3 replies to this topic

[AquaMacker]

Hi~~~

Today is hard day
Sooooo hard

This is GameLoop the best post !!!!!
http://www.koonsolo.com/news/dewitters-gameloop/

In this post, "Constant Game Speed independent of Variable FPS"

const int TICKS_PER_SECOND = 25;
const int SKIP_TICKS = 1000 / TICKS_PER_SECOND;
const int MAX_FRAMESKIP = 5;

while ( GetTickCount() > next_game_tick && loops < MAX_FRAMESKIP )
{
update_game();

next_game_tick += SKIP_TICKS;
}

Please Look bold...

I don't understand...

What does mean "GetTickCount() > next_game_tick && loops < MAX_FRAMESKIP" ?
How many "Update()" call ?
Why ? next_game_tick += SKIP_TICKS;(==40 Tick)
Why add 40 tick ?

I don't understanding really...

I do not know how to be to find information.

Please let me us.....
Please.....

It's so hard......

[eppo]

The idea is to let the games logic/physics run at a fixed (say 40 ms) interval and the renderer at the best it can come up with (say it manages only 5 fps).

So whenever rendering is finished, logic-time needs 5 steps to overtake (you make the assumption the next frame will take 200 ms to render as well).

Perhaps you find this a bit more readable:
[source lang="java"]renderTimePos = 0;logicTimePos = 0;logicTimeStep = 40;loop{ render_game(); //rendering took 200 ms renderTimePos += 200; while(logicTimePos < renderTimePos) update_game(), logicTimePos += logicTimeStep;}[/source]

Edited by eppo, 16 July 2012 - 05:48 AM.

[L. Spiro]

I have written an article that tries to explain this concept a little more clearly, with graphics to make it clear.
http://lspiroengine.com/?p=378

If you can read it you should be able to understand everything.
Because it is long, I will tell you to look mostly at the section called “But How Can That Work? Don’t I Need to Know its Next Position, Not its Last Position?” and the graphic in that section.


L. Spiro

[AquaMacker]

@eppo, @L.Spiro

Really Thanks you so much.

I Will try very hard to read and try to solve the problem ^^a

Thanks more ~~~