Selection in QOpenGLWidget

[KirstenS]

I am trying to use Qt 5 and the QOpenGLWidget instead of QGLWidget from Qt 4 which is what I am familiar with. I have gotten most things to work in the QOpenGLWidget but I am unsure how to get process hits to work. That is, I want to double click on an object (e.g. a triangle in a mesh of triangles generated with glDrawArrays(GL_TRIANGLES, 0,numVerts )) and have it return the index of the triangle drawn. Is there anything with Qt 5 and QOpenGLWidget similar to this?

Edit: Added code tags -- @Wieland