immvertex is an implementation of OpenGL's immediate mode function API which runs on top of OpenGLES - specifically, the version that runs on the iPhone.
Simply pretend it's still the 90's, and use those GL API's, except instead of "gl" prefix them with "vx".
For example:
vxBegin(GL_TRIANGLE_STRIP);
vxColor4f(1.0, 1.0, 0.0, 1.0);
vxVertex2f(-0.5f, -0.5f);
vxColor4f(0.0, 1.0, 1.0, 1.0);
vxVertex2f(0.5f, -0.5f);
vxColor4f(0.0, 0.0, 0.0, 0.0);
vxVertex2f(-0.5f, 0.5f);
vxColor4f(1.0, 0.0, 1.0, 1.0);
vxVertex2f(0.5f, 0.5f);
vxEnd();
Will draw a lovely square to the screen!
A word of warning however. When your app exits, you'd best clear the temporary memory used to build the vertex array!
vxDestroyState();
Yes - but if you knew that, then why are you looking at this?
Have fun!