ChipmunkConstraint Class Reference

Constraints connect two ChipmunkBody objects together. More...

#import <ChipmunkConstraint.h>

Inherits NSObject, and <ChipmunkBaseObject>.

Inherited by ChipmunkDampedRotarySpring, ChipmunkDampedSpring, ChipmunkGearJoint, ChipmunkGrooveJoint, ChipmunkPinJoint, ChipmunkPivotJoint, ChipmunkRatchetJoint, ChipmunkRotaryLimitJoint, ChipmunkSimpleMotor, and ChipmunkSlideJoint.

Instance Methods
(void)	- preSolve:
	Override this method to update a constraints parameters just before running the physics each step.
(void)	- postSolve:
	Override this method to poll values from a constraint each frame after the physics runs. More...

Class Methods
(ChipmunkConstraint *)	+ constraintFromCPConstraint:
	Get the ChipmunkConstraint object associciated with a cpConstraint pointer. More...

Properties
cpConstraint *	constraint
	Returns a pointer to the underlying cpConstraint C struct.
ChipmunkBody *	bodyA
	The first ChipmunkBody the constraint controls.
ChipmunkBody *	bodyB
	The second ChipmunkBody the constraint controls.
cpFloat	maxForce
	Maximum force this constraint is allowed to use (defalts to infinity). More...
cpFloat	errorBias
	The rate at which joint error is corrected. More...
cpFloat	maxBias
	Maximum rate (speed) that a joint can be corrected at (defaults to infinity). More...
BOOL	collideBodies
	Whether or not the connected bodies should checked for collisions. More...
cpFloat	impulse
	Get the most recent impulse applied by this constraint.
ChipmunkSpace *	space
	Get the space the body is added to.
id	userData
	An object that this constraint is associated with. More...

Detailed Description

Constraints connect two ChipmunkBody objects together.

Most often constraints are simple joints, but can also be things like motors, friction generators or servos.

Method Documentation

+ (ChipmunkConstraint *) constraintFromCPConstraint:

(cpConstraint *)

constraint

Get the ChipmunkConstraint object associciated with a cpConstraint pointer.

Undefined if the cpConstraint wasn't created using Objective-Chipmunk.

- (void) postSolve:

(ChipmunkSpace *)

space

Override this method to poll values from a constraint each frame after the physics runs.

This can be used to implement breakable joints for instance.

Property Documentation

- (BOOL) collideBodies

readwritenonatomicassign

Whether or not the connected bodies should checked for collisions.

Collisions are filtered before calling callbacks. Defaults to TRUE.

- (cpFloat) errorBias

readwritenonatomicassign

The rate at which joint error is corrected.

Defaults to pow(1.0 - 0.1, 60.0) meaning that it will correct 10% of the error every 1/60th of a second.

- (cpFloat) maxBias

readwritenonatomicassign

Maximum rate (speed) that a joint can be corrected at (defaults to infinity).

Setting this value to a finite value allows you to control a joint like a servo motor.

- (cpFloat) maxForce

readwritenonatomicassign

Maximum force this constraint is allowed to use (defalts to infinity).

This allows joints to be pulled apart if too much force is applied to them. It also allows you to use constraints as force or friction generators for controlling bodies.

- (id) userData

readwritenonatomicassign

An object that this constraint is associated with.

You can use this get a reference to your game object or controller object from within callbacks.

Attention

Like most delegate properties this is a weak reference and does not call retain. This prevents reference cycles from occuring.

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

• ChipmunkConstraint.h