add MultiplyBlendEffect

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -68,6 +68,8 @@
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\LinearGeometryKeyFrame.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\ResolvedKeyFrameEntry.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\SplineGeometryKeyFrame.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Media\Effects\BlendEffect.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Media\Effects\BlendEffectMode.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Effects\BrightnessEffect.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Effects\ColorComplementEffect.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Effects\ColorMatrixEffect.cs" />
@@ -972,7 +974,10 @@
     </Page>
   </ItemGroup>
   <ItemGroup>
+    <None Include="$(MSBuildThisFileDirectory)Resources\Effects\BrightnessEffect.fx" />
     <None Include="$(MSBuildThisFileDirectory)Resources\Effects\ColorComplementEffect.fx" />
+    <None Include="$(MSBuildThisFileDirectory)Resources\Effects\ColorMatrixEffect.fx" />
+    <None Include="$(MSBuildThisFileDirectory)Resources\Effects\ContrastEffect.fx" />
     <None Include="$(MSBuildThisFileDirectory)Resources\Effects\GrayScaleEffect.fx" />
   </ItemGroup>
   <ItemGroup>

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
+    }
+}

src/Shared/HandyControl_Shared/Resources/Effects/ColorMatrixEffect.fx

@@ -46,11 +46,6 @@ float4 main(float2 uv : TEXCOORD) : COLOR
         k, l, m, n,
         p, q, r, s
     };
-
-    float4 matrixA2 =
-    {
-        e, j, o, t
-    };
     
-    return mul(matrixA1, color) + matrixA2;
+    return mul(matrixA1, color) + float4( e, j, o, t );
 }

src/Shared/HandyControl_Shared/Resources/Effects/MultiplyBlendEffect.fx

@@ -0,0 +1,15 @@
+sampler2D background : register(s0);
+sampler2D foreground : register(s1);
+
+float4 main(float2 uv : TEXCOORD) : COLOR
+{
+	float4 b = tex2D(background, uv);
+	float4 f = tex2D(foreground, uv);
+	float4 o = b;
+
+	f.rgb *= f.a;
+	b.rgb *= b.a;
+	o.rgb = f.rgb * b.rgb + f.rgb * (1 - b.a) + b.rgb * (1 - f.a);
+
+	return o;
+}