SuperGIS Server JavaScript API Reference > sg/geometry > Polygon

new sg.geometry.Polygon()

Description

create a polygon object.

Position

Geometry.js

Properties

Properties	Type	Description
extent	sg.geometry.Extent	Geometry extent
type	String	Geometry type
area	Number	Polygon area
rings	Array.<sg.geometry.LinearRing>	Array of polygon rings

Methods

Type

Description

getExtent()

Returns:

sg.geometry.Extent

Return geometry extent object.

Returns:

Type	Description
sg.geometry.Extent	The extent

toWkt()

Returns:

String

Convert to WKT string

Returns:

Type	Description
String	wkt string

addRing(ring)

sg.geometry.LinearRing

Add rings to polygon

Name	Type	Description
ring	sg.geometry.LinearRing	An array of points.

contains(pt)

pt:sg.geometry.Point

Returns:Boolean

Define whether a point is contained in the polygon

Name	Type	Description
pt	sg.geometry.Point	The location defined by an X- and Y- coordinate in map units.

Returns:

Type

Description

Boolean

Check on the client if the specific point is inside the polygon

True: Inside the polygon

False:Not inside

getArea()

Returns:

Number

Return geometry area

Returns:

Type	Description
Number	The area

getCentroid()

Returns:

sg.geometry.Point

Return geometry centroid

Returns:

Type	Description
sg.geometry.Point	The point

isClockwise(ring)

ring:sg.geometry.LinearRing

Returns:Boolean

Check if the polygon ring is clockwise.

Name	Type	Description
ring	sg.geometry.LinearRing	rings

Returns:

Type	Description
Boolean	True:The ring is clockwise. False:The ring is not clockwise.

update()

Update geometry extent, area etc.

forEachVertex(callback)

function

Get the each vertex by a callback function.

callback(context)

{

//Each point (sg.geometry.Point)

context.point;

//The index of ring

context.ringIndex;

//The index of point

context.pointIndex;

}

getFirstPoint_()

Returns:

sg.geometry.point

Get the first vertex of a polygon

Returns:

Type	Description
sg.geometry.Point	The point

Example

var polygon = new sg.geometry.Polygon;

var ring = new sg.geometry.LinearRing;

ring.path.push(new sg.geometry.Point(1528256, 5628329));

ring.path.push(new sg.geometry.Point(2001868, 5663128));

ring.path.push(new sg.geometry.Point(2174538, 5446056));

ring.path.push(new sg.geometry.Point(1841530, 5458390));

polygon.addRing(ring);

polygon.update();

See live example