org.gicentre.geomap

Class Polygon

java.lang.Object

org.gicentre.geomap.Polygon

All Implemented Interfaces:

Feature

public class Polygon
extends java.lang.Object
implements Feature

Class for drawing a polygon in screen coordinate space.

Version:

1.3, 4th March, 2017.

Author:

Jo Wood and Iain Dillingham, giCentre, City University London.

Constructor Summary

Constructors

Constructor and Description
Polygon(float[] x, float[] y, processing.core.PApplet parent) Constructs a new polygon object with the given geometry.
Polygon(processing.core.PApplet parent) Constructs a new polygon object with the default geometry.

Method Summary

Modifier and Type	Method and Description
void	addPart(float[] x, float[] y) Adds a new part to the polygon.
boolean	contains(float geoX, float geoY) Tests whether the given point is contained within the polygon.
void	draw(Geographic transformer) Draws the polygon in the parent sketch.
int	getNumVertices() Reports the number of vertices that make up the polygon feature.
java.util.ArrayList<java.lang.Integer>	getSubPartPointers() Reports pointers to the vertex index for each of the partss that make up the polygon feature.
FeatureType	getType() Report the type of feature (polygon).
float[]	getXCoords() Reports the x coordinates coordinates of the polygon feature.
float[]	getYCoords() Reports the y coordinates coordinates of the polygon feature.
void	setRenderer(Drawable renderer) Sets the renderer to be used for drawing this feature.

Methods inherited from class java.lang.Object

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

Constructor Detail

Polygon

public Polygon(processing.core.PApplet parent)

Constructs a new polygon object with the default geometry.

Parameters:

parent - The parent sketch.

Polygon

public Polygon(float[] x,
               float[] y,
               processing.core.PApplet parent)

Constructs a new polygon object with the given geometry.

Parameters:

x - x coordinates of the polygon.

y - y coordinates of the polygon.

parent - The parent sketch.

Method Detail

addPart

public void addPart(float[] x,
                    float[] y)

Adds a new part to the polygon. This allows complex polygons with islands, holes and multiple parts to be created.

Parameters:

x - x coordinates of the polygon.

y - y coordinates of the polygon.

setRenderer

public void setRenderer(Drawable renderer)

Sets the renderer to be used for drawing this feature. This need only be set if some non-default rendering is required (such as the sketchy rendering produced by the Handy library).

Specified by:

setRenderer in interface Feature

Parameters:

renderer - New renderer to use or null if default rendering is to be used.

draw

public void draw(Geographic transformer)

Draws the polygon in the parent sketch.

Specified by:

draw in interface Feature

Parameters:

transformer - Class that handles the geographic to screen transformations.

getNumVertices

public int getNumVertices()

Reports the number of vertices that make up the polygon feature.

Specified by:

getNumVertices in interface Feature

Returns:

number of vertices that make up the polygon.

getSubPartPointers

public java.util.ArrayList<java.lang.Integer> getSubPartPointers()

Reports pointers to the vertex index for each of the partss that make up the polygon feature. Simple polygons have one part with a vertex index of 0. Complex polygons can comprise many parts such as islands, holes etc. The position in the list of coordinates returned by getXcoord()s and getYCoords() of the start of each part is returned here.

Returns:

Pointers to the start of each polygon part.

getXCoords

public float[] getXCoords()

Reports the x coordinates coordinates of the polygon feature. This includes the coordinates for all parts in multi-part polygons. To break down the coordinates into parts, call getSubPartPointers() to find the position in the array corresponding to the start of each part.

Returns:

x coordinates of the polygon feature.

getYCoords

public float[] getYCoords()

Reports the y coordinates coordinates of the polygon feature. This includes the coordinates for all parts in multi-part polygons. To break down the coordinates into parts, call getSubPartPointers() to find the position in the array corresponding to the start of each part.

Returns:

y coordinates of the polygon feature.

getType

public FeatureType getType()

Report the type of feature (polygon).

Specified by:

getType in interface Feature

Returns:

Type of feature

contains

public boolean contains(float geoX,
                        float geoY)

Tests whether the given point is contained within the polygon.

Specified by:

contains in interface Feature

Parameters:

geoX - x coordinate in geographic coordinates.

geoY - y coordinate in geographic coordinates.

Returns:

True if the given point is contained within the polygon, false if not.