RE: [pygame] kind of animation

[Chris Ashurst <CAshurst@xxxxxxxx>]

To satisfy my own curiosity, what is the fundamental difference between
time-based and frame-based... Oh wait, never mind, I answered my own
question :D

To throw in my own two cents, why not use all three types of animation, that
way if you have three different animation "engines" available, you could
have a flag in a sprite class that defines which engine is pushing the
sprite at any given time. For example, a Space Invaders type-game would use
time-based animation (for the descending rows of aliens, which inevitably
speed up as more and more get destroyed), frame-based animation for the
flying saucer that randomly rolls across top of the screen, and event-based
animation for moving the player ship around.

-----Original Message-----
From: owner-pygame-users@xxxxxxxx [mailto:owner-pygame-users@xxxxxxxx]On
Behalf Of DR0ID
Sent: Wednesday, May 24, 2006 10:51
To: pygame-users@xxxxxxxx
Subject: Re: [pygame] kind of animation


Peter Shinners schrieb:
> On Mon, 2006-05-15 at 22:34 +0200, DR0ID wrote:
>   
>> I want to implement some animation and came up with 3 different ways to 
>> do that:
>>
>> 1. frame based animation
>> 2. time based animation
>> 3. event based animation
>>     
>
> I'd have to say go with time based animation. It's not really harder
> than frame based and you end up with a consistent game. I will offer the
> following tips:
>
> Keep all your times and positions as floating point values. This means
> you won't be able to store positions with pygame.Rect
>
> Pay attention when you have something that randomly happens each frame.
> You'll need to scale the odds of things happening by how long the frame
> took. A better approach is to randomly pick an amount of time for the
> next "event" to happen and wait for that. Then you could fire multiple
> events in a single frame if it took too long.
>
> There really isn't much in there to worry about. You'll need floating
> point positions anyways once you want something that moves slower than
> one pixel per frame.
>
>
>
>   
Hello

Thank you for your tips. I was more interessted in how and when change 
the image of an animation rather than moving it around. But your right, 
for the position one should use a float tuple because rect can only 
store integers.

I had planned to use rects for collision detection, but if I do, then I 
have to round my position coordinates to integers to use rect for that. 
I have to rethink that although I assume it makes not a big difference.

If I understand you right you suggest to make the objects and functions 
time dependent. What do you mean with "you end up with a consistent game"?

As said, I was more interested how to update the image of an animation. 
But this leads to a other question which I will ask in an other email.


~DR0ID
 




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