World: r3wp

abstract: http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/pact/2004/2229/00/2229toc.xml&DOI=10.1109/PACT.2004.10021

you can convert ps to pdf on http://www.ps2pdf.comfor free

...and it works well!

here is example of simple cells animation with custom rebcode's preprocessor 
--> do http://box.lebeda.ws/~hmm/rebol/projects/boids/latest/rc-cells-1.r

hehe funny! :-)

hm, but now I want to work with decimals as well and wonder if will 
be faster to use block to store the cell variables, or if I will 
use my own decimal format and binary structer as I'm using now

how to write: [ 2 ** exponent ] in rebcode?

stupid question:) mul.d i i

mul.d i i is i ** 2 and not 2 ** i

2 ** exponent:

set a 2.0
log-e a
mul.d a exponent
exp a

or you can use set a 0.693147180559945 to save one instruction

thanks, but kru, I will save instruction but will deal with rounding 
error:

>> x: rebcode [exponent][set a 2.0 log-e a mul.d a exponent exp a 
return a] x 3.0
== 8.0

>> x: rebcode [exponent][mul.d exponent 0.693147180559945 exp exponent 
return exponent] x 3.0
== 7.99999999999999

interesting, it looks it will be faster to use rebol blocks to store 
Rebol values instead of binary format I used in the cell example 
before (which was faster in the early rebcode versions)

do http://box.lebeda.ws/~hmm/rebol/projects/boids/latest/rc-cells-2.r
  <--- same like the version 1 but without the rebcode preprocessor 
using Rebol block to store cell variables instead of the binary format.

how do you tell the speed difference? I can't see it....

It's not in the script, I did local tests.

how great is the speed difference?

using rebol block is 3x faster

that's quite a lot...

how to get random number between 0 and 1?

I generate random number from 0 to milion and divede it by milion

:) i fought there will be better method

so it's: rnd: rebcode[][set d 1000000000 randz d to-dec d div.d d 
1000000000.0 return d]

how to write atan2(sin,cos) in rebcode?

Oldes, can we include rc-cells on the rebcode demo page?

yes, why not

Thanks! I just want to make sure we get permission from authors.

can I return error! from rebcode?

Nice demo Oldes. :)

I rewrote my old 3d demo to rebcode to see the speed difference. 
But I found that normal rebol can draw 120+ triangles without slowing 
down and because I became bored adding more objects I stopped testing 
it :) Anyway, rebcode optimalised (just three or four functions - 
matrix multiplication, inversion and 3d to 2d conversion - are rewritten 
to rebcode, it can be optimalized more) version is here - http://krutek.info/rebol/ratrix.r
. z-buffer does not work very well as you can see.

and the speedup is? :-)

maybe it would be nice to have some button, have functions saved, 
and toggle between rebcode/non-rebcode version ....

hm, from my tests, matrix operations are just 3x faster, 3d to 2d 
conversion is cca. 11x faster. But old rebol-only version can show 
120+ triangles without problem so in this simple demo, rebcode is 
not needed :)

:-) hmm, and if you would like to make object movement faster?

To make objects move faster you can just change their speed, it's 
not rebol vs. rebcode thing :)

yes, but if I would like some of them to rotate like mad, rebol limitation 
would just show, so it might become rebol vs rebcode thing ;-)

rebol limitation may show but it won't be rebol math speed limitation 
but rebol face refresh speed limitation :)

not necessarily - you don't have to refresh more than 24/sec, yet 
rebol math speed may become limiting factor, depending upon how complex 
your scene is .... but - I am not here to argue with you about single 
details, just wanted to see those two versions compared, that is 
all ...

Pekr as I said, here on this computer, classic rebol is capable of 
updating more than 120 trinagles at full speed (rate: 0) without 
problem. And after 120 triangles I became bored adding more so I 
did not test it :)

looks neat, but I think people use more than 120 triangles in their 
own demos. :-) is it open or flexible enough to be used as a general 
engine?

Henrik I know that 120 triangles is not that much, but I'm adding 
them manually, I have no loader for some 3d files, so that was the 
reason why I stopped :) Basic idea is four years old but I think 
it can be used as general engines after some little changes. Feel 
free to look at the code, if you want to.

I think it would be fun to have a little engine. I'm thinking something 
like:

view 3d-layout [sphere 50 red .... ] etc. :-)

This is also how Maya is built. A powerful 3D engine and a comprehensive 
programming language which builds the editor. A little like Emacs.

There are "entities" like "faces" in View. And 3d "pane". It can 
be dialected as you wrote.

a pity pairs don't have a third dimension... otherwise you'd have 
to use tuples except it would be confusing with positions vs. colours.

kru, yes I think dialects would be ideal for describing a 3D environment, 
at least the parts that are not related to motion perhaps.

i use blocks of decimals for 3d points, it's much more precise

I remember some talk between Cyphre and Carl about "subpixel accuracy" 
in regards to AGG, but dunno if related. Carl was thinking if he 
should allow decimals for pairs IIRC.

I also remember, that he said that rebol is good fit even for 3D, 
where 3D is another container, and result put back to face (bitmap). 
But dunno if I got it right. I doubt it :-)