Package ca.cgjennings.graphics.shapes

Class ShapeUtilities

java.lang.Object

ca.cgjennings.graphics.shapes.ShapeUtilities

public final class ShapeUtilities
extends java.lang.Object

Utility methods for shapes and the paths that delineate them.

Author:

Chris Jennings

Field Summary

Fields

Modifier and Type	Field	Description
static double	DEFAULT_FLATNESS	The default flatness for flattening path iterators; equal to 1.
static int	DEFAULT_LIMIT	The default limit for flattening path iterators; equal to 10.

Method Summary

Modifier and Type	Method	Description
static java.awt.geom.Area	add(java.awt.Shape lhs, java.awt.Shape rhs)	Returns a Shape that is the union of the two shape parameters: all areas that are part of either shape will be in the returned shape.
static java.awt.geom.Area	exclusiveOr(java.awt.Shape lhs, java.awt.Shape rhs)	Returns a Shape that is the exclusive or of the two shape parameters: areas in one shape or the other will be included in the returned shape, excluding areas that are present in both.
static java.awt.geom.Area	intersect(java.awt.Shape lhs, java.awt.Shape rhs)	Returns a Shape that is the intersection of the two shape parameters: only areas that are part both shapes will be in the returned shape.
static double	pathLength(java.awt.Shape shape)	Measures the length of a shape's outline by flattening its path to a sequence of line segments.
static double	pathLength(java.awt.Shape shape, double flatness)	Measures the length of a shape's outline by flattening its path to a sequence of line segments.
static double	pathLength(java.awt.Shape shape, double flatness, int limit)	Measures the length of a shape's outline by flattening its path to a sequence of line segments.
static java.awt.geom.Area	subtract(java.awt.Shape lhs, java.awt.Shape rhs)	Returns a Shape that is the difference of the two shape parameters: the result is the lhs shape with any parts that overlap the rhs removed.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FLATNESS

public static final double DEFAULT_FLATNESS

The default flatness for flattening path iterators; equal to 1.

See Also:

Constant Field Values

DEFAULT_LIMIT

public static final int DEFAULT_LIMIT

The default limit for flattening path iterators; equal to 10.

See Also:

Constant Field Values

Method Detail

pathLength

public static double pathLength(java.awt.Shape shape)

Measures the length of a shape's outline by flattening its path to a sequence of line segments. Jumps caused by moving to another point without creating a line or curve are not counted.

Parameters:

shape - the shape whose outline is to be measured

Returns:

the sum of the lengths of the line segments of the flattened curve

Throws:

java.lang.NullPointerException - if shape is null

java.lang.IllegalArgumentException - if flatness or limit is less than 0

pathLength

public static double pathLength(java.awt.Shape shape,
                                double flatness)

Measures the length of a shape's outline by flattening its path to a sequence of line segments. Jumps caused by moving to another point without creating a line or curve are not counted.

Parameters:

shape - the shape whose outline is to be measured

flatness - the maximum allowable distance between the control points and the flattened curve

Returns:

the sum of the lengths of the line segments of the flattened curve

Throws:

java.lang.NullPointerException - if shape is null

java.lang.IllegalArgumentException - if flatness or limit is less than 0

pathLength

public static double pathLength(java.awt.Shape shape,
                                double flatness,
                                int limit)

Measures the length of a shape's outline by flattening its path to a sequence of line segments. Jumps caused by moving to another point without creating a line or curve are not counted.

Parameters:

shape - the shape whose outline is to be measured

flatness - the maximum allowable distance between the control points and the flattened curve

limit - log₂ of the maximum number of line segments that will be generated for any curved segment of the path

Returns:

the sum of the lengths of the line segments of the flattened curve

Throws:

java.lang.NullPointerException - if shape is null

java.lang.IllegalArgumentException - if flatness or limit is less than 0

add

public static java.awt.geom.Area add(java.awt.Shape lhs,
                                     java.awt.Shape rhs)

Returns a Shape that is the union of the two shape parameters: all areas that are part of either shape will be in the returned shape. Neither of original shapes will be modified.

Parameters:

lhs - the primary shape

rhs - the shape to add to the primary shape

Returns:

the union of the two shapes

subtract

public static java.awt.geom.Area subtract(java.awt.Shape lhs,
                                          java.awt.Shape rhs)

Returns a Shape that is the difference of the two shape parameters: the result is the lhs shape with any parts that overlap the rhs removed. Neither of original shapes will be modified.

Parameters:

lhs - the primary shape

rhs - the shape to subtract from the primary shape

Returns:

the difference of the two shapes

intersect

public static java.awt.geom.Area intersect(java.awt.Shape lhs,
                                           java.awt.Shape rhs)

Returns a Shape that is the intersection of the two shape parameters: only areas that are part both shapes will be in the returned shape. Neither of original shapes will be modified.

Parameters:

lhs - the primary shape

rhs - the shape to intersect with the primary shape

Returns:

the intersection of the two shapes

exclusiveOr

public static java.awt.geom.Area exclusiveOr(java.awt.Shape lhs,
                                             java.awt.Shape rhs)

Returns a Shape that is the exclusive or of the two shape parameters: areas in one shape or the other will be included in the returned shape, excluding areas that are present in both. This is equivalent to union(lhs,subtract(lhs,rhs)). Neither of original shapes will be modified.

Parameters:

lhs - the primary shape

rhs - the shape to intersect with the primary shape

Returns:

the intersection of the two shapes