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`java.lang.Object`

`java.awt.geom.FlatteningPathIterator`

**Implemented Interfaces:**- PathIterator

A PathIterator for approximating curved path segments by sequences
of straight lines. Instances of this class will only return
segments of type

`PathIterator.SEG_MOVETO`

, `PathIterator.SEG_LINETO`

, and `PathIterator.SEG_CLOSE`

.
The accuracy of the approximation is determined by two parameters:

- The
*flatness*is a threshold value for deciding when a curved segment is consided flat enough for being approximated by a single straight line. Flatness is defined as the maximal distance of a curve control point to the straight line that connects the curve start and end. A lower flatness threshold means a closer approximation. See`QuadCurve2D.getFlatness()`

and`CubicCurve2D.getFlatness()`

for drawings which illustrate the meaning of flatness. - The
*recursion limit*imposes an upper bound for how often a curved segment gets subdivided. A limit of*n*means that for each individual quadratic and cubic Bézier spline segment, at most 2^{n}`PathIterator.SEG_LINETO`

segments will be created.

**Memory Efficiency:** The memory consumption grows linearly
with the recursion limit. Neither the *flatness* parameter nor
the number of segments in the flattened path will affect the memory
consumption.

**Thread Safety:** Multiple threads can safely work on
separate instances of this class. However, multiple threads should
not concurrently access the same instance, as no synchronization is
performed.

**Since:**- 1.2

**See Also:**`Implementation Note`

### Fields inherited from interface java.awt.geom.PathIterator

`SEG_CLOSE`

,`SEG_CUBICTO`

,`SEG_LINETO`

,`SEG_MOVETO`

,`SEG_QUADTO`

,`WIND_EVEN_ODD`

,`WIND_NON_ZERO`

## Constructor Summary

`FlatteningPathIterator(PathIterator src, double flatness)`

- Constructs a new PathIterator for approximating an input PathIterator with straight lines.

`FlatteningPathIterator(PathIterator src, double flatness, int limit)`

- Constructs a new PathIterator for approximating an input PathIterator with straight lines.

## Method Summary

`int`

`currentSegment(double[] coords)`

- Returns the coordinates of the next point(s), as well as the type of line segment.

`int`

`currentSegment(float[] coords)`

- Returns the coordinates of the next point(s), as well as the type of line segment.

`double`

`getFlatness()`

- Returns the maximally acceptable flatness.

`int`

`getRecursionLimit()`

- Returns the maximum number of recursive curve subdivisions.

`int`

`getWindingRule()`

- Returns the winding rule to determine which points are inside this path.

`boolean`

`isDone()`

- Tests if the iterator is exhausted.

`void`

`next()`

- Advance to the next segment in the iteration.

### Methods inherited from class java.lang.Object

`clone`

,`equals`

,`extends Object> getClass`

,`finalize`

,`hashCode`

,`notify`

,`notifyAll`

,`toString`

,`wait`

,`wait`

,`wait`

public FlatteningPathIterator(PathIterator src, double flatness)

Constructs a new PathIterator for approximating an input PathIterator with straight lines. The approximation works by recursive subdivisons, until the specified flatness threshold is not exceeded.There will not be more than 10 nested recursion steps, which means that a single

`SEG_QUADTO`

or`SEG_CUBICTO`

segment is approximated by at most 2^{10}= 1024 straight lines.

public FlatteningPathIterator(PathIterator src, double flatness, int limit)

Constructs a new PathIterator for approximating an input PathIterator with straight lines. The approximation works by recursive subdivisons, until the specified flatness threshold is not exceeded. Additionally, the number of recursions is also bound by the specified recursion limit.

public int currentSegment(double[] coords)

Returns the coordinates of the next point(s), as well as the type of line segment. The input array must be at least a double[6], to accomodate up to three (x,y) point pairs (although if you know the iterator is flat, you can probably get by with a double[2]). If the returned type is SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if the returned type is SEG_QUADTO, the first two points are modified; if the returned type is SEG_CUBICTO, all three points are modified; and if the returned type is SEG_CLOSE, the array is untouched.

Specified by:- currentSegment in interface PathIterator

Parameters:`coords`

- the array to place the point coordinates in

Returns:- the segment type

Throws:`NullPointerException`

- if coords is null`ArrayIndexOutOfBoundsException`

- if coords is too small`NoSuchElementException`

- optional when isDone() is true

public int currentSegment(float[] coords)

Returns the coordinates of the next point(s), as well as the type of line segment. The input array must be at least a float[6], to accomodate up to three (x,y) point pairs (although if you know the iterator is flat, you can probably get by with a float[2]). If the returned type is SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if the returned type is SEG_QUADTO, the first two points are modified; if the returned type is SEG_CUBICTO, all three points are modified; and if the returned type is SEG_CLOSE, the array is untouched.

Specified by:- currentSegment in interface PathIterator

Parameters:`coords`

- the array to place the point coordinates in

Returns:- the segment type

Throws:`NullPointerException`

- if coords is null`ArrayIndexOutOfBoundsException`

- if coords is too small`NoSuchElementException`

- optional when isDone() is true

public int getRecursionLimit()

Returns the maximum number of recursive curve subdivisions.

public int getWindingRule()

Returns the winding rule to determine which points are inside this path.

Specified by:- getWindingRule in interface PathIterator

Returns:- the winding rule

public boolean isDone()

Tests if the iterator is exhausted. If this returns true, currentSegment and next may throw a NoSuchElementException (although this is not required).

Specified by:- isDone in interface PathIterator

Returns:- true if the iteration is complete

public void next()

Advance to the next segment in the iteration. It is not specified what this does if called when isDone() returns true.

Specified by:- next in interface PathIterator

Throws:`NoSuchElementException`

- optional when isDone() is true

FlatteningPathIterator.java -- Approximates curves by straight lines
Copyright (C) 2003 Free Software Foundation
This file is part of GNU Classpath.
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