add fx files

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -909,7 +909,7 @@
     </Page>
   </ItemGroup>
   <ItemGroup>
-    <Folder Include="$(MSBuildThisFileDirectory)Controls\Growl\" />
-    <Folder Include="$(MSBuildThisFileDirectory)Tools\Generator\" />
+    <None Include="$(MSBuildThisFileDirectory)Resources\Effects\ColorComplementEffect.fx" />
+    <None Include="$(MSBuildThisFileDirectory)Resources\Effects\GrayScaleEffect.fx" />
   </ItemGroup>
 </Project>

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

@@ -0,0 +1,10 @@
+float4 main(float2 uv : TEXCOORD) : COLOR
+{
+    float4 color = tex2D(implicitInput, uv);
+    float4 complement;
+
+    complement.rgb = color.a - color.rgb;
+    complement.a = color.a;
+
+    return complement;
+}

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

@@ -0,0 +1,15 @@
+sampler2D implicitInput : register(s0);
+float scale : register(c0);
+
+float4 main(float2 uv : TEXCOORD) : COLOR
+{
+    float4 color = tex2D(implicitInput, uv);
+   
+    float4 complement;
+    float intensity = (color.r + color.g + color.b) / 3;
+
+    complement.rgb = color.rgb * (1 - scale) + intensity * scale;
+    complement.a = color.a;
+    
+    return complement;
+}