GeneralPath

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java.awt.geom
Class GeneralPath

java.lang.Object
  java.awt.geom.GeneralPath

All Implemented Interfaces:: java.lang.Cloneable, java.awt.Shape

public final class GeneralPath
extends java.lang.Object
implements java.awt.Shape, java.lang.Cloneable

A general geometric path, consisting of any number of subpaths constructed out of straight lines and cubic or quadratic Bezier curves.

The inside of the curve is defined for drawing purposes by a winding rule. Either the WIND_EVEN_ODD or WIND_NON_ZERO winding rule can be chosen.

A drawing of a GeneralPath

The EVEN_ODD winding rule defines a point as inside a path if: A ray from the point towards infinity in an arbitrary direction intersects the path an odd number of times. Points A and C in the image are considered to be outside the path. (both intersect twice) Point B intersects once, and is inside.

The NON_ZERO winding rule defines a point as inside a path if: The path intersects the ray in an equal number of opposite directions. Point A in the image is outside (one intersection in the ’up’ direction, one in the ’down’ direction) Point B in the image is inside (one intersection ’down’) Point C in the image is outside (two intersections ’down’)

Since:: 1.2

Nested Class Summary

private static class GeneralPath.GeneralPathIterator
          A PathIterator that iterates over the segments of a GeneralPath.

Field Summary

private static double BIG_VALUE
          A big number, but not so big it can't survive a few float operations

(package private) int index
          The next available index into points.

private static int INIT_SIZE
          Initial size if not specified.

(package private) int rule
          The winding rule.

private int subpath
          The index of the most recent moveto point, or null.

(package private) byte[] types
          The path type in points.

static int WIND_EVEN_ODD
          Same constant as WIND_EVEN_ODD 55 .

static int WIND_NON_ZERO
          Same constant as PathIterator.WIND_NON_ZERO.

(package private) float[] xpoints
          The list of all points seen.

(package private) float[] ypoints


Constructor Summary

GeneralPath()
          Constructs a GeneralPath with the default (NON_ZERO) winding rule and initial capacity (20).

GeneralPath(int rule)
          Constructs a GeneralPath with a specific winding rule and the default initial capacity (20).

GeneralPath(int rule, int capacity)
          Constructs a GeneralPath with a specific winding rule and the initial capacity.

GeneralPath(java.awt.Shape s)
          Constructs a GeneralPath from an arbitrary shape object.

Method Summary

void append(PathIterator iter, boolean connect)
          Appends the segments of a PathIterator to this GeneralPath.

void append(java.awt.Shape s, boolean connect)
          Appends the segments of a Shape to the path.

java.lang.Object clone()
          Creates a new shape of the same run-time type with the same contents as this one.

void closePath()
          Closes the current subpath by drawing a line back to the point of the last moveTo.

boolean contains(double x, double y)
          Evaluates if a point is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.

boolean contains(double x, double y, double w, double h)
          Evaluates if a rectangle is completely contained within the path.

boolean contains(Point2D p)
          Evaluates if a Point2D is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.

boolean contains(Rectangle2D r)
          Evaluates if a rectangle is completely contained within the path.

java.awt.Shape createTransformedShape(AffineTransform xform)
          Creates a transformed version of the path.

void curveTo(float x1, float y1, float x2, float y2, float x3, float y3)
          Appends a cubic Bezier curve to the current path.

private void ensureSize(int size)
          Helper method - ensure the size of the data arrays, otherwise, reallocate new ones twice the size

private int evaluateCrossings(double x, double y, boolean neg, boolean useYaxis, double distance)
          Helper method - evaluates the number of intersections on an axis from the point (x,y) to the point (x,y+distance) or (x+distance,y).

private int getAxisIntersections(double x, double y, boolean useYaxis, double distance)
          Helper method - Get the total number of intersections from (x,y) along a given axis, within a given distance.

java.awt.Rectangle getBounds()
          Returns the path’s bounding box.

Rectangle2D getBounds2D()
          Returns the path’s bounding box, in float precision

Point2D getCurrentPoint()
          Returns the current appending point of the path.

PathIterator getPathIterator(AffineTransform at)
          Creates a PathIterator for iterating along the segments of the path.

PathIterator getPathIterator(AffineTransform at, double flatness)
          Creates a new FlatteningPathIterator for the path

private int getWindingNumber(double x, double y)
          Helper method - returns the winding number of a point.

int getWindingRule()
          Returns the path’s current winding rule.

boolean intersects(double x, double y, double w, double h)
          Evaluates if a rectangle intersects the path.

boolean intersects(Rectangle2D r)
          Evaluates if a Rectangle2D intersects the path.

void lineTo(float x, float y)
          Appends a straight line to the current path.

void moveTo(float x, float y)
          Adds a new point to a path.

void quadTo(float x1, float y1, float x2, float y2)
          Appends a quadratic Bezier curve to the current path.

void reset()
          Resets the path.

void setWindingRule(int rule)
          Sets the path’s winding rule, which controls which areas are considered ’inside’ or ’outside’ the path on drawing.

void transform(AffineTransform xform)
          Applies a transform to the path.

Methods inherited from class java.lang.Object

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

Field Detail

WIND_EVEN_ODD

public static final int WIND_EVEN_ODD

Same constant as WIND_EVEN_ODD 55 .

See Also:: Constant Field Values

WIND_NON_ZERO

public static final int WIND_NON_ZERO

Same constant as PathIterator.WIND_NON_ZERO.

See Also:: Constant Field Values

INIT_SIZE

private static final int INIT_SIZE

Initial size if not specified.

See Also:: Constant Field Values

BIG_VALUE

private static final double BIG_VALUE

A big number, but not so big it can't survive a few float operations

See Also:: Constant Field Values

rule

int rule

The winding rule. This is package-private to avoid an accessor method.

types

byte[] types

The path type in points. Note that xpoints[index] and ypoints[index] maps to types[index]; the control points of quad and cubic paths map as well but are ignored. This is package-private to avoid an accessor method.

xpoints

float[] xpoints

The list of all points seen. Since you can only append floats, it makes sense for these to be float[]. I have no idea why Sun didn't choose to allow a general path of double precision points. Note: Storing x and y coords seperately makes for a slower transforms, But it speeds up and simplifies box-intersection checking a lot. These are package-private to avoid accessor methods.

ypoints

float[] ypoints

subpath

private int subpath

The index of the most recent moveto point, or null.

index

int index

The next available index into points. This is package-private to avoid an accessor method.

Constructor Detail

GeneralPath

public GeneralPath()

Constructs a GeneralPath with the default (NON_ZERO) winding rule and initial capacity (20).

GeneralPath

public GeneralPath(int rule)

Constructs a GeneralPath with a specific winding rule and the default initial capacity (20).

GeneralPath

public GeneralPath(int rule,
                   int capacity)

Constructs a GeneralPath with a specific winding rule and the initial capacity. The initial capacity should be the approximate number of path segments to be used.

GeneralPath

public GeneralPath(java.awt.Shape s)

Constructs a GeneralPath from an arbitrary shape object. The Shapes PathIterator path and winding rule will be used.

Method Detail

moveTo

public void moveTo(float x,
                   float y)

Adds a new point to a path.

lineTo

public void lineTo(float x,
                   float y)

Appends a straight line to the current path.

quadTo

public void quadTo(float x1,
                   float y1,
                   float x2,
                   float y2)

Appends a quadratic Bezier curve to the current path.

curveTo

public void curveTo(float x1,
                    float y1,
                    float x2,
                    float y2,
                    float x3,
                    float y3)

Appends a cubic Bezier curve to the current path.

closePath

public void closePath()

Closes the current subpath by drawing a line back to the point of the last moveTo.

append

public void append(java.awt.Shape s,
                   boolean connect)

Appends the segments of a Shape to the path. If connect is true, the new path segments are connected to the existing one with a line. The winding rule of the Shape is ignored.

append

public void append(PathIterator iter,
                   boolean connect)

Appends the segments of a PathIterator to this GeneralPath. Optionally, the initial PathIterator.SEG_MOVETO 55 segment of the appended path is changed into a PathIterator.SEG_LINETO 55 segment.

getWindingRule

public int getWindingRule()

Returns the path’s current winding rule.

setWindingRule

public void setWindingRule(int rule)

Sets the path’s winding rule, which controls which areas are considered ’inside’ or ’outside’ the path on drawing. Valid rules are WIND_EVEN_ODD for an even-odd winding rule, or WIND_NON_ZERO for a non-zero winding rule.

getCurrentPoint

public Point2D getCurrentPoint()

Returns the current appending point of the path.

reset

public void reset()

Resets the path. All points and segments are destroyed.

transform

public void transform(AffineTransform xform)

Applies a transform to the path.

createTransformedShape

public java.awt.Shape createTransformedShape(AffineTransform xform)

Creates a transformed version of the path.

getBounds

public java.awt.Rectangle getBounds()

Returns the path’s bounding box.

Specified by:: getBounds in interface java.awt.Shape

getBounds2D

public Rectangle2D getBounds2D()

Returns the path’s bounding box, in float precision

Specified by:: getBounds2D in interface java.awt.Shape

contains

public boolean contains(double x,
                        double y)

Evaluates if a point is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.

Specified by:: contains in interface java.awt.Shape

contains

public boolean contains(Point2D p)

Evaluates if a Point2D is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.

Specified by:: contains in interface java.awt.Shape

contains

public boolean contains(double x,
                        double y,
                        double w,
                        double h)

Evaluates if a rectangle is completely contained within the path. This method will return false in the cases when the box intersects an inner segment of the path. (i.e.: The method is accurate for the EVEN_ODD winding rule)

Specified by:: contains in interface java.awt.Shape

contains

public boolean contains(Rectangle2D r)

Specified by:: contains in interface java.awt.Shape

intersects

public boolean intersects(double x,
                          double y,
                          double w,
                          double h)

Evaluates if a rectangle intersects the path.

Specified by:: intersects in interface java.awt.Shape

intersects

public boolean intersects(Rectangle2D r)

Evaluates if a Rectangle2D intersects the path.

Specified by:: intersects in interface java.awt.Shape

getPathIterator

public PathIterator getPathIterator(AffineTransform at)

Creates a PathIterator for iterating along the segments of the path.

Specified by:: getPathIterator in interface java.awt.Shape

getPathIterator

public PathIterator getPathIterator(AffineTransform at,
                                    double flatness)

Creates a new FlatteningPathIterator for the path

Specified by:: getPathIterator in interface java.awt.Shape

clone

public java.lang.Object clone()

Creates a new shape of the same run-time type with the same contents as this one.

Since:: 1.2

ensureSize

private void ensureSize(int size)

Helper method - ensure the size of the data arrays, otherwise, reallocate new ones twice the size

getAxisIntersections

private int getAxisIntersections(double x,
                                 double y,
                                 boolean useYaxis,
                                 double distance)

Helper method - Get the total number of intersections from (x,y) along a given axis, within a given distance.

getWindingNumber

private int getWindingNumber(double x,
                             double y)

Helper method - returns the winding number of a point.

evaluateCrossings

private int evaluateCrossings(double x,
                              double y,
                              boolean neg,
                              boolean useYaxis,
                              double distance)

Helper method - evaluates the number of intersections on an axis from the point (x,y) to the point (x,y+distance) or (x+distance,y).

Overview

Package

Class

Use

Deprecated

Index

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Nested Class Summary
`private static class`	`GeneralPath.GeneralPathIterator` A PathIterator that iterates over the segments of a GeneralPath.

Field Summary
`private static double`	`BIG_VALUE` A big number, but not so big it can't survive a few float operations
`(package private) int`	`index` The next available index into points.
`private static int`	`INIT_SIZE` Initial size if not specified.
`(package private) int`	`rule` The winding rule.
`private int`	`subpath` The index of the most recent moveto point, or null.
`(package private) byte[]`	`types` The path type in points.
`static int`	`WIND_EVEN_ODD` Same constant as `WIND_EVEN_ODD` 55 .
`static int`	`WIND_NON_ZERO` Same constant as `PathIterator.WIND_NON_ZERO`.
`(package private) float[]`	`xpoints` The list of all points seen.
`(package private) float[]`	`ypoints`

Constructor Summary
`GeneralPath()` Constructs a GeneralPath with the default (NON_ZERO) winding rule and initial capacity (20).
`GeneralPath(int rule)` Constructs a GeneralPath with a specific winding rule and the default initial capacity (20).
`GeneralPath(int rule, int capacity)` Constructs a GeneralPath with a specific winding rule and the initial capacity.
`GeneralPath(java.awt.Shape s)` Constructs a GeneralPath from an arbitrary shape object.

Method Summary
`void`	`append(PathIterator iter, boolean connect)` Appends the segments of a PathIterator to this GeneralPath.
`void`	`append(java.awt.Shape s, boolean connect)` Appends the segments of a Shape to the path.
`java.lang.Object`	`clone()` Creates a new shape of the same run-time type with the same contents as this one.
`void`	`closePath()` Closes the current subpath by drawing a line back to the point of the last moveTo.
`boolean`	`contains(double x, double y)` Evaluates if a point is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.
`boolean`	`contains(double x, double y, double w, double h)` Evaluates if a rectangle is completely contained within the path.
`boolean`	`contains(Point2D p)` Evaluates if a Point2D is within the GeneralPath, The NON_ZERO winding rule is used, regardless of the set winding rule.
`boolean`	`contains(Rectangle2D r)` Evaluates if a rectangle is completely contained within the path.
`java.awt.Shape`	`createTransformedShape(AffineTransform xform)` Creates a transformed version of the path.
`void`	`curveTo(float x1, float y1, float x2, float y2, float x3, float y3)` Appends a cubic Bezier curve to the current path.
`private void`	`ensureSize(int size)` Helper method - ensure the size of the data arrays, otherwise, reallocate new ones twice the size
`private int`	`evaluateCrossings(double x, double y, boolean neg, boolean useYaxis, double distance)` Helper method - evaluates the number of intersections on an axis from the point (x,y) to the point (x,y+distance) or (x+distance,y).
`private int`	`getAxisIntersections(double x, double y, boolean useYaxis, double distance)` Helper method - Get the total number of intersections from (x,y) along a given axis, within a given distance.
`java.awt.Rectangle`	`getBounds()` Returns the path’s bounding box.
`Rectangle2D`	`getBounds2D()` Returns the path’s bounding box, in `float` precision
`Point2D`	`getCurrentPoint()` Returns the current appending point of the path.
`PathIterator`	`getPathIterator(AffineTransform at)` Creates a PathIterator for iterating along the segments of the path.
`PathIterator`	`getPathIterator(AffineTransform at, double flatness)` Creates a new FlatteningPathIterator for the path
`private int`	`getWindingNumber(double x, double y)` Helper method - returns the winding number of a point.
`int`	`getWindingRule()` Returns the path’s current winding rule.
`boolean`	`intersects(double x, double y, double w, double h)` Evaluates if a rectangle intersects the path.
`boolean`	`intersects(Rectangle2D r)` Evaluates if a Rectangle2D intersects the path.
`void`	`lineTo(float x, float y)` Appends a straight line to the current path.
`void`	`moveTo(float x, float y)` Adds a new point to a path.
`void`	`quadTo(float x1, float y1, float x2, float y2)` Appends a quadratic Bezier curve to the current path.
`void`	`reset()` Resets the path.
`void`	`setWindingRule(int rule)` Sets the path’s winding rule, which controls which areas are considered ’inside’ or ’outside’ the path on drawing.
`void`	`transform(AffineTransform xform)` Applies a transform to the path.

java.awt.geom Class GeneralPath

WIND_EVEN_ODD

WIND_NON_ZERO

INIT_SIZE

BIG_VALUE

rule

types

xpoints

ypoints

subpath

index

GeneralPath

GeneralPath

GeneralPath

GeneralPath

moveTo

lineTo

quadTo

curveTo

closePath

append

append

getWindingRule

setWindingRule

getCurrentPoint

reset

transform

createTransformedShape

getBounds

getBounds2D

contains

contains

contains

contains

intersects

intersects

getPathIterator

getPathIterator

clone

ensureSize

getAxisIntersections

getWindingNumber

evaluateCrossings

java.awt.geom
Class GeneralPath