Passing keyword from script to shader

Hi. I am learning to write my own image effect with the new Postprocessing (2.0.5 preview) but I am having trouble to pass the keyword from my script to the shader. Technically the following codes work as intended by passing the _ARITHMETICS keyword, but it is definitely inefficient when I have more keywords to switch. Please recommend a better way to handle this, especially for KeywordEnum. Thank you.

Code (CSharp):

1. using System;
2. using UnityEngine;
3. using UnityEngine.Rendering.PostProcessing;
4.  
5. public enum ArithTypeDrawer
6. {
7.     ADDITIVE,
8.     MULTIPLICATION,
9.     POWER
10. }
11. [Serializable]
12. public sealed class ArithTypeParameter : ParameterOverride<ArithTypeDrawer> {}
13.  
14. [PostProcess(typeof(ArithmeticsRenderer), PostProcessEvent.AfterStack, "Hidden/Custom/Arithmetics")]
15.  
16. public sealed class Arithmetics : PostProcessEffectSettings
17. {
18.     public FloatParameter _Constant = new FloatParameter { value = 1f };
19.     public ArithTypeParameter ArithType = new ArithTypeParameter { value = ArithTypeDrawer.Additive };
20. }
21. public sealed class ArithmeticsRenderer : PostProcessEffectRenderer<Arithmetics>
22. {
23.     public override void Render(PostProcessRenderContext context)
24.     {
25.         var sheet = context.propertySheets.Get(Shader.Find("Hidden/Custom/Arithmetics"));
26.         sheet.properties.SetFloat("_Constant", settings._Constant);
27.         if (settings.ArithType == ArithTypeDrawer.ADDITIVE) {
28.             DisableAllKeywords(sheet);
29.             sheet.EnableKeyword("_ARITHMETICS_ADDITIVE");
30.         } else if (settings.ArithType == ArithTypeDrawer.MULTIPLICATION) {
31.             DisableAllKeywords(sheet);
32.             sheet.EnableKeyword("_ARITHMETICS_MULTIPLICATION");
33.         } else if (settings.ArithType == ArithTypeDrawer.POWER) {
34.             DisableAllKeywords(sheet);
35.             sheet.EnableKeyword("_ARITHMETICS_POWER");
36.         }
37.         context.command.BlitFullscreenTriangle(context.source, context.destination, sheet, 0);
38.     }
39.  
40.    void DisableAllKeywords(PropertySheet sheet) {
41.        sheet.DisableKeyword("_ARITHMETICS_ADDITIVE");
42.        sheet.DisableKeyword("_ARITHMETICS_MULTIPLICATION");
43.        sheet.DisableKeyword("_ARITHMETICS_TEST");
44.    }
45. }

Code (CSharp):

1. Shader "Hidden/Custom/Arithmetics"
2. {
3.     HLSLINCLUDE
4.         #include "PostProcessing/Shaders/StdLib.hlsl"
5.  
6.         TEXTURE2D_SAMPLER2D(_MainTex, sampler_MainTex);
7.         float _Constant;
8.         #pragma multi_compile _ARITHMETICS_ADDITIVE _ARITHMETICS_MULTIPLICATION_ARITHMETICS_POWER
9.  
10.         float4 Frag(VaryingsDefault i) : SV_Target
11.         {
12.             #ifdef _ARITHMETICS_ADDITIVE
13.             i.texcoord.x += _Constant;
14.             #elif _ARITHMETICS_MULTIPLICATION
15.             i.texcoord.x *= _Constant + 1;
16.             #elif _ARITHMETICS_POWER
17.             i.texcoord.x = pow(abs(i.texcoord.x), _Constant);
18.             #endif
19.      
20.             return SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.texcoord);
21.         }
22.     ENDHLSL
23.  
24.     SubShader
25.     {
26.         Cull Off ZWrite Off ZTest Always
27.  
28.         Pass
29.         {
30.             HLSLPROGRAM
31.  
32.                 #pragma vertex VertDefault
33.                 #pragma fragment Frag
34.  
35.             ENDHLSL
36.         }
37.     }
38. }

 

On the C# side, System.Enum.GetValues() might help

Code (CSharp):

1.     public override void Render(PostProcessRenderContext context)
2.     {
3.         var sheet = context.propertySheets.Get(Shader.Find("Hidden/Custom/Arithmetics"));
4.         sheet.properties.SetFloat("_Constant", settings._Constant);
5.  
6. //-----------      
7.         var enumValues = System.Enum.GetValues(typeof(ArithTypeDrawer));
8.         foreach (ArithTypeDrawere in enumValues) {
9.             var s = "_ARITHMETICS_" + e.ToString();
10.             if (e == settings.ArithType) {
11.                 sheet.EnableKeyword(s);
12.             } else {
13.                 sheet.DisableKeyword(s);
14.             }
15.         }
16. //-------------
17.      
18.         context.command.BlitFullscreenTriangle(context.source, context.destination, sheet, 0);
19.     }

 

Thanks. It seems it works once I changed foreach (var e in enumValues) { to foreach (ArithTypeDrawer e in enumValues) {.

 

right, the enumValues is Array of object, need to tell the type explicitly
so I changed my code above
from

Code (CSharp):

1. foreach (var in enumValues)

to

Code (CSharp):

1. foreach (ArithTypeDrawere in enumValues)