예제 #1
0
        public void GetKeywordsDeclaration(ShaderStringBuilder builder, GenerationMode mode)
        {
            if (keywords.Count == 0)
            {
                return;
            }

            // Declare keywords
            foreach (var keyword in keywords)
            {
                // Hardcode active keywords in preview to reduce compiled variants
                if (mode == GenerationMode.Preview)
                {
                    string declaration = keyword.GetKeywordPreviewDeclarationString();
                    if (!string.IsNullOrEmpty(declaration))
                    {
                        builder.AppendLine(declaration);
                    }
                }
                else
                {
                    string declaration = keyword.GetKeywordDeclarationString();
                    if (!string.IsNullOrEmpty(declaration))
                    {
                        builder.AppendLine(declaration);
                    }
                }
            }

            // Declare another keyword per permutation for simpler if/defs in the graph code
            builder.AppendNewLine();
            KeywordUtil.GetKeywordPermutationDeclarations(builder, permutations);
            builder.AppendNewLine();
        }
예제 #2
0
        static void GenerateDescriptionForNode(
            AbstractMaterialNode activeNode,
            List <int> keywordPermutations,
            FunctionRegistry functionRegistry,
            ShaderStringBuilder descriptionFunction,
            PropertyCollector shaderProperties,
            KeywordCollector shaderKeywords,
            GraphData graph,
            GenerationMode mode)
        {
            if (activeNode is IGeneratesFunction functionNode)
            {
                functionRegistry.builder.currentNode = activeNode;
                functionNode.GenerateNodeFunction(functionRegistry, mode);
                functionRegistry.builder.ReplaceInCurrentMapping(PrecisionUtil.Token, activeNode.concretePrecision.ToShaderString());
            }

            if (activeNode is IGeneratesBodyCode bodyNode)
            {
                if (keywordPermutations != null)
                {
                    descriptionFunction.AppendLine(KeywordUtil.GetKeywordPermutationSetConditional(keywordPermutations));
                }

                descriptionFunction.currentNode = activeNode;
                bodyNode.GenerateNodeCode(descriptionFunction, mode);
                descriptionFunction.ReplaceInCurrentMapping(PrecisionUtil.Token, activeNode.concretePrecision.ToShaderString());

                if (keywordPermutations != null)
                {
                    descriptionFunction.AppendLine("#endif");
                }
            }

            activeNode.CollectShaderProperties(shaderProperties, mode);

            if (activeNode is SubGraphNode subGraphNode)
            {
                subGraphNode.CollectShaderKeywords(shaderKeywords, mode);
            }
        }
        public static void BuildType(System.Type t, ActiveFields activeFields, ShaderGenerator result, bool isDebug)
        {
            result.AddShaderChunk("struct " + t.Name);
            result.AddShaderChunk("{");
            result.Indent();

            foreach (FieldInfo field in t.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public))
            {
                if (field.MemberType == MemberTypes.Field)
                {
                    bool isOptional = false;

                    var fieldIsActive = false;
                    var keywordIfdefs = string.Empty;

                    if (activeFields.permutationCount > 0)
                    {
                        // Evaluate all activeFields instance
                        var instances = activeFields
                                        .allPermutations.instances
                                        .Where(i => ShouldSpliceField(t, field, i, out isOptional))
                                        .ToList();

                        fieldIsActive = instances.Count > 0;
                        if (fieldIsActive)
                        {
                            keywordIfdefs = KeywordUtil.GetKeywordPermutationSetConditional(instances
                                                                                            .Select(i => i.permutationIndex).ToList());
                        }
                    }
                    else
                    {
                        fieldIsActive = ShouldSpliceField(t, field, activeFields.baseInstance, out isOptional);
                    }


                    if (fieldIsActive)
                    {
                        // The field is used, so generate it
                        var semanticString = GetFieldSemantic(field);
                        int componentCount;
                        var fieldType   = GetFieldType(field, out componentCount);
                        var conditional = GetFieldConditional(field);

                        if (conditional != null)
                        {
                            result.AddShaderChunk("#if " + conditional);
                        }
                        if (!string.IsNullOrEmpty(keywordIfdefs))
                        {
                            result.AddShaderChunk(keywordIfdefs);
                        }

                        var fieldDecl = fieldType + " " + field.Name + semanticString + ";" + (isOptional & isDebug ? " // optional" : string.Empty);
                        result.AddShaderChunk(fieldDecl);

                        if (!string.IsNullOrEmpty(keywordIfdefs))
                        {
                            result.AddShaderChunk("#endif" + (isDebug ? " // Shader Graph Keywords" : string.Empty));
                        }
                        if (conditional != null)
                        {
                            result.AddShaderChunk("#endif" + (isDebug ? $" // {conditional}" : string.Empty));
                        }
                    }
                }
            }
            result.Deindent();
            result.AddShaderChunk("};");

            object[] packAttributes = t.GetCustomAttributes(typeof(InterpolatorPack), false);
            if (packAttributes.Length > 0)
            {
                result.AddNewLine();

                if (activeFields.permutationCount > 0)
                {
                    var generatedPackedTypes = new Dictionary <string, (ShaderGenerator, List <int>)>();
                    foreach (var instance in activeFields.allPermutations.instances)
                    {
                        var instanceGenerator = new ShaderGenerator();
                        BuildPackedType(t, instance, instanceGenerator, isDebug);
                        var key = instanceGenerator.GetShaderString(0);
                        if (generatedPackedTypes.TryGetValue(key, out var value))
                        {
                            value.Item2.Add(instance.permutationIndex);
                        }
                        else
                        {
                            generatedPackedTypes.Add(key, (instanceGenerator, new List <int> {
                                instance.permutationIndex
                            }));
예제 #4
0
        public static bool GenerateShaderPass(AbstractMaterialNode masterNode, ShaderPass pass, GenerationMode mode,
                                              ActiveFields activeFields, ShaderGenerator result, List <string> sourceAssetDependencyPaths,
                                              List <Dependency[]> dependencies, string resourceClassName, string assemblyName)
        {
            // --------------------------------------------------
            // Debug

            // Get scripting symbols
            BuildTargetGroup buildTargetGroup = EditorUserBuildSettings.selectedBuildTargetGroup;
            string           defines          = PlayerSettings.GetScriptingDefineSymbolsForGroup(buildTargetGroup);

            bool isDebug = defines.Contains(kDebugSymbol);

            // --------------------------------------------------
            // Setup

            // Initiailize Collectors
            var propertyCollector = new PropertyCollector();
            var keywordCollector  = new KeywordCollector();

            masterNode.owner.CollectShaderKeywords(keywordCollector, mode);

            // Get upstream nodes from ShaderPass port mask
            List <AbstractMaterialNode> vertexNodes;
            List <AbstractMaterialNode> pixelNodes;

            GetUpstreamNodesForShaderPass(masterNode, pass, out vertexNodes, out pixelNodes);

            // Track permutation indices for all nodes
            List <int>[] vertexNodePermutations = new List <int> [vertexNodes.Count];
            List <int>[] pixelNodePermutations  = new List <int> [pixelNodes.Count];

            // Get active fields from upstream Node requirements
            ShaderGraphRequirementsPerKeyword graphRequirements;

            GetActiveFieldsAndPermutationsForNodes(masterNode, pass, keywordCollector, vertexNodes, pixelNodes,
                                                   vertexNodePermutations, pixelNodePermutations, activeFields, out graphRequirements);

            // GET CUSTOM ACTIVE FIELDS HERE!

            // Get active fields from ShaderPass
            AddRequiredFields(pass.requiredAttributes, activeFields.baseInstance);
            AddRequiredFields(pass.requiredVaryings, activeFields.baseInstance);

            // Get Port references from ShaderPass
            var pixelSlots  = FindMaterialSlotsOnNode(pass.pixelPorts, masterNode);
            var vertexSlots = FindMaterialSlotsOnNode(pass.vertexPorts, masterNode);

            // Function Registry
            var functionBuilder  = new ShaderStringBuilder();
            var functionRegistry = new FunctionRegistry(functionBuilder);

            // Hash table of named $splice(name) commands
            // Key: splice token
            // Value: string to splice
            Dictionary <string, string> spliceCommands = new Dictionary <string, string>();

            // --------------------------------------------------
            // Dependencies

            // Propagate active field requirements using dependencies
            // Must be executed before types are built
            foreach (var instance in activeFields.all.instances)
            {
                ShaderSpliceUtil.ApplyDependencies(instance, dependencies);
            }

            // --------------------------------------------------
            // Pass Setup

            // Name
            if (!string.IsNullOrEmpty(pass.displayName))
            {
                spliceCommands.Add("PassName", $"Name \"{pass.displayName}\"");
            }
            else
            {
                spliceCommands.Add("PassName", "// Name: <None>");
            }

            // Tags
            if (!string.IsNullOrEmpty(pass.lightMode))
            {
                spliceCommands.Add("LightMode", $"\"LightMode\" = \"{pass.lightMode}\"");
            }
            else
            {
                spliceCommands.Add("LightMode", "// LightMode: <None>");
            }

            // Render state
            BuildRenderStatesFromPass(pass, ref spliceCommands);

            // --------------------------------------------------
            // Pass Code

            // Pragmas
            using (var passPragmaBuilder = new ShaderStringBuilder())
            {
                if (pass.pragmas != null)
                {
                    foreach (string pragma in pass.pragmas)
                    {
                        passPragmaBuilder.AppendLine($"#pragma {pragma}");
                    }
                }
                if (passPragmaBuilder.length == 0)
                {
                    passPragmaBuilder.AppendLine("// PassPragmas: <None>");
                }
                spliceCommands.Add("PassPragmas", passPragmaBuilder.ToCodeBlack());
            }

            // Includes
            using (var passIncludeBuilder = new ShaderStringBuilder())
            {
                if (pass.includes != null)
                {
                    foreach (string include in pass.includes)
                    {
                        passIncludeBuilder.AppendLine($"#include \"{include}\"");
                    }
                }
                if (passIncludeBuilder.length == 0)
                {
                    passIncludeBuilder.AppendLine("// PassIncludes: <None>");
                }
                spliceCommands.Add("PassIncludes", passIncludeBuilder.ToCodeBlack());
            }

            // Keywords
            using (var passKeywordBuilder = new ShaderStringBuilder())
            {
                if (pass.keywords != null)
                {
                    foreach (KeywordDescriptor keyword in pass.keywords)
                    {
                        passKeywordBuilder.AppendLine(keyword.ToDeclarationString());
                    }
                }
                if (passKeywordBuilder.length == 0)
                {
                    passKeywordBuilder.AppendLine("// PassKeywords: <None>");
                }
                spliceCommands.Add("PassKeywords", passKeywordBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Graph Vertex

            var vertexBuilder = new ShaderStringBuilder();

            // If vertex modification enabled
            if (activeFields.baseInstance.Contains("features.graphVertex"))
            {
                // Setup
                string vertexGraphInputName       = "VertexDescriptionInputs";
                string vertexGraphOutputName      = "VertexDescription";
                string vertexGraphFunctionName    = "VertexDescriptionFunction";
                var    vertexGraphInputGenerator  = new ShaderGenerator();
                var    vertexGraphFunctionBuilder = new ShaderStringBuilder();
                var    vertexGraphOutputBuilder   = new ShaderStringBuilder();

                // Build vertex graph inputs
                ShaderSpliceUtil.BuildType(GetTypeForStruct("VertexDescriptionInputs", resourceClassName, assemblyName), activeFields, vertexGraphInputGenerator, isDebug);

                // Build vertex graph outputs
                // Add struct fields to active fields
                SubShaderGenerator.GenerateVertexDescriptionStruct(vertexGraphOutputBuilder, vertexSlots, vertexGraphOutputName, activeFields.baseInstance);

                // Build vertex graph functions from ShaderPass vertex port mask
                SubShaderGenerator.GenerateVertexDescriptionFunction(
                    masterNode.owner as GraphData,
                    vertexGraphFunctionBuilder,
                    functionRegistry,
                    propertyCollector,
                    keywordCollector,
                    mode,
                    masterNode,
                    vertexNodes,
                    vertexNodePermutations,
                    vertexSlots,
                    vertexGraphInputName,
                    vertexGraphFunctionName,
                    vertexGraphOutputName);

                // Generate final shader strings
                vertexBuilder.AppendLines(vertexGraphInputGenerator.GetShaderString(0, false));
                vertexBuilder.AppendNewLine();
                vertexBuilder.AppendLines(vertexGraphOutputBuilder.ToString());
                vertexBuilder.AppendNewLine();
                vertexBuilder.AppendLines(vertexGraphFunctionBuilder.ToString());
            }

            // Add to splice commands
            if (vertexBuilder.length == 0)
            {
                vertexBuilder.AppendLine("// GraphVertex: <None>");
            }
            spliceCommands.Add("GraphVertex", vertexBuilder.ToCodeBlack());

            // --------------------------------------------------
            // Graph Pixel

            // Setup
            string pixelGraphInputName       = "SurfaceDescriptionInputs";
            string pixelGraphOutputName      = "SurfaceDescription";
            string pixelGraphFunctionName    = "SurfaceDescriptionFunction";
            var    pixelGraphInputGenerator  = new ShaderGenerator();
            var    pixelGraphOutputBuilder   = new ShaderStringBuilder();
            var    pixelGraphFunctionBuilder = new ShaderStringBuilder();

            // Build pixel graph inputs
            ShaderSpliceUtil.BuildType(GetTypeForStruct("SurfaceDescriptionInputs", resourceClassName, assemblyName), activeFields, pixelGraphInputGenerator, isDebug);

            // Build pixel graph outputs
            // Add struct fields to active fields
            SubShaderGenerator.GenerateSurfaceDescriptionStruct(pixelGraphOutputBuilder, pixelSlots, pixelGraphOutputName, activeFields.baseInstance);

            // Build pixel graph functions from ShaderPass pixel port mask
            SubShaderGenerator.GenerateSurfaceDescriptionFunction(
                pixelNodes,
                pixelNodePermutations,
                masterNode,
                masterNode.owner as GraphData,
                pixelGraphFunctionBuilder,
                functionRegistry,
                propertyCollector,
                keywordCollector,
                mode,
                pixelGraphFunctionName,
                pixelGraphOutputName,
                null,
                pixelSlots,
                pixelGraphInputName);

            using (var pixelBuilder = new ShaderStringBuilder())
            {
                // Generate final shader strings
                pixelBuilder.AppendLines(pixelGraphInputGenerator.GetShaderString(0, false));
                pixelBuilder.AppendNewLine();
                pixelBuilder.AppendLines(pixelGraphOutputBuilder.ToString());
                pixelBuilder.AppendNewLine();
                pixelBuilder.AppendLines(pixelGraphFunctionBuilder.ToString());

                // Add to splice commands
                if (pixelBuilder.length == 0)
                {
                    pixelBuilder.AppendLine("// GraphPixel: <None>");
                }
                spliceCommands.Add("GraphPixel", pixelBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Graph Functions

            if (functionBuilder.length == 0)
            {
                functionBuilder.AppendLine("// GraphFunctions: <None>");
            }
            spliceCommands.Add("GraphFunctions", functionBuilder.ToCodeBlack());

            // --------------------------------------------------
            // Graph Keywords

            using (var keywordBuilder = new ShaderStringBuilder())
            {
                keywordCollector.GetKeywordsDeclaration(keywordBuilder, mode);
                if (keywordBuilder.length == 0)
                {
                    keywordBuilder.AppendLine("// GraphKeywords: <None>");
                }
                spliceCommands.Add("GraphKeywords", keywordBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Graph Properties

            using (var propertyBuilder = new ShaderStringBuilder())
            {
                propertyCollector.GetPropertiesDeclaration(propertyBuilder, mode, masterNode.owner.concretePrecision);
                if (propertyBuilder.length == 0)
                {
                    propertyBuilder.AppendLine("// GraphProperties: <None>");
                }
                spliceCommands.Add("GraphProperties", propertyBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Graph Defines

            using (var graphDefines = new ShaderStringBuilder())
            {
                graphDefines.AppendLine("#define {0}", pass.referenceName);

                if (graphRequirements.permutationCount > 0)
                {
                    List <int> activePermutationIndices;

                    // Depth Texture
                    activePermutationIndices = graphRequirements.allPermutations.instances
                                               .Where(p => p.requirements.requiresDepthTexture)
                                               .Select(p => p.permutationIndex)
                                               .ToList();
                    if (activePermutationIndices.Count > 0)
                    {
                        graphDefines.AppendLine(KeywordUtil.GetKeywordPermutationSetConditional(activePermutationIndices));
                        graphDefines.AppendLine("#define REQUIRE_DEPTH_TEXTURE");
                        graphDefines.AppendLine("#endif");
                    }

                    // Opaque Texture
                    activePermutationIndices = graphRequirements.allPermutations.instances
                                               .Where(p => p.requirements.requiresCameraOpaqueTexture)
                                               .Select(p => p.permutationIndex)
                                               .ToList();
                    if (activePermutationIndices.Count > 0)
                    {
                        graphDefines.AppendLine(KeywordUtil.GetKeywordPermutationSetConditional(activePermutationIndices));
                        graphDefines.AppendLine("#define REQUIRE_OPAQUE_TEXTURE");
                        graphDefines.AppendLine("#endif");
                    }
                }
                else
                {
                    // Depth Texture
                    if (graphRequirements.baseInstance.requirements.requiresDepthTexture)
                    {
                        graphDefines.AppendLine("#define REQUIRE_DEPTH_TEXTURE");
                    }

                    // Opaque Texture
                    if (graphRequirements.baseInstance.requirements.requiresCameraOpaqueTexture)
                    {
                        graphDefines.AppendLine("#define REQUIRE_OPAQUE_TEXTURE");
                    }
                }

                // Add to splice commands
                spliceCommands.Add("GraphDefines", graphDefines.ToCodeBlack());
            }

            // --------------------------------------------------
            // Main

            // Main include is expected to contain vert/frag definitions for the pass
            // This must be defined after all graph code
            using (var mainBuilder = new ShaderStringBuilder())
            {
                mainBuilder.AppendLine($"#include \"{pass.varyingsInclude}\"");
                mainBuilder.AppendLine($"#include \"{pass.passInclude}\"");

                // Add to splice commands
                spliceCommands.Add("MainInclude", mainBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Debug

            // Debug output all active fields

            using (var debugBuilder = new ShaderStringBuilder())
            {
                if (isDebug)
                {
                    // Active fields
                    debugBuilder.AppendLine("// ACTIVE FIELDS:");
                    foreach (string field in activeFields.baseInstance.fields)
                    {
                        debugBuilder.AppendLine("// " + field);
                    }
                }
                if (debugBuilder.length == 0)
                {
                    debugBuilder.AppendLine("// <None>");
                }

                // Add to splice commands
                spliceCommands.Add("Debug", debugBuilder.ToCodeBlack());
            }

            // --------------------------------------------------
            // Finalize

            // Get Template
            string templateLocation = GetTemplatePath("PassMesh.template");

            if (!File.Exists(templateLocation))
            {
                return(false);
            }

            // Get Template preprocessor
            string templatePath         = "Assets/com.unity.render-pipelines.universal/Editor/ShaderGraph/Templates";
            var    templatePreprocessor = new ShaderSpliceUtil.TemplatePreprocessor(activeFields, spliceCommands,
                                                                                    isDebug, templatePath, sourceAssetDependencyPaths, assemblyName, resourceClassName);

            // Process Template
            templatePreprocessor.ProcessTemplateFile(templateLocation);
            result.AddShaderChunk(templatePreprocessor.GetShaderCode().ToString(), false);
            return(true);
        }
예제 #5
0
        // TODO: could get rid of this if we could run a codegen prepass (with proper keyword #ifdef)
        public static void GenerateVirtualTextureFeedback(
            List <AbstractMaterialNode> downstreamNodesIncludingRoot,
            List <int>[] keywordPermutationsPerNode,
            ShaderStringBuilder surfaceDescriptionFunction,
            KeywordCollector shaderKeywords)
        {
            // A note on how we handle vt feedback in combination with keywords:
            // We essentially generate a fully separate feedback path for each permutation of keywords
            // so per permutation we gather variables contribution to feedback and we generate
            // feedback gathering for each permutation individually.

            var feedbackVariablesPerPermutation = PooledList <PooledList <string> > .Get();

            try
            {
                if (shaderKeywords.permutations.Count >= 1)
                {
                    for (int i = 0; i < shaderKeywords.permutations.Count; i++)
                    {
                        feedbackVariablesPerPermutation.Add(PooledList <string> .Get());
                    }
                }
                else
                {
                    // Create a dummy single permutation
                    feedbackVariablesPerPermutation.Add(PooledList <string> .Get());
                }

                int index = 0; //for keywordPermutationsPerNode
                foreach (var node in downstreamNodesIncludingRoot)
                {
                    if (node is SampleVirtualTextureNode vtNode)
                    {
                        if (vtNode.noFeedback)
                        {
                            continue;
                        }
                        if (keywordPermutationsPerNode[index] == null)
                        {
                            Debug.Assert(shaderKeywords.permutations.Count == 0, $"Shader has {shaderKeywords.permutations.Count} permutations but keywordPermutationsPerNode of some nodes are null.");
                            feedbackVariablesPerPermutation[0].Add(vtNode.GetFeedbackVariableName());
                        }
                        else
                        {
                            foreach (int perm in keywordPermutationsPerNode[index])
                            {
                                feedbackVariablesPerPermutation[perm].Add(vtNode.GetFeedbackVariableName());
                            }
                        }
                    }

                    if (node is SubGraphNode sgNode)
                    {
                        if (sgNode.asset == null)
                        {
                            continue;
                        }
                        if (keywordPermutationsPerNode[index] == null)
                        {
                            Debug.Assert(shaderKeywords.permutations.Count == 0, $"Shader has {shaderKeywords.permutations.Count} permutations but keywordPermutationsPerNode of some nodes are null.");
                            foreach (var feedbackSlot in sgNode.asset.vtFeedbackVariables)
                            {
                                feedbackVariablesPerPermutation[0].Add(node.GetVariableNameForNode() + "_" + feedbackSlot);
                            }
                        }
                        else
                        {
                            foreach (var feedbackSlot in sgNode.asset.vtFeedbackVariables)
                            {
                                foreach (int perm in keywordPermutationsPerNode[index])
                                {
                                    feedbackVariablesPerPermutation[perm].Add(node.GetVariableNameForNode() + "_" + feedbackSlot);
                                }
                            }
                        }
                    }

                    index++;
                }

                index = 0;
                foreach (var feedbackVariables in feedbackVariablesPerPermutation)
                {
                    // If it's a dummy single always-on permutation don't put an ifdef around the code
                    if (shaderKeywords.permutations.Count >= 1)
                    {
                        surfaceDescriptionFunction.AppendLine(KeywordUtil.GetKeywordPermutationConditional(index));
                    }

                    using (surfaceDescriptionFunction.BlockScope())
                    {
                        if (feedbackVariables.Count == 0)
                        {
                            string feedBackCode = "surface.VTPackedFeedback = float4(1.0f,1.0f,1.0f,1.0f);";
                            surfaceDescriptionFunction.AppendLine(feedBackCode);
                        }
                        else if (feedbackVariables.Count == 1)
                        {
                            string feedBackCode = "surface.VTPackedFeedback = GetPackedVTFeedback(" + feedbackVariables[0] + ");";
                            surfaceDescriptionFunction.AppendLine(feedBackCode);
                        }
                        else if (feedbackVariables.Count > 1)
                        {
                            surfaceDescriptionFunction.AppendLine("float4 VTFeedback_array[" + feedbackVariables.Count + "];");

                            int arrayIndex = 0;
                            foreach (var variable in feedbackVariables)
                            {
                                surfaceDescriptionFunction.AppendLine("VTFeedback_array[" + arrayIndex + "] = " + variable + ";");
                                arrayIndex++;
                            }

                            // TODO: should read from NDCPosition instead...
                            surfaceDescriptionFunction.AppendLine("uint pixelColumn = (IN.ScreenPosition.x / IN.ScreenPosition.w) * _ScreenParams.x;");
                            surfaceDescriptionFunction.AppendLine(
                                "surface.VTPackedFeedback = GetPackedVTFeedback(VTFeedback_array[(pixelColumn + _FrameCount) % (uint)" + feedbackVariables.Count + "]);");
                        }
                    }

                    if (shaderKeywords.permutations.Count >= 1)
                    {
                        surfaceDescriptionFunction.AppendLine("#endif");
                    }

                    index++;
                }
            }
            finally
            {
                foreach (var list in feedbackVariablesPerPermutation)
                {
                    list.Dispose();
                }
                feedbackVariablesPerPermutation.Dispose();
            }
        }
            private bool ProcessPredicate(Token predicate, int endLine, ref int cur, ref bool appendEndln)
            {
                // eval if(param)
                var fieldName     = predicate.GetString();
                var nonwhitespace = SkipWhitespace(predicate.s, predicate.end + 1, endLine);

                if (!fieldName.StartsWith("features") && activeFields.permutationCount > 0)
                {
                    var passedPermutations = activeFields.allPermutations.instances.Where(i => i.Contains(fieldName)).ToList();

                    if (passedPermutations.Count > 0)
                    {
                        var ifdefs = KeywordUtil.GetKeywordPermutationSetConditional(
                            passedPermutations.Select(i => i.permutationIndex).ToList()
                            );
                        result.AppendLine(ifdefs);
                        //Append the rest of the line
                        AppendSubstring(predicate.s, nonwhitespace, true, endLine, false);
                        result.AppendNewLine();
                        result.AppendLine("#endif");

                        return(false);
                    }
                    else
                    {
                        appendEndln = false; //if line isn't active, remove whitespace
                    }

                    return(false);
                }
                else
                {
                    // eval if(param)
                    if (activeFields.baseInstance.Contains(fieldName))
                    {
                        // predicate is active
                        // append everything before the beginning of the escape sequence
                        AppendSubstring(predicate.s, cur, true, predicate.start - 1, false);

                        // continue parsing the rest of the line, starting with the first nonwhitespace character
                        cur = nonwhitespace;
                        return(true);
                    }
                    else
                    {
                        // predicate is not active
                        if (isDebug)
                        {
                            // append everything before the beginning of the escape sequence
                            AppendSubstring(predicate.s, cur, true, predicate.start - 1, false);
                            // append the rest of the line, commented out
                            result.Append("// ");
                            AppendSubstring(predicate.s, nonwhitespace, true, endLine, false);
                        }
                        else
                        {
                            // don't append anything
                            appendEndln = false;
                        }
                        return(false);
                    }
                }
            }