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// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
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// ****************************************************************************
// This snippet illustrates the use of simple contact reports.
//
// It defines a filter shader function that requests touch reports for 
// all pairs, and a contact callback function that saves the contact points.  
// It configures the scene to use this filter and callback, and prints the 
// number of contact reports each frame. If rendering, it renders each 
// contact as a line whose length and direction are defined by the contact 
// impulse.
// 
// ****************************************************************************

#include <vector>

#include "PxPhysicsAPI.h"

#include "../snippetutils/SnippetUtils.h"
#include "../snippetcommon/SnippetPrint.h"
#include "../snippetcommon/SnippetPVD.h"


using namespace physx;


PxDefaultAllocator		gAllocator;
PxDefaultErrorCallback	gErrorCallback;

PxFoundation*			gFoundation = NULL;
PxPhysics*				gPhysics	= NULL;

PxDefaultCpuDispatcher*	gDispatcher = NULL;
PxScene*				gScene		= NULL;
PxMaterial*				gMaterial	= NULL;
PxPvd*                  gPvd        = NULL;

std::vector<PxVec3> gContactPositions;
std::vector<PxVec3> gContactImpulses;


PxFilterFlags contactReportFilterShader(PxFilterObjectAttributes attributes0, PxFilterData filterData0, 
										PxFilterObjectAttributes attributes1, PxFilterData filterData1,
										PxPairFlags& pairFlags, const void* constantBlock, PxU32 constantBlockSize)
{
	PX_UNUSED(attributes0);
	PX_UNUSED(attributes1);
	PX_UNUSED(filterData0);
	PX_UNUSED(filterData1);
	PX_UNUSED(constantBlockSize);
	PX_UNUSED(constantBlock);

	// all initial and persisting reports for everything, with per-point data
	pairFlags = PxPairFlag::eSOLVE_CONTACT | PxPairFlag::eDETECT_DISCRETE_CONTACT
			  |	PxPairFlag::eNOTIFY_TOUCH_FOUND 
			  | PxPairFlag::eNOTIFY_TOUCH_PERSISTS
			  | PxPairFlag::eNOTIFY_CONTACT_POINTS;
	return PxFilterFlag::eDEFAULT;
}

class ContactReportCallback: public PxSimulationEventCallback
{
	void onConstraintBreak(PxConstraintInfo* constraints, PxU32 count)	{ PX_UNUSED(constraints); PX_UNUSED(count); }
	void onWake(PxActor** actors, PxU32 count)							{ PX_UNUSED(actors); PX_UNUSED(count); }
	void onSleep(PxActor** actors, PxU32 count)							{ PX_UNUSED(actors); PX_UNUSED(count); }
	void onTrigger(PxTriggerPair* pairs, PxU32 count)					{ PX_UNUSED(pairs); PX_UNUSED(count); }
	void onAdvance(const PxRigidBody*const*, const PxTransform*, const PxU32) {}
	void onContact(const PxContactPairHeader& pairHeader, const PxContactPair* pairs, PxU32 nbPairs) 
	{
		PX_UNUSED((pairHeader));
		std::vector<PxContactPairPoint> contactPoints;
		
		for(PxU32 i=0;i<nbPairs;i++)
		{
			PxU32 contactCount = pairs[i].contactCount;
			if(contactCount)
			{
				contactPoints.resize(contactCount);
				pairs[i].extractContacts(&contactPoints[0], contactCount);

				for(PxU32 j=0;j<contactCount;j++)
				{
					gContactPositions.push_back(contactPoints[j].position);
					gContactImpulses.push_back(contactPoints[j].impulse);
				}
			}
		}
	}
};

ContactReportCallback gContactReportCallback;

void createStack(const PxTransform& t, PxU32 size, PxReal halfExtent)
{
	PxShape* shape = gPhysics->createShape(PxBoxGeometry(halfExtent, halfExtent, halfExtent), *gMaterial);
	for(PxU32 i=0; i<size;i++)
	{
		for(PxU32 j=0;j<size-i;j++)
		{
			PxTransform localTm(PxVec3(PxReal(j*2) - PxReal(size-i), PxReal(i*2+1), 0) * halfExtent);
			PxRigidDynamic* body = gPhysics->createRigidDynamic(t.transform(localTm));
			body->attachShape(*shape);
			PxRigidBodyExt::updateMassAndInertia(*body, 10.0f);
			gScene->addActor(*body);
		}
	}
	shape->release();
}

void initPhysics(bool /*interactive*/)
{
	gFoundation = PxCreateFoundation(PX_PHYSICS_VERSION, gAllocator, gErrorCallback);
	gPvd = PxCreatePvd(*gFoundation);
	PxPvdTransport* transport = PxDefaultPvdSocketTransportCreate(PVD_HOST, 5425, 10);
	gPvd->connect(*transport,PxPvdInstrumentationFlag::eALL);
	gPhysics = PxCreatePhysics(PX_PHYSICS_VERSION, *gFoundation, PxTolerancesScale(),true,gPvd);
	PxInitExtensions(*gPhysics,gPvd);
	PxU32 numCores = SnippetUtils::getNbPhysicalCores();
	gDispatcher = PxDefaultCpuDispatcherCreate(numCores == 0 ? 0 : numCores - 1);
	PxSceneDesc sceneDesc(gPhysics->getTolerancesScale());
	sceneDesc.cpuDispatcher = gDispatcher;
	sceneDesc.gravity = PxVec3(0, -9.81f, 0);
	sceneDesc.filterShader	= contactReportFilterShader;			
	sceneDesc.simulationEventCallback = &gContactReportCallback;	
	gScene = gPhysics->createScene(sceneDesc);

	PxPvdSceneClient* pvdClient = gScene->getScenePvdClient();
	if(pvdClient)
	{
		pvdClient->setScenePvdFlag(PxPvdSceneFlag::eTRANSMIT_CONTACTS, true);
	}
	gMaterial = gPhysics->createMaterial(0.5f, 0.5f, 0.6f);

	PxRigidStatic* groundPlane = PxCreatePlane(*gPhysics, PxPlane(0,1,0,0), *gMaterial);
	gScene->addActor(*groundPlane);
	createStack(PxTransform(PxVec3(0,3.0f,10.0f)), 5, 2.0f);
}

void stepPhysics(bool /*interactive*/)
{
	gContactPositions.clear();
	gContactImpulses.clear();

	gScene->simulate(1.0f/60.0f);
	gScene->fetchResults(true);
	printf("%d contact reports\n", PxU32(gContactPositions.size()));
}
	
void cleanupPhysics(bool /*interactive*/)
{
	PX_RELEASE(gScene);
	PX_RELEASE(gDispatcher);
	PxCloseExtensions();
	PX_RELEASE(gPhysics);
	if(gPvd)
	{
		PxPvdTransport* transport = gPvd->getTransport();
		gPvd->release();	gPvd = NULL;
		PX_RELEASE(transport);
	}
	PX_RELEASE(gFoundation);
	
	printf("SnippetContactReport done.\n");
}

int snippetMain(int, const char*const*)
{
#ifdef RENDER_SNIPPET
	extern void renderLoop();
	renderLoop();
#else
	initPhysics(false);
	for(PxU32 i=0; i<250; i++)
		stepPhysics(false);
	cleanupPhysics(false);
#endif

	return 0;
}