GetShaderVariantsExtention

GetShaderVariantsExtention.cs

/**
MIT License
Copyright (c) 2022 Unity Technologies Japan
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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***/


using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using UnityEngine.Rendering;

namespace UTJ.Sample
{
    public static class GetShaderVariantsExtention
    {
        public static List<ShaderVariantCollection.ShaderVariant> GetVariants(this ShaderVariantCollection collection)
        {
            if(collection == null) { return null; }
            var results = new List<ShaderVariantCollection.ShaderVariant>(collection.variantCount);
            SerializedObject serializedObject = new SerializedObject(collection);
            /* for debug
            var it = serializedObject.GetIterator();
            while (it.NextVisible(true))
            {
                Debug.Log(it.propertyPath + "::" + it.propertyType);
            }
            */
            var shaderProps = serializedObject.FindProperty("m_Shaders");
            if(shaderProps == null)
            {
                Debug.LogError("m_Shaders not found!!");
                return null;
            }
            for(int i = 0;i< shaderProps.arraySize; ++i)
            {
                var shaderProp = shaderProps.GetArrayElementAtIndex(i);
                var shaderObjProp = shaderProp.FindPropertyRelative("first");
                if(shaderObjProp == null)
                {
                    Debug.LogError("m_Shaders[x].first not found!!");
                    continue;
                }
                
                var shaderObj = shaderObjProp.objectReferenceValue as Shader;

                var variantProps = shaderProp.FindPropertyRelative("second.variants");

                if (variantProps == null)
                {
                    Debug.LogError("m_Shaders[x].second.variants not found!!");
                    continue;
                }
                for(int j =0;j< variantProps.arraySize; ++j)
                {
                    var variantProp = variantProps.GetArrayElementAtIndex(j);
                    var passTypeProp = variantProp.FindPropertyRelative("passType");
                    var keywordProp = variantProp.FindPropertyRelative("keywords");

                    if (passTypeProp == null)
                    {
                        Debug.LogError("m_Shaders[x].second.variants[y].passType not found!!");
                        continue;
                    }
                    if (keywordProp == null)
                    {
                        Debug.LogError("m_Shaders[x].second.variants[y].keywords not found!!");
                        continue;
                    }

                    var keyword = keywordProp.stringValue;
                    var passType = (PassType)passTypeProp.intValue;

                    //Debug.Log(shaderObj + "::" + passType + "::" + keyword);
                    try
                    {
                        var variant = new ShaderVariantCollection.ShaderVariant(shaderObj, passType, ConvertKeywords(keyword));
                        results.Add(variant);
                    }catch(System.Exception e)
                    {
                        Debug.LogError(e);
                    }
                }
            }

            return results;
        }
        private static string[] ConvertKeywords(string keyword)
        {
            if(string.IsNullOrEmpty(keyword))
            {
                return new string[0];
            }
            var split = keyword.Split(' ');
            return split;
        }
    }
}