The following program generates a GeoWin geow. Then it creates an editable scene sc of polygons and changes the color attributes for the polygon scene.

Then the interactive mode for sc is started.

On the right there is a screenshot of the program after adding some polygons interactively. Clicking on the picture shows the GeoWin in original size.

#include <LEDA/graphics/GeoWin.h>
#include <LEDA/core/list.h>
#include <LEDA/geo/polygon.h>

using namespace leda;

int main() 
{
  GeoWin geow;

  list<polygon> L;
  geo_scene sc=geow.new_scene(L);

  geow.set_color(sc,black);
  geow.set_fill_color(sc,grey1);
 
  geow.edit(sc);

  geow.get_window().screenshot("geowin_first");

  return 0;
}