DynamicMeshBuilder.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
/*=============================================================================
    DynamicMeshBuilder.h: Dynamic mesh builder definitions.
=============================================================================*/
 
#pragma once
 
#include "Components.h"
#include "CoreMinimal.h"
#include "PackedNormal.h"
#include "HitProxies.h"
#include "RenderResource.h"
#include "RenderUtils.h"
#include "RenderMath.h"
 
class FMaterialRenderProxy;
class FMeshBuilderOneFrameResources;
class FMeshElementCollector;
class FPrimitiveDrawInterface;
class FPrimitiveUniformShaderParameters;
struct FMeshBatch;
 
struct FDynamicMeshVertex
{
    FDynamicMeshVertex() {}
    FDynamicMeshVertex( const FVector3f& InPosition ):
        Position(InPosition),
        TangentX(FVector3f(1,0,0)),
        TangentZ(FVector3f(0,0,1)),
        Color(FColor(255,255,255)) 
    {
        // basis determinant default to +1.0
        TangentZ.Vector.W = 127;
 
        for (int i = 0; i < MAX_STATIC_TEXCOORDS; i++)
        {
            TextureCoordinate[i] = FVector2f::ZeroVector;
        }
    }
 
    FDynamicMeshVertex(const FVector3f& InPosition, const FVector2f& InTexCoord, const FColor& InColor) :
        Position(InPosition),
        TangentX(FVector3f(1, 0, 0)),
        TangentZ(FVector3f(0, 0, 1)),
        Color(InColor)
    {
        // basis determinant default to +1.0
        TangentZ.Vector.W = 127;
 
        for (int i = 0; i < MAX_STATIC_TEXCOORDS; i++)
        {
            TextureCoordinate[i] = InTexCoord;
        }
    }
 
    FDynamicMeshVertex(const FVector3f& InPosition,const FVector3f& InTangentX,const FVector3f& InTangentZ,const FVector2f& InTexCoord, const FColor& InColor):
        Position(InPosition),
        TangentX(InTangentX),
        TangentZ(InTangentZ),
        Color(InColor)
    {
        // basis determinant default to +1.0
        TangentZ.Vector.W = 127;
 
        for (int i = 0; i < MAX_STATIC_TEXCOORDS; i++)
        {
            TextureCoordinate[i] = InTexCoord;
        }
    }
 
    FDynamicMeshVertex(const FVector3f& InPosition, const FVector3f& LayerTexcoords, const FVector2f& WeightmapTexcoords)
        : Position(InPosition)
        , TangentX(FVector3f(1, 0, 0))
        , TangentZ(FVector3f(0, 0, 1))
        , Color(FColor::White)
    {
        // TangentZ.w contains the sign of the tangent basis determinant. Assume +1
        TangentZ.Vector.W = 127;
 
        TextureCoordinate[0] = FVector2f(LayerTexcoords.X, LayerTexcoords.Y);
        TextureCoordinate[1] = FVector2f(LayerTexcoords.X, LayerTexcoords.Y); // Z not currently set, so use Y
        TextureCoordinate[2] = FVector2f(LayerTexcoords.Y, LayerTexcoords.X); // Z not currently set, so use X
        TextureCoordinate[3] = WeightmapTexcoords;
    };
 
    void SetTangents( const FVector3f& InTangentX, const FVector3f& InTangentY, const FVector3f& InTangentZ )
    {
        TangentX = InTangentX;
        TangentZ = InTangentZ;
        // store determinant of basis in w component of normal vector
        TangentZ.Vector.W = GetBasisDeterminantSignByte(InTangentX,InTangentY,InTangentZ);
    }
 
    FVector3f GetTangentY() const
    {
        return FVector3f(GenerateYAxis(TangentX, TangentZ));    //LWC_TODO: Precision loss
    };
 
    FVector3f Position;
    FVector2f TextureCoordinate[MAX_STATIC_TEXCOORDS];
    FPackedNormal TangentX;
    FPackedNormal TangentZ;
    FColor Color;
};
 
struct FDynamicMeshDrawOffset
{
    uint32 FirstIndex = 0;
    uint32 MinVertexIndex = 0;
    uint32 MaxVertexIndex = 0;
    uint32 NumPrimitives = 0;
};
 
struct FDynamicMeshBuilderSettings
{
    bool CastShadow = true;
    bool bDisableBackfaceCulling = false;
    bool bWireframe = false;
    bool bReceivesDecals = true;
    bool bUseSelectionOutline = true;
    bool bCanApplyViewModeOverrides = false;
    bool bUseWireframeSelectionColoring = false;
    bool bIsFirstPerson = false;
};
 
class FDynamicMeshBufferAllocator
{
public:
    ENGINE_API int32 GetIndexBufferSize(uint32 NumElements) const;
    ENGINE_API int32 GetVertexBufferSize(uint32 Stride, uint32 NumElements) const;
    ENGINE_API virtual ~FDynamicMeshBufferAllocator();
 
    ENGINE_API virtual FBufferRHIRef AllocIndexBuffer(FRHICommandListBase& RHICmdList, uint32 NumElements);
    ENGINE_API virtual void ReleaseIndexBuffer(FBufferRHIRef& IndexBufferRHI);
    ENGINE_API virtual FBufferRHIRef AllocVertexBuffer(FRHICommandListBase& RHICmdList, uint32 Stride, uint32 NumElements);
    ENGINE_API virtual void ReleaseVertexBuffer(FBufferRHIRef& VertexBufferRHI);
 
    UE_DEPRECATED(5.4, "AllocIndexBuffer requires a command list.")
    ENGINE_API virtual FBufferRHIRef AllocIndexBuffer(uint32 NumElements) final;
 
    UE_DEPRECATED(5.4, "AllocVertexBuffer requires a command list.")
    ENGINE_API virtual FBufferRHIRef AllocVertexBuffer(uint32 Stride, uint32 NumElements) final;
};
 
class FDynamicMeshBuilder
{
public:
 
    ENGINE_API FDynamicMeshBuilder(ERHIFeatureLevel::Type InFeatureLevel, uint32 InNumTexCoords = 1, uint32 InLightmapCoordinateIndex = 0, bool InUse16bitTexCoord = false, FDynamicMeshBufferAllocator* InDynamicMeshBufferAllocator = nullptr);
 
    ENGINE_API ~FDynamicMeshBuilder();
 
    ENGINE_API int32 AddVertex(
        const FVector3f& InPosition,
        const FVector2f& InTextureCoordinate,
        const FVector3f& InTangentX,
        const FVector3f& InTangentY,
        const FVector3f& InTangentZ,
        const FColor& InColor
        );
 
    ENGINE_API int32 AddVertex(const FDynamicMeshVertex &InVertex);
 
    ENGINE_API void AddTriangle(int32 V0,int32 V1,int32 V2);
 
    ENGINE_API int32 AddVertices(const TArray<FDynamicMeshVertex> &InVertices);
 
    ENGINE_API void AddTriangles(const TArray<uint32> &InIndices);
 
    ENGINE_API void ReserveVertices(int32 InNumVertices);
 
    ENGINE_API void ReserveTriangles(int32 InNumTriangles);
 
    ENGINE_API void GetMesh(const FMatrix& LocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, bool bDisableBackfaceCulling, bool bReceivesDecals, int32 ViewIndex, FMeshElementCollector& Collector);
    ENGINE_API void GetMesh(const FMatrix& LocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, bool bDisableBackfaceCulling, bool bReceivesDecals, bool bUseSelectionOutline, int32 ViewIndex, 
                            FMeshElementCollector& Collector, HHitProxy* HitProxy);
    ENGINE_API void GetMesh(const FMatrix& LocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, bool bDisableBackfaceCulling, bool bReceivesDecals, bool bUseSelectionOutline, int32 ViewIndex, 
                            FMeshElementCollector& Collector, const FHitProxyId HitProxyId = FHitProxyId());
    ENGINE_API void GetMesh(const FMatrix& LocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, const FDynamicMeshBuilderSettings& Settings, FDynamicMeshDrawOffset const * const DrawOffset, int32 ViewIndex,
        FMeshElementCollector& Collector, const FHitProxyId HitProxyId = FHitProxyId());
    ENGINE_API void GetMesh(const FMatrix& LocalToWorld, const FMatrix& PrevLocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, const FDynamicMeshBuilderSettings& Settings,
        FDynamicMeshDrawOffset const * const DrawOffset, int32 ViewIndex, FMeshElementCollector& Collector, const FHitProxyId HitProxyId = FHitProxyId());
 
    ENGINE_API void GetMeshElement(const FMatrix& LocalToWorld, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, bool bDisableBackfaceCulling, bool bReceivesDecals, int32 ViewIndex, FMeshBuilderOneFrameResources& OneFrameResource, FMeshBatch& Mesh);
    ENGINE_API void GetMeshElement(const FPrimitiveUniformShaderParameters& PrimitiveParams, const FMaterialRenderProxy* MaterialRenderProxy, uint8 DepthPriorityGroup, bool bDisableBackfaceCulling, int32 ViewIndex, FMeshBuilderOneFrameResources& OneFrameResource, FMeshBatch& Mesh);
 
    ENGINE_API void Draw(FPrimitiveDrawInterface* PDI,const FMatrix& LocalToWorld,const FMaterialRenderProxy* MaterialRenderProxy,uint8 DepthPriorityGroup,bool bDisableBackfaceCulling=false, bool bReceivesDecals=true, const FHitProxyId HitProxyId = FHitProxyId());
 
private:
    class FMeshBuilderOneFrameResources* OneFrameResources = nullptr;
    class FPooledDynamicMeshIndexBuffer* IndexBuffer = nullptr;
    class FPooledDynamicMeshVertexBuffer* VertexBuffer = nullptr;
    ERHIFeatureLevel::Type FeatureLevel;
    FDynamicMeshBufferAllocator* DynamicMeshBufferAllocator;
};
 
class FDynamicMeshIndexBuffer32 : public FIndexBuffer
{
public:
    ENGINE_API FDynamicMeshIndexBuffer32();
    ENGINE_API virtual ~FDynamicMeshIndexBuffer32();
 
    TArray<uint32> Indices;
    EBufferUsageFlags UsageFlags = EBufferUsageFlags::Static;
 
    ENGINE_API virtual void InitRHI(FRHICommandListBase& RHICmdList) override;
};
 
class FDynamicMeshIndexBuffer16 : public FIndexBuffer
{
public:
    ENGINE_API FDynamicMeshIndexBuffer16();
    ENGINE_API virtual ~FDynamicMeshIndexBuffer16();
 
    TArray<uint16> Indices;
    EBufferUsageFlags UsageFlags = EBufferUsageFlags::Static;
 
    ENGINE_API virtual void InitRHI(FRHICommandListBase& RHICmdList) override;
};
 
#if UE_ENABLE_INCLUDE_ORDER_DEPRECATED_IN_5_6
#include "LocalVertexFactory.h"
#endif