The strange passed value in resizeGL(int w, int h) each time I resize the window

Yixun

Hi,
On Windows10, I implement a MyOpenGLWidet class by inheriting QOpenGLWidget and overwrite the void resizeGL(int w, int h) method.

The code snippet is as follows:

class OGLWidget : 
public QOpenGLWidget,
public QOpenGLFunctions
{
  Q_OBJECT
  public:   
  OGLWidget();
  ~OGLWidget() {};
  resizeGL();
}

void OGLWidget::resizeGL(int width, int height)
{
   //The output width and height are not correct, very small than 
   //actual sizes
   qDebug() << "The resized width and height is: " << width << ", " 
   << height;

   m_width = width;
   m_height = height;
}

//add the widget
m_planningView = new OGLWidget();       
QSurfaceFormat format;
format.setRenderableType(QSurfaceFormat::OpenGL);
format.setProfile(QSurfaceFormat::CoreProfile);
format.setVersion(3, 3);
format.setSamples(4);

m_planningView->setFormat(format);
QGridLayout *preOperationLayout = new QGridLayout();    
preOperationLayout->addWidget(m_planningView, 0, 0);

m_preOperationFrame = new QFrame();
m_preOperationFrame->setFrameStyle(QFrame::Box | QFrame::Raised);
m_preOperationFrame->setLayout(preOperationLayout);

However, each time as I resize the parent window, I found the passed value of w and h are not correct. The passed value are very small compared with the real size.

Many thanks.
YL

Christian Ehrlicher

@Yixun said in The strange passed value in resizeGL(int w, int h) each time I resize the window:

void OGLWidget::resizeGL(int width, int height)
{
//The output width and height are not correct, very small than
//actual sizes
m_width = width;
m_height = height;
}

You're missing to call to the base class.

Yixun

I output the size at the beginning of method resizeGL(), so I think it is not related to the calling the base.
I found the reason is the setting of the display. If I set the display with 3840x2160., the output of QScreen is actually 1280x720. If I set the display to 1920x1080 and the output of QScreen is the same and then the resizeGL works.