Chipmunk Physics

I was playing around with the cocos2d engine demos and tried the chipmunk demos. On the iPhone they run insanely slow but I came across a video of something who had the same demos but with faster performance.

http://tlrobinson.net/blog/2008/02/21/c ... he-iphone/

I'm wondering how this person might have gotten such a clean performance out of the iPhone? I say this because I'm looking at trying to simulate fluids by having many small balls with small friction. It looks nice on the simulator but runs slow on the phone. I managed to speed it up a bit by playing around with the steps, hashes and increasing size of the circles but it's still kind of choppy and due to increase in circle size it looks less like water.

Clearly this guy managed to find a way to get great performance and I'm wondering if you guys knew what was wrong with the cocos2d integration of chipmunk?

arian487 wrote:I was playing around with the cocos2d engine demos and tried the chipmunk demos. On the iPhone they run insanely slow but I came across a video of something who had the same demos but with faster performance.

http://tlrobinson.net/blog/2008/02/21/c ... he-iphone/

I'm wondering how this person might have gotten such a clean performance out of the iPhone? I say this because I'm looking at trying to simulate fluids by having many small balls with small friction. It looks nice on the simulator but runs slow on the phone. I managed to speed it up a bit by playing around with the steps, hashes and increasing size of the circles but it's still kind of choppy and due to increase in circle size it looks less like water.

Clearly this guy managed to find a way to get great performance and I'm wondering if you guys knew what was wrong with the cocos2d integration of chipmunk?

I have spent very little time inside Cocos2d, but I know earlier they were having problems with running on 3.0. It could still be performance issues from that you're seeing. Anything I've thrown at the iPhone using Chipmunk it has handled beautifully so far.

You need to disable the [x] compile for Thumb checkmark.
With that enabled, FP is much slower. Instead of inline asm, it does dll calls for floating point.

I find the performance on iPhone pretty good, also on 3.0 firmware.
Simulator is much faster, yes, but the device can still do reasonable complex simulations.

Bram