Using a Pixmap as Geometry Description
To use graphical input for the description of complex 2D
geometries is an interesting possibility of IBG.
The example file mainpix.c creates a 2D grid using the
pixmap test.ppm. To create this
program, simply
make pix
The picture is assumed to describe the geometry by using a single
color for each region.
Example: Rügen Island (Germany):
This test picture I have created in the following way:
- A picture of the region around
Rügen was obtained with the Xerox PARC Map Viewer and
the xv grab function.
- xpaint was used to manipulate this picture:
- At first, a picture which contains
only two colors was created.
- The two segments have been subdivided into six more convex
subsegments with slightly different colors. This technique allows to
avoid topological errors for very small islands.
- The resulting picture has been
saved in the PPM format.