add MultiplyBlendEffect

src/Shared/HandyControl_Shared/Media/Effects/BlendEffect.cs

@@ -0,0 +1,61 @@
+//reference doc : https://docs.microsoft.com/en-us/windows/win32/direct2d/blend#blending-examples
+
+using System;
+using System.Collections.Generic;
+using System.Windows;
+using System.Windows.Media;
+using System.Windows.Media.Effects;
+
+namespace HandyControl.Media.Effects
+{
+    public class BlendEffect : ShaderEffect
+    {
+        private static readonly Dictionary<BlendEffectMode, PixelShader> ShaderDic;
+
+        public static readonly DependencyProperty BackgroundProperty = RegisterPixelShaderSamplerProperty("Background", typeof(BlendEffect), 0);
+
+        public static readonly DependencyProperty ForegroundProperty = RegisterPixelShaderSamplerProperty("Foreground", typeof(BlendEffect), 1);
+
+        static BlendEffect()
+        {
+            ShaderDic = new Dictionary<BlendEffectMode, PixelShader>();
+        }
+
+        public BlendEffect()
+        {
+            if (!ShaderDic.ContainsKey(Mode))
+            {
+                ShaderDic[Mode] = new PixelShader
+                {
+                    UriSource = new Uri($"pack://application:,,,/HandyControl;component/Resources/Effects/{Mode.ToString()}BlendEffect.ps")
+                };
+            }
+
+            PixelShader = ShaderDic[Mode];
+
+            UpdateShaderValue(BackgroundProperty);
+            UpdateShaderValue(ForegroundProperty);
+        }
+
+        public Brush Background
+        {
+            get => (Brush)GetValue(BackgroundProperty);
+            set => SetValue(BackgroundProperty, value);
+        }
+
+        public Brush Foreground
+        {
+            get => (Brush)GetValue(ForegroundProperty);
+            set => SetValue(ForegroundProperty, value);
+        }
+
+        public static readonly DependencyProperty ModeProperty = DependencyProperty.Register(
+            "Mode", typeof(BlendEffectMode), typeof(BlendEffect), new PropertyMetadata(default(BlendEffectMode), PixelShaderConstantCallback(0)));
+
+        public BlendEffectMode Mode
+        {
+            get => (BlendEffectMode) GetValue(ModeProperty);
+            set => SetValue(ModeProperty, value);
+        }
+    }
+}

src/Shared/HandyControl_Shared/Media/Effects/BlendEffectMode.cs

@@ -0,0 +1,32 @@
+namespace HandyControl.Media.Effects
+{
+    public enum BlendEffectMode
+    {
+        Multiply,
+        Screen,
+        Darken,
+        Lighten,
+        Dissolve,
+        ColorBurn,
+        LinearBurn,
+        DarkerColor,
+        LighterColor,
+        ColorDodge,
+        LinearDodge,
+        Overlay,
+        SoftLight,
+        HardLight,
+        VividLight,
+        LinearLight,
+        PinLight,
+        HardMix,
+        Difference,
+        Exclusion,
+        Hue,
+        Saturation,
+        Color,
+        Luminosity,
+        Subtract,
+        Division
+    }
+}