {
+                AcrylicBackgroundSource.Backdrop => PipelineBuilder.FromBackdrop(),
+                AcrylicBackgroundSource.HostBackdrop => PipelineBuilder.FromHostBackdrop(),
+                _ => throw new ArgumentException($"Invalid source for backdrop effect: {Source}")
+            };
+        }
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/BlendEffect.cs

@@ -3,29 +3,48 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Generic;
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Interfaces;
+using Microsoft.Graphics.Canvas.Effects;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 
 namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
 {
     /// <summary>
-    /// A blend effect that merges the current pipeline with an input one
+    /// A blend effect that merges the current builder with an input one
     /// </summary>
     /// <remarks>This effect maps to the Win2D <see cref="Graphics.Canvas.Effects.BlendEffect"/> effect</remarks>
-    public sealed class BlendEffect : IPipelineEffect
+    public sealed class BlendEffect : IPipelineNode
     {
         /// <summary>
-        /// Gets or sets the input pipeline to merge with the current instance
+        /// Gets or sets the input to merge with the current instance
         /// </summary>
-        public IList<IPipelineEffect> Input { get; set; } = new List<IPipelineEffect>();
+        public IPipelineInput Input { get; set; }
+
+        /// <summary>
+        /// Gets or sets the effects to apply to the input to merge with the current instance
+        /// </summary>
+        public List<IPipelineNode> Effects { get; set; } = new List<IPipelineNode>();
 
         /// <summary>
         /// Gets or sets the blending mode to use (the default mode is <see cref="ImageBlendMode.Multiply"/>)
         /// </summary>
         public ImageBlendMode Mode { get; set; }
 
         /// <summary>
-        /// Gets or sets the placement of the input pipeline with respect to the current one (the default is <see cref="Placement.Foreground"/>)
+        /// Gets or sets the placement of the input builder with respect to the current one (the default is <see cref="Placement.Foreground"/>)
         /// </summary>
         public Placement Placement { get; set; } = Placement.Foreground;
+
+        /// <inheritdoc/>
+        public PipelineBuilder AppendToPipeline(PipelineBuilder builder)
+        {
+            PipelineBuilder inputBuilder = Input.StartPipeline();
+
+            foreach (IPipelineNode effect in this.Effects)
+            {
+                inputBuilder = effect.AppendToPipeline(inputBuilder);
+            }
+
+            return builder.Blend(inputBuilder, (BlendEffectMode)Mode, Placement);
+        }
     }
 }

Microsoft.Toolkit.Uwp.UI.Media/Effects/BlurEffect.cs

@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Microsoft.Toolkit.Uwp.UI.Media.Effects.Abstract;
+using Microsoft.Toolkit.Uwp.UI.Media.Pipelines;
 
 namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
 {
@@ -12,5 +12,10 @@ namespace Microsoft.Toolkit.Uwp.UI.Media.Effects
     /// <remarks>This effect maps to the Win2D <see cref="Graphics.Canvas.Effects.GaussianBlurEffect"/> effect</remarks>
     public sealed class BlurEffect : ValueEffectBase
     {
+        /// <inheritdoc/>
+        public override PipelineBuilder AppendToPipeline(PipelineBuilder builder)
+        {
+            return builder.Blur((float)Value);
+        }
     }
 }