static void ProcessSubGraph(SubGraphAsset asset, GraphData graph)
{
var graphIncludes = new IncludeCollection();
var registry = new FunctionRegistry(new ShaderStringBuilder(), graphIncludes, true);
asset.functions.Clear();
asset.isValid = true;
graph.OnEnable();
graph.messageManager.ClearAll();
graph.ValidateGraph();
var assetPath = AssetDatabase.GUIDToAssetPath(asset.assetGuid);
asset.hlslName = NodeUtils.GetHLSLSafeName(Path.GetFileNameWithoutExtension(assetPath));
asset.inputStructName = $"Bindings_{asset.hlslName}_{asset.assetGuid}_$precision";
asset.functionName = $"SG_{asset.hlslName}_{asset.assetGuid}_$precision";
asset.path = graph.path;
var outputNode = graph.outputNode;
var outputSlots = PooledList <MaterialSlot> .Get();
outputNode.GetInputSlots(outputSlots);
List <AbstractMaterialNode> nodes = new List <AbstractMaterialNode>();
NodeUtils.DepthFirstCollectNodesFromNode(nodes, outputNode);
asset.effectiveShaderStage = ShaderStageCapability.All;
foreach (var slot in outputSlots)
{
var stage = NodeUtils.GetEffectiveShaderStageCapability(slot, true);
if (stage != ShaderStageCapability.All)
{
asset.effectiveShaderStage = stage;
break;
}
}
asset.vtFeedbackVariables = VirtualTexturingFeedbackUtils.GetFeedbackVariables(outputNode as SubGraphOutputNode);
asset.requirements = ShaderGraphRequirements.FromNodes(nodes, asset.effectiveShaderStage, false);
// output precision is whatever the output node has as a graph precision, falling back to the graph default
asset.outputGraphPrecision = outputNode.graphPrecision.GraphFallback(graph.graphDefaultPrecision);
// this saves the graph precision, which indicates whether this subgraph is switchable or not
asset.subGraphGraphPrecision = graph.graphDefaultPrecision;
asset.previewMode = graph.previewMode;
asset.includes = graphIncludes;
GatherDescendentsFromGraph(new GUID(asset.assetGuid), out var containsCircularDependency, out var descendents);
asset.descendents.AddRange(descendents.Select(g => g.ToString()));
asset.descendents.Sort(); // ensure deterministic order
var childrenSet = new HashSet <string>();
var anyErrors = false;
foreach (var node in nodes)
{
if (node is SubGraphNode subGraphNode)
{
var subGraphGuid = subGraphNode.subGraphGuid;
childrenSet.Add(subGraphGuid);
}
if (node.hasError)
{
anyErrors = true;
}
asset.children = childrenSet.ToList();
asset.children.Sort(); // ensure deterministic order
}
if (!anyErrors && containsCircularDependency)
{
Debug.LogError($"Error in Graph at {assetPath}: Sub Graph contains a circular dependency.", asset);
anyErrors = true;
}
if (anyErrors)
{
asset.isValid = false;
registry.ProvideFunction(asset.functionName, sb => {});
return;
}
foreach (var node in nodes)
{
if (node is IGeneratesFunction generatesFunction)
{
registry.builder.currentNode = node;
generatesFunction.GenerateNodeFunction(registry, GenerationMode.ForReals);
}
}
// provide top level subgraph function
// NOTE: actual concrete precision here shouldn't matter, it's irrelevant when building the subgraph asset
registry.ProvideFunction(asset.functionName, asset.subGraphGraphPrecision, ConcretePrecision.Single, sb =>
{
GenerationUtils.GenerateSurfaceInputStruct(sb, asset.requirements, asset.inputStructName);
sb.AppendNewLine();
// Generate the arguments... first INPUTS
var arguments = new List <string>();
foreach (var prop in graph.properties)
{
// apply fallback to the graph default precision (but don't convert to concrete)
// this means "graph switchable" properties will use the precision token
GraphPrecision propGraphPrecision = prop.precision.ToGraphPrecision(graph.graphDefaultPrecision);
string precisionString = propGraphPrecision.ToGenericString();
arguments.Add(prop.GetPropertyAsArgumentString(precisionString));
}
// now pass surface inputs
arguments.Add(string.Format("{0} IN", asset.inputStructName));
// Now generate output arguments
foreach (MaterialSlot output in outputSlots)
{
arguments.Add($"out {output.concreteValueType.ToShaderString(asset.outputGraphPrecision.ToGenericString())} {output.shaderOutputName}_{output.id}");
}
// Vt Feedback output arguments (always full float4)
foreach (var output in asset.vtFeedbackVariables)
{
arguments.Add($"out {ConcreteSlotValueType.Vector4.ToShaderString(ConcretePrecision.Single)} {output}_out");
}
// Create the function prototype from the arguments
sb.AppendLine("void {0}({1})"
, asset.functionName
, arguments.Aggregate((current, next) => $"{current}, {next}"));
// now generate the function
using (sb.BlockScope())
{
// Just grab the body from the active nodes
foreach (var node in nodes)
{
if (node is IGeneratesBodyCode generatesBodyCode)
{
sb.currentNode = node;
generatesBodyCode.GenerateNodeCode(sb, GenerationMode.ForReals);
if (node.graphPrecision == GraphPrecision.Graph)
{
// code generated by nodes that use graph precision stays in generic form with embedded tokens
// those tokens are replaced when this subgraph function is pulled into a graph that defines the precision
}
else
{
sb.ReplaceInCurrentMapping(PrecisionUtil.Token, node.concretePrecision.ToShaderString());
}
}
}
foreach (var slot in outputSlots)
{
sb.AppendLine($"{slot.shaderOutputName}_{slot.id} = {outputNode.GetSlotValue(slot.id, GenerationMode.ForReals)};");
}
foreach (var slot in asset.vtFeedbackVariables)
{
sb.AppendLine($"{slot}_out = {slot};");
}
}
});
// save all of the node-declared functions to the subgraph asset
foreach (var name in registry.names)
{
var source = registry.sources[name];
var func = new FunctionPair(name, source.code, source.graphPrecisionFlags);
asset.functions.Add(func);
}
var collector = new PropertyCollector();
foreach (var node in nodes)
{
int previousPropertyCount = Math.Max(0, collector.propertyCount - 1);
node.CollectShaderProperties(collector, GenerationMode.ForReals);
// This is a stop-gap to prevent the autogenerated values from JsonObject and ShaderInput from
// resulting in non-deterministic import data. While we should move to local ids in the future,
// this will prevent cascading shader recompilations.
for (int i = previousPropertyCount; i < collector.propertyCount; ++i)
{
var prop = collector.GetProperty(i);
var namespaceId = node.objectId;
var nameId = prop.referenceName;
prop.OverrideObjectId(namespaceId, nameId + "_ObjectId_" + i);
prop.OverrideGuid(namespaceId, nameId + "_Guid_" + i);
}
}
asset.WriteData(graph.properties, graph.keywords, collector.properties, outputSlots, graph.unsupportedTargets);
outputSlots.Dispose();
}