[Programming a pushbutton to do a certain task]

appdev

@jsulm First of all.
Thank you for your reply.

The problem is that I need this push button to execute a function that can only be called inside the paintGL() method of the class MainWidget.

The paintGL() method render the object and ensure its rotation using the

void QMatrix4x4::rotate(const QQuaternion &quaternion)

I don't see how I can access to that function and execute it using the push button.

jsulm

@appdev As IU wrote: add a public method to your MainWidget class:

class MainWidget...
public:
    void rotate()
    {
        localMatrix.rotate(quaternion);
    }

And then simply call that method in MainWindow:

void MainWindow::on_pushButton_3_clicked()
{
    ui->mainwidget->rotate();
}

You would need to implement MainWidget as a stand-alone widget and promote it to your ui.

JonB

@appdev
I can't get into a discussion about OpenGl or matrices or quaternions because I know nothing about any of it :)

But consider your line

this->ui->mainwidget->localMatrix.rotate(this->ui->mainwidget->quaternion);

Note how both the method call and the parameter start with this->ui->mainwidget. So you can factor what this does away into your definition of your MainWidget class.

EDIT Oh @jsulm has just shown you :)

appdev

@jsulm @JonB I tried to do that but there is a problem.

To make that public method work, localMatrix should be a member variable of mainwidget. However I want it to be a local variable of the paintGL() function. Otherwise, a problem will occur when it comes to rendering the object and its coordinate system.
The localMatrix here is my modelview matrix. I used it to render an object ( a cube ) and two coordinate systems that are attached to it.
When I declare localMatrix as a member variable, one of the coordinate system becomes detached from the object.

jsulm

@appdev said in [Programming a pushbutton to do a certain task]:

localMatrix should be a member variable of mainwidget

It is already according to your code:

this->ui->mainwidget->localMatrix.rotate(this->ui->mainwidget->quaternion);

So, don't know what the problem is...

appdev

Yes, according to my code, it is a member variable, I changed it so I can use it in the mainwindow.cpp.
But then, I had some problems when rendering the scene ( as I mentioned one of the coordinate system became detached of the object so something went wrong).
But I don't want it to be a member variable. I want it to be a local so that I can avoid the rendering problem.

appdev

Update:
@jsulm @JonB
I declared a boolean variable in my mainwidget.h:

Bool ApplyRotation;

Then each time ApplyRotation is true, the object changes its orientation.

In mainwindow.cpp:

void MainWindow::on_pushButton_3_clicked()
{

      this->ui->mainwidget->ApplyRotation = true;
}

In my mainwidget.cpp:

if(ApplyRotation == true)
    {
        ApplyRotation=False;
        EulerAngles.append(quaternion.toEulerAngles()); //rotation order is 213.
        localMatrix.rotate(quaternion);
}

However, when I insert quaternion values in the spin boxes and then click on Apply button, the object changes its orientation and then goes back to its initial orientation. I want it to stay at the new position.

So I removed the line

ApplyRotation=False;

Now after inserting the quaternion values in the spin boxes and then clicking on the apply button, the object changes its orientation.
But, when I change again the values in the spin boxes the object keeps rotating. It means I don't need to click on the button anymore. That's the problem.

My goal is to make the object rotate each time I click on the push button.
I don't get why it is not working with the first code I posted. However what I did seems so logical.

appdev

Can anyone help me please ?
Thank you all.

JonB

@appdev
I don't see anything in your code where anyone could possibly comment on your behaviour. All we see is setting & testing a boolean variable, how can that tell us/you what your issue is?

My goal is to make the object rotate each time I click on the push button.

Then you need to call whatever code from your pushbutton clicked slot. Simply setting a variable there won't even make anything hit the if(ApplyRotation == true) elsewhere in your code.

appdev

Okay,
I put that code because I thought that the rest of it isn't necessary to show .
Here is my paintGL() method in the class MainWidget:

void MainWidget::paintGL()
{

    //qDebug()<<__func__;
    // Clear color and depth buffer

       glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);


//================Orbital Frame ==========================================//
     QMatrix4x4 localMatrix;

     glMatrixMode(GL_PROJECTION);
     glLoadMatrixf(projection.constData());

     glMatrixMode(GL_MODELVIEW);
     glLoadMatrixf(localMatrix.constData());
     gluLookAt(2.0,2.0,0.0,0.0,0.0,-5.0,0.0,1.0,0.0);


     glTranslatef(0.0,0.0,-5.0);

     glRotatef(180.0,0.0,1.0,0.0);
     glRotatef(-90.0,1.0,0.0,0.0);

     glScalef(0.4,0.4,0.4);

    //glMatrixMode(GL_PROJECTION);
    DrawOrbitalFrame();

 
   
    program.bind(); 

    texture->bind(); 

    // Calculate model view transformation



    //qDebug()<<"modelview before transformation"<<matrix;

    //qDebug()<<"modelview matrix"<<localMatrix;
    localMatrix.setToIdentity();
    localMatrix.lookAt(QVector3D(2.0, 2.0, 0.0), QVector3D(0.0,0.0,-5.0),QVector3D(0.0,1.0,0.0));

    localMatrix.translate(0.0, 0.0, -5.0);

    localMatrix.scale(0.4,0.4,0.4);




    quaternion = QQuaternion(quat_w, quat_x, quat_y, quat_z);

    quaternion.normalize(); // Normalizing my quaternion
   


    if(ApplyRotation == true)
    {

        EulerAngles.append(quaternion.toEulerAngles()); //rotation order is 213.
        localMatrix.rotate(quaternion);


    }


     program.setUniformValue("mvp_matrix", projection * localMatrix);


     update();

    //! [6]
    //!

    // Use texture unit 0 which contains cube.png
    program.setUniformValue("texture", 0);


    // Draw cube geometry
    geometries->drawCubeGeometry(&program);

    texture->release();
    
    program.release();

}

And in my MainWindow class where I programmed the push button:

void MainWindow::on_pushButton_3_clicked()
{

      this->ui->mainwidget->ApplyRotation = true;

}

That's what I actually did, I called the variable applyRotation in my my piantGL() method to rotate the object once the user inserts the quaternion value and click on the push button.