org.newdawn.slick.geom
Class GeomUtil

java.lang.Object
  org.newdawn.slick.geom.GeomUtil

public class GeomUtil
extends java.lang.Object

A set of utilities to play with geometry

Author:

kevin

Nested Class Summary

class

GeomUtil.HitResult A lightweigtht description of a intersection between a shape and line.

Field Summary

float	EDGE_SCALE The tolerance for determining direction change
float	EPSILON The tolerance for determining changes and steps
GeomUtilListener	listener The listener to notify of operations
int	MAX_POINTS The maximum number of points returned by an operation - prevents full lockups

Constructor Summary

GeomUtil()

Method Summary

Line	getLine(Shape shape, float sx, float sy, int e) Get a line between two points in a shape
Line	getLine(Shape shape, int s, int e) Get a line between two points in a shape
GeomUtil.HitResult	intersect(Shape shape, Line line) Intersect a line with a shape
static int	rationalPoint(Shape shape, int p) Rationalise a point in terms of a given shape
void	setListener(GeomUtilListener listener) Set the listener to be notified of geometry based operations
Shape[]	subtract(Shape target, Shape missing) Subtract one shape from another - note this is experimental and doesn't currently handle islands
Shape[]	union(Shape target, Shape other) Join to shapes together.

Methods inherited from class java.lang.Object

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

Field Detail

EPSILON

public float EPSILON

The tolerance for determining changes and steps

EDGE_SCALE

public float EDGE_SCALE

The tolerance for determining direction change

MAX_POINTS

public int MAX_POINTS

The maximum number of points returned by an operation - prevents full lockups

listener

public GeomUtilListener listener

The listener to notify of operations

Constructor Detail

GeomUtil

public GeomUtil()

Method Detail

subtract

public Shape[] subtract(Shape target,
                        Shape missing)

Subtract one shape from another - note this is experimental and doesn't currently handle islands

Parameters:

target - The target to be subtracted from

missing - The shape to subtract

Returns:

The newly created shapes

setListener

public void setListener(GeomUtilListener listener)

Set the listener to be notified of geometry based operations

Parameters:

listener - The listener to be notified of geometry based operations

union

public Shape[] union(Shape target,
                     Shape other)

Join to shapes together. Note that the shapes must be touching for this method to work.

Parameters:

target - The target shape to union with

other - The additional shape to union

Returns:

The newly created shapes

intersect

public GeomUtil.HitResult intersect(Shape shape,
                                    Line line)

Intersect a line with a shape

Parameters:

shape - The shape to compare

line - The line to intersect against the shape

Returns:

The result describing the intersection or null if none

rationalPoint

public static int rationalPoint(Shape shape,
                                int p)

Rationalise a point in terms of a given shape

Parameters:

shape - The shape

p - The index of the point

Returns:

The index that is rational for the shape

getLine

public Line getLine(Shape shape,
                    int s,
                    int e)

Get a line between two points in a shape

Parameters:

shape - The shape

s - The index of the start point

e - The index of the end point

Returns:

The line between the two points

getLine

public Line getLine(Shape shape,
                    float sx,
                    float sy,
                    int e)

Get a line between two points in a shape

Parameters:

shape - The shape

sx - The x coordinate of the start point

sy - The y coordinate of the start point

e - The index of the end point

Returns:

The line between the two points