Adding shapes to a map, clipping at coastlines etc..

Topics: General Topics
Oct 5, 2006 at 1:54 PM
Can I add colour filled polgons to a layer? for example if I wanted to highlight an arbitrary area on a map to show, say population density how would I do it?
Steps could be:
1. Define the polygon which I want to highlight then color the polygon in layer - I don't know how to do this, but I'm sure
SharpMap'll do that.
2. The problem comes if I need the polygon to be clipped by a coastline or country border say? is there any way of doing it?
I don't want to calculate the polygon exactly as it'll be more of a bounded box , but I do need it to be neat when it hits borders and coastlines.

Oct 6, 2006 at 2:46 PM
You'll have to build the polygon your self. But that should be pretty trivial if you use the NetTopologySuite ( Then take that polygon and feed it into a GeometryProvider object. Create a new layer based on the GeometryProvider.

Oct 6, 2006 at 3:50 PM
Thanks, for the reply. Will that get round the problem of clipping at borders and coastlines ?