Re: ocaml, simd, & fftwgel RE: [Caml-list] Caml productivity.

[John Max Skaller <skaller@ozemail.com.au>]

Damien Doligez wrote:

>>From: John Max Skaller <skaller@ozemail.com.au>
>>
>
>>Huh? Which parts of a real time interactive game aren't real time??
>>The whole thing, from gameplay interaction to graphics and sound,
>>must be done in 'real-time'.
>>
>
>I'd say no part of a real-time interactive game is real-time.  To me,
>real-time means something like the Ariane 5 rocket, where you have a
>deadline every 36ms for the 12 hours of the mission.  And if you miss
>even one deadline your 100M$ rocket will crash.
>
Heh! I suppose I have to agree. My Real Time work involved phase control 
lighting systems,
where timing is even tighter than your Ariane's 36ms. Surprisingly, 
switching phase controlled
lighing circuits require precision measured in microseconds -- a single 
machine extra instruction
on a 2Mhz microcontroller can turn an acceptable performance into an 
unacceptable one.

>With Objective Caml on a fast machine, if you're not doing heap
>compaction, GC pauses should be somewhere between 1 and 10
>milliseconds.  Quite workable for an interactive game, I'd say, but
>then again it's not the future of my company that is at stake.
>
Well, games like Diablo freeze for much longer than that: Baal's 
minions, 5-15 second lockup,
fighting Diablo with perspective on, on a 800Mhz machine: frame rate of 
1 frame per second
or worse with a lag of up to 5 seconds. ARGGG!!! Totally unacceptable: 
lag is responsible
for at least half the deaths on the internet servers.

As I commented in another post, Ocaml could only improve the quality of 
these games
by allowing the programmers to actually get the structure of the real time
operation right.

-- 
John Max Skaller, mailto:skaller@ozemail.com.au
snail:10/1 Toxteth Rd, Glebe, NSW 2037, Australia.
voice:61-2-9660-0850




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