com.almasb.fxgl.physics.box2d.collision.shapes

Class Shape

java.lang.Object

com.almasb.fxgl.physics.box2d.collision.shapes.Shape

Direct Known Subclasses:

ChainShape, CircleShape, EdgeShape, PolygonShape

public abstract class Shape
extends Object

A shape is used for collision detection. You can create a shape however you like. Shapes used for simulation in World are created automatically when a Fixture is created. Shapes may encapsulate one or more child shapes.

Constructor Summary

Constructors

Constructor and Description
Shape(ShapeType type, float radius)

Method Summary

Modifier and Type	Method and Description
abstract Shape	clone()
abstract void	computeAABB(AABB aabb, Transform xf, int childIndex) Given a transform, compute the associated axis aligned bounding box for a child shape.
abstract float	computeDistanceToOut(Transform xf, Vec2 p, int childIndex, Vec2 normalOut) Compute the distance from the current shape to the specified point.
abstract void	computeMass(MassData massData, float density) Compute the mass properties of this shape using its dimensions and density.
abstract int	getChildCount()
float	getRadius() The radius of the underlying shape.
ShapeType	getType() Get the type of this shape.
abstract boolean	raycast(RayCastOutput output, RayCastInput input, Transform transform, int childIndex) Cast a ray against a child shape.
void	setRadius(float radius) Sets the radius of the underlying shape.
abstract boolean	testPoint(Transform xf, Vec2 p) Test a point for containment in this shape.

Methods inherited from class java.lang.Object

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

Constructor Detail

Shape

public Shape(ShapeType type,
             float radius)

Method Detail

clone

public abstract Shape clone()

Overrides:

clone in class Object

getType

public ShapeType getType()

Get the type of this shape. You can use this to down cast to the concrete shape.

Returns:

the shape type

getRadius

public float getRadius()

The radius of the underlying shape. This can refer to different things depending on the shape implementation.

Returns:

shape radius

setRadius

public void setRadius(float radius)

Sets the radius of the underlying shape. This can refer to different things depending on the implementation.

Parameters:

radius - shape radius

getChildCount

public abstract int getChildCount()

Returns:

the number of child primitives

testPoint

public abstract boolean testPoint(Transform xf,
                                  Vec2 p)

Test a point for containment in this shape. This only works for convex shapes.

Parameters:

xf - the shape world transform.

p - a point in world coordinates.

raycast

public abstract boolean raycast(RayCastOutput output,
                                RayCastInput input,
                                Transform transform,
                                int childIndex)

Cast a ray against a child shape.

Parameters:

output - the ray-cast results.

input - the ray-cast input parameters.

transform - the transform to be applied to the shape.

childIndex - the child shape index

Returns:

if hit

computeAABB

public abstract void computeAABB(AABB aabb,
                                 Transform xf,
                                 int childIndex)

Given a transform, compute the associated axis aligned bounding box for a child shape.

Parameters:

aabb - returns the axis aligned box

xf - the world transform of the shape

childIndex - the child shape index

computeMass

public abstract void computeMass(MassData massData,
                                 float density)

Compute the mass properties of this shape using its dimensions and density. The inertia tensor is computed about the local origin.

Parameters:

massData - returns the mass data for this shape.

density - the density in kilograms per meter squared.

computeDistanceToOut

public abstract float computeDistanceToOut(Transform xf,
                                           Vec2 p,
                                           int childIndex,
                                           Vec2 normalOut)

Compute the distance from the current shape to the specified point. This only works for convex shapes.

Parameters:

xf - the shape world transform.

p - a point in world coordinates.

normalOut - returns the direction in which the distance increases.

Returns:

the distance from the current shape.