World: r3wp

...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 :-)

btw - don't you expect any possible rebol 3D engine, even if we have 
rebcode, as simply slow? Isn't the only chance linking rebol to external 
engine/library (e.g. OpenGL)?

that's probably the only way... also you shouldn't expect to do any 
serious 3D without access to 3D hardware acceleration. it would be 
nice to do this through openGL somehow, but it would take up too 
much footprint to build this into rebol directly