org.oscim.core

Class GeometryBuffer

java.lang.Object

org.oscim.core.GeometryBuffer

Direct Known Subclasses:

MapElement

public class GeometryBuffer
extends java.lang.Object

The GeometryBuffer class holds temporary geometry data for processing. Only One geometry type can be set at a time. Use 'clear()' to reset the internal state.

'points[]' holds interleaved x,y coordinates

'index[]' is used to store number of points within a geometry and encode multi-linestrings and (multi-)polygons.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GeometryBuffer.GeometryType The Enum GeometryType.

Field Summary

Fields

Modifier and Type	Field and Description
int[]	index The indexes.
int	indexPos The current index position.
int	pointPos The current position in points array.
float[]	points The points.
GeometryBuffer.GeometryType	type The current geometry type.

Constructor Summary

Constructors

Constructor and Description
GeometryBuffer()
GeometryBuffer(float[] points, int[] index) Instantiates a new geometry buffer.
GeometryBuffer(int numPoints, int numIndices) Instantiates a new geometry buffer.

Method Summary

Modifier and Type	Method and Description
GeometryBuffer	addPoint(float x, float y) Adds a point with the coordinate x, y.
void	addPoint(Point p)
void	addPoint(PointF p)
float	area() Calculates geometry area, only polygon outer ring is taken into account.
GeometryBuffer	clear() Reset buffer.
int[]	ensureIndexSize(int size, boolean copy) Ensure index size.
float[]	ensurePointSize(int size, boolean copy) Ensure that 'points' array can hold the number of points.
int	getNumPoints()
PointF	getPoint(int i)
void	getPoint(int i, PointF out)
float	getPointX(int i)
float	getPointY(int i)
boolean	isLine()
boolean	isPoint()
boolean	isPoly()
static GeometryBuffer	makeCircle(float x, float y, float radius, int segments)
static GeometryBuffer	makeCircle(GeometryBuffer g, float x, float y, float radius, int segments)
GeometryBuffer	scale(float scaleX, float scaleY)
void	setPoint(int pos, float x, float y) Sets the point x,y at position pos.
void	simplify(float minSqDist, boolean keepLines) Remove points with distance less than minSqDist TODO could avoid superfluous copying
void	startHole() Starts a new polygon hole (inner ring).
GeometryBuffer	startLine() Start a new line.
void	startPoints() Set geometry type for points.
GeometryBuffer	startPolygon() Start a new polygon.
java.lang.String	toString()
GeometryBuffer	translate(float dx, float dy)

Methods inherited from class java.lang.Object

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

Field Detail

points

public float[] points

The points.

index

public int[] index

The indexes.

indexPos

public int indexPos

The current index position.

pointPos

public int pointPos

The current position in points array.

type

public GeometryBuffer.GeometryType type

The current geometry type.

Constructor Detail

GeometryBuffer

public GeometryBuffer()

GeometryBuffer

public GeometryBuffer(int numPoints,
                      int numIndices)

Instantiates a new geometry buffer.

Parameters:

numPoints - the num of expected points

numIndices - the num of expected indices

GeometryBuffer

public GeometryBuffer(float[] points,
                      int[] index)

Instantiates a new geometry buffer.

Parameters:

points - the points

index - the index

Method Detail

getPoint

public void getPoint(int i,
                     PointF out)

Parameters:

out - PointF to set coordinates to.

getPointX

public float getPointX(int i)

getPointY

public float getPointY(int i)

getPoint

public PointF getPoint(int i)

Returns:

PointF belongs to GeometryBuffer.

getNumPoints

public int getNumPoints()

clear

public GeometryBuffer clear()

Reset buffer.

addPoint

public GeometryBuffer addPoint(float x,
                               float y)

Adds a point with the coordinate x, y.

Parameters:

x - the x ordinate

y - the y ordinate

isPoly

public boolean isPoly()

isLine

public boolean isLine()

isPoint

public boolean isPoint()

setPoint

public void setPoint(int pos,
                     float x,
                     float y)

Sets the point x,y at position pos.

Parameters:

pos - the pos

x - the x ordinate

y - the y ordinate

startPoints

public void startPoints()

Set geometry type for points.

startLine

public GeometryBuffer startLine()

Start a new line. Sets geometry type for lines.

startPolygon

public GeometryBuffer startPolygon()

Start a new polygon. Sets geometry type for polygons.

startHole

public void startHole()

Starts a new polygon hole (inner ring).

translate

public GeometryBuffer translate(float dx,
                                float dy)

scale

public GeometryBuffer scale(float scaleX,
                            float scaleY)

ensurePointSize

public float[] ensurePointSize(int size,
                               boolean copy)

Ensure that 'points' array can hold the number of points.

Parameters:

size - the number of points to hold

copy - the the current data when array is reallocated

Returns:

the float[] array holding current coordinates

ensureIndexSize

public int[] ensureIndexSize(int size,
                             boolean copy)

Ensure index size.

Parameters:

size - the size

copy - the copy

Returns:

the short[] array holding current index

addPoint

public void addPoint(Point p)

addPoint

public void addPoint(PointF p)

simplify

public void simplify(float minSqDist,
                     boolean keepLines)

Remove points with distance less than minSqDist

TODO could avoid superfluous copying

Parameters:

minSqDist -

keepLines - keep endpoint when line would otherwise collapse into a single point

area

public float area()

Calculates geometry area, only polygon outer ring is taken into account.

Returns:

polygon area, 0 for other geometries

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

makeCircle

public static GeometryBuffer makeCircle(float x,
                                        float y,
                                        float radius,
                                        int segments)

makeCircle

public static GeometryBuffer makeCircle(GeometryBuffer g,
                                        float x,
                                        float y,
                                        float radius,
                                        int segments)