Which is best?

Question

I have a couple of questions regarding sprite animation in Java, I know a lot of you might say "we've seen this all before" but most of the answers I've found relate to specific Java game API's, which I don't want to use, I'd like to have a shot at doing it myself, so that I actually learn! So! Which is the best way of doing Sprite animation with the Java2D API:
1) Use a single image (sprite sheet) and have a PixelGrabber "grab" the bits you need as and when you need them.
2) Use lots of individual images to make up the frames of animation, cycling through an array of Images. (this is what my app. uses)
And how is it best to time the animation:
1) Use some kind of thread seperate from the main one, use Interrupts to determine when updates are required.
2) Use a javax.swing.Timer that calls repaint 24 times a second and have the game logic run on a seperate timer. (this is what my app. uses)
The reason I ask, is that I have implemented a simple extensible animation system, but it runs very slow on anything under about 800Mhz, any ideas? For those interested, my full source code is available here:
http://www.macs.hw.ac.uk/~ceetfc/ait/ait.zip
Hope someone can shed some light on what I'm doing wrong.
Cheers,
Tom

Answer 1

You can have the animations and game logic on the very same thread (and should in my opinion). Just call the animations "update" everytime you loop through your game logic. If you don't want to perform the animation every loop (which I am guessing you don't), then pass the time that has passed since the last update call, and once enough time has gone by, then do update. Something to the extent of this in your animation code....
public void update(long timePast) {
   timeSinceUpdate += timePast
   if (timeSinceUpdate  >= UPDATE_TIME) {
            timeSinceUpdate = timeSinceUpdate - UPDATE_TIME;
             ........[insert your stuff here]........