Clickable Images Configuration File - Polygon

The next statement in the configuration file:


polygon  http://eelab.usyd.edu.au/~rodica/itopics/map-gren.htmll 183,90 222,18 261,89 183,90

defines the URL to be displayed when the user clicks in the polygon area defined by the coordinates. The format used to specify the coordinates is:
x1,y1 x2,y2 ... xn,yn.

Since a polygon can be defined as a figure with several angles and sides, you can specify many coordinates when using the polygon specification. Each coordinate becomes a point in the overall shape of the polygon, and an imagenary straight line is used to connect the points into a shape.
The polygon specification is used to define any area on the image which can't be defined by the square or circle specifications. Thus, triangles, stars, or any other odd shaped area can be defined using the polygon specification.Maximum 100 coordinates can be defined.

In the square-circle-triangle configuration file, the polygon specification defines the area of the green triangle in the image by specifying the coordinates of 183,90, 222,18, and 261,89, which are the three points of the triangle.

You can close the polygon line by specifying the last coordinates equal to the start point . Otherwise the polygon will be automatically closed by a straight line that connects the first point with the last specified.

Okay, I understand the polygon specification, what's next?


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Revised: Friday, 23 July 1999 by EIE WebMistress