QOpenGLWidget not found in Qt version 6.3.0

[makopo]

Hi eveybody,

I'am very confused because it is not possible to integrateQOpenGLWidget into one of my classes.

As described in the docs I have to include the QOpenGLWidget into the corresponding class and add qopenglwidgets to my .pro file.
The QT topic in my project file look like this: QT += core gui opengl openglwidgets

QOpenGLWidget is included like this:

#pragma once
#include <QObject>
#include <QWidget>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>

class ClassName : public QOpenGLWidget, protected QOpenGLFunctions

With QOpenGLFunctions there are no problems. I'am using version 6.3.0., with version 5.15.1 it works.

Any hints?

[jsulm]

@makopo What is the exact error?
Did you try a complete rebuild after editing pro file:

1. Delete build folder
2. Run qmake
3. Build

[makopo]

@jsulm

I'am using Visual Studio 2019 . The error message is: C1083: Cannot open filetype file: 'QOpenGLWidget': message. No such file in directory.

Deleting the build folder and rebuild the program did not solve the issue.

EDIT: I can include the QOpenGLWidget on this way: #include <QtOpenGLWidgets/QOpenGLWidget>. But than I get 14 horrible linker error messages, depending on the OpenGL Widget.

[JoeCFD]

try to add widgets?
QT += core gui opengl widgets openglwidgets

in Qt5, QOpenGLWidget in module widgets. in Qt6 it is moved to openglwidgets. But you still need widgets module.

[makopo]

@JoeCFD said in QOpenGLWidget not found in Qt version 6.3.0:

try to add widgets?

I added it, but it changed nothing. I also understand the difference between the versions, but it still not work.

Its also possible to use #include QOpenGLWidget if you add the folder of the module, thats located in the include-directory, to the include path of VC++ in the project settings of Visual Studio.

A curious thing: If I derive my class from QOpenGLWidgets it looks like that it is necessary to implement all methods of QOpenGLWidgets into my class. Thats something that was not required in 5.15.1.

[JoeCFD]

Go check the include path in the make file. If the include path of module openglwidgets is not there, there must be a bug in the qt plugin for VS. You can add its include path in your VS project manually.

[makopo]

@JoeCFD

I had added the include path in the project settings like this: C:\Qt\6.3.0\msvc2019_64\include\QtOpenGLWidgets. And after that it works with #include <QOpenGLWidget>.

The problem now is that I have to implement ALL protected functions of QOpenGLWidget, although I only need initializeGL(), paintGL() and resizeGL().

But that is not the problem of this topic.

[JoeCFD]

@makopo check the definitions of these functions in QOpenGLWidget.h to see if they have = 0 at the end; if yes, you have to do it.

[makopo]

@JoeCFD

I checked it. It is not necessary to implement all methods of this class.

I'am not sure if this problem is a problem of the project setting, Qt VS Tools or version 6.3.0. Because I'am a beginner, I'am sitting the half day on this problem..

[JonB]

@makopo
You should not have to implement a method just because the base is protected. Perhaps show what error makes you say this?

[makopo]

@JonB said in QOpenGLWidget not found in Qt version 6.3.0:

You should not have to implement a method just because the base is protected

I know that. My problem is that this is the opinon of Visual Studio (or IntelliSense). I get error with the error code E1696 and C1083.

Let my explain what I had done:

I had created a Qt project with the Qt Widgets Application template. I setup the include-directory and library-directory in the project settings. I also add the library to the linker.

I add QT += core gui widgets opengl openglwidgets to the .pro/qmake file.

With this setup I can include the modules QObject, QWidget, QDebug, QPainter, QOpenGLFunctions. When I include QOpenGLWidget IntelliSense show me the error that the module can not be found. So I include the whole module C:\Qt\6.3.0\msvc2019_64\include\QtOpenGLWidgets to my project settings. With this I get no error message from IntelliSense. But if I derive QOpenGLWidgets to implement the three protected functions of the class I get Linker errors according to the "reimplemented protected functions" and it looks like that the implementation is required.
These errors look like:
LNK2001 Nicht aufgelöstes externes Symbol ""protected: virtual bool __cdecl QOpenGLWidget::event(class QEvent *)" (?event@QOpenGLWidget@@MEAA_NPEAVQEvent@@@Z)"

[makopo]

I solved it.

I checked the Qt project settings in Visual Studio and found that openglwidgets was not added to the QtModules section.
Befor I realize that I added openglwidgets only to the qmake file.

A communication problem between QtVSTools and the .pro file?

[JoeCFD]

@makopo Good for you. Now I remember there is a step to select modules in the plugin. Is this step really needed? not sure.

[SimonSchroeder]

@makopo said in QOpenGLWidget not found in Qt version 6.3.0:

A communication problem between QtVSTools and the .pro file?

There is no communication between Visual Studio and the .pro file. If you change the .pro file you have to recreate the VS project file. (At least, this has always been my understanding and I started using qmake to create the VS project file, as the VS Qt plugin is (used to be???) terrible.)

[makopo]

@SimonSchroeder

Many thanks for your advice! I got the same problems as descriped in my first post, after I had created a new class file in VS and include Qt Widget. After that I got errors in ALL my classes, that include Qt modules. I recreate the VS project and that helps to fix the issue.

I think your advice is the right way to troubleshoot this.

[AnandRathi]

In VC++ / Visual Studio C++
rihght Click Project - > Properties -> Qt Project settings -> QT Modules -> drop down select QT Modules and click Qt Opengl

[juejuezi]

@AnandRathi best way