Glew Linking Problems in Qt Creator?

Question

I'm trying to link GLEW (with SDL and OpenGL - note, not SDL's implementation of OpenGL) in Qt Creator via a QMake file, though I'm not having much luck. No matter what I try, I seem to get the same string errors which deals with conflicting declaration problems stemming from a few typedefs. What I'd like to know is why this is happening, along with what can be done about it.

Example

/usr/include/SDL/SDL_opengl.h:4855: error: conflicting declaration ‘typedef void (* PFNGLFRAGMENTLIGHTFVSGIXPROC)(GLenum, GLenum, const GLfloat*)’
/usr/include/GL/glew.h:12201: error: ‘PFNGLFRAGMENTLIGHTFVSGIXPROC’ has a previous declaration as ‘typedef void (* PFNGLFRAGMENTLIGHTFVSGIXPROC)(GLenum, GLenum, GLfloat*)’

Is this because I'm linking with SDL (seeing as how it has OpenGL support), or is there something else going on here?

Qmake File

QT += core

LIBS += -lSDL -lSDL_image -lopengl32 -lGLU -lGLEW

stdafx.h

#pragma once

/*************/
/* #includes */
/*************/

//GL / SDL
#include <GL/glew.h>
#define GLEW_STATIC
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glext.h>
#include <SDL/SDL.h>
#include <SDL/SDL_opengl.h>

//STD
#include <iostream>
#include <fstream>

//Qt
#include <QListIterator>
#include <QMapIterator>
#include <QVector4D>
#include <QColor>

/********************/
/* Using Statements */
/********************/

using std::cout;
using std::endl;
using std::cin;

using std::fstream;

stdafx.cpp

#define GL_GLEXT_PROTOTYPES

Why are you including SDL at all? Qt does everything SDL would do. — datenwolf, Jan 24 '12 at 16:15
I'm building a Game Engine, something which Qt isn't quite meant for. — zeboidlund, Jan 24 '12 at 16:37
Actually, Qt can provide you with an OpenGL context just as SDL can. The actual engine part would be separate in both cases. If you're using Qt you might as well use its OpenGL capabilities. — Bart, Jan 24 '12 at 16:42

score 0 · Answer 1 · answered Jan 24 '12 at 16:07

0

The only solution to your problem is not to use one (either GLEW, or SDL_opengl), or at least do not include both GL/glew.h and SDL/SDL_opengl.h headers in any source or header file.

answered Jan 24 '12 at 16:07

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score 0 · Answer 2 · answered Jan 24 '12 at 16:14

I have had similar issues before which we "solved" by defining NO_SDL_GLEXT before the inclusion of <SDL/SDL_opengl.h>, so:

#define NO_SDL_GLEXT
#include <SDL/SDL_opengl.h>

I say "solved", because it made the errors go away, but I never investigated possible side-effects or problems (we ended up moving away from SDL shortly after that and never really used it anymore). Perhaps worth a try...

Glew Linking Problems in Qt Creator?

2 Answers2