#228 Repainting issue with v3.0.0.0 on Windows

[dexterity2000]

Dear freeglut team

I am encountering a repainting issue with freeglut v3.0.0.0 on Windows 7. As soon as I move the
glut main window below another top level window the glutDisplayFunc callback function isn't called anymore. The repainting happens only at the end of the move when the WM_LBUTTONUP mouse message is processed by the window procedure. A cross check with v2.8.1.0 revealed no such problem.

All mentioned freeglut binaries were downloaded from http://www.transmissionzero.co.uk/software/freeglut-devel/.

Please find attached a screenshot illustrating the problem. If you have further questions don't hesitate to ask.

I am looking forward to your reply.

Best regards
Frank

[Diederick C. Niehorster]

Hi Frank,

Thanks for the report. The way drawing is done has changed slightly,
so indeed, it is possible things behave differently between versions.
I think for both versions drawing/animation is paused when you start
dragging the window (it is very hard to implement continuous animation
in this case due to the way mouse drags are handled by Windows), but
such smearing as seen in your screenshot should not occur. This
happens not when you drag the window, but only when it moves under
another top level window (and appears again out from under it)? Could
you add a little message (printf) to std out in your display callback
and see if there are any differences in when and if at all it gets
called between the two freeglut versions as you drag the window like
that?

Thanks and all the best,
Dee

[dexterity2000]

Hi Dee

This
happens not when you drag the window, but only when it moves under
another top level window (and appears again out from under it)?

Correct.

Could
you add a little message (printf) to std out in your display callback
and see if there are any differences in when and if at all it gets
called between the two freeglut versions as you drag the window like
that?

Already did this.:-)

v2.8.1.0: Callback function is continuously called when dragging glut window while another top level window is above. But when no top level window is above, the callback function gets only called when the left mouse button is released.

v3.0.0.0: Callback function is only called, without exceptions, when the left mouse button is released.

Added another screenshot showing this effect when the glut window is dragged from the left border of the screen towards the centre.

Frank

[Diederick C. Niehorster]

Hi Frank,

Cool, thanks for those further details, testing and screenshot. I'll
look into it. I can't promise it'll be very soon, but it should be
either fixed or not fixed (not sure how this interacts with the new
drawing method, that has other benefits that we wish to keep) by then.
I'm aiming for fixed of course!

Thanks,
Dee

[dexterity2000]

Hi Dee

I would be very happy if you solved this. In my opinion this is a bug. Thanks in advance for your efforts.

Regards
Frank