Extending opengl_renderer

[Lars Jahr Røine]

Hello,

As part of my master thesis I'm going to make customized plotting 
function for the plotting of unstructured grids in octave. I've decided 
to do this by modifying and extending the opengl_renderer class located 
in gl-render.cc (Part of the thesis is to speed up plotting which now 
uses the patch() function, so I'm going to make use of OpenGL3.3 or 
newer and avoid the fixed function pipeline.)

I've played around a bit with the gl-code and the code in graphics.cc. 
My problem however is that whenever I do a change and compile the code 
it takes forever (1.5 minutes). What is the normal approach to writing 
and testing part of the graphics code? Is there some way to compile only 
certain parts of the source code? Any hints and tips are greatly 
appreciated.

I should mention that I'm quite unaccustomed to working with such a 
large code base, so I apologize if my questions seem naive :)

Regards,

Lars