UnrealEngineUWP/Engine/Source/Runtime/ClothingSystemRuntimeInterface/Private/ClothCollisionData.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "ClothCollisionData.h"

void FClothCollisionData::Reset()
{
	Spheres.Reset();
	SphereConnections.Reset();
	Convexes.Reset();
	Boxes.Reset();
}

void FClothCollisionData::Append(const FClothCollisionData& InOther)
{
	const int32 NumSpheresBefore = Spheres.Num();
	const int32 NumSphereConnectionsBefore = SphereConnections.Num();

	Spheres.Append(InOther.Spheres);
	SphereConnections.Append(InOther.SphereConnections);

	const int32 NumSphereConnectionsAfter = SphereConnections.Num();

	if(NumSpheresBefore > 0)
	{
		// Each connection that was added needs to have its sphere indices increased to match the new spheres that were added
		for(int32 NewConnectionIndex = NumSphereConnectionsBefore; NewConnectionIndex < NumSphereConnectionsAfter; ++NewConnectionIndex)
		{
			FClothCollisionPrim_SphereConnection& Connection = SphereConnections[NewConnectionIndex];
			Connection.SphereIndices[0] += NumSpheresBefore;
			Connection.SphereIndices[1] += NumSpheresBefore;
		}
	}

	Convexes.Append(InOther.Convexes);

	Boxes.Append(InOther.Boxes);
}