b2Manifold Struct Reference

#include <b2_collision.h>

Public Types
enum	Type { e_circles, e_faceA, e_faceB }

Public Attributes
b2Vec2	localNormal
	not use for Type::e_points More...
b2Vec2	localPoint
	usage depends on manifold type More...
int32	pointCount
	the number of manifold points More...
b2ManifoldPoint	points [b2_maxManifoldPoints]
	the points of contact More...
Type	type

Detailed Description

A manifold for two touching convex shapes. Box2D supports multiple types of contact:

• clip point versus plane with radius
• point versus point with radius (circles) The local point usage depends on the manifold type: -e_circles: the local center of circleA -e_faceA: the center of faceA -e_faceB: the center of faceB Similarly the local normal usage: -e_circles: not used -e_faceA: the normal on polygonA -e_faceB: the normal on polygonB We store contacts in this way so that position correction can account for movement, which is critical for continuous physics. All contact scenarios must be expressed in one of these types. This structure is stored across time steps, so we keep it small.

Definition at line 99 of file b2_collision.h.

Member Enumeration Documentation

Type

enum b2Manifold::Type

Enumerator
e_circles
e_faceA
e_faceB

Definition at line 101 of file b2_collision.h.

Member Data Documentation

localNormal

b2Vec2 b2Manifold::localNormal

not use for Type::e_points

Definition at line 109 of file b2_collision.h.

localPoint

b2Vec2 b2Manifold::localPoint

usage depends on manifold type

Definition at line 110 of file b2_collision.h.

pointCount

int32 b2Manifold::pointCount

the number of manifold points

Definition at line 112 of file b2_collision.h.

points

b2ManifoldPoint b2Manifold::points[b2_maxManifoldPoints]

the points of contact

Definition at line 108 of file b2_collision.h.

type

Type b2Manifold::type

Definition at line 111 of file b2_collision.h.

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

• b2_collision.h