c# - Setting pixel shader uniform variable -

dummy question, guess. have custom shader looks this:

 sampler2d inputtexture;  float parameter1, parameter2 etc  float4 main(float2 uv : texcoord) : color {     float4 result = blah-blah-blah calculations using parameter1, parameter2 etc.      return result; } 

i'm trying use via wrapper looks this:

 class myshadereffect : shadereffect {     private pixelshader _pixelshader = new pixelshader();     public readonly dependencyproperty inputproperty = shadereffect.registerpixelshadersamplerproperty("input", typeof(myshadereffect), 0);      public myshadereffect()     {         _pixelshader.urisource = new uri("myshader.ps", urikind.relative);         this.pixelshader = _pixelshader;         this.updateshadervalue(inputproperty);     }      public brush input     {         { return (brush)this.getvalue(inputproperty); }         set { this.setvalue(inputproperty, value); }     } } 

so, question is: how set shader parameters c# program?

it's right there in documentation of shadereffect class. need create dependency properties every parameter. example:

class myshadereffect {     public myshadereffect()     {         pixelshader = _pixelshader;          updateshadervalue(inputproperty);         updateshadervalue(thresholdproperty);     }      public double threshold     {         { return (double)getvalue(thresholdproperty); }         set { setvalue(thresholdproperty, value); }     }      public static readonly dependencyproperty thresholdproperty =         dependencyproperty.register("threshold", typeof(double), typeof(myshadereffect),                 new uipropertymetadata(0.5, pixelshaderconstantcallback(0))); } 

the 0 in pixelshaderconstantcallback refers register use in hlsl:

float threshold : register(c0); 

this way wpf knows update shader when property changes. it's important call updateshadervalue in constructor pass value.