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>3</minvalue>
/// <maxvalue>15</maxvalue>
/// <defaultvalue>5</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;
}

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 = 0;
        id3dxbuffer ppshader2;
        id3dxbuffer pperrormsgs2;
        if (!usedx10)
        {
            hr2 = ((intptr.size != 8) ?
                dxhelper.d3dxcompileshader(codetext, codetext.length, defines, includes, methodname, targetprofile2, 0, out ppshader2, out pperrormsgs2, out ppconstanttable)
                :
                dxhelper.d3dxcompileshader64bit(codetext, codetext.length, defines, includes, methodname, targetprofile2, 0, out ppshader2, out pperrormsgs2, out ppconstanttable));
        }
        else
        {
            int phr = 0;
            hr2 = dxhelper.d3dx10compilefrommemory(codetext, codetext.length, string.empty, intptr.zero, intptr.zero, methodname, targetprofile2, 0, 0, intptr.zero, out ppshader2, out pperrormsgs2, ref phr);
        }
        if (hr2 != 0)
        {
            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, 0, compiledps.length);
            using (filestream psfile = file.open(pspath, filemode.create, fileaccess.write))
            {
                psfile.write(compiledps, 0, compiledps.length);
            }
        }
        if (ppshader2 != null)
        {
            marshal.releasecomobject(ppshader2);
        }
        ppshader2 = null;
        if (pperrormsgs2 != null)
        {
            marshal.releasecomobject(pperrormsgs2);
        }
        pperrormsgs2 = null;
        compilefinished();
    }

 

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;
        }
    }

 

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), 0);
        
        public static readonly dependencyproperty levelsproperty = dependencyproperty.register("levels", typeof(double), typeof(toonshadereffect), new uipropertymetadata(((double)(5d)), pixelshaderconstantcallback(0)));
        
        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);
            }
        }
    }
}

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 == 0)
            return results.compiledassembly;
        else
            return null;
    }

7.源码： https://github.com/lenkasetgithub/song_wpf_pixelshader （exe图标来自easyicon）