Added BulletCharacter Dummy code.

test/Physics/Include/BulletCharacterController.h

@@ -21,6 +21,7 @@
 #ifdef HAVE_PHYS_USE_BULLET
 #include "core.h"
 #include "EasyPhysics.h"
+//#include "BulletDynamics\Character\btCharacterControllerInterface.h"
 #endif
 
 namespace lol
@@ -29,6 +30,141 @@ namespace lol
 	namespace phys
 	{
 
+#define 0
+#ifdef HAVE_PHYS_USE_BULLET
+
+		///BulletKinematicCharacterController is an object that supports a sliding motion in a world.
+		///It uses a ghost object and convex sweep test to test for upcoming collisions. This is combined with discrete collision detection to recover from penetrations.
+		///Interaction between btKinematicCharacterController and dynamic rigid bodies needs to be explicity implemented by the user.
+		class BulletKinematicCharacterController : public btCharacterControllerInterface
+		{
+		protected:
+
+			btScalar m_halfHeight;
+
+			btPairCachingGhostObject* m_ghostObject;
+			btConvexShape*	m_convexShape;//is also in m_ghostObject, but it needs to be convex, so we store it here to avoid upcast
+
+			btScalar m_verticalVelocity;
+			btScalar m_verticalOffset;
+			btScalar m_fallSpeed;
+			btScalar m_jumpSpeed;
+			btScalar m_maxJumpHeight;
+			btScalar m_maxSlopeRadians; // Slope angle that is set (used for returning the exact value)
+			btScalar m_maxSlopeCosine;  // Cosine equivalent of m_maxSlopeRadians (calculated once when set, for optimization)
+			btScalar m_gravity;
+
+			btScalar m_turnAngle;
+
+			btScalar m_stepHeight;
+
+			btScalar	m_addedMargin;//@todo: remove this and fix the code
+
+			///this is the desired walk direction, set by the user
+			btVector3	m_walkDirection;
+			btVector3	m_normalizedDirection;
+
+			//some internal variables
+			btVector3 m_currentPosition;
+			btScalar  m_currentStepOffset;
+			btVector3 m_targetPosition;
+
+			///keep track of the contact manifolds
+			btManifoldArray	m_manifoldArray;
+
+			bool m_touchingContact;
+			btVector3 m_touchingNormal;
+
+			bool  m_wasOnGround;
+			bool  m_wasJumping;
+			bool	m_useGhostObjectSweepTest;
+			bool	m_useWalkDirection;
+			btScalar	m_velocityTimeInterval;
+			int m_upAxis;
+
+			static btVector3* getUpAxisDirections();
+
+			btVector3 computeReflectionDirection (const btVector3& direction, const btVector3& normal);
+			btVector3 parallelComponent (const btVector3& direction, const btVector3& normal);
+			btVector3 perpindicularComponent (const btVector3& direction, const btVector3& normal);
+
+			bool recoverFromPenetration ( btCollisionWorld* collisionWorld);
+			void stepUp (btCollisionWorld* collisionWorld);
+			void updateTargetPositionBasedOnCollision (const btVector3& hit_normal, btScalar tangentMag = btScalar(0.0), btScalar normalMag = btScalar(1.0));
+			void stepForwardAndStrafe (btCollisionWorld* collisionWorld, const btVector3& walkMove);
+			void stepDown (btCollisionWorld* collisionWorld, btScalar dt);
+		public:
+			BulletKinematicCharacterController (btPairCachingGhostObject* ghostObject,btConvexShape* convexShape,btScalar stepHeight, int upAxis = 1);
+			~BulletKinematicCharacterController ();
+
+
+			///btActionInterface interface
+			virtual void updateAction( btCollisionWorld* collisionWorld,btScalar deltaTime)
+			{
+				preStep ( collisionWorld);
+				playerStep (collisionWorld, deltaTime);
+			}
+
+			///btActionInterface interface
+			void	debugDraw(btIDebugDraw* debugDrawer);
+
+			void setUpAxis (int axis)
+			{
+				if (axis < 0)
+					axis = 0;
+				if (axis > 2)
+					axis = 2;
+				m_upAxis = axis;
+			}
+
+			/// This should probably be called setPositionIncrementPerSimulatorStep.
+			/// This is neither a direction nor a velocity, but the amount to
+			///	increment the position each simulation iteration, regardless
+			///	of dt.
+			/// This call will reset any velocity set by setVelocityForTimeInterval().
+			virtual void	setWalkDirection(const btVector3& walkDirection);
+
+			/// Caller provides a velocity with which the character should move for
+			///	the given time period.  After the time period, velocity is reset
+			///	to zero.
+			/// This call will reset any walk direction set by setWalkDirection().
+			/// Negative time intervals will result in no motion.
+			virtual void setVelocityForTimeInterval(const btVector3& velocity,
+				btScalar timeInterval);
+
+			void reset ();
+			void warp (const btVector3& origin);
+
+			void preStep (  btCollisionWorld* collisionWorld);
+			void playerStep ( btCollisionWorld* collisionWorld, btScalar dt);
+
+			void setFallSpeed (btScalar fallSpeed);
+			void setJumpSpeed (btScalar jumpSpeed);
+			void setMaxJumpHeight (btScalar maxJumpHeight);
+			bool canJump () const;
+
+			void jump ();
+
+			void setGravity(btScalar gravity);
+			btScalar getGravity() const;
+
+			/// The max slope determines the maximum angle that the controller can walk up.
+			/// The slope angle is measured in radians.
+			void setMaxSlope(btScalar slopeRadians);
+			btScalar getMaxSlope() const;
+
+			btPairCachingGhostObject* getGhostObject();
+			void	setUseGhostSweepTest(bool useGhostObjectSweepTest)
+			{
+				m_useGhostObjectSweepTest = useGhostObjectSweepTest;
+			}
+
+			bool onGround () const;
+		};
+
+#endif // HAVE_PHYS_USE_BULLET
+#endif // 0
+
 	} /* namespace phys */
 
 } /* namespace lol */

test/Physics/Src/BulletCharacterController.cpp

@@ -17,6 +17,15 @@
 #include "../Include/LolBtPhysicsIntegration.h"
 #include "../Include/LolPhysics.h"
 #include "../Include/EasyCharacterController.h"
+#include "../Include/BulletCharacterController.h"
+//#include "LinearMath/btIDebugDraw.h"
+//#include "BulletCollision/CollisionDispatch/btGhostObject.h"
+//#include "BulletCollision/CollisionShapes/btMultiSphereShape.h"
+//#include "BulletCollision/BroadphaseCollision/btOverlappingPairCache.h"
+//#include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"
+//#include "BulletCollision/CollisionDispatch/btCollisionWorld.h"
+//#include "LinearMath/btDefaultMotionState.h"
+
 
 namespace lol
 {
@@ -24,9 +33,628 @@ namespace lol
 	namespace phys
 	{
 
+#define 0
 #ifdef HAVE_PHYS_USE_BULLET
 
+// static helper method
+static btVector3
+getNormalizedVector(const btVector3& v)
+{
+	btVector3 n = v.normalized();
+	if (n.length() < SIMD_EPSILON) {
+		n.setValue(0, 0, 0);
+	}
+	return n;
+}
+
+
+///@todo Interact with dynamic objects,
+///Ride kinematicly animated platforms properly
+///More realistic (or maybe just a config option) falling
+/// -> Should integrate falling velocity manually and use that in stepDown()
+///Support jumping
+///Support ducking
+class btKinematicClosestNotMeRayResultCallback : public btCollisionWorld::ClosestRayResultCallback
+{
+public:
+	btKinematicClosestNotMeRayResultCallback (btCollisionObject* me) : btCollisionWorld::ClosestRayResultCallback(btVector3(0.0, 0.0, 0.0), btVector3(0.0, 0.0, 0.0))
+	{
+		m_me = me;
+	}
+
+	virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult,bool normalInWorldSpace)
+	{
+		if (rayResult.m_collisionObject == m_me)
+			return 1.0;
+
+		return ClosestRayResultCallback::addSingleResult (rayResult, normalInWorldSpace);
+	}
+protected:
+	btCollisionObject* m_me;
+};
+
+class btKinematicClosestNotMeConvexResultCallback : public btCollisionWorld::ClosestConvexResultCallback
+{
+public:
+	btKinematicClosestNotMeConvexResultCallback (btCollisionObject* me, const btVector3& up, btScalar minSlopeDot)
+	: btCollisionWorld::ClosestConvexResultCallback(btVector3(0.0, 0.0, 0.0), btVector3(0.0, 0.0, 0.0))
+	, m_me(me)
+	, m_up(up)
+	, m_minSlopeDot(minSlopeDot)
+	{
+	}
+
+	virtual btScalar addSingleResult(btCollisionWorld::LocalConvexResult& convexResult,bool normalInWorldSpace)
+	{
+		if (convexResult.m_hitCollisionObject == m_me)
+			return btScalar(1.0);
+
+		btVector3 hitNormalWorld;
+		if (normalInWorldSpace)
+		{
+			hitNormalWorld = convexResult.m_hitNormalLocal;
+		} else
+		{
+			///need to transform normal into worldspace
+			hitNormalWorld = convexResult.m_hitCollisionObject->getWorldTransform().getBasis()*convexResult.m_hitNormalLocal;
+		}
+
+		btScalar dotUp = m_up.dot(hitNormalWorld);
+		if (dotUp < m_minSlopeDot) {
+			return btScalar(1.0);
+		}
+
+		return ClosestConvexResultCallback::addSingleResult (convexResult, normalInWorldSpace);
+	}
+protected:
+	btCollisionObject* m_me;
+	const btVector3 m_up;
+	btScalar m_minSlopeDot;
+};
+
+/*
+ * Returns the reflection direction of a ray going 'direction' hitting a surface with normal 'normal'
+ *
+ * from: http://www-cs-students.stanford.edu/~adityagp/final/node3.html
+ */
+btVector3 BulletKinematicCharacterController::computeReflectionDirection (const btVector3& direction, const btVector3& normal)
+{
+	return direction - (btScalar(2.0) * direction.dot(normal)) * normal;
+}
+
+/*
+ * Returns the portion of 'direction' that is parallel to 'normal'
+ */
+btVector3 BulletKinematicCharacterController::parallelComponent (const btVector3& direction, const btVector3& normal)
+{
+	btScalar magnitude = direction.dot(normal);
+	return normal * magnitude;
+}
+
+/*
+ * Returns the portion of 'direction' that is perpindicular to 'normal'
+ */
+btVector3 BulletKinematicCharacterController::perpindicularComponent (const btVector3& direction, const btVector3& normal)
+{
+	return direction - parallelComponent(direction, normal);
+}
+
+BulletKinematicCharacterController::BulletKinematicCharacterController (btPairCachingGhostObject* ghostObject,btConvexShape* convexShape,btScalar stepHeight, int upAxis)
+{
+	m_upAxis = upAxis;
+	m_addedMargin = 0.02;
+	m_walkDirection.setValue(0,0,0);
+	m_useGhostObjectSweepTest = true;
+	m_ghostObject = ghostObject;
+	m_stepHeight = stepHeight;
+	m_turnAngle = btScalar(0.0);
+	m_convexShape=convexShape;	
+	m_useWalkDirection = true;	// use walk direction by default, legacy behavior
+	m_velocityTimeInterval = 0.0;
+	m_verticalVelocity = 0.0;
+	m_verticalOffset = 0.0;
+	m_gravity = 9.8 * 3 ; // 3G acceleration.
+	m_fallSpeed = 55.0; // Terminal velocity of a sky diver in m/s.
+	m_jumpSpeed = 10.0; // ?
+	m_wasOnGround = false;
+	m_wasJumping = false;
+	setMaxSlope(btRadians(45.0));
+}
+
+BulletKinematicCharacterController::~BulletKinematicCharacterController ()
+{
+}
+
+btPairCachingGhostObject* BulletKinematicCharacterController::getGhostObject()
+{
+	return m_ghostObject;
+}
+
+bool BulletKinematicCharacterController::recoverFromPenetration ( btCollisionWorld* collisionWorld)
+{
+
+	bool penetration = false;
+
+	collisionWorld->getDispatcher()->dispatchAllCollisionPairs(m_ghostObject->getOverlappingPairCache(), collisionWorld->getDispatchInfo(), collisionWorld->getDispatcher());
+
+	m_currentPosition = m_ghostObject->getWorldTransform().getOrigin();
+	
+	btScalar maxPen = btScalar(0.0);
+	for (int i = 0; i < m_ghostObject->getOverlappingPairCache()->getNumOverlappingPairs(); i++)
+	{
+		m_manifoldArray.resize(0);
+
+		btBroadphasePair* collisionPair = &m_ghostObject->getOverlappingPairCache()->getOverlappingPairArray()[i];
+		
+		if (collisionPair->m_algorithm)
+			collisionPair->m_algorithm->getAllContactManifolds(m_manifoldArray);
+
+		
+		for (int j=0;j<m_manifoldArray.size();j++)
+		{
+			btPersistentManifold* manifold = m_manifoldArray[j];
+			btScalar directionSign = manifold->getBody0() == m_ghostObject ? btScalar(-1.0) : btScalar(1.0);
+			for (int p=0;p<manifold->getNumContacts();p++)
+			{
+				const btManifoldPoint&pt = manifold->getContactPoint(p);
+
+				btScalar dist = pt.getDistance();
+
+				if (dist < 0.0)
+				{
+					if (dist < maxPen)
+					{
+						maxPen = dist;
+						m_touchingNormal = pt.m_normalWorldOnB * directionSign;//??
+
+					}
+					m_currentPosition += pt.m_normalWorldOnB * directionSign * dist * btScalar(0.2);
+					penetration = true;
+				} else {
+					//printf("touching %f\n", dist);
+				}
+			}
+			
+			//manifold->clearManifold();
+		}
+	}
+	btTransform newTrans = m_ghostObject->getWorldTransform();
+	newTrans.setOrigin(m_currentPosition);
+	m_ghostObject->setWorldTransform(newTrans);
+//	printf("m_touchingNormal = %f,%f,%f\n",m_touchingNormal[0],m_touchingNormal[1],m_touchingNormal[2]);
+	return penetration;
+}
+
+void BulletKinematicCharacterController::stepUp ( btCollisionWorld* world)
+{
+	// phase 1: up
+	btTransform start, end;
+	m_targetPosition = m_currentPosition + getUpAxisDirections()[m_upAxis] * (m_stepHeight + (m_verticalOffset > 0.f?m_verticalOffset:0.f));
+
+	start.setIdentity ();
+	end.setIdentity ();
+
+	/* FIXME: Handle penetration properly */
+	start.setOrigin (m_currentPosition + getUpAxisDirections()[m_upAxis] * (m_convexShape->getMargin() + m_addedMargin));
+	end.setOrigin (m_targetPosition);
+
+	btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, -getUpAxisDirections()[m_upAxis], btScalar(0.7071));
+	callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
+	callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;
+	
+	if (m_useGhostObjectSweepTest)
+	{
+		m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, world->getDispatchInfo().m_allowedCcdPenetration);
+	}
+	else
+	{
+		world->convexSweepTest (m_convexShape, start, end, callback);
+	}
+	
+	if (callback.hasHit())
+	{
+		// Only modify the position if the hit was a slope and not a wall or ceiling.
+		if(callback.m_hitNormalWorld.dot(getUpAxisDirections()[m_upAxis]) > 0.0)
+		{
+			// we moved up only a fraction of the step height
+			m_currentStepOffset = m_stepHeight * callback.m_closestHitFraction;
+			m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);
+		}
+		m_verticalVelocity = 0.0;
+		m_verticalOffset = 0.0;
+	} else {
+		m_currentStepOffset = m_stepHeight;
+		m_currentPosition = m_targetPosition;
+	}
+}
+
+void BulletKinematicCharacterController::updateTargetPositionBasedOnCollision (const btVector3& hitNormal, btScalar tangentMag, btScalar normalMag)
+{
+	btVector3 movementDirection = m_targetPosition - m_currentPosition;
+	btScalar movementLength = movementDirection.length();
+	if (movementLength>SIMD_EPSILON)
+	{
+		movementDirection.normalize();
+
+		btVector3 reflectDir = computeReflectionDirection (movementDirection, hitNormal);
+		reflectDir.normalize();
+
+		btVector3 parallelDir, perpindicularDir;
+
+		parallelDir = parallelComponent (reflectDir, hitNormal);
+		perpindicularDir = perpindicularComponent (reflectDir, hitNormal);
+
+		m_targetPosition = m_currentPosition;
+		if (0)//tangentMag != 0.0)
+		{
+			btVector3 parComponent = parallelDir * btScalar (tangentMag*movementLength);
+//			printf("parComponent=%f,%f,%f\n",parComponent[0],parComponent[1],parComponent[2]);
+			m_targetPosition +=  parComponent;
+		}
+
+		if (normalMag != 0.0)
+		{
+			btVector3 perpComponent = perpindicularDir * btScalar (normalMag*movementLength);
+//			printf("perpComponent=%f,%f,%f\n",perpComponent[0],perpComponent[1],perpComponent[2]);
+			m_targetPosition += perpComponent;
+		}
+	} else
+	{
+//		printf("movementLength don't normalize a zero vector\n");
+	}
+}
+
+void BulletKinematicCharacterController::stepForwardAndStrafe ( btCollisionWorld* collisionWorld, const btVector3& walkMove)
+{
+	// printf("m_normalizedDirection=%f,%f,%f\n",
+	// 	m_normalizedDirection[0],m_normalizedDirection[1],m_normalizedDirection[2]);
+	// phase 2: forward and strafe
+	btTransform start, end;
+	m_targetPosition = m_currentPosition + walkMove;
+
+	start.setIdentity ();
+	end.setIdentity ();
+	
+	btScalar fraction = 1.0;
+	btScalar distance2 = (m_currentPosition-m_targetPosition).length2();
+//	printf("distance2=%f\n",distance2);
+
+	if (m_touchingContact)
+	{
+		if (m_normalizedDirection.dot(m_touchingNormal) > btScalar(0.0))
+		{
+			updateTargetPositionBasedOnCollision (m_touchingNormal);
+		}
+	}
+
+	int maxIter = 10;
+
+	while (fraction > btScalar(0.01) && maxIter-- > 0)
+	{
+		start.setOrigin (m_currentPosition);
+		end.setOrigin (m_targetPosition);
+		btVector3 sweepDirNegative(m_currentPosition - m_targetPosition);
+
+		btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, sweepDirNegative, btScalar(0.0));
+		callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
+		callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;
+
+
+		btScalar margin = m_convexShape->getMargin();
+		m_convexShape->setMargin(margin + m_addedMargin);
+
+
+		if (m_useGhostObjectSweepTest)
+		{
+			m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
+		} else
+		{
+			collisionWorld->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
+		}
+		
+		m_convexShape->setMargin(margin);
+
+		
+		fraction -= callback.m_closestHitFraction;
+
+		if (callback.hasHit())
+		{	
+			// we moved only a fraction
+			btScalar hitDistance;
+			hitDistance = (callback.m_hitPointWorld - m_currentPosition).length();
+
+//			m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);
+
+			updateTargetPositionBasedOnCollision (callback.m_hitNormalWorld);
+			btVector3 currentDir = m_targetPosition - m_currentPosition;
+			distance2 = currentDir.length2();
+			if (distance2 > SIMD_EPSILON)
+			{
+				currentDir.normalize();
+				/* See Quake2: "If velocity is against original velocity, stop ead to avoid tiny oscilations in sloping corners." */
+				if (currentDir.dot(m_normalizedDirection) <= btScalar(0.0))
+				{
+					break;
+				}
+			} else
+			{
+//				printf("currentDir: don't normalize a zero vector\n");
+				break;
+			}
+
+		} else {
+			// we moved whole way
+			m_currentPosition = m_targetPosition;
+		}
+
+	//	if (callback.m_closestHitFraction == 0.f)
+	//		break;
+
+	}
+}
+
+void BulletKinematicCharacterController::stepDown ( btCollisionWorld* collisionWorld, btScalar dt)
+{
+	btTransform start, end;
+
+	// phase 3: down
+	/*btScalar additionalDownStep = (m_wasOnGround && !onGround()) ? m_stepHeight : 0.0;
+	btVector3 step_drop = getUpAxisDirections()[m_upAxis] * (m_currentStepOffset + additionalDownStep);
+	btScalar downVelocity = (additionalDownStep == 0.0 && m_verticalVelocity<0.0?-m_verticalVelocity:0.0) * dt;
+	btVector3 gravity_drop = getUpAxisDirections()[m_upAxis] * downVelocity; 
+	m_targetPosition -= (step_drop + gravity_drop);*/
+
+	btScalar downVelocity = (m_verticalVelocity<0.f?-m_verticalVelocity:0.f) * dt;
+	if(downVelocity > 0.0 && downVelocity < m_stepHeight
+		&& (m_wasOnGround || !m_wasJumping))
+	{
+		downVelocity = m_stepHeight;
+	}
+
+	btVector3 step_drop = getUpAxisDirections()[m_upAxis] * (m_currentStepOffset + downVelocity);
+	m_targetPosition -= step_drop;
+
+	start.setIdentity ();
+	end.setIdentity ();
+
+	start.setOrigin (m_currentPosition);
+	end.setOrigin (m_targetPosition);
+
+	btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, getUpAxisDirections()[m_upAxis], m_maxSlopeCosine);
+	callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
+	callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;
+	
+	if (m_useGhostObjectSweepTest)
+	{
+		m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
+	} else
+	{
+		collisionWorld->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
+	}
+
+	if (callback.hasHit())
+	{
+		// we dropped a fraction of the height -> hit floor
+		m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);
+		m_verticalVelocity = 0.0;
+		m_verticalOffset = 0.0;
+		m_wasJumping = false;
+	} else {
+		// we dropped the full height
+		
+		m_currentPosition = m_targetPosition;
+	}
+}
+
+
+
+void BulletKinematicCharacterController::setWalkDirection
+(
+const btVector3& walkDirection
+)
+{
+	m_useWalkDirection = true;
+	m_walkDirection = walkDirection;
+	m_normalizedDirection = getNormalizedVector(m_walkDirection);
+}
+
+
+
+void BulletKinematicCharacterController::setVelocityForTimeInterval
+(
+const btVector3& velocity,
+btScalar timeInterval
+)
+{
+//	printf("setVelocity!\n");
+//	printf("  interval: %f\n", timeInterval);
+//	printf("  velocity: (%f, %f, %f)\n",
+//		 velocity.x(), velocity.y(), velocity.z());
+
+	m_useWalkDirection = false;
+	m_walkDirection = velocity;
+	m_normalizedDirection = getNormalizedVector(m_walkDirection);
+	m_velocityTimeInterval = timeInterval;
+}
+
+
+
+void BulletKinematicCharacterController::reset ()
+{
+}
+
+void BulletKinematicCharacterController::warp (const btVector3& origin)
+{
+	btTransform xform;
+	xform.setIdentity();
+	xform.setOrigin (origin);
+	m_ghostObject->setWorldTransform (xform);
+}
+
+
+void BulletKinematicCharacterController::preStep (  btCollisionWorld* collisionWorld)
+{
+	
+	int numPenetrationLoops = 0;
+	m_touchingContact = false;
+	while (recoverFromPenetration (collisionWorld))
+	{
+		numPenetrationLoops++;
+		m_touchingContact = true;
+		if (numPenetrationLoops > 4)
+		{
+			//printf("character could not recover from penetration = %d\n", numPenetrationLoops);
+			break;
+		}
+	}
+
+	m_currentPosition = m_ghostObject->getWorldTransform().getOrigin();
+	m_targetPosition = m_currentPosition;
+//	printf("m_targetPosition=%f,%f,%f\n",m_targetPosition[0],m_targetPosition[1],m_targetPosition[2]);
+
+	
+}
+
+#include <stdio.h>
+
+void BulletKinematicCharacterController::playerStep (  btCollisionWorld* collisionWorld, btScalar dt)
+{
+//	printf("playerStep(): ");
+//	printf("  dt = %f", dt);
+
+	// quick check...
+	if (!m_useWalkDirection && m_velocityTimeInterval <= 0.0) {
+//		printf("\n");
+		return;		// no motion
+	}
+
+	m_wasOnGround = onGround();
+
+	// Update fall velocity.
+	m_verticalVelocity -= m_gravity * dt;
+	if(m_verticalVelocity > 0.0 && m_verticalVelocity > m_jumpSpeed)
+	{
+		m_verticalVelocity = m_jumpSpeed;
+	}
+	if(m_verticalVelocity < 0.0 && btFabs(m_verticalVelocity) > btFabs(m_fallSpeed))
+	{
+		m_verticalVelocity = -btFabs(m_fallSpeed);
+	}
+	m_verticalOffset = m_verticalVelocity * dt;
+
+
+	btTransform xform;
+	xform = m_ghostObject->getWorldTransform ();
+
+//	printf("walkDirection(%f,%f,%f)\n",walkDirection[0],walkDirection[1],walkDirection[2]);
+//	printf("walkSpeed=%f\n",walkSpeed);
+
+	stepUp (collisionWorld);
+	if (m_useWalkDirection) {
+		stepForwardAndStrafe (collisionWorld, m_walkDirection);
+	} else {
+		//printf("  time: %f", m_velocityTimeInterval);
+		// still have some time left for moving!
+		btScalar dtMoving =
+			(dt < m_velocityTimeInterval) ? dt : m_velocityTimeInterval;
+		m_velocityTimeInterval -= dt;
+
+		// how far will we move while we are moving?
+		btVector3 move = m_walkDirection * dtMoving;
+
+		//printf("  dtMoving: %f", dtMoving);
+
+		// okay, step
+		stepForwardAndStrafe(collisionWorld, move);
+	}
+	stepDown (collisionWorld, dt);
+
+	// printf("\n");
+
+	xform.setOrigin (m_currentPosition);
+	m_ghostObject->setWorldTransform (xform);
+}
+
+void BulletKinematicCharacterController::setFallSpeed (btScalar fallSpeed)
+{
+	m_fallSpeed = fallSpeed;
+}
+
+void BulletKinematicCharacterController::setJumpSpeed (btScalar jumpSpeed)
+{
+	m_jumpSpeed = jumpSpeed;
+}
+
+void BulletKinematicCharacterController::setMaxJumpHeight (btScalar maxJumpHeight)
+{
+	m_maxJumpHeight = maxJumpHeight;
+}
+
+bool BulletKinematicCharacterController::canJump () const
+{
+	return onGround();
+}
+
+void BulletKinematicCharacterController::jump ()
+{
+	if (!canJump())
+		return;
+
+	m_verticalVelocity = m_jumpSpeed;
+	m_wasJumping = true;
+
+#if 0
+	currently no jumping.
+	btTransform xform;
+	m_rigidBody->getMotionState()->getWorldTransform (xform);
+	btVector3 up = xform.getBasis()[1];
+	up.normalize ();
+	btScalar magnitude = (btScalar(1.0)/m_rigidBody->getInvMass()) * btScalar(8.0);
+	m_rigidBody->applyCentralImpulse (up * magnitude);
+#endif
+}
+
+void BulletKinematicCharacterController::setGravity(btScalar gravity)
+{
+	m_gravity = gravity;
+}
+
+btScalar BulletKinematicCharacterController::getGravity() const
+{
+	return m_gravity;
+}
+
+void BulletKinematicCharacterController::setMaxSlope(btScalar slopeRadians)
+{
+	m_maxSlopeRadians = slopeRadians;
+	m_maxSlopeCosine = btCos(slopeRadians);
+}
+
+btScalar BulletKinematicCharacterController::getMaxSlope() const
+{
+	return m_maxSlopeRadians;
+}
+
+bool BulletKinematicCharacterController::onGround () const
+{
+	return m_verticalVelocity == 0.0 && m_verticalOffset == 0.0;
+}
+
+
+btVector3* BulletKinematicCharacterController::getUpAxisDirections()
+{
+	static btVector3 sUpAxisDirection[3] = { btVector3(1.0f, 0.0f, 0.0f), btVector3(0.0f, 1.0f, 0.0f), btVector3(0.0f, 0.0f, 1.0f) };
+	
+	return sUpAxisDirection;
+}
+
+void BulletKinematicCharacterController::debugDraw(btIDebugDraw* debugDrawer)
+{
+}
+
+
 #endif // HAVE_PHYS_USE_BULLET
+#endif // 0
 
 	} /* namespace phys */