In a message to me Steve Lamont wrote:
> > The "glBegin" _always_ returns INVALID_OPERATION.
> > So I never get to the real drawing part (which is actually rather simple).
>
> Does the program draw anything at all?
No, just the empty window (which is made by XForms, not Mesa).
> Do you have a corresponding glEnd() call?
Of course, and some "vertex2f" calls in between. I'm trying to draw line
strips.
> the callback a second time, you're going to get the GL_INVALID_OPERATION
> error.
It already happens the FIRST time the "expose" handler is entered and
the very first glBegin in that. So the "state" of the OpenGL engine is
such that it _seems_ to think it cannot draw anything yet.
I must be missing something in the initialisation part, at least, that
is what I'm thinking.
-- \ / / /#. # #- # / ## ## ## ## ## # # ## ## ## " " # ## ## "." ". "./ TTTTTTTTTT UU UU Eef Hartman, System Administrator TT UU UU TT UU UU Delft University of Technology TT UU UU Mathematics (Applied Analysis) dept. TT UU UU Mekelweg 4, P.O. Box 5031 TT UU UU 2600 GA Delft, The Netherlands TT UU UU e-mail : E.J.M.Hartman@math.tudelft.nl TT UUUUUU fax : +31-15-278 7209 _________________________________________________ To unsubscribe, send the message "unsubscribe" to xforms-request@bob.usuf2.usuhs.mil or see http://bob.usuf2.usuhs.mil/mailserv/xforms.html XForms Home Page: http://bragg.phys.uwm.edu/xforms List Archive: http://bob.usuf2.usuhs.mil/mailserv/list-archives/