Add non-SRP versions for all compatible shaders with automated generation and update (#234) (#243)

* Add AssetPostprocessor for generating non-SRP versions ov GraphicsTools shaders. Generate non-SRP shaders

---------

Co-authored-by: OkDan <danylo.okulov@proton.me>

Author: UniversalLanguageAlgorithm

GraphicsToolsUnityProject/Assets/NonSrpShaderAssetGenerator.cs

@@ -0,0 +1,77 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+#define PATCHING_ACTIVE
+using UnityEditor;
+using System.IO;
+using System.Text.RegularExpressions;
+
+public class NonSrpShaderAssetGenerator : AssetPostprocessor
+{
+
+    static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets, string[] movedAssets, string[] movedFromAssetPaths, bool didDomainReload)
+    {
+#if PATCHING_ACTIVE
+        bool assetDBDirty = false;
+        foreach (string str in importedAssets)
+        {
+            if (str.EndsWith(".shader") && !str.EndsWith("NonSrp.shader"))
+            {
+                string resultFile = copyAndPatchShader(str);
+                if (resultFile != null)
+                {
+                    assetDBDirty = true;
+                }
+            }   
+        }
+        if (assetDBDirty) { AssetDatabase.Refresh(); }
+#endif
+    }
+
+    static string copyAndPatchShader(string path)
+    {
+        if (!File.Exists(path)) { return null; }
+
+        bool isPatched = false;
+        
+        string shaderText = File.ReadAllText(path);
+        string sourceDirectory = Path.GetDirectoryName(path);
+        string targetDirectory = sourceDirectory + "/NonSRP";
+
+        // Only work with shaders from Graphics Tools
+        string nameDeclaration = Regex.Match(shaderText, " *Shader *\"Graphics Tools\\/.*\"").Value;
+        if (nameDeclaration.Length <= 0 ) { return null; }
+        
+        string outputPath = Path.Combine( sourceDirectory, Path.GetFileNameWithoutExtension(path) +"NonSrp" +  Path.GetExtension(path));
+        
+        // Put "_NON_SRP" befor StandardProgram include (in Standard and StandardCanvas)
+        MatchCollection matchesStandardProgram = Regex.Matches(shaderText, "(?<tab> *)(#include_with_pragmas \"GraphicsToolsStandardProgram.hlsl\")");
+        if (matchesStandardProgram.Count > 0)
+        {
+            string tab = matchesStandardProgram[1].Groups["tab"].Value;
+            shaderText = Regex.Replace(shaderText, matchesStandardProgram[0].Value,  tab + "#define _NON_SRP\r\n" + matchesStandardProgram[0].Value);
+            isPatched = true;
+        }
+
+        // Remove CBUFFER statements
+        MatchCollection matchCBuff = Regex.Matches(shaderText, " *(CBUFFER_START\\(UnityPerMaterial\\))| *(CBUFFER_END)");
+        if (matchCBuff.Count > 0)
+        {
+            shaderText = Regex.Replace(shaderText, " *(CBUFFER_START\\(UnityPerMaterial\\))| *(CBUFFER_END)", "");
+            isPatched = true;
+        }
+
+        // Rename shader, put it under NonSrp directory, write to file
+        if (isPatched)
+        {
+            Match shaderDirAndName = Regex.Match(nameDeclaration, "(?<dir>.*\\/)(?<name>.*)\"");
+            string newNameDeclaration = shaderDirAndName.Groups["dir"].Value + "Non-SRP/" + shaderDirAndName.Groups["name"].Value + "NonSrp\"" ;
+            shaderText = Regex.Replace(shaderText, nameDeclaration, newNameDeclaration);
+            
+            File.WriteAllText(outputPath, shaderText);
+            return outputPath;
+        }
+        else { return null; }
+
+    }
+
+}