                       ****   ***   ****  **** *  ***  *   *
                       *   * *   * *     *     * *   * **  *
                       *   * *   *  ***   ***  * *   * * * *
                       ****  *****     *     * * *   * *  **
                       *     *   * ****  ****  *  ***  *   *

                       *************************************
                       
  Ok, Dracula on the keys! I will write all I want and you will suffer...
  This text is not supposed to be "sorted", it's only a big messy shit....

  
1. Spreading the demo.
~~~~~~~~~~~~~~~~~~~~~~

  Copying the demo and the sources is allowed only if no profit is made when
copying it... Not even a small copying fee. Public Doman Libraries must have a
written agreement to put this demo in their list. To get this agreement write
to:
			Dracula / Positivity
                	  Alain BROBECKER
              		  rte de Dardagny
                   	   01630 CHALLEX
                    	       FRANCE

                       
2. Full Credits.
~~~~~~~~~~~~~~~~

* The Tune "SYNTHESIS HYMN" was composed by Nikom of Positivity.
  By my point of view, this is a really great tune, but it is a bit short
  and I didn' t have time to ask Nikom to "polish" it. (In fact, at this
  time, Nikom do even not know I am using one of its tune I think.)
	
* The soundtracker rout was coded by Wizzcat of Delta Force,
  and improved by Metal Ages of Cybernetics and Kasar of Positivity.

* The Positivity logo was drawn by Captain Schmurtz of Positivity.
 
* The members were drawn by STelex and Dracula of Positivity. As you can see
  we are all ugly. In fact most of the "portraits" are coming out of STelex's
  strange and dirty mind. He is a frog guy anyway...
  
* The nice Girlie was drawn by Pegase of Adrenaline. Very nice...
  (I especially like the banana!)

* The "STONEHENGE" hill was again drawn by STelex. A nice composition...
  I think the thema was choosen because we are "des irreductibles ST-istes"...
  But only STelex can say...

* The "TRUCK" was drawn by Captain Schmurtz. It looks like coming out of
  a Mad-Max film..

* "ROCKET FUEL" was, again, drawn by Captain Schmurtz. I find it quite cool for
  an image with only three colors. (colours?!)          

* The "Teddy Bear" image (Nounours in french) was drawn by Dracula. Yes, it' s
  me, so a comment will look a bit on the wrong side... The only thing I want
  to say is that the inspiration come from Bruno BELLAMY, but the hand drawing
  was made by me too.
  
* All the code was made by Dracula. It's still me.


3. The Greetings.
~~~~~~~~~~~~~~~~~

  Here comes my greeting list, I hope I have forgotten no one, anyway, if you
are a friend of mine, or of Positivity you should know that we send you our best
regards... By the way, there is no special order...

  * Survivor / Mafiamiga.   ( Thanks for getting me started with 68000.)
  * Chris - Creeks / Mafiamiga.   ( Thanks for being so cool guys.)
  * Elf / Intense.   ( 42 je crois, mais chuis pas sur!)
  * Onyx.  ( T'es pas fou? Chez les Anglicshs?!?!?)
  * Nullos / DNT-Crew.   ( Thanks for the tricks! What about USA?)
  * Flips / DNT-Crew.	( Are you dead? Still waiting the reply...)
  * ArmOric / Arm's Tech.   ( Thanks a lot for your help with the ARM...)
  * Wann-STC-Sam / HMD.	  ( Preparation H rules.)
  * Tomcat-Lector-Skillion / STeelers.
  * Zorgan & all others Heretiques.   ( La trisomie regne...)
  * Daubeman.   ( Enfin un ardent defenseur du ST! Arf, arf...)
  * Creator / Aggression.   ( Utopos is fun!...)
  * Marco Polo / HMD.   ( Thanks for saying nice things...)
  
  I would also like to send my best regards to all the cool guys who are
coding, drawing, "noising" or else on any kind of computers, and a special
hi to all the ones who have made me be interested in demo writing. ( Survivor,
Red Sector, The Union, Alcatraz, Lost Boys...)
    
  
4. Positivity' s Memberlist.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  * Anneli..........................Swapper, giant.
  * Captain Scmurtz........................Grafist.
  * Dracula..................................Coder.
  * Kasar..............................Boss, coder.
  * Nikom.................................Musician.
  * Silver Eagle...........................Swapper.
  * SpearHead................................Coder.
  * ST-Mixes..............................Musician.
  * STelex.................................Grafist.

  Now I will say some words about the crew and its atmosphere: fucking damn
shit, it's too lame... Arf, arf, arf, only joking... In fact we are not a top
crew, but considering the way some great crews (especially on the Amiga) are
behaving themselves it' s a good thing. The only thing I really don' t like is
the absolute lazyness in mailing: I don' t own a minitel, and for this reason
I have approximately no contacts with other members. Only STelex is answering
quite quickly. And that's sad, coz some of them are really very cool...
( Anneli is really funny...) Excepted this lazyness, the atmosphere is quite
cool, and that's important!...


5. Technical details.
~~~~~~~~~~~~~~~~~~~~~

  Ok, we leave the "scene" (aaaaaargh, I HATE this word) and I will spent some
time writing comments about the effects contained in this demo. I think that
it could be interesting if you are a coder and you don' t want to spend hours
looking in my sources to know how I do everything.

* The scroll zoomer:
  No interest, it' s the only screen which really uses the blitter a lot.
  
* The Jelly Zoomer:
  Well it' s the first screen coded for this demo in the beginning of the
  summer. All the points in the jelly are plotted individually and I must
  say that it' s near realtime. "Near" because I use 35 Kb of generated
  code. I have made a version with an image scrolling in the jelly box,
  but it was looking crappy, so...
  
* The rotative zoomer:
  Well, I think many people will say it' s really lame, but in fact I don' t
  think it is, only because for once there are no big squares and that it is
  TOTALLY REALTIME! I even not use generated code. The core of the routine
  is very similar to the one in the mapping, but it looks tiny. With a 12.5
  KHz soundtrack, the 64*60 tiny image is rotated-zoomed in three VBls.
  By the way, talking about big squares, I did NEVER understood why so many
  guys are making zoomers with so big squares! When they were on C64 or on CPC
  they were complaining about the shitty resolutions, and now that they have
  decent ones they make shitty big squares only to gain processor time! Could
  someone explain me that???
  
* The hatched gouraud shading.
  You think it looks like shit? I do too. The hatching is obtained with no
  loss of power compared to a normal (and stinky) gouraud shading. I have
  found an algorithm which makes my gouraud filling look like the one by Griff
  of Electronic Images,(I call it floyd-shading) but I was lacking of registers
  to make a 4 planes filling and it was slower than this version... I have
  progressed a lot during the creation of this demo, so I think I am now able
  to do this, but....
  
* The Z buffer:
  It' s the last effect I coded. The algorithm was given to me by ArmOric of
  Arm's Tech (thanx again) and it is not very fast. It also have a lot of
  bugs in it! Hope you will not see them. Oh, by the way, all the algorithm
  in this demo were created by my own, and if it is not the case I mention it
  in this text.
  
* The (False) Texture Mapping:
  This is, by my point of view, the only effect who has a quite good level of
  code in this demo. Again it is totally realtime, and no tricks are used.
  But why is it false texture mapping then? Well quite simply, like almost
  every mapping I have seen so far, the depth is not taken in account for the
  calculation of the points, so it's not real texture mapping. (The one you can
  see with raytracers.) Putting a rotative zoomer in each face instead of a
  stupid image takes no processor time and I think it looks OK, so...
  By the way, if you wonder how to make texture mapping with bitplanes, let me
  give you a small advice. When I was searching how to make fast planar to
  linear images conversion, I found (by my own) that the extend bit is very
  usefull, consider the following:
    add.w    d0,d0     ; eXtend bit takes the value of the upper bit in d0.
    addx.w   d1,d1     ; d1 rotated left, last bit set the same as eXtend.
          
  Also, I would like to thank Nullos of DNT crew for the other hint about the
  addx.l coz it makes me gain some time. Thanks. (Yes, there are others hints
  with the addx, but I will not explain them in this text, else it would be
  longer than the demo!) If you want to code texture mapping, I recommend you
  begin by coding normal polygon routines, then code a rotative zoomer, and
  then you would be ready!
  
* The mapping+shading:
  The little cube which looks like wood is a combination of the shading and
  of the mapping routines. No interest coz the routines were fastly (one hour)
  adapted to 3 and 1 bitplanes respectively without optimisations (I have
  registers left when I'm going through the sp!) and that the result looks like
  shit. Too bad, but I don' t want to waste time coding uninteresting things.
  
* The fractal:
  Well, it was coded very fastly, but the result is not optimised. I think the
  mandelbrot set with z-depth effect looks nice, and it has 32 colors. Also,
  there are up to 32 iterations per point, and it is really slow...
  
  Well, this demo is the result of approximately one month and a half of fun,
but in fact when I code a screen I usually go on this way: I spent a lot of
time thinking to the algorithm, up to 2 weeks, and then when I begin to code
everything goes fast, that' s why the Texture Mapping was made in 3 days for
example. (Also it is very similar with the rotative zoomer and the shading.)
  Also note that the "polishing" of the demo is the thing which took me most
time, because I was not motivated with this. I didn' t count it in the time
used to do the demo.
  This demo could have been made on the STf, as it uses no specific STe tricks,
but I am really too lazy to do a new version, except if someone says me he
would pay for it! (Hehe..)


6. Mama was a Fuzion.
~~~~~~~~~~~~~~~~~~~~~

  Well, if you are a Falcon owner, you may be interested in knowing I have
converted my mapping routine to the Falcon. The conversion was made really
fastly (2~3 hours, maybe less) during the Garden Party 4. ( This party was
organised by "les Heretiques" and was an opportunity to see some cool but
totally brain destroyed amigamens, like "Syntex" (Salut Max et Avoriaz)
or "les Heretiques".) The result gives a quite nice mapped cube in true color
which runs quite fast, even if it is not optimised. (I don't know what is good
with the 68030) I decided to give it this strange name coz I like very much
the "Papa was a BladeRunner" demo by Eko, and I hope Maxx Out will not judge
my mapping too lame. The mapped 56*56*56 cube runs in one frame per VBl.


7. Computers.
~~~~~~~~~~~~~

  I am happy cos I just bought a new computer, and as all purchaser I am happy
with my new fantastic machine. Well, you may be wondering which compy I have
purchased... A 486 DX2 66Mhz?.......  No, no way, I will never buy such a
shitty machine... Those computers are speedy, but it' s a kind of masochism to
code in assembly on it. (Even worse if you use a VGA Card. I really admire the
guys who are coding demos on it.) So almost nobody codes in assembly with PCs
and the power then flush down...
  An Amiga 1200??? No, no, no... The 1200 gives no changes from an Amiga 500
or from an Atari ST. I also don' t like to have all this fucking DMA shits
running around...
  A Falcon?? Well, humm.... This would have been my second choice! The linear
true color mode is interesting, but it' s too expensive and I think I am not
good enough to code the DSP!... (As you may have noticed if you are a coder,
I am not wasting time programming the hardware and co, I am only interested
in algorithms.)
  Well, it seems we have seen all the existing machine so far. Have I bought a
Commodore 64 or a CPC. (Which are both still alive in fact, even if you don' t
hear of them very often..) No, the machine I bought is.... (Drum roll...)
 
  An ARCHIMEDES!....
  
  Surprising, huh.... You thought this compy was born dead? In fact this is
certainly the only machine which was created without a commercial purpose.
It was created for English schools by the BBC, and it is surprising to see
how good it is for an old machine. (1988) There are many interesting features:
 * Linear 1 byte=1 pixie mode.
 * The risc microprocessor:
    - almost all instructions take one cycle.
    - all instructions are conditionnal. This seems nothing, but when you have
      a pipeline, it is really interesting to avoid all the branchs. It also
      makes the code be smaller sometimes.
 * The OS is really fast (Totally written in assembly) and powerfull. The roms
are containing a basic, an assembly language, the OS handles with vectorial
anti-aliased fonts, and there is much more on RISC OS 3. (2Mb of Roms, and
everything is in Assembly, woooow! It changes from Windows....)
  			   
  To give you an idea of how the machine is powerfull I will tell you that
I have coded a line routine on the archie and that I draw approximately 120
(0;0)->(319;199) diagonals in one VBl on a 8MHz Archie and that my best
routine on the ST achieves only 15 diags per VBl...

  I must thank ArmOric of Arm'sTech for all the infos and the help he has
given to me... You are very cool...

  As far as I have seen, there are some problems with the computer, and ArmOric
did not try to hide them, so he is a really objective guy. ( Instead of all the
PC or Amiga (or ST) owners who say their computers have only qualities.)
  * There is sometimes a lack of software. (The best way to have the utility
    you want is... to code it!) (Strange, games are usually converted to the
    Archie, they have Speedball 2, Lemmings 2, Populous 2... But there are
    no decent drawing utilities, like Neochrom Master.)
  * The RISC processor is powerfull, but it's sometimes strange (even if it is
    totally logical) when you are accoutumed to 680x0 or 80x86 based computers,
    I think it will go better when I will have coded on the Archie for some
    months.
  * It is English. (Arf, it is a Joke!... Well, a tentative of joke.)
    
  
8. Sources.
~~~~~~~~~~~

  The sources for this demo are released freely! I' am sorry but I can not
comment them anymore, a lot of work waits me on the Archie. I think I will
write an article about texture mapping for the DNT paper (In fact I have
already started it.) but I am busy those days.... By the way, the sources
for the "Mama was a Fuzion" are filled with bugs, I gave them but it is better
to recode the mapping routine completly instead of using my own. ( I think
my routine is not a bad example, but it is not "serious".)


9. No Future.
~~~~~~~~~~~~~

  As I' m going on to the Archie, I will stop, maybe definitely, to code on the
Atari STe. But I will continue to see what is produced on this machine, the
same way I am looking the Amiga and PC demo production. If you continue to code
on Atari ST, Commodore 64, CPC 6128, To7, Mo6, Alice, and even on PC you must
know I will be respectuous of your work, because I think the fun you can have
with a computer and your imagination is by far more important than the kind of
computer(s) you are using....
  Oh, by the way, talking about future, on the Archimedes, if you decide to
join the few froggies owning this machine, my pseudonyme will be "baah".
I'm fed up with my current ST pseudo, and the baaah really have a sense:
It sounds like the guys looking a demo I have coded! Arf...

 
  Dracula signs off on 24th of july 1994.
