//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//  * Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//  * Neither the name of NVIDIA CORPORATION nor the names of its
//    contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2008-2019 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.  


#include "PxsMaterialCombiner.h"
#include "PsMathUtils.h"
#include "CmPhysXCommon.h"
#include "PsFoundation.h"

namespace physx   
{


PxsMaterialCombiner::PxsMaterialCombiner(PxReal staticFrictionScaling, PxReal dynamicFrictionScaling)
:	mStaticFrictionScaling(staticFrictionScaling), mDynamicFrictionScaling(dynamicFrictionScaling)
{}


PxReal PxsMaterialCombiner::combineRestitution(const PxsMaterialData& mat0, const PxsMaterialData& mat1)
{
	/*return combineScalars(mat0.restitution, mat1.restitution, PxMax(mat0.restitutionCombineMode, mat1.restitutionCombineMode));*/
	return combineScalars(mat0.restitution, mat1.restitution, PxMax(mat0.getRestitutionCombineMode(), mat1.getRestitutionCombineMode()));
}
   
PxsMaterialCombiner::PxsCombinedMaterial PxsMaterialCombiner::combineIsotropicFriction(const PxsMaterialData& mat0, const PxsMaterialData& mat1)
{
	PxsCombinedMaterial dest;

	dest.flags = (mat0.flags | mat1.flags); //& (PxMaterialFlag::eDISABLE_STRONG_FRICTION|PxMaterialFlag::eDISABLE_FRICTION);	//eventually set DisStrongFric flag, lower all others.

	if (!(dest.flags & PxMaterialFlag::eDISABLE_FRICTION))
	{
		const PxI32 fictionCombineMode = PxMax(mat0.getFrictionCombineMode(), mat1.getFrictionCombineMode());
		PxReal dynFriction = 0.f;
		PxReal staFriction = 0.f;


		switch (fictionCombineMode)
		{
		case PxCombineMode::eAVERAGE:
			dynFriction = 0.5f * (mat0.dynamicFriction + mat1.dynamicFriction);
			staFriction = 0.5f * (mat0.staticFriction + mat1.staticFriction);
			break;
		case PxCombineMode::eMIN:
			dynFriction = PxMin(mat0.dynamicFriction, mat1.dynamicFriction);
			staFriction = PxMin(mat0.staticFriction, mat1.staticFriction);
			break;
		case PxCombineMode::eMULTIPLY:
			dynFriction = (mat0.dynamicFriction * mat1.dynamicFriction);
			staFriction = (mat0.staticFriction * mat1.staticFriction);
			break;
		case PxCombineMode::eMAX:
			dynFriction = PxMax(mat0.dynamicFriction, mat1.dynamicFriction);
			staFriction = PxMax(mat0.staticFriction, mat1.staticFriction);
			break;
		}   

		dynFriction*=mDynamicFrictionScaling;
		staFriction*=mStaticFrictionScaling;
		//isotropic case
		const PxReal fDynFriction = PxMax(dynFriction, 0.f);

		const PxReal fStaFriction = physx::intrinsics::fsel(staFriction - fDynFriction, staFriction, fDynFriction);
		dest.dynFriction = fDynFriction;
		dest.staFriction = fStaFriction;
	}
	else
	{
		dest.flags |= PxMaterialFlag::eDISABLE_STRONG_FRICTION;
		dest.staFriction = 0.0f;
		dest.dynFriction = 0.0f;
	}

	return dest;
}
}
