This mostly comes under the category of "Well don't do that, then!" but here goes anyway...
Imagine that I have some fltk GL code, partly written using glut, and for various reasons I have a couple of idle functions trundling away in the background. Now, glut only really supports 1 idle function, so I've used Fl::add_idle() to attach my various background functions. So far, all well and good. Now... Elsewhere in the (legacy) code, which is more or less regular glut code, there's a "visible()" function, called by glutVisibilityFunc(). Now, the visible() func, when run, checks to see if its window is visible or not, then calls glutIdleFunc(...) depending on the result. Pretty standard stuff... In particular, if the window is not visible, then it will call glutIdleFunc(NULL); Which maps to the fltk call Fl::set_idle(NULL); Hmmm, this has the effect of hosing *all* the fltk idle functions in one fell swoop if the window is minimised, on a fairly permanent basis - subsequent calls to Fl::add_idle() will not work either... So, the correct thing for me to do is replace all the calls to glutIdleFunc(); with calls to either Fl::add_idle() or Fl::remove_idle() - whichever is appropriate based on the current visibility state. Ok, that works... So, I have a couple of observations about this: 1. Others porting glut code to fltk might trip over the same problem, or a variant of it (for example, if you replace the glutIdleFunc(my_idle); call in your initialisation with a call to Fl::add_idle(my_idle); but forget to fix the one in visible();) 2. Fl::set_idle() is marked as deprecated, so we perhaps should not be using it internally. 3. I can't see how to make glutIdleFunc() work more like add/remove_timeout, so I don't think we can really fix this... I guess I just have to be careful not to mix'n'match my idle function coding styles! -- Ian SELEX Sensors and Airborne Systems Limited Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England & Wales. Company no. 02426132 ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ******************************************************************** _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
