Physics Class Reference

Inheritance diagram for Physics:

Classes
class	CollisionList
class	CollisionPair
	Bullet can report the same collision more than once (up to 4 contact points per collision. More...

Public Member Functions
void	init (const Vec3 &min_world, const Vec3 &max_world)
	The actual initialisation of the physics, which is called after the track model is loaded.
void	addKart (const AbstractKart *k)
	Adds a kart to the physics engine.
void	addBody (btRigidBody *b)
void	removeKart (const AbstractKart *k)
	Removes a kart from the physics engine.
void	removeBody (btRigidBody *b)
void	KartKartCollision (AbstractKart *ka, const Vec3 &contact_point_a, AbstractKart *kb, const Vec3 &contact_point_b)
	Handles the special case of two karts colliding with each other, which means that bombs must be passed on.
void	update (int ticks)
	Updates the physics simulation and handles all collisions.
void	draw ()
	A debug draw function to show the track and all karts.
STKDynamicsWorld *	getPhysicsWorld () const
void	nextDebugMode ()
	Activates the next debug mode (or switches it off again).
void	setDebugMode (IrrDebugDrawer::DebugModeType mode)
bool	isDebug () const
	Returns true if the debug drawer is enabled.
IrrDebugDrawer *	getDebugDrawer ()
virtual btScalar	solveGroup (btCollisionObject **bodies, int numBodies, btPersistentManifold **manifold, int numManifolds, btTypedConstraint **constraints, int numConstraints, const btContactSolverInfo &info, btIDebugDraw *debugDrawer, btStackAlloc *stackAlloc, btDispatcher *dispatcher)
	This function is called at each internal bullet timestep.

Static Public Member Functions
static Physics *	get ()
static void	create ()
static void	destroy ()

Private Member Functions
	Physics ()
	Initialise physics.

Private Attributes
bool	m_physics_loop_active
	This flag is set while bullets time step processing is taking place.
std::vector< const AbstractKart * >	m_karts_to_delete
	If kart need to be removed from the physics world while physics processing is taking place, store the pointers to the karts to be removed here, and remove them once the physics processing is finished.
STKDynamicsWorld *	m_dynamics_world
	Pointer to the physics dynamics world.
IrrDebugDrawer *	m_debug_drawer
	Used in physics debugging to draw the physics world.
btCollisionDispatcher *	m_dispatcher
btBroadphaseInterface *	m_axis_sweep
btDefaultCollisionConfiguration *	m_collision_conf
CollisionList	m_all_collisions

Constructor & Destructor Documentation

Physics()

Physics::Physics ( )

private

Initialise physics.

Create the bullet dynamics world.

Member Function Documentation

addKart()

void Physics::addKart

(

const AbstractKart *

kart

)

Adds a kart to the physics engine.

This adds the rigid body and the vehicle but only if the kart is not already in the physics world.

Parameters

kart	The kart to add.
vehicle	The raycast vehicle object.

init()

void Physics::init	(	const Vec3 &	world_min,
		const Vec3 &	world_max
	)

The actual initialisation of the physics, which is called after the track model is loaded.

This allows the physics to use the actual track dimension for the axis sweep.

KartKartCollision()

void Physics::KartKartCollision	(	AbstractKart *	kart_a,
		const Vec3 &	contact_point_a,
		AbstractKart *	kart_b,
		const Vec3 &	contact_point_b
	)

Handles the special case of two karts colliding with each other, which means that bombs must be passed on.

If both karts have a bomb, they'll explode immediately. This function is called from physics::update() on the server and if no networking is used, and from race_state on the client to replay what happened on the server.

Parameters

kart_a	First kart involved in the collision.
contact_point_a	Location of collision at first kart (in kart coordinates).
kart_b	Second kart involved in the collision.
contact_point_b	Location of collision at second kart (in kart coordinates).

removeKart()

void Physics::removeKart

(

const AbstractKart *

kart

)

Removes a kart from the physics engine.

This is used when rescuing a kart (and during cleanup).

Parameters

kart	The kart to remove.

solveGroup()

btScalar Physics::solveGroup ( btCollisionObject **  bodies, int  numBodies, btPersistentManifold **  manifold, int  numManifolds, btTypedConstraint **  constraints, int  numConstraints, const btContactSolverInfo &  info, btIDebugDraw *  debugDrawer, btStackAlloc *  stackAlloc, btDispatcher *  dispatcher  )

virtual

This function is called at each internal bullet timestep.

It is used here to do the collision handling: using the contact manifolds after a physics time step might miss some collisions (when more than one internal time step was done, and the collision is added and removed). So this function stores all collisions in a list, which is then handled after the actual physics timestep. This list only stores a collision if it's not already in the list, so a collisions which is reported more than once is nevertheless only handled once. The list of collision Parameters: see bullet documentation for details.

update()

void Physics::update

(

int

ticks

)

Updates the physics simulation and handles all collisions.

Parameters

ticks

Number of physics steps to simulate.

Member Data Documentation

m_physics_loop_active

bool Physics::m_physics_loop_active

private

This flag is set while bullets time step processing is taking place.

It is used to avoid altering data structures that might be used (e.g. removing a kart while a loop over all karts is taking place, as can happen in collision handling).

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The documentation for this class was generated from the following files:

• physics/physics.hpp
• physics/physics.cpp