Re: [Dev-C++] WinAPI help...

[Emiliano <sky...@fa...>]

----- Original Message ----- 
From: "Per Westermark" <pw...@ia...>
To: "Emiliano" <sky...@fa...>
Cc: <dev...@li...>
Sent: Friday, February 27, 2004 6:13 PM
Subject: Re: [Dev-C++] WinAPI help...


> I don't think that you should run run your drawing code in
> THREAD_PRIORITY_IDLE - it should be THREAD_PRIORITY_BELOW_NORMAL or
> THREAD_PRIORITY_LOWEST, since you don't want any background processing on
> the machine to starve the drawing code.

Yes. I put that just for testing, in the first tests..

> Why don't you remove the timer thread, since the work may easily be
> performed in the drawing thread? I don't have the exact specifications
> available right now, but for WinNT, Win2k, WinXP... you may also use
> waitable timers to implement delays.

Thank you!! I found that CreateWT() works quite better! Now I get 50 fps
with a 20 msecs period, and 94 fps with 10 (well, that difference, about ~
0,5 msecs is accettable in a multitasking environment).

Anyway, I DO need to keep drawing and updating as separate tasks. If I don't
do this, I risk (on crowded and slow scenes) that the update won't take
place (since the task is busy drawing the scene). This is right what happens
with the Glut library, which has some timer functions that simply use the
crappy "SetTimer()" (or similar). So, if you have a long task to do, the
timer is not seen at all (you have to restart the "GetMessage()" loop,
despite what the WinAPI docs say!!).

The simplest method is probably to add to all movements, a multiply factor
that depends on time spent between two frames. Thus, the more time passes,
the more speed objects must have in the next frame. I think I'll implement
this later on, since I've tried it now and it would make collision detection
harder (ie: doesn't work as expected :D).

Anyhow, I still LOOSE escape key presses sometimes... this doesn't happen
with a single thread, why?? :(((

> See CreateWaitableTimer, SetWaitableTimer, WaitForSingleObject,
> WaitForMultipleObjects...

> When your application is minimized, you really should teach your drawing
> thread to just sleep.

Yes this can be easily implemented. Anyway, it could be a feature (maybe one
wants the rendering to go on while the app is minimized away).

Thanks again, your help is really worth a lot! :)

Emiliano