I'm just trying out my first bit of OpenGL...

I've successfully managed to output something into my main form using the
main form's Canvas.Handle, but if I want to output in a TPaintBox object
that I've placed on that form (using TPaintBox1.Canvas.Handle) nothing
appears.  Can anyone help me understand why not?

Many thanks

Nigel

--
See me here: http://www.minddata.co.uk/

You can save a lot of time by using existing code :

http:\\glscene.org

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com

You don't want to use Canvas.Handle. I know that the Canvas.Handle is the
handle to the device context, but it is very transitory, so your rendering
context will become invalid at some point; instead use GetDC and keep the
result. I discuss this fact early on in "Delphi Developers' Guide to
OpenGL." (see link below).
Jon
http://home1.gte.net/jqjacobs/index.htm
"Follow not the null pointer, for therein lies chaos and madness" (Author
Unknown)

news:3996F795.A3C7E9BB@dplanet.ch...

That may be right ;-)   - but I'm doing this to help understand some OpenGL
and I think I get a better understanding by making my own mistakes first...
however..

I'll certainly check this out...

Thanks alot,

Nigel

--
See me here: http://www.minddata.co.uk/

Jon Q. Jacobs <jqjac...@gte.net> wrote in message news:39970d48_2@dnews...

I did try that as well - maybe there was something else wrong there...
anyhow I'll follow the link - thanks very much

Nigel.
--
See me here: http://www.minddata.co.uk/

This is not OpenGL yet. It is getting OpenGL running on Windows
and Delphi. OpenGL itself is platform independant, these are
points to get there.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com

By the way, TPaintBox is not a descendant of TWinControl, so you don't have
a window handle from which to get a device context, from which to build a
rendering context. Forget using TPaintBox. With great effort you might be
able to kludge a way to use TPaintBox, but it definitely would not be worth
the effort. Many people have successfully used descendants of TCustomPanel
to use for rendering on a portion of a form, if that is what you are after.
--
Jon
http://home1.gte.net/jqjacobs/index.htm
"Follow not the null pointer, for therein lies chaos and madness" (Author
Unknown)