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Jeff Labute · Guest

Hi Everyone...

{using delphi 6 pro}

I've wanted to switch to a multimedia timer for better time resolution.
Currently in my code, I am using an onidle event to redraw my opengl scene.
If i switch to a ttimer, i get about the same time resolution depending on
the
hardware platform... and everything works fine.

Now, I've tried to use third part multimedia timer
wrappers in place of the Timer... but my scene does not appear to draw, I
just get a black window. I get nothing at all if I don't have a
SwapBuffers(DC); command at the end of my draw scene. Apparently it's not
straightforward to switch to a multi media timer? I am using a timer that I
got off Torry's Delphi site... and it seems to just have the standard
settimer and timegettime procedures and stuff.
If i put a label that updates every 10ms or other stuff in the window to
update it works fine at the frequency i chose.. just not working for opengl
stuff. (Some components called Wave Audio comes with a multimedia timer).
If I delete this multimedia timer and put the ttimer or onidle back in to
the code, everything is fine again. If I slow the multimedia timer down to
100ms it still doesn't work... I don't think it's a speed issue. I've used
examples from nehe to put my little project together.. plus it uses serial
components and zeos sql db components.

help

Jeff

Eric Grange · Guest

Multimedia timer events are triggered in the context of another thread,
unless your component does a Synchronize for you.
OpenGL context activation is per-thread, so if you initialize in the
main thread and try rendering in a secondary thread, nothing will happen.

Eric