Shape objects describe backgrounds, boxes, circles, ellipses, diamonds, etc. 
designed to make an image for a presentation more clear and pretty. The aim 
is therefore to fill the gap between text and arrow objects. Shape objects can 
own text objects only. This is useful, for example to include a message in a box. 
Nice functionality to have in GAMGI shape objects includes: 1) several styles 
should be provided for shape objects, including solid, contour, partially 
transparent, etc.; 2) mechanisms should be provided to allow users to choose 
and apply OpenGL textures, in 2D and 3D shape objects; 3) mechanisms should 
be provided to allow users to make textures, namely profile gradients, as in 
the GIMP. The low-level engine infra-structure required to implement shape 
objects is fully implemented but everything else is not done yet.