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Gfa demo - best screen

Posted: Sat Mar 03, 2007 5:39 pm
by ryo
Hello, somebody did it already think coded a megademo in GFA taking again most famous screen coming from the cuddly, mindbomb, ...... that would be a super challenge??

Posted: Sat Mar 03, 2007 5:55 pm
by bod/STAX
Overlanders did a screen in the Ultimate GFA Demo whereby they tried to match the TCB-SUPER-SINE-AND-A-WHOLE-LOTTA-THINGS-MORE screen in the Union Demo.

You couldn't beet some screens with GFA Basic, but you could come close to matching them or making screens "look like" other screens coded in 68K.

Posted: Sat Mar 03, 2007 8:16 pm
by Mug UK
There's also Stew's GFA demo as well as the Bunch Demos to look at for proper GFA demo screens.

Posted: Mon Mar 12, 2007 5:18 pm
by ryo
My idea is of launching a competition having for objective to create screen in GFA taking again best the demonstrations of the best groups. Interested??

Posted: Tue Mar 13, 2007 12:11 pm
by tobe
Yes, but only on STE ;)

Posted: Tue Mar 13, 2007 1:40 pm
by Nyh
ryo wrote:My idea is of launching a competition having for objective to create screen in GFA taking again best the demonstrations of the best groups. Interested??

What about Omikron basic?

Hans Wessels

Posted: Tue Mar 13, 2007 1:50 pm
by SkylineDave
the Anti-Assembleur Team had a good crack at it with the Ultimate GFA Demo 2 but the Overlanders' Ultimate GFA Demo 1 was better

Posted: Tue Mar 13, 2007 3:21 pm
by tobe
GFA ! GFA !

But well, rules must be clear, no generated assembler code inside :)
To check for this is another problem...

Posted: Tue Apr 17, 2007 8:15 pm
by ryo
Would be you interested by a competition having for object the conversion of the best screens (tcb, tlb,…)in BASIC (GFA, Omikron, Stos,...)? So yes I takes contact with the administrators of the forum in order to publish the rules.

Thanks

Posted: Wed Apr 18, 2007 8:01 am
by p01
tobe wrote:GFA ! GFA !

But well, rules must be clear, no generated assembler code inside :)
To check for this is another problem...

Even if the generated assembler code is in fact compiled GFA ?!

15years ago, I was a real purist of GFA, using 68k code for anything but a replay routine was, and still is, an absolute NO-NO. But I see no problem with generating compiled GFA.

If the goal is to make a megademo, this might be necessary to go easy on the disk space. Heavy GFA screens tend to use a LOT of generated code ( I think the biggest .LST I generated was 40+k lines, and the usuals were 10+k ) and inflate the file size of the final .PRG. Generating compiled GFA should be rather trivial ( just have to make sure to 'cleanly' init the variables you need before so you don't trash A5: GFA's 'stack' of variables ).

Posted: Wed Apr 18, 2007 8:45 am
by tobe
Then all you have to do is to write a 68k code generator in GFA and then you better write directly 68k assembler ;)

Posted: Wed Apr 18, 2007 9:49 am
by p01
Most of the huge LSTs I generated where repeating a pattern of 2-5 GFA instructions where only the index of the variable and an offset changes. It's dead simple to compile one pattern, grab the compiled code and generate the code towers with modified offsets.

Posted: Wed Apr 18, 2007 11:38 am
by tobe
Ah yes I agree with you, it makes very long listing and takes lots of room once compiled. But on the other hand I'm pretty sure UPX can make it smaller.
I don't disagree with duplicating/modifying compiled GFA code, but if it came to compare screens then we must be able to check the code to be sure its not generating 68k code.

Posted: Wed Apr 18, 2007 11:51 am
by Tomchi
Yeah ... The last posts bring me to a sublevel question :

Would you need to be part of gfa elite coders to enter the challenge or is it worth for someone who never coded before ( meaning me for example ;) ), trying to contribute ... I'd like to have non-alcoholic headacke :p

Posted: Wed Apr 18, 2007 11:54 am
by tobe
Well in my opinion it *must* be open to everyone.

Note that you can easily avoid the alcoholic headache by drinking enough water before going to bed ;)

Posted: Wed Apr 18, 2007 12:23 pm
by Marcer
well.. the rulez could be quite easy made.

1. all use the same Zik + GFX.
2. No DATA Commands (since this is an way to convert pure machine code).
3. No Inlines
4. Format must be .LST.
5. Code controller & Compiler should be Simon Sunnyboy or such.

how about that?

// Marcer

Posted: Wed Apr 18, 2007 12:47 pm
by p01
Marcer: I understand these rules.

It might be a bit painful to generate all the LUTs a screen might need ( think about raytraced based effects e.g.s tunnels, worm hole, wobbly scrollers with reflection, ... )

Also it does not prevent to generate compiled GFA code towers. One can look for some markers in the code ( ~n --> moveq #n,d0. Place 2-4 of them around the base pattern for your code tower and voila ).

Posted: Wed Apr 18, 2007 1:37 pm
by leonard
Hi ! A coding contest with contrainst, cool :-) I personnaly made some optimizing contest on ARM processor (GBA cpu) wich were funny. We made three contest, all uses GBA emulator as cool platform (no GBA specific, just write pixel on a memory buffer). We made three contest:

1) the faster flat polygon routine on ARM (asm was used)
2) The smalled executable of a spinning 3d flat cube (very fun, kind of "boot sector" atari :-))
3) optimize to the death a public JPEG GBA depacker (35kb of cpp source code only). Only use C/C++ (no ASM allowed for that contest)

One day I'll create a website about these challenge, cool be very cool. Unfortunatly I guess I probably never had time to do it :-)


Btw, you spoke about simon-sunnyboy GFA compiler? What's this exactly? I'm quite interested. By old days, I made a complete GFA compiler "IDE" using a cool gui interface. I never spread it (exept to OVR). Maybe someone has that tool? I don't find it anymore on my disks...

Cheers

Posted: Wed Apr 18, 2007 3:29 pm
by simonsunnyboy
I think he wants me to be a supevisor or such and put the thing together in the end.
No INLINES is very strict, how to load the music? nd if you want proper quality you just _need_ some m68k for the replayer, it won't sound right otherwise.

Posted: Wed Apr 18, 2007 4:26 pm
by tobe
Yep, and it's easier too use gfxs with inlines :roll:

Posted: Wed Apr 18, 2007 8:34 pm
by Marcer
simonsunnyboy wrote:I think he wants me to be a supevisor or such and put the thing together in the end.
No INLINES is very strict, how to load the music? nd if you want proper quality you just _need_ some m68k for the replayer, it won't sound right otherwise.


you dont need to inline the music to make the call of it correctly.. :wink:

infact it took me some time before I noticed the function "inline" I used to load the music + gfx. and as I recall I didnt have much trouble about it..

// Marcer

Posted: Wed Apr 18, 2007 8:41 pm
by p01
:? but it's so much more elegant to inline the data in the final PRG file. And you'll have to check the LST file anyway to make sure people didn't sneak some 68k code in their external data files.

Posted: Thu Apr 19, 2007 6:10 am
by simonsunnyboy
File loading stuff is a nuisance, esp. for small productions. INLINES just load it in one go.

Posted: Sat May 26, 2007 7:03 pm
by ryo
Here rules for the GFA-screen competition: The screens proposed will not be allowed that if they are entirely programmed in BASIC (GFA, Omikron, STos, .....). Only musical routines (chip, soundtrack.) can be programmed in another language. The converted screens must come only from the great following Méga-demon: Cuddly demonstration, Mind Bomb, European Demon, Just Buggin', Ooh Crikey, Wot A Scorcher, Sowatt Demo, Dark of the spoon, The Union Demo, inner circle,........

The various screens will be subjected to the vote of the members of the Atari-forum.

The Date of beginning of the competition: today

The completion Date: 31/12/2007.

I hope that this forum will promote this challenge

Posted: Sat Jun 02, 2007 3:12 pm
by p01
Thanks for the late deadline.

Hopefully this will allow me to go back into GFA black magic :)
Will be fun to see what I manage after 12+ years