Lines & Polygons

Lines & Polygons
In addition to points, worldKit can draw polygons, lines, and boxes. In the RSS file, instead of specifying coordinates in <georss:point>, a space seperated list of coordinates is provided in either <georss:polygon>, <georss:line>, or <georss:box>. Each coordinate is a space seperated lat/long pair.

GeoRSS Simple (shown here) and GeoRSS GML are both supported and recommended. The old informal specification of geo:polygon and geo:line is still supported but not recommended.

Here is a simple example of a polygon, a line, and a box in RSS.

<?xml version="1.0"?>
<rss version="2.0" xmlns:georss="http://www.georss.org/georss">
<channel>

...

<item>
 <title>An example polygon</title>
 <link>http://example.com/geo</link>
 <description>Just an example</description>
 <georss:polygon>30 -120 30 -100 20 -100 30 -120</georss:polygon>
</item>

...

<item>
 <title>An example line</title>
 <link>http://example.com/geo</link>
 <description>Just an example</description>
 <georss:line>50 -0.2 54 3 59 2.56</georss:line>

...

</channel> </rss>

...

<item>
 <title>An example box</title>
 <link>http://example.com/geo</link>
 <description>Just an example</description>
 <georss:box>42.943 -71.032 43.039 -69.856</georss:box>

...

</channel> </rss>
As for colors, the line/polygon/box border will be drawn with the hex color listed in config option <linecolor>. The polygon/box will be filled with colors specified in <initialplotcolor> and <restingplotcolor>. The alpha of borders and lines is specified in <linealpha>, and of fill in <fillalpha>.

Annotation textboxes are positioned at the first coordinate in the list. Polygons/boxes are filled with 30% transparency, so annotations plotted before are visible. However, those covered annotations are not clickable. One way to adjust this behavior is through the <zlevel> config option.

If <zoomto> is set, the zoom will be centered on the first coordinate listed in the line or polygon. Alternately, if <georss:point> is specified, the zoom will center to that point.