QOpenGLWidget content stretching on resize

calier

Hi !

I'm having some issues keeping a fixed aspect ratio for the content of my QOpenGLWidget.
I'm trying to get my "scene" with a fixed aspect ratio adding Horizontal or Vertical "empty" areas next to my image when necessary. (please see example image to illustrate the issue below)
I got this to work fine with GLFW but for some reasons I can't get it to work in Qt. It almost looks like my layout stretches the QOpenGLWidget no matter what my resizeGL method does.

Code:

void GLViewer::resizeGL(int w, int h)
{
    if (h == 0) h = 1; 
    GLfloat aspectRatio = (GLfloat)w / (GLfloat)h;

    glViewport(0, 0, w, h);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity()

    if (w >= h) {
       glOrtho(-0.5 * aspectRatio, 0.5 * aspectRatio, -0.5, 0.5, 0.1, 100);
    } else {
      glOrtho(-0.5, 0.5, -0.5 / aspectRatio, 0.5 / aspectRatio, 0.1, 100);
    }
    glMatrixMode(GL_MODELVIEW);
}

Any help would be greatly appreciated. Thanks !

johngod

Probably is just something that is messed up with with your multiplcation or division on the aspect ratio.
I'm just too lazy right now to think about it properly, so I just goint to copy paste one example of my that I know it works, so can try to adapt your code.

if (width() <= height())
        projection.ortho(-(Range),Range,-Range*h/w,Range*h/w,-(Range*2),Range*2);
else
        projection.ortho(-(Range*w/h),Range*w/h,-Range,Range,-(Range*2),Range*2);