<span class="Apple-style-span" style="font-size: small;">Regarding </span><span class="Apple-style-span" style="border-collapse: collapse; white-space: pre; -webkit-border-horizontal-spacing: 2px; -webkit-border-vertical-spacing: 2px; "><span class="Apple-style-span" style="font-size: small;">hpysics, d</span></span><span class="Apple-style-span" style="font-size: small;">id anybody did some experiments with this? The blog seems to be inactive since december 2008; has development ceased? </span><div>
<span class="Apple-style-span" style="font-size: small;"><br></span></div><div><span class="Apple-style-span" style="font-size: small;">Do alternatives exist? Maybe good wrappers (hopefully pure...) around existing engines?</span></div>
<div><span class="Apple-style-span" style="font-size: small;"><br></span></div><div><div><div><div><div><span class="Apple-style-span" style="font-size: small;">Integrating hpysics with Grapefruit might be a good topic for the Hackaton, trying to make a simple game (e.g. Pong or Breakout) without using recursive signal functions, but with correct collision response and better-than-Euler integration, all handled by the physics engine. Other FRP engines could be tried, but Grapefruit hacking is already a topic on the Hackaton, so it would combine efforts. </span></div>
<div><span class="Apple-style-span" style="font-size: small;"><br></span></div><div><span class="Apple-style-span" style="font-size: small;">It feels as if none of the current FRP engines can handle physics correctly, since a typical physics implementations requires "time backtracking", in the sense that when you want to advance the current simulation time by a timestep, collision events can happen during that time interval, and hence the FRP engine can only advance time until the earliest collision event. So to do physics *with* an FRP engine, the implementation and maybe even semantics of the FRP system might need to be changed. *Using* a physics engine as a blackbox inside an FRP system might make more sense.</span></div>
<div><span class="Apple-style-span" style="font-size: small;"><br></span></div><div><span class="Apple-style-span" style="font-size: small;">Thanks to Wolfgang Jeltsch and Christopher Lane Hinson for having a discussion with me that lead to this. Interestingly a similar discussion was help by other people in the Reactive mailing list at the same time :-)<br>
</span></div><div><span class="Apple-style-span" style="font-size: small;"><br></span></div><div><span class="Apple-style-span" style="font-size: small;">Cheers,</span></div><div><span class="Apple-style-span" style="font-size: small;">Peter Verswyvelen</span></div>
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