[Gridflow-dev] OpenGL wrangling

[Claude Heiland-Allen]

Hi,

Despite having a recent GPU with up-to-date drivers, I can't compile 
GridFlow SVN trunk with opengl as my gl.h is only for 1.1 [1], and 
moreover one function used is in an optional part of the specification.

$ grep VERSION /usr/include/GL/gl.h
#define GL_VERSION_1_1                    1

glBlendEquation requires GL_ARB_imaging extension
glTexImage3D, glTexSubImage3D, glCopyTexSubImage3D require GL >= 1.2
glLoadTransposeMatrix, glMultTransposeMatrixf require GL >= 1.3

My standard workaround is to use GLEW[2] which usually makes things just 
work (unless a function really isn't supported, in which case the 
function pointer is 0 - shifting existence checks from compile-time to 
run-time has some problems too of course...).  I don't know how this 
would interact with Gem's usage (or not) of GLEW, though.

[1] http://www.opengl.org/wiki/Getting_started#OpenGL_2.0.2B_and_extensions
[2] http://glew.sourceforge.net/


Claude
-- 
http://claudiusmaximus.goto10.org