8.3. Adding GD Graphics to Restrictionmap.pm

Now that you've seen an overview of the GD.pm Perl module, let's enhance the Restrictionmap.pm module that you've seen previously in Chapter 5, Chapter 6, and Chapter 7 so it can output PNG graphics files.

Reviewing how the Restrictionmap.pm module works, you can see that its get_graphic method examines the _graphictype attribute to determine what graphics drawing method to call. Following is the get_graphic method again, along with the attributes the class defines. (Recall that this class inherits from the class Restriction.pm, so many things are defined there):