C++ FPoly::Init方法代码示例

//
// Build an FPoly representing an "infinite" plane (which exceeds the maximum
// dimensions of the world in all directions) for a particular Bsp node.
//
FPoly FBSPOps::BuildInfiniteFPoly( UModel* Model, int32 iNode )
{
	FBspNode &Node   = Model->Nodes  [iNode       ];
	FBspSurf &Poly   = Model->Surfs  [Node.iSurf  ];
	FVector  Base    = Poly.Plane * Poly.Plane.W;
	FVector  Normal  = Poly.Plane;
	FVector	 Axis1,Axis2;

	// Find two non-problematic axis vectors.
	Normal.FindBestAxisVectors( Axis1, Axis2 );

	// Set up the FPoly.
	FPoly EdPoly;
	EdPoly.Init();
	EdPoly.Normal      = Normal;
	EdPoly.Base        = Base;
	new(EdPoly.Vertices) FVector(Base + Axis1*WORLD_MAX + Axis2*WORLD_MAX);
	new(EdPoly.Vertices) FVector(Base - Axis1*WORLD_MAX + Axis2*WORLD_MAX);
	new(EdPoly.Vertices) FVector(Base - Axis1*WORLD_MAX - Axis2*WORLD_MAX);
	new(EdPoly.Vertices) FVector(Base + Axis1*WORLD_MAX - Axis2*WORLD_MAX);

	return EdPoly;
}

int32 FPoly::Triangulate( ABrush* InOwnerBrush, TArray<FPoly>& OutTriangles )
{
#if WITH_EDITOR

    if( Vertices.Num() < 3 )
    {
        return 0;
    }

    FClipSMPolygon Polygon(0);

    for( int32 v = 0 ; v < Vertices.Num() ; ++v )
    {
        FClipSMVertex vtx;
        vtx.Pos = Vertices[v];

        // Init other data so that VertsAreEqual won't compare garbage
        vtx.TangentX = FVector::ZeroVector;
        vtx.TangentY = FVector::ZeroVector;
        vtx.TangentZ = FVector::ZeroVector;
        vtx.Color = FColor(0, 0, 0);
        for( int32 uvIndex=0; uvIndex<ARRAY_COUNT(vtx.UVs); ++uvIndex )
        {
            vtx.UVs[uvIndex] = FVector2D(0.f, 0.f);
        }


        Polygon.Vertices.Add( vtx );
    }

    Polygon.FaceNormal = Normal;

    // Attempt to triangulate this polygon
    TArray<FClipSMTriangle> Triangles;
    if( TriangulatePoly( Triangles, Polygon ) )
    {
        // Create a set of FPolys from the triangles

        OutTriangles.Empty();
        FPoly TrianglePoly;

        for( int32 p = 0 ; p < Triangles.Num() ; ++p )
        {
            FClipSMTriangle* tri = &(Triangles[p]);

            TrianglePoly.Init();
            TrianglePoly.Base = tri->Vertices[0].Pos;

            TrianglePoly.Vertices.Add( tri->Vertices[0].Pos );
            TrianglePoly.Vertices.Add( tri->Vertices[1].Pos );
            TrianglePoly.Vertices.Add( tri->Vertices[2].Pos );

            if( TrianglePoly.Finalize( InOwnerBrush, 0 ) == 0 )
            {
                OutTriangles.Add( TrianglePoly );
            }
        }
    }

#endif

    return OutTriangles.Num();
}

int32 GenerateKDopAsSimpleCollision(UStaticMesh* StaticMesh, const TArray<FVector> &Dirs)
{
	// Make sure rendering is done - so we are not changing data being used by collision drawing.
	FlushRenderingCommands();

	if (!PromptToRemoveExistingCollision(StaticMesh))
	{
		return INDEX_NONE;
	}

	UBodySetup* bs = StaticMesh->BodySetup;

	// Do k- specific stuff.
	int32 kCount = Dirs.Num();
	TArray<float> maxDist;
	for(int32 i=0; i<kCount; i++)
		maxDist.Add(-MY_FLTMAX);

	// Construct temporary UModel for kdop creation. We keep no refs to it, so it can be GC'd.
	auto TempModel = NewObject<UModel>();
	TempModel->Initialize(nullptr, 1);

	// For each vertex, project along each kdop direction, to find the max in that direction.
	const FStaticMeshLODResources& RenderData = StaticMesh->RenderData->LODResources[0];
	for(int32 i=0; i<RenderData.GetNumVertices(); i++)
	{
		for(int32 j=0; j<kCount; j++)
		{
			float dist = RenderData.PositionVertexBuffer.VertexPosition(i) | Dirs[j];
			maxDist[j] = FMath::Max(dist, maxDist[j]);
		}
	}

	// Inflate kdop to ensure it is no degenerate
	const float MinSize = 0.1f;
	for(int32 i=0; i<kCount; i++)
	{
		maxDist[i] += MinSize;
	}

	// Now we have the planes of the kdop, we work out the face polygons.
	TArray<FPlane> planes;
	for(int32 i=0; i<kCount; i++)
		planes.Add( FPlane(Dirs[i], maxDist[i]) );

	for(int32 i=0; i<planes.Num(); i++)
	{
		FPoly*	Polygon = new(TempModel->Polys->Element) FPoly();
		FVector Base, AxisX, AxisY;

		Polygon->Init();
		Polygon->Normal = planes[i];
		Polygon->Normal.FindBestAxisVectors(AxisX,AxisY);

		Base = planes[i] * planes[i].W;

		new(Polygon->Vertices) FVector(Base + AxisX * HALF_WORLD_MAX + AxisY * HALF_WORLD_MAX);
		new(Polygon->Vertices) FVector(Base + AxisX * HALF_WORLD_MAX - AxisY * HALF_WORLD_MAX);
		new(Polygon->Vertices) FVector(Base - AxisX * HALF_WORLD_MAX - AxisY * HALF_WORLD_MAX);
		new(Polygon->Vertices) FVector(Base - AxisX * HALF_WORLD_MAX + AxisY * HALF_WORLD_MAX);

		for(int32 j=0; j<planes.Num(); j++)
		{
			if(i != j)
			{
				if(!Polygon->Split(-FVector(planes[j]), planes[j] * planes[j].W))
				{
					Polygon->Vertices.Empty();
					break;
				}
			}
		}

		if(Polygon->Vertices.Num() < 3)
		{
			// If poly resulted in no verts, remove from array
			TempModel->Polys->Element.RemoveAt(TempModel->Polys->Element.Num()-1);
		}
		else
		{
			// Other stuff...
			Polygon->iLink = i;
			Polygon->CalcNormal(1);
		}
	}

	if(TempModel->Polys->Element.Num() < 4)
	{
		TempModel = NULL;
		return INDEX_NONE;
	}

	// Build bounding box.
	TempModel->BuildBound();

	// Build BSP for the brush.
	FBSPOps::bspBuild(TempModel,FBSPOps::BSP_Good,15,70,1,0);
	FBSPOps::bspRefresh(TempModel,1);
	FBSPOps::bspBuildBounds(TempModel);

//.........这里部分代码省略.........