Qt 5.0.1 and glext.h

[kmt11]

Hi,

Newbie here, and evaluating QT with a view to deploying it company-wide for app development, including for ios. I am aware that the ios side of QT is some time off, and willing to wait if QT works well on Windows.

However, I have :

#include <GL/gl.h>
#include <GL/glext.h>
#include <GL/glu.h>

with the error message :

fatal error C1083: Cannot open include file: 'GL/glext.h': No such file or directory

No combination of also including, or substituting <QtOpenGL>, <QGLFormat>, etc seem to work, instead generating over a hundred errors.

Any advice would be much appreciated.

[SGaist]

Hi and welcome to devnet,

You might be missing the "glew":http://glew.sourceforge.net/ library

EDIT:
Forgot to ask, which version of Qt did you download ?

As a side note it's Qt, QT stands for Apple's QuickTime :)

[kmt11]

Hi,

I stand corrected. Qt it is then.
What did I download ? Qt 5.0.2 64bit for desktop (MSVC2012)

Trying to port a 4.8 project on Unix built by my colleague, to my 5.0.2 on windows, and suspect the problem is that he has used legacy opengl.

[SGaist]

What could be the most simple is to try Qt 5.1.

IIRC, there should have been some patches that remove the needs for glew

Hope it helps

[kmt11]

Thanks. Well, I'm just evaluating it with a view to a commercial multi-seat licence, so interested if it is a configuration issue or a simple workaround. Having used many other development packages over the years to develop a variety of apps, I am somewhat disappointed with our experience of Qt to date.

I'm also trying 4.8 on a Mac, so don't get me started there !

Nevertheless, I'll persevere, who knows, could be a simple fix.

[SGaist]

On my side, I've been developing with Qt since the version 3 days without major problems.

Currently on Windows and OS X with the 4.8.X series and it's going quite well. So if you encounter some problem I might be able to help

[kmt11]

Thank you for your offer. Seems to be up and running on Mac, after having downloaded multi-Gb to update the OS and update xcode.

Qt Demo examples compile and run, but a ported project is failing to find GL/gl.h, GL/glext.h, etc.

[SGaist]

Do you have QT += opengl in your pro file ?

[kmt11]

Yes, most certainly

[SGaist]

Is it a simple project ? (Meaning one pro file for all)

If not check that every other project that uses these class also includes opengl

[kmt11]

It is one pro file only.

I now notice that, if I try #include <QtOpenGL>, I get "library not found for -IGLU", if that helps.

[SGaist]

I think I found out the first problem (must be sleepy to have been so long...):

on mac you have to:

@#include <OpenGL/gl.h>@

That is: framework_name/filename.h

You can surround that with

@#ifdef Q_OS_MACX
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif@

[kmt11]

Thank you. That seems to have fixed it.

Now builds with no errors.

The app runs perfectly. Brilliant. You've made my day.

[SGaist]

You're welcome !

Don't forget to update your thread's title to solved so other forum users may know that a solution has been found :)

[kmt11]

well, the original QT 5 on Windows and glext.h problem isn't solved....

[SGaist]

IIRC, there's no glext.h by default on windows. But you can get the file "here":http://www.opengl.org/registry/

[kmt11]

Got the file thanks. Throwing up an error, but that may be down to internal programming, so will look into that and report back.....

[kmt11]

Seems that trying to use glext.h throws up dozens of errors, and it's simply too much of a pain to sort this. I have to conclude that legacy opengl cannot be used with Qt 5.
Tried reverting to Qt Creator 2.7.1 and Qt 4.8.4 on Windows, but this just refuses to configure a project, and ignores anything set up in the kit options.
Qt 4.8 seems to be fine on Mac and a unix box, but Qt 5 has too many problems for us to think about using it as a future ipad app tool. If it has too many problems on Windows, it gives us no confidence that it will be safe for ios development.

[SGaist]

There must be a glitch in QtCreator's configuration.
4.8.4 works pretty well on windows (even custom builds)

Depending on your problem, you might consider contacting Digia to sort things out