bullet3/examples/Constraints/TestHingeTorque.cpp

#include "TestHingeTorque.h"

#include "../CommonInterfaces/CommonRigidBodyBase.h"
#include "../CommonInterfaces/CommonParameterInterface.h"

int collisionFilterGroup = int(btBroadphaseProxy::CharacterFilter);
int collisionFilterMask = int(btBroadphaseProxy::AllFilter ^ (btBroadphaseProxy::CharacterFilter));
static btScalar radius(0.2);

struct TestHingeTorque : public CommonRigidBodyBase
{
	bool m_once;
	btAlignedObjectArray<btJointFeedback*> m_jointFeedback;

	TestHingeTorque(struct GUIHelperInterface* helper);
	virtual ~TestHingeTorque();
	virtual void initPhysics();

	virtual void stepSimulation(float deltaTime);

	virtual void resetCamera()
	{
		float dist = 5;
		float pitch = -21;
		float yaw = 270;
		float targetPos[3] = {-1.34, 3.4, -0.44};
		m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
	}
};

TestHingeTorque::TestHingeTorque(struct GUIHelperInterface* helper)
	: CommonRigidBodyBase(helper),
	  m_once(true)
{
}
TestHingeTorque::~TestHingeTorque()
{
	for (int i = 0; i < m_jointFeedback.size(); i++)
	{
		delete m_jointFeedback[i];
	}
}

void TestHingeTorque::stepSimulation(float deltaTime)
{
	if (0)  //m_once)
	{
		m_once = false;
		btHingeConstraint* hinge = (btHingeConstraint*)m_dynamicsWorld->getConstraint(0);

		btRigidBody& bodyA = hinge->getRigidBodyA();
		btTransform trA = bodyA.getWorldTransform();
		btVector3 hingeAxisInWorld = trA.getBasis() * hinge->getFrameOffsetA().getBasis().getColumn(2);
		hinge->getRigidBodyA().applyTorque(-hingeAxisInWorld * 10);
		hinge->getRigidBodyB().applyTorque(hingeAxisInWorld * 10);
	}

	m_dynamicsWorld->stepSimulation(1. / 240, 0);

	static int count = 0;
	if ((count & 0x0f) == 0)
	{
		btRigidBody* base = btRigidBody::upcast(m_dynamicsWorld->getCollisionObjectArray()[0]);

		b3Printf("base angvel = %f,%f,%f", base->getAngularVelocity()[0],
				 base->getAngularVelocity()[1],

				 base->getAngularVelocity()[2]);

		btRigidBody* child = btRigidBody::upcast(m_dynamicsWorld->getCollisionObjectArray()[1]);

		b3Printf("child angvel = %f,%f,%f", child->getAngularVelocity()[0],
				 child->getAngularVelocity()[1],

				 child->getAngularVelocity()[2]);

		for (int i = 0; i < m_jointFeedback.size(); i++)
		{
			b3Printf("Applied force at the COM/Inertial frame B[%d]:(%f,%f,%f), torque B:(%f,%f,%f)\n", i,

					 m_jointFeedback[i]->m_appliedForceBodyB.x(),
					 m_jointFeedback[i]->m_appliedForceBodyB.y(),
					 m_jointFeedback[i]->m_appliedForceBodyB.z(),
					 m_jointFeedback[i]->m_appliedTorqueBodyB.x(),
					 m_jointFeedback[i]->m_appliedTorqueBodyB.y(),
					 m_jointFeedback[i]->m_appliedTorqueBodyB.z());
		}
	}
	count++;

	//CommonRigidBodyBase::stepSimulation(deltaTime);
}

void TestHingeTorque::initPhysics()
{
	int upAxis = 1;
	m_guiHelper->setUpAxis(upAxis);

	createEmptyDynamicsWorld();
	m_dynamicsWorld->getSolverInfo().m_splitImpulse = false;

	m_dynamicsWorld->setGravity(btVector3(0, 0, -10));

	m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
	int mode = btIDebugDraw::DBG_DrawWireframe + btIDebugDraw::DBG_DrawConstraints + btIDebugDraw::DBG_DrawConstraintLimits;
	m_dynamicsWorld->getDebugDrawer()->setDebugMode(mode);

	{  // create a door using hinge constraint attached to the world

		int numLinks = 2;
		//    bool selfCollide = false;
		btVector3 linkHalfExtents(0.05, 0.37, 0.1);
		btVector3 baseHalfExtents(0.05, 0.37, 0.1);

		btBoxShape* baseBox = new btBoxShape(baseHalfExtents);
		btVector3 basePosition = btVector3(-0.4f, 3.f, 0.f);
		btTransform baseWorldTrans;
		baseWorldTrans.setIdentity();
		baseWorldTrans.setOrigin(basePosition);

		//mbC->forceMultiDof();							//if !spherical, you can comment this line to check the 1DoF algorithm
		//init the base
		btVector3 baseInertiaDiag(0.f, 0.f, 0.f);
		float baseMass = 0.f;
		float linkMass = 1.f;

		btRigidBody* base = createRigidBody(baseMass, baseWorldTrans, baseBox);
		m_dynamicsWorld->removeRigidBody(base);
		base->setDamping(0, 0);
		m_dynamicsWorld->addRigidBody(base, collisionFilterGroup, collisionFilterMask);
		btBoxShape* linkBox1 = new btBoxShape(linkHalfExtents);
		btSphereShape* linkSphere = new btSphereShape(radius);

		btRigidBody* prevBody = base;

		for (int i = 0; i < numLinks; i++)
		{
			btTransform linkTrans;
			linkTrans = baseWorldTrans;

			linkTrans.setOrigin(basePosition - btVector3(0, linkHalfExtents[1] * 2.f * (i + 1), 0));

			btCollisionShape* colOb = 0;

			if (i == 0)
			{
				colOb = linkBox1;
			}
			else
			{
				colOb = linkSphere;
			}
			btRigidBody* linkBody = createRigidBody(linkMass, linkTrans, colOb);
			m_dynamicsWorld->removeRigidBody(linkBody);
			m_dynamicsWorld->addRigidBody(linkBody, collisionFilterGroup, collisionFilterMask);
			linkBody->setDamping(0, 0);
			btTypedConstraint* con = 0;

			if (i == 0)
			{
				//create a hinge constraint
				btVector3 pivotInA(0, -linkHalfExtents[1], 0);
				btVector3 pivotInB(0, linkHalfExtents[1], 0);
				btVector3 axisInA(1, 0, 0);
				btVector3 axisInB(1, 0, 0);
				bool useReferenceA = true;
				btHingeConstraint* hinge = new btHingeConstraint(*prevBody, *linkBody,
																 pivotInA, pivotInB,
																 axisInA, axisInB, useReferenceA);
				con = hinge;
			}
			else
			{
				btTransform pivotInA(btQuaternion::getIdentity(), btVector3(0, -radius, 0));  //par body's COM to cur body's COM offset
				btTransform pivotInB(btQuaternion::getIdentity(), btVector3(0, radius, 0));   //cur body's COM to cur body's PIV offset
				btGeneric6DofSpring2Constraint* fixed = new btGeneric6DofSpring2Constraint(*prevBody, *linkBody,
																						   pivotInA, pivotInB);
				fixed->setLinearLowerLimit(btVector3(0, 0, 0));
				fixed->setLinearUpperLimit(btVector3(0, 0, 0));
				fixed->setAngularLowerLimit(btVector3(0, 0, 0));
				fixed->setAngularUpperLimit(btVector3(0, 0, 0));

				con = fixed;
			}
			btAssert(con);
			if (con)
			{
				btJointFeedback* fb = new btJointFeedback();
				m_jointFeedback.push_back(fb);
				con->setJointFeedback(fb);

				m_dynamicsWorld->addConstraint(con, true);
			}
			prevBody = linkBody;
		}
	}

	if (1)
	{
		btVector3 groundHalfExtents(1, 1, 0.2);
		groundHalfExtents[upAxis] = 1.f;
		btBoxShape* box = new btBoxShape(groundHalfExtents);
		box->initializePolyhedralFeatures();

		btTransform start;
		start.setIdentity();
		btVector3 groundOrigin(-0.4f, 3.f, 0.f);
		//	btVector3 basePosition = btVector3(-0.4f, 3.f, 0.f);
		btQuaternion groundOrn(btVector3(0, 1, 0), 0.25 * SIMD_PI);

		groundOrigin[upAxis] -= .5;
		groundOrigin[2] -= 0.6;
		start.setOrigin(groundOrigin);
		//	start.setRotation(groundOrn);
		btRigidBody* body = createRigidBody(0, start, box);
		body->setFriction(0);
	}
	m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}

class CommonExampleInterface* TestHingeTorqueCreateFunc(CommonExampleOptions& options)
{
	return new TestHingeTorque(options.m_guiHelper);
}