I want to draw an object in OpenGl but it draws strange thing

Hi, I want to draw objects in OpenGl. but It draws strange things. I think that It draws from buffer .I put my cpp ve h files . do you know What the problem is..

What do you mean by "strange things"?

It draws a shape from buffer so different shape is created

But your "grafik" class is not even a QGLWidget...

I can not understand can you explain it.

The widget has to be a subclass of QGLWidget to be able to use OpenGL. Your class is derived from QMainWindow and not QGLWidget so the methods related to painting using OpenGL are never called.