Files
UShaderLab/Source/UShaderLabBuilder/Public/ShaderLabGraphBuilder.h
2026-07-05 11:26:32 +08:00

62 lines
3.0 KiB
C++

// Copyright UShaderLab. All Rights Reserved.
#pragma once
#include "CoreMinimal.h"
class UMaterial;
struct FShaderLabModel;
/**
* Turns a parsed FShaderLabModel into a UMaterial expression graph: property parameter nodes + a Custom
* HLSL node for the Surface body wired into a Substrate Slab BSDF (-> FrontMaterial), plus an optional
* Vertex Custom node for WPO/displacement/UVs. Lives in the UncookedOnly UShaderLabBuilder module, so it
* runs in the editor AND under `-game` on uncooked data (not in cooked builds — see AIDoc §2.9).
*
* The build is fully deterministic for a given model (node creation order, input/output order,
* generated HLSL) so the cook-time and editor-time graphs — and therefore the baked uniform
* expression set — match.
*/
class USHADERLABBUILDER_API FShaderLabGraphBuilder
{
public:
/**
* Clear `Material`'s expression graph and rebuild it from `Model`, applying settings
* (domain/blend/two-sided) and updating cached expression data. Does NOT trigger shader
* compilation — callers decide when to compile. Returns false with diagnostics on failure.
*/
static bool BuildInto(UMaterial& Material, const FShaderLabModel& Model, TArray<FString>& OutErrors);
/**
* Replace `Material`'s graph with a minimal Substrate material whose single Custom node emits a
* `#line`-mapped `#error` for `Diagnostics`, so it deliberately fails to compile with those messages
* mapped back to `SrcPath` (an absolute, forward-slashed .usl path). This routes .usl parse/build
* errors through the standard shader-compile path — MIC editor red text, GetCompileErrors, cook —
* instead of dropping them. The graph itself is always valid; the failure is intentional and happens
* at shader compile. Does NOT trigger compilation (the caller decides when).
*/
static void BuildPoisonInto(UMaterial& Material, const TArray<FString>& Diagnostics, const FString& SrcPath);
/**
* Resolve a virtual shader path ("/Project/Lib/X.uslfunc", "/Plugin/ShaderLab/...", "/Engine/...") to an
* absolute disk path via the registered shader-source directory mappings (longest-prefix match, exact-root
* allowed). Returns false if no mapping root contains the path. The single canonical reversal of the
* shader-source mappings — used to load `.uslfunc` imports, by the editor hot-reload loader, and by the
* VSCode button. (Forward direction: FShaderLabMaterialRegistry::MakeVirtualShaderPath.)
*/
static bool ResolveVirtualShaderFile(const FString& VirtualPath, FString& OutDiskPath);
/**
* Virtual shader root under which per-shader generated local-code headers live
* (e.g. "/UShaderLabGen"). The editor module maps it to GetGeneratedShaderDir() at startup.
*/
static const TCHAR* GetGeneratedVirtualRoot();
/**
* Absolute disk directory backing GetGeneratedVirtualRoot(): the plugin's
* `Intermediate/ShaderLabGen`. A build-time artifact only (never staged into a pak); the cooked
* runtime never builds graphs and skips the mapping. Empty string if the plugin can't be found.
*/
static FString GetGeneratedShaderDir();
};