OpenGL Example - Cube Doesn't run

iamcreasy

When I try to run the example program, OpenGL/cube, I get the following 2 errors,

C:\QtSDK\Examples\4.7\opengl\cube-build-desktop..\cube\mainwidget.cpp:135: error: 'GL_TEXTURE0' was not declared in this scope

C:\QtSDK\Examples\4.7\opengl\cube-build-desktop..\cube\mainwidget.cpp:135: error: 'glActiveTexture' was not declared in this scope

What can I do to solve this?

SimonL

is the Qt+=opengl in your .pro file to tell the compiler to use the opengl examples. Also what is your current operating system?

iamcreasy

added this line in the cubo.pro file,

QT += opengl

but, no change. Still, its showing 2 errors.

I am using windows 7.

sigrid

This is caused by a bug in the Cube example which has already been fixed in our repository for an upcoming version. Applying the following patch should solve it for you:

@
#ifndef GEOMETRYENGINE_H
#define GEOMETRYENGINE_H

+#include <QtOpenGL/QGLFunctions>
#include <QtOpenGL/QGLShaderProgram>

-class GeometryEngine
+class GeometryEngine : protected QGLFunctions
{
public:
GeometryEngine();
@

iamcreasy

Previous errors hasn't solved. It also says,

C:\QtSDK\Examples\4.7\opengl\cube-build-desktop..\cube\geometryengine.h:4: error: QtOpenGL/QGLFunctions: No such file or directory

Code:
@#ifndef GEOMETRYENGINE_H
#define GEOMETRYENGINE_H

#include <QtOpenGL/QGLFunctions>
#include <QtOpenGL/QGLShaderProgram>

class GeometryEngine : protected QGLFunctions
{
public:
GeometryEngine();
virtual ~GeometryEngine();

void init();

void drawCubeGeometry(QGLShaderProgram *program);

private:
void initCubeGeometry();

GLuint *vboIds;

};

#endif // GEOMETRYENGINE_H@

sigrid

The qglfunctions.cpp is only available in Qt 4.8, so this example will not build against Qt 4.7, you need a Qt 4.8 snapshot to make it build. I have created a "bug report":http://bugreports.qt.nokia.com/browse/QTBUG-19970 for this in our Bug Tracker.

iamcreasy

Any idea when Qt 4.8 is gonna be available?

sigrid

We don't have an exact date for this yet, but you can find some information on this in the public roadmap provided "here":http://developer.qt.nokia.com/wiki/Category:Developing_Qt::Qt_Planning::Qt_Public_Roadmap.

iamcreasy

I really needed to run this example to investigate some procedures. Is there any way to run this example? :(

andre

Sure, get a Qt 4.8 from GIT, and compile it yourself. That should work.

mikecarlos

Hi,

Download the modified cube project in the zip here
https://bugreports.qt-project.org/browse/QTBUG-24555

It worked for me.

iamcreasy

Thank you!

I'll check it out sometime later.