何时在OS X上使用OpenGL vs GL

Question

After fighting to get something to try to compile I realized some code needed to change:

#ifdef __APPLE__
#include "OpenGL/gl.h"
#include "OpenGL/glx.h"
#else 
...

needed to change into:

#ifdef __APPLE__ 
#include "GL/gl.h"
#include "GL/glx.h"
#else
#...

After installing Quartz. However, this also worked:

#ifdef __APPLE__ 
#include "OpenGL/gl.h"
#include "GL/glx.h"
#else
#...

But OpenGL/glx.h doesn't exist.

What do the different header locations on OS X mean? Why do I have two different places for OpenGL files?

Answer 1

First: You're using the wrong kind of include path; I'm surprised this works at all. What you want is:

#include <OpenGL/gl.h>

Note the use of angle brackets instead of quotation marks and he capitalization of OpenGL .

(You may need to add the OpenGL framework to your project to make this work. If you aren't using XCode, add -framework OpenGL to your compiler flags.)

Second: Don't use glx.h in Mac applications. GLX is an extension to the X11 windowing system that provides support for GL -- it is primarily meant for use on UNIX/Linux systems that use X11 as their desktop interface. The macOS desktop interface is not based on X11, so you shouldn't need GLX.

---

An explanation of the paths:

• The GL/ path on macOS refers to the X11 GL headers, which may be present if you have XQuartz installed. They are not what you want.

• OpenGL/ refers to the OpenGL framework.