仿制shazzam的简单功能，将hlsl转换为WPF中的ShaderEffect

(此文章只是在对WPF的Effect产生兴趣才稍微研究了一点后面的知识;需要了解更多可参考https://archive.codeplex.com/?p=shazzam的源代码以及WPF基础知识)

1.之前一直使用blend里自带的几个特效，突然有一天比较好奇这些特效是怎么来的。

然后就听说了shazzam并看到更多的特效

2.在参考网址下载了shazzam的代码来研究研究，只抽取出里面【如何将.fx文件编译为.ps，再产生一个调用.ps文件的.cs文件,然后就可以像正常使用其它自带Effect一样使用了】这一过程

3.HLSL语法网上有很多教程啊，目前就直接拿一些写好的来用就行，一个简单的ToonShader.fx

/// <description>An effect that applies cartoon-like shading (posterization).</description>

sampler2D inputSampler : register(S0);

//-----------------------------------------------------------------------------------------
// Shader constant register mappings (scalars - float, double, Point, Color, Point3D, etc.)
//-----------------------------------------------------------------------------------------

/// <summary>The number of color levels to use.</summary>
/// <minValue></minValue>
/// <maxValue></maxValue>
/// <defaultValue></defaultValue>
float Levels : register(C0);

float4 main(float2 uv : TEXCOORD) : COLOR
{
    float4 color = tex2D( inputSampler, uv );
    color.rgb /= color.a;

    int levels = floor(Levels);
    color.rgb *= levels;
    color.rgb = floor(color.rgb);
    color.rgb /= levels;
    color.rgb *= color.a;
    return color;
}

ToonShader

4.ShaderCompiler：利用dxd的D3DXCompileShader将.fx文件转换为.ps文件

    public void Compile(string codeText, string output, string fxName, ShaderProfile shaderProfile = ShaderProfile.ps_2_0)
    {
        IsCompiled = false;
        string path = output;
        IntPtr defines = IntPtr.Zero;
        IntPtr includes = IntPtr.Zero;
        IntPtr ppConstantTable = IntPtr.Zero;
        string methodName = "main";
        string targetProfile2 = "ps_2_0";
        targetProfile2 = ((shaderProfile != ShaderProfile.ps_3_0) ? "ps_2_0" : "ps_3_0");
        bool useDx10 = false;
        int hr2 = ;
        ID3DXBuffer ppShader2;
        ID3DXBuffer ppErrorMsgs2;
        if (!useDx10)
        {
            hr2 = ((IntPtr.Size != ) ?
                DxHelper.D3DXCompileShader(codeText, codeText.Length, defines, includes, methodName, targetProfile2, , out ppShader2, out ppErrorMsgs2, out ppConstantTable)
                :
                DxHelper.D3DXCompileShader64Bit(codeText, codeText.Length, defines, includes, methodName, targetProfile2, , out ppShader2, out ppErrorMsgs2, out ppConstantTable));
        }
        else
        {
            int pHr = ;
            hr2 = DxHelper.D3DX10CompileFromMemory(codeText, codeText.Length, string.Empty, IntPtr.Zero, IntPtr.Zero, methodName, targetProfile2, , , IntPtr.Zero, out ppShader2, out ppErrorMsgs2, ref pHr);
        }
        if (hr2 != )
        {
            IntPtr errors = ppErrorMsgs2.GetBufferPointer();
            ppErrorMsgs2.GetBufferSize();
            ErrorText = Marshal.PtrToStringAnsi(errors);
            IsCompiled = false;
        }
        else
        {
            ErrorText = "";
            IsCompiled = true;
            string psPath = path + fxName;
            IntPtr pCompiledPs = ppShader2.GetBufferPointer();
            int compiledPsSize = ppShader2.GetBufferSize();
            byte[] compiledPs = new byte[compiledPsSize];
            Marshal.Copy(pCompiledPs, compiledPs, , compiledPs.Length);
            using (FileStream psFile = File.Open(psPath, FileMode.Create, FileAccess.Write))
            {
                psFile.Write(compiledPs, , compiledPs.Length);
            }
        }
        if (ppShader2 != null)
        {
            Marshal.ReleaseComObject(ppShader2);
        }
        ppShader2 = null;
        if (ppErrorMsgs2 != null)
        {
            Marshal.ReleaseComObject(ppErrorMsgs2);
        }
        ppErrorMsgs2 = null;
        CompileFinished();
    }

Compile(string codeText, string output, string fxName, ShaderProfile shaderProfile)

5.CodeGenerator：生成引用.ps文件的effect.cs文件

private static string GenerateCode(CodeDomProvider provider, CodeCompileUnit compileUnit)
    {
        // Generate source code using the code generator.
        using (StringWriter writer = new StringWriter())
        {
            string indentString = IndentUsingTabs ? "\t" : String.Format("{0," + IndentSpaces.ToString() + "}", " ");
            CodeGeneratorOptions options = new CodeGeneratorOptions { IndentString = indentString, BlankLinesBetweenMembers = true, BracingStyle = "C" };
            provider.GenerateCodeFromCompileUnit(compileUnit, writer, options);
            string text = writer.ToString();
            // Fix up code: make static DP fields readonly, and use triple-slash or triple-quote comments for XML doc comments.
            if (provider.FileExtension == "cs")
            {
                text = text.Replace("public static DependencyProperty", "public static readonly DependencyProperty");
                text = Regex.Replace(text, @"// <(?!/?auto-generated)", @"/// <");
            }
            else
                if (provider.FileExtension == "vb")
            {
                text = text.Replace("Public Shared ", "Public Shared ReadOnly ");
                text = text.Replace("'<", "'''<");
            }
            return text;
        }
    }

GenerateCode(CodeDomProvider provider, CodeCompileUnit compileUnit)

生成的cs文件内容如下：

//------------------------------------------------------------------------------
// <auto-generated>
//     此代码由工具生成。
//     运行时版本:4.0.30319.42000
//
//     对此文件的更改可能会导致不正确的行为，并且如果
//     重新生成代码，这些更改将会丢失。
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Effects;
using System.Windows.Media.Media3D;

namespace ShaderPan
{

    /// <summary>An effect that applies cartoon-like shading (posterization).</summary>
    public class ToonShaderEffect : ShaderEffect
    {

        public static readonly DependencyProperty InputProperty = ShaderEffect.RegisterPixelShaderSamplerProperty("Input", typeof(ToonShaderEffect), );

        public static readonly DependencyProperty LevelsProperty = DependencyProperty.Register("Levels", typeof(double), typeof(ToonShaderEffect), new UIPropertyMetadata(((double)(5D)), PixelShaderConstantCallback()));

        public ToonShaderEffect()
        {
            PixelShader pixelShader = new PixelShader();
            pixelShader.UriSource = new Uri("C:\\Users\\Administrator\\Desktop\\WpfTPL\\shader\\ToonShader.ps", UriKind.Absolute);
            this.PixelShader = pixelShader;

            this.UpdateShaderValue(InputProperty);
            this.UpdateShaderValue(LevelsProperty);
        }

        public Brush Input
        {
            get
            {
                return ((Brush)(this.GetValue(InputProperty)));
            }
            set
            {
                this.SetValue(InputProperty, value);
            }
        }

        /// <summary>The number of color levels to use.</summary>
        public double Levels
        {
            get
            {
                return ((double)(this.GetValue(LevelsProperty)));
            }
            set
            {
                this.SetValue(LevelsProperty, value);
            }
        }
    }
}

ToonShaderEffect : ShaderEffect

6.ShaderPanTest：测试功能--运用C#动态编译生成来使用Effect

 public static Assembly CompileInMemory(string code)
    {
        var provider = new CSharpCodeProvider(new Dictionary<string, string>() { { "CompilerVersion", "v4.0" } });

        CompilerParameters options = new CompilerParameters();
        options.ReferencedAssemblies.Add("System.dll");
        options.ReferencedAssemblies.Add("System.Core.dll");
        options.ReferencedAssemblies.Add("WindowsBase.dll");
        options.ReferencedAssemblies.Add("PresentationFramework.dll");
        options.ReferencedAssemblies.Add("PresentationCore.dll");
        options.IncludeDebugInformation = false;
        options.GenerateExecutable = false;
        options.GenerateInMemory = true;
        CompilerResults results = provider.CompileAssemblyFromSource(options, code);
        provider.Dispose();
        if (results.Errors.Count == )
            return results.CompiledAssembly;
        else
            return null;
    }

CompileInMemory(string code)

7.源码： https://github.com/lenkasetGitHub/Song_WPF_PixelShader （exe图标来自easyicon）

https://gitee.com/github-19276270/Song_WPF_PixelShader