org.jbox2d.collision

Class Collision

java.lang.Object

org.jbox2d.collision.Collision

public class Collision
extends java.lang.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 SingletonPool. Should not be finalructed.

Author:

Daniel Murphy

Nested Class Summary

Nested Classes

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

Field Summary

Fields

Modifier and Type	Field and Description
static int	NULL_FEATURE

Constructor Summary

Constructors

Constructor and Description
Collision(IWorldPool argPool)

Method Summary

Modifier and Type	Method and Description
static int	clipSegmentToLine(Collision.ClipVertex[] vOut, Collision.ClipVertex[] vIn, Vec2 normal, float offset, int vertexIndexA) Clipping for contact manifolds.
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)
void	collidePolygonAndCircle(Manifold manifold, PolygonShape polygon, Transform xfA, CircleShape circle, Transform xfB) Compute the collision manifold between a polygon and a circle.
void	collidePolygons(Manifold manifold, PolygonShape polyA, Transform xfA, PolygonShape polyB, Transform xfB) Compute the collision manifold between two polygons.
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.
void	findIncidentEdge(Collision.ClipVertex[] c, PolygonShape poly1, Transform xf1, int edge1, PolygonShape poly2, Transform xf2)
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 void	getPointStates(Collision.PointState[] state1, Collision.PointState[] state2, Manifold manifold1, Manifold manifold2) Compute the point states given two manifolds.
boolean	testOverlap(Shape shapeA, int indexA, Shape shapeB, int indexB, Transform xfA, Transform xfB) Determine if two generic shapes overlap.

Methods inherited from class java.lang.Object

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

Field Detail

NULL_FEATURE

public static final int NULL_FEATURE

See Also:

Constant Field Values

Constructor Detail

Collision

public Collision(IWorldPool argPool)

Method Detail

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:

edgeIndex -

poly1 -

xf1 -

poly2 -

xf2 -

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)