Class Collision

java.lang.Object

org.jbox2d.collision.Collision

public class Collision
extends Object

Functions used for computing contact points, distance queries, and TOI queries. Collision methods are non-static for pooling speed, retrieve a collision object from the

invalid reference

SingletonPool

. Should not be finalructed.

Author:

Daniel Murphy

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Collision.ClipVertex	Used for computing contact manifolds.
static enum	Collision.PointState	This is used for determining the state of contact points.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NULL_FEATURE

Constructor Summary

Constructors

Constructor	Description
Collision(IWorldPool argPool)

Method Summary

Modifier and Type	Method	Description
static final int	clipSegmentToLine(Collision.ClipVertex[] vOut, Collision.ClipVertex[] vIn, Vec2 normal, float offset, int vertexIndexA)	Clipping for contact manifolds.
final void	collideCircles(Manifold manifold, CircleShape circle1, Transform xfA, CircleShape circle2, Transform xfB)	Compute the collision manifold between two circles.
void	collideEdgeAndCircle(Manifold manifold, EdgeShape edgeA, Transform xfA, CircleShape circleB, Transform xfB)
void	collideEdgeAndPolygon(Manifold manifold, EdgeShape edgeA, Transform xfA, PolygonShape polygonB, Transform xfB)
final void	collidePolygonAndCircle(Manifold manifold, PolygonShape polygon, Transform xfA, CircleShape circle, Transform xfB)	Compute the collision manifold between a polygon and a circle.
final void	collidePolygons(Manifold manifold, PolygonShape polyA, Transform xfA, PolygonShape polyB, Transform xfB)	Compute the collision manifold between two polygons.
final float	edgeSeparation(PolygonShape poly1, Transform xf1, int edge1, PolygonShape poly2, Transform xf2)	Find the separation between poly1 and poly2 for a given edge normal on poly1.
final void	findIncidentEdge(Collision.ClipVertex[] c, PolygonShape poly1, Transform xf1, int edge1, PolygonShape poly2, Transform xf2)
final void	findMaxSeparation(org.jbox2d.collision.Collision.EdgeResults results, PolygonShape poly1, Transform xf1, PolygonShape poly2, Transform xf2)	Find the max separation between poly1 and poly2 using edge normals from poly1.
static final void	getPointStates(Collision.PointState[] state1, Collision.PointState[] state2, Manifold manifold1, Manifold manifold2)	Compute the point states given two manifolds.
final boolean	testOverlap(Shape shapeA, int indexA, Shape shapeB, int indexB, Transform xfA, Transform xfB)	Determine if two generic shapes overlap.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

NULL_FEATURE

public static final int NULL_FEATURE

See Also:

• Constant Field Values

Constructor Details

Collision

public Collision(IWorldPool argPool)

Method Details

testOverlap

public final boolean testOverlap(Shape shapeA,
 int indexA,
 Shape shapeB,
 int indexB,
 Transform xfA,
 Transform xfB)

Determine if two generic shapes overlap.

Parameters:

shapeA -

shapeB -

xfA -

xfB -

Returns:

getPointStates

public static final void getPointStates(Collision.PointState[] state1,
 Collision.PointState[] state2,
 Manifold manifold1,
 Manifold manifold2)

Compute the point states given two manifolds. The states pertain to the transition from manifold1 to manifold2. So state1 is either persist or remove while state2 is either add or persist.

Parameters:

state1 -

state2 -

manifold1 -

manifold2 -

clipSegmentToLine

public static final int clipSegmentToLine(Collision.ClipVertex[] vOut,
 Collision.ClipVertex[] vIn,
 Vec2 normal,
 float offset,
 int vertexIndexA)

Clipping for contact manifolds. Sutherland-Hodgman clipping.

Parameters:

vOut -

vIn -

normal -

offset -

Returns:

collideCircles

public final void collideCircles(Manifold manifold,
 CircleShape circle1,
 Transform xfA,
 CircleShape circle2,
 Transform xfB)

Compute the collision manifold between two circles.

Parameters:

manifold -

circle1 -

xfA -

circle2 -

xfB -

collidePolygonAndCircle

public final void collidePolygonAndCircle(Manifold manifold,
 PolygonShape polygon,
 Transform xfA,
 CircleShape circle,
 Transform xfB)

Compute the collision manifold between a polygon and a circle.

Parameters:

manifold -

polygon -

xfA -

circle -

xfB -

edgeSeparation

public final float edgeSeparation(PolygonShape poly1,
 Transform xf1,
 int edge1,
 PolygonShape poly2,
 Transform xf2)

Find the separation between poly1 and poly2 for a given edge normal on poly1.

Parameters:

poly1 -

xf1 -

edge1 -

poly2 -

xf2 -

findMaxSeparation

public final void findMaxSeparation(org.jbox2d.collision.Collision.EdgeResults results,
 PolygonShape poly1,
 Transform xf1,
 PolygonShape poly2,
 Transform xf2)

Find the max separation between poly1 and poly2 using edge normals from poly1.

Parameters:

poly1 -

xf1 -

poly2 -

xf2 -

edgeIndex -

findIncidentEdge

public final void findIncidentEdge(Collision.ClipVertex[] c,
 PolygonShape poly1,
 Transform xf1,
 int edge1,
 PolygonShape poly2,
 Transform xf2)

collidePolygons

public final void collidePolygons(Manifold manifold,
 PolygonShape polyA,
 Transform xfA,
 PolygonShape polyB,
 Transform xfB)

Compute the collision manifold between two polygons.

Parameters:

manifold -

polygon1 -

xf1 -

polygon2 -

xf2 -

collideEdgeAndCircle

public void collideEdgeAndCircle(Manifold manifold,
 EdgeShape edgeA,
 Transform xfA,
 CircleShape circleB,
 Transform xfB)

collideEdgeAndPolygon

public void collideEdgeAndPolygon(Manifold manifold,
 EdgeShape edgeA,
 Transform xfA,
 PolygonShape polygonB,
 Transform xfB)