gl4java-usergroup

[gl4java-usergroup] what is the recommended way of swapping one canvas for another?

[Combe, C. <C....@na...>]

hi,
if you've looked at any of my previous emails you'll know that i'm trying to
replace a GLCanvas of one sort with a AWTCanvas or a GLCanvas of a different
sort inside a Frame. No matter what I try it doesn't work. Destroying the
canvas then creating a new object appears to work but it is always leaving
behind a reference to a THread and eventually the prog slows to a crawl. I'm
pretty certain that i'm not leaving behind this reference elsewhere in my
prog. If I avoid creating new objects then after doing cvsDispose and
removing the canvas I cannot get the GLCanvas to be initialised again.
Removing and adding the canvas without ever calling cvsDispose works
sometimes but eventually crashes (this is expected as the documentation says
to always call cvsDispose before removing).

Attatched is a version of my Frame class which tries to destroy and create
the new GL canvas objects.

What is the recommended way of swapping one canvas for another? I'll be most
grateful for any advice. I'd really like to use gl4java for this project and
the actual drawing of the scene works fine and is fast - its just this
canvas changing thing that is the problem. :-(

please help...
colin

Re: [gl4java-usergroup] what is the recommended way of swapping one canvas for another?

[Max G. <gi...@li...>]

Combe, Colin wrote:

>What is the recommended way of swapping one canvas for another? I'll be most
>grateful for any advice. I'd really like to use gl4java for this project and
>the actual drawing of the scene works fine and is fast - its just this
>canvas changing thing that is the problem. :-(
>
Is there any reason you have to destroy the canvas each time? It is very 
inefficient as initialization takes time each time you create a canvas. 
If I were you I would keep two instances of GL canvas, one on screen and 
one in inactive state. If the canvas is invisible (ie. removed from the 
GUI) it won't do anything and you can safely keep it in memory, 
re-adding to the GUI later and it will draw perfectly well. cvsDispose 
call is required when you dump the canvas completely and want it to be GC'd.

HTH,
Max