Qt 5 - OpenGL Problem

ZapB · wrote on 16 Jan 2013, 12:24

Well, just that you need to compile your own build of the Qt libraries to enable Desktop OpenGL on windows at present. Helpful instructions can be found at http://qt-project.org/wiki/Building_Qt_5_from_Git

DamianPrg · wrote on 16 Jan 2013, 12:25

http://www.youtube.com/watch?v=K0O6mvD6uk4 - It also can help you :-)

sierdzio · wrote on 16 Jan 2013, 12:27

Qt is a set of libraries and tools. What you download from Qt Project web site is - most probably - a pack of precompiled libraries, ready to be used. Necessarily, this general package is compiled with default, fit-for-all settings.

However, Qt is a big project, and can be compiled in thousands of ways (by passing flags to configure script) and for some usages it's better to define those flags as you want to.

Qt Project is open sourced, you can download sources yourself and take a look ("link":http://qt-project.org/wiki/Building_Qt_5_from_Git).

EDIT whoosh, I was waaaay too slow on this one ;)

DamianPrg · wrote on 16 Jan 2013, 12:31

@

C:\qt5>configure -developer-build -opensource -opengl desktop -nomake examples -
nomake tests

C:/qt5/qtbase/configure -developer-build -opensource -opengl desktop -nomake e
xamples -nomake tests
'C:\qt5\qtbase\configure.exe' is not recognized as an internal or external comm
and,
operable program or batch file.
*** qtbase/configure exited with non-zero status.

C:\qt5>
@

This is what I get when I try to configure. Note that i have Perl, Python installed. Source code is downloaded from http://qt-project.org/downloads

sierdzio · wrote on 16 Jan 2013, 12:34

On Windows, you need to rdowload the .zip file, not tarball. Also, I think you need to run configure.exe, not the configure script. I'm using Linux, though, this info is second-hand at best ;)

ZapB · wrote on 16 Jan 2013, 12:35

Probably best to get a git clone as it is easier to get back to a clean state. Also it makes sure you have the same exact source tree as the Qt devs so it's easier to trouble shoot. The packaging may remove some files needed to do a fresh build. Does the configure.exe actually exist at that path?

DamianPrg · wrote on 16 Jan 2013, 12:39

[quote author="sierdzio" date="1358339671"]On Windows, you need to rdowload the .zip file, not tarball. Also, I think you need to run configure.exe, not the configure script. I'm using Linux, though, this info is second-hand at best ;)[/quote]

I tried ZIP, but it wont extract on my PC. Do you think thats problem? Because Tarball is often used on linux?

@ZapB - Does the configure.exe actually exist at that path?

No, just .bat and one with no extenstion.

sierdzio · wrote on 16 Jan 2013, 12:45

Qt packaging strips tarballs of things that are not needed on unix (so, Windows stuff is missing there), and uses unix line endings. So you need the .zip.

As ZapB mentioned, using git is a much better idea.

DamianPrg · wrote on 16 Jan 2013, 12:52

Ok thanks, guys. I will install from there.

DamianPrg · wrote on 16 Jan 2013, 14:20

Ok, i downloaded source from GitHub, and I have new problem.

@

C:\Users\Damian\Documents\GitHub\qt5>configure -developer-build -opensource -ope
ngl desktop -nomake examples -nomake tests

C:/Users/Damian/Documents/GitHub/qt5/qtbase/configure -developer-build -openso
urce -opengl desktop -nomake examples -nomake tests
Please wait while bootstrapping configure ...
<srcbase> = C:/Users/Damian/Documents/GitHub/qt5/qtbase
<outbase> = C:/Users/Damian/Documents/GitHub/qt5/qtbase
No suitable compiler found in PATH. Aborting.
*** qtbase/configure exited with non-zero status.

C:\Users\Damian\Documents\GitHub\qt5>
@

I have VS10 Pro, VS11 Pro, so why it says "No suitable compiler found in PATH", should I add VS to PATH, or what?

ZapB · wrote on 16 Jan 2013, 14:33

Run configure from a MS VS10 command prompt so that the environment variables are set up to find the compiler etc on the %PATH%

DamianPrg · wrote on 16 Jan 2013, 14:39

Ok, configure works, thanks for the help.

utcenter · wrote on 16 Jan 2013, 15:46

Hey, wouldn't it be far better if solutions for both ANGLE and desktop OpenGL are being built and switching is runtime like the QPA plugin works? Same for QWidgets without OpenGL dependencies.

Even if OpenGL is buried deep into QtGui, it should still be possible to patch it in as a dynamic library. After all, even having 3 different version of QtGui is better than having 3 different version of Qt plus the time to build those.

ZapB · wrote on 16 Jan 2013, 16:03

Yes but that's a lot of work and requires somebody to do it.

DamianPrg · wrote on 16 Jan 2013, 18:05

Ok, compiled. I relaunched my project - run qmake. And when I want to build/run I get.

@
c:\users\damian\documents\github\qt5\qtbase\src\opengl\qgl.h:70: error: C1083: Cannot open include file: 'GLES2/gl2.h': No such file or directory
@

which is right, because I added -opengl desktop, so i should use desktop opengl, so why it want to include GLES?

now i get
@:-1: error: LNK1104: cannot open file 'libEGLd.lib'@

utcenter · wrote on 16 Jan 2013, 20:08

Even if you compiled to use desktop OpenGL, GLES is still crucial as it is the compatibility layer Qt relies on across different platforms. What you did essentially allows YOU to use desktop OpenGL if avaiable, there is no separate implementation of the functionality Qt relies on internally. EGL fits in that context as well.

DamianPrg · wrote on 16 Jan 2013, 20:21

Ok I try to restore old GLES files. Thanks

ZapB · wrote on 16 Jan 2013, 20:30

[quote author="utcenter" date="1358366924"]Even if you compiled to use desktop OpenGL, GLES is still crucial as it is the compatibility layer Qt relies on across different platforms. What you did essentially allows YOU to use desktop OpenGL if avaiable, there is no separate implementation of the functionality Qt relies on internally. EGL fits in that context as well.[/quote]

Sorry but that is incorrect. Qt can use either OpenGL ES 2 and EGL or Desktop GL and WGL (on Windows). Check the source code of the windows qpa plugin for confirmation. It will use whichever GL it has been compiled for. So in this case it should be using the desktop GL.

DamianPrg, for some reason it seems that you project is still trying to link to the old setup. Stale makefiles perhaps? Are you sure you are using the correct Qt build? i.e. is your new qmake the first in your %PATH%?

Did configure say that it was building for Desktop OpenGL?

utcenter · wrote on 16 Jan 2013, 22:20

My bad, an incorrect assumption.

Also, it seems that the "default" Qt5 offline package for windows will switch to desktop OpenGL in the near future, which makes good sense. Unfortunately, that won't happen in 5.0.1

DamianPrg · wrote on 17 Jan 2013, 12:43

I will just wait for new Qt release. Anyway thanks Guys for help.