Opengl doesn't work with Qt

ludde

You are saying that you can use GLUT from plain C++ code, but not from Qt code? In that case you must have it installed somewhere already. You just need to tell where, in your .pro file, so that qmake can find it. I.e., you must add something like:
@
LIBS += -lglut
LIBS += -LC:/location/of/glut
@
I'm not sure this is what's missing, though. Since you don't get an error saying it cannot find the glut library. Looks like it actually finds it, but not the symbols it needs. Strange.

Which compiler are you using? The same one you use when compiling plain C++ code?

fery13

Yes I am using in plain C++ without problem,
But I can not find any file like lglut in my pc(where can I get this file) ??????
I have only glut, glut32 (header file and lib file )....
but I never tried the second line which you mentioned above, I will try the second one seems by the second line error should be gone hopefully by the way now I uninstall the Qt and trying to get the new version as soon as I install I will apply this and I will let you know about it .... many many thanks to you that spend your time for my problem .....

ucomesdag

-l stands for library and -L for library path, see "qmake doc":http://doc.qt.nokia.com/4.7/qmake-variable-reference.html#libs
[quote author="fery13" date="1309197219"]Yes I am using in plain C++ without problem,
But I can not find any file like lglut in my pc(where can I get this file) ??????
I have only glut, glut32 (header file and lib file ).... [/quote]

ludde

-lglut is like a command line option, which you use to tell qmake to use a library. -l is the option and glut the argument. On Windows, the file should be called glut.lib. -L is used to add a directory in which to look for libraries.

I don't think this is the problem, though. It seems to find GLUT and is unable to link with it. Maybe you simply cannot do this, because using those functions mentioned above together with Qt really makes no sense.

ucomesdag

Try @LIBS += -L/path/to/your/lib -lLibfile_without_exstension@

ludde

Just had a look in my OpenGL installation, which is the one that comes with mingw / Qt Creator, and it contains glu, but not glut. So your glut must come from somewhere else.

fery13

That's strange I tried all, but still errors, also I re install Qt ... here is my .pro:
@
#-------------------------------------------------

Project created by QtCreator 2011-06-23T18:42:17

#-------------------------------------------------

TARGET = open1

TEMPLATE = app

DEPENDPATH += .

INCLUDEPATH += .

SOURCES += open1.cpp

HEADERS += open1.h
open1_global.h

CONFIG += opengl
release

QT += opengl

LIBS += -lglut
LIBS += C:\Users\FGHASSEMIT\Documents\qt\GL\glut.lib
@
and here errors :

:-1: error: cannot find -lglut
:-1: error: collect2: ld returned 1 exit status

.................
this is the same if I write glut32 instead of glut ....
:(

Edit: Added @ tags

ZapB

Try also adding:

@
LIBS += -LC:/path/to/your/glut/lib
@

fery13

I did then I have again error :

:-1: error: LC:/Users/FGHASSEMIT/Documents/qt/GL/glut.lib: Invalid argument

I guess LC is used for Linux ....

ludde

You are now trying to link with glut twice... Your .pro file should contain
@
LIBS += -lglut
LIBS += -LC:\Users\FGHASSEMIT\Documents\qt\GL
@
or just
@
LIBS += C:\Users\FGHASSEMIT\Documents\qt\GL\glut.lib
@
but not both.

Nevertheless, I think you should try to get rid of the glut dependency, because using it with Qt will most likely create problems.

fery13

sorry I forget to put dash (-) behind so the errors turn to be like this :

C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to `__glutInitWithExit' C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to` glutInitDisplayMode'
C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to `glutInitWindowSize' . . . C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to` _imp__glBegin'
C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to `_imp__glVertex2f' C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to` _imp__glEnd'
C:\Users\FGHASSEMIT\open1\open1.cpp:-1: error: undefined reference to `_imp__glFlush'
:-1: error: collect2: ld returned 1 exit status

ZapB

I agree with ludde. You are trying to use glut to reproduce functionality that is already in Qt. Some glut functions can still make sense to use within Qt (ie for drawing basic geometric shapes such as a sphere).

Take a look at my repository to see a few very simple OpenGL apps that use Qt rather than glut for the windowing functionality. Just use svn to checkout:

@
https://svn.theharmers.co.uk/svn/codes/public/opengl/trunk/
@

cd into one of the directories e.g. 06-solar-system then run:

@
qmake
make
@