プロジェクト内にあるShaderVariantCollectionにないKeywordはビルドに含まないようにするEditor拡張です

StrippingByVariantCollection.cs

/*
MIT License
Copyright (c) 2020 Yusuke Kurokawa
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

// どのデータが書き出されたかデバッグ用にお使いください。
// #define DEBUG_LOG_STRIPPING_VARIANT

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


public class StrippingByVariantCollection : IPreprocessShaders
{
    private List<ShaderVariantsInfo> shaderVariants;

    private class SortShaderKeyword : IComparer<ShaderKeyword>
    {
        public int Compare(ShaderKeyword x, ShaderKeyword y)
        {
            return x.GetKeywordName().CompareTo(y.GetKeywordName());
        }
    }

    public struct ShaderVariantsInfo
    {
        public Shader shader;
        public PassType passType;
        public string[] keywords;
        private List<ShaderKeyword> keywordInfos;

        public List<string> keywordsForCheck;

        public ShaderVariantsInfo(Shader sh, PassType pass, string[] words)
        {
            this.shader = sh;
            this.passType = pass;
            this.keywords = words;
            this.keywordInfos = new List<ShaderKeyword>(words.Length);
            for( int i = 0; i < words.Length; ++i)
            {
                if (string.IsNullOrEmpty(words[i]) ) { continue; }
                ShaderKeyword shKeyword = null;
#if UNITY_2019_OR_NEWER
                shKeyword = new ShaderKeyword(sh,words[i]);
                keywordInfos.Add(  new ShaderKeyword(sh,words[i]) );
#else
                shKeyword = new ShaderKeyword(words[i]);
#endif
                keywordInfos.Add(shKeyword);
            }
            keywordsForCheck = new List<string>();
            foreach( var keywordInfo in keywordInfos)
            {
                if ( !string.IsNullOrEmpty(keywordInfo.GetKeywordName()) && 
                    keywordInfo.GetKeywordType() != ShaderKeywordType.BuiltinAutoStripped ){
                    keywordsForCheck.Add(keywordInfo.GetKeywordName());
                }
            }
            keywordsForCheck.Sort();
        }
    }

#if DEBUG_LOG_STRIPPING_VARIANT
    private const string SaveDirectory = "ShaderVariants";

    private string dateTimeStr;

    private StringBuilder includeVariantsBuffer = new StringBuilder(1024);
    private StringBuilder excludeVariantsBuffer = new StringBuilder(1024);
    private StringBuilder shaderKeywordBuffer0 = new StringBuilder();
    private StringBuilder shaderKeywordBuffer1 = new StringBuilder();
    private StringBuilder projectVaritantsBuffer = new StringBuilder();

    private struct ShaderInfoData
    {
        public Shader shader;
        public ShaderSnippetData snippetData;

        public ShaderInfoData(Shader sh, ShaderSnippetData data)
        {
            this.shader = sh;
            this.snippetData = data;
        }
        public override int GetHashCode()
        {
            return this.shader.name.GetHashCode() + this.snippetData.passName.GetHashCode() +
                this.snippetData.passType.GetHashCode() + this.snippetData.shaderType.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            ShaderInfoData data = (ShaderInfoData)obj;
            if (data.shader != this.shader)
            {
                return false;
            }
            if (this.snippetData.passName == data.snippetData.passName &&
               this.snippetData.passType == data.snippetData.passType &&
               this.snippetData.shaderType == data.snippetData.shaderType)
            {
                return true;
            }

            return false;
        }
    }

    private HashSet<ShaderInfoData> alreadyWriteShader = new HashSet<ShaderInfoData>();
#endif

    public StrippingByVariantCollection()
    {
        Initialize();
    }

    private void Initialize() { 
        var variantCollections = GetProjectShaderVariantCollections();
        this.shaderVariants = new List<ShaderVariantsInfo>();
        foreach (var variantCollection in variantCollections)
        {
            CollectVariants(this.shaderVariants, variantCollection);
        }
#if DEBUG_LOG_STRIPPING_VARIANT
        this.InitData();
        this.SaveProjectVaraiants();

#endif
    }

    private static List<ShaderVariantCollection> GetProjectShaderVariantCollections()
    {
        List<ShaderVariantCollection> collections = new List<ShaderVariantCollection>();
        var guids = AssetDatabase.FindAssets("t: ShaderVariantCollection");
        foreach (var guid in guids)
        {
            var path = AssetDatabase.GUIDToAssetPath(guid);
            var obj = AssetDatabase.LoadAssetAtPath<ShaderVariantCollection>(path);
            if (obj != null)
            {
                collections.Add(obj);
            }
        }
        return collections;
    }

    private void CollectVariants(List<ShaderVariantsInfo> shaderVariants,
        ShaderVariantCollection variantCollection)
    {
        var obj = new SerializedObject(variantCollection);
        var shadersProp = obj.FindProperty("m_Shaders");
        for (int i = 0; i < shadersProp.arraySize; ++i)
        {
            var shaderProp = shadersProp.GetArrayElementAtIndex(i);
            var shader = shaderProp.FindPropertyRelative("first").objectReferenceValue as Shader;

            var variantsProp = shaderProp.FindPropertyRelative("second.variants");
            CollectVariants(shaderVariants, shader, variantsProp);
        }
    }

    private void CollectVariants(List<ShaderVariantsInfo> shaderVariants, Shader shader, SerializedProperty variantsProp)
    {
        for (int i = 0; i < variantsProp.arraySize; ++i)
        {
            var variantProp = variantsProp.GetArrayElementAtIndex(i);
            var keywords = variantProp.FindPropertyRelative("keywords").stringValue;
            var passType = variantProp.FindPropertyRelative("passType").intValue;

            string[] keywordsArray = null;
            if (keywords != null)
            {
                keywords = keywords.Trim();
            }
            if (string.IsNullOrEmpty(keywords))
            {
                keywordsArray = new string[] { "" };
            }
            else
            {
                keywordsArray = keywords.Split(' ');
            }
            ShaderVariantsInfo variant = new ShaderVariantsInfo(shader, (PassType)passType, keywordsArray);
            shaderVariants.Add(variant);
        }
    }


    private bool IsExistShader(List<ShaderVariantsInfo> shaderVariants, Shader shader)
    {
        foreach (var variant in shaderVariants)
        {
            if (variant.shader == shader)
            {
                return true;
            }
        }
        return false;
    }

    private bool IsExist(List<ShaderVariantsInfo> shaderVariants,
        Shader shader, ShaderSnippetData snippet, ShaderCompilerData data)
    {
        var keywords = data.shaderKeywordSet.GetShaderKeywords();
        var compiledKeyword = Convert(keywords);

        if (compiledKeyword.Count == 0)
        {
            return true;
        }
        foreach (var variant in shaderVariants)
        {
            if (variant.shader != shader)
            {
                continue;
            }
            if (variant.passType != snippet.passType)
            {
                continue;
            }
            if (IsMatch(variant.keywordsForCheck, compiledKeyword))
            {
                return true;
            }
        }
        return false;
    }

    private bool IsMatch(List<string> a, List<string> b)
    {
        if (a.Count != b.Count) { return false; }

        for (int i = 0; i < a.Count; ++i)
        {
            if (a[i] != b[i]) { return false; }
        }
        return true;
    }
    private List<string> Convert(ShaderKeyword[] keywords)
    {
        List<string> converted = new List<string>(keywords.Length);
        for (int i = 0; i < keywords.Length; ++i)
        {
            if (!string.IsNullOrEmpty(keywords[i].GetKeywordName()) &&
                keywords[i].GetKeywordType() != ShaderKeywordType.BuiltinAutoStripped)
            {
                converted.Add(keywords[i].GetKeywordName());
            }
        }
        converted.Sort();
        return converted;
    }

    public int callbackOrder
    {
        get
        {
            return 0;
        }
    }

    public void OnProcessShader(Shader shader, ShaderSnippetData snippet, IList<ShaderCompilerData> shaderCompilerData)
    {
#if DEBUG_LOG_STRIPPING_VARIANT
        this.includeVariantsBuffer.Length = 0;
        this.excludeVariantsBuffer.Length = 0;
#endif
        bool isExistShader = IsExistShader(this.shaderVariants, shader);
        for (int i = 0; i < shaderCompilerData.Count; ++i)
        {
            bool shouldRemove = false;
            if (isExistShader)
            {
                bool isExists = IsExist(this.shaderVariants, shader, snippet, shaderCompilerData[i]);
                shouldRemove = !isExists;
            }
#if DEBUG_LOG_STRIPPING_VARIANT

            if (shouldRemove)
            {
                AppendShaderInfo(excludeVariantsBuffer, shader, snippet, shaderCompilerData[i]);
            }
            else
            {
                AppendShaderInfo(includeVariantsBuffer, shader, snippet, shaderCompilerData[i]);
            }
#endif

            if (shouldRemove)
            {
                shaderCompilerData.RemoveAt(i);
                --i;
            }
        }
#if DEBUG_LOG_STRIPPING_VARIANT
        var data = new ShaderInfoData(shader, snippet);
        if (!alreadyWriteShader.Contains(data))
        {
            SaveResult(shader, snippet);
            alreadyWriteShader.Add(data);
        }
#endif
    }





#if DEBUG_LOG_STRIPPING_VARIANT

    private void InitData()
    {
        var dateTime = System.DateTime.Now;
        this.dateTimeStr = dateTime.ToString("yyyyMMdd_HHmmss");
        alreadyWriteShader.Clear();
    }

    private void SaveProjectVaraiants()
    {
        var list = new List<ShaderVariantsInfo>(shaderVariants);
        list.Sort((a, b) =>
        {
            int shaderName = a.shader.name.CompareTo(b.shader.name);
            if (shaderName != 0)
            {
                return shaderName;
            }

            int passType = a.passType - b.passType;
            if (passType != 0)
            {
                return passType;
            }

            int keywordLengthVal = a.keywords.Length - b.keywords.Length;
            if (keywordLengthVal != 0)
            {
                return keywordLengthVal;
            }

            shaderKeywordBuffer0.Length = 0;
            shaderKeywordBuffer1.Length = 0;

            foreach (var keyword in a.keywords)
            {
                shaderKeywordBuffer0.Append(keyword).Append(" ");
            }
            foreach (var keyword in b.keywords)
            {
                shaderKeywordBuffer1.Append(keyword).Append(" ");
            }

            return shaderKeywordBuffer0.ToString().CompareTo(shaderKeywordBuffer1.ToString());
        });

        string shName = null;
        foreach (var variant in list)
        {
            if (shName != variant.shader.name)
            {
                projectVaritantsBuffer.Append(variant.shader.name);
                projectVaritantsBuffer.Append("\n");
                shName = variant.shader.name;
            }
            projectVaritantsBuffer.Append(" type:").
                Append(variant.passType).Append("\n").Append(" keyword:");
            foreach (var keyword in variant.keywords)
            {
                projectVaritantsBuffer.Append(keyword).Append(" ");
            }
            projectVaritantsBuffer.Append("\n\n");
        }

        string dir = SaveDirectory + "/" + dateTimeStr;
        if (!System.IO.Directory.Exists(dir))
        {
            System.IO.Directory.CreateDirectory(dir);
        }
        System.IO.File.WriteAllText(dir + "/ProjectVariants.txt", projectVaritantsBuffer.ToString());
    }

    private void SaveResult(Shader shader, ShaderSnippetData snippet)
    {
        string shaderName = shader.name.Replace("/", "_");
        string includeDir = SaveDirectory + "/" + dateTimeStr+ "/Include/" + shaderName;
        string excludeDir = SaveDirectory + "/" + dateTimeStr + "/Exclude/" + shaderName;
        string name = shaderName + "_" + snippet.shaderType.ToString() + "_" + snippet.passName + "_" + snippet.passType;

        if (includeVariantsBuffer.Length != 0)
        {
            if (!System.IO.Directory.Exists(includeDir))
            {
                System.IO.Directory.CreateDirectory(includeDir);
            }
            System.IO.File.WriteAllText(System.IO.Path.Combine(includeDir, name) + ".txt", includeVariantsBuffer.ToString());
        }
        if (excludeVariantsBuffer.Length != 0)
        {
            if (!System.IO.Directory.Exists(excludeDir))
            {
                System.IO.Directory.CreateDirectory(excludeDir);
            }
            System.IO.File.WriteAllText(System.IO.Path.Combine(excludeDir, name) + ".txt", excludeVariantsBuffer.ToString());
        }
    }

    private void AppendShaderInfo(StringBuilder sb, Shader shader, ShaderSnippetData snippet, ShaderCompilerData compilerData)
    {
        if (sb.Length == 0)
        {
            sb.Append("Shader:" + shader.name).Append("\n");
            sb.Append("ShaderType:").Append(snippet.shaderType).Append("\n").
                Append("PassName:").Append(snippet.passName).Append("\n").
                Append("PassType:").Append(snippet.passType).Append("\n\n");
        }

        var keywords = compilerData.shaderKeywordSet.GetShaderKeywords();

        var sortKeywords = new ShaderKeyword[keywords.Length];
        for( int i = 0; i < keywords.Length; ++i)
        {
            sortKeywords[i] = keywords[i];
        }
        System.Array.Sort(sortKeywords, new SortShaderKeyword());
        sb.Append(" Keyword:");
        foreach (var keyword in sortKeywords)
        {
            sb.Append(keyword.GetKeywordName()).Append(" ");
        }
        sb.Append("\n KeywordType:");
        foreach (var keyword in sortKeywords)
        {
            sb.Append(keyword.GetKeywordType()).Append(" ");
        }
        sb.Append("\n").Append("\n");
    }


#endif

}