An Example: drawing the French tricolour
You can create images using Perl and the Image Magic Library. The first tutorial Flags looks at drawing flags of the world, from simple flags such as Libya to more complicated flags such as the Stars and Stripes of the USA.
Notice that the blue rectangle is at (0,0), it is 50 wide and 100 deep so the commands to draw the blue rectangle are:
$g->filledRectangle(0,0, 50,100, $g->colorAllocate(0,0,255));
Consult the User's Guide for information on changing material in progzoo.
You can mess about in the Playpen.