World: r3wp

just that if you have some bugs or wandering about specifics, he 
has deep knowledge of it, he might even be able to give you hints 
on how to go around a few missing things.

is there a way to test if a var is set to none ?

NONE? word

yep

ah sorry - rebcode - not sure :--x

^^^

is the T flag positionned after AND opcode execution ?

i should test that

seems not

so, i have to do something like that, to set the T flag, i mean :
 
AND tmp 255
eq.i  tmp 255

i have to do many operations like that to emulate the Z80 8-bit ship, 
Z80 modify his T-flag after any logical operation. i think Rebcode 
should do that  too :-)

Please write it to Rambo, better now, before R3

done

another prob is that all opcode operate on 32 bit integers only, 
in my case it would be cool if they can act as well on chars (8 bit)

i can do without, but my code is more verbose

...and slower

espacially with bit rotation opcode, which are useless in my case 
^^^

i need a speed reverse byte function with rebcode , for example 1100 
0000 => 000 0011
any idea ?

* 1100 0000 =>  0000 0011

I get strange result from the sin opcode, is there something special 
to know or is it a bug ?

rad or degres?

degree

I try with rad too but I should make a mistake

I'm not an expert only that I know by having many 3d cgi scripts 
that many apis have a mix and match of rad and degres... but it seems 
you looked at that too...

To test, I use this code :

test-sin: rebcode [value [decimal!]][sin value return value]

>> test-sin 90.
== 0.893996663600558
>> test-sin 100.
== -0.506365641109759
>> test-sin 0.0
== 0.0
>> test-sin 1.
== 0.841470984807897
>> test-sin .1
== 9.98334166468282E-2
>>

hum... its possible that some values just don't map directly to precise 
values (floating point errors)

but I agree that sin 90 should give you something closer to 1

et sin 1 devrait donner quelque chose de proche de 0

sorry in english, and sin 1 should give something near to 0

just tested  and well... the values supplied really are in radians 
 :-)

>> sine/radians 90
== 0.893996663600556

and a radian is pi / 2, right ?

2 * pi

Yes, right. It's OK now my script is running well. Thanks you.

Thanks to rebcode I can generate 6 minutes of music in 20 seconds 
instead of 5 minutes with a standard script. Great.

if you want fast sine, use tables, it's 10x times faster (that's 
without interpolation, but even with interpolation it will be still 
faster).

or if you need continuos sine wave, use self oscilating filter

I'm a newbe in music generation so ... I don't know what is self 
oscilating filter.

you can generate sine wave aproximation faster than using sin func

some example code (in C, but easy to rewrite):

float a = 2.f*(float)sin(Pi*frequency/samplerate);

float s[2];

s[0] = 0.5f;
s[1] = 0.f;

loop:
s[0] = s[0] - a*s[1];
s[1] = s[1] + a*s[0];
output_sine = s[0];
output_cosine = s[1]

this is much faster than calling SIN

Very simple indeed. I will test.

have you seen my Sintezar PM-101 in rebol.org library? maybe it will 
be interesting for you. I've got rebcode version on my disk, but 
because rebcode is not part of official rebol, it's not released. 
if you're interested, i can send you some examples. now i'm rewriting 
that synth as VST instrument in C(++), it's much faster then :)

No, I will look at now.

Thanks Rebolek, I reduce the time to produce 6 minutes 44 of music 
from 20 to 15 second.

you're welcome. 25x faster, very nice!

btw, what are you generating? it's your own synth, or some emulation? 
It's very interesting for me :)

It's to emulate the PSG AY-3-8910
Just for the fun and to understand a little about music

oh I see. But I thought AY-3-8910 has 4bit osc. with square and saw 
waves(plus some combinations), no sine? or does it have same lfo 
with better resolution and sine wave? don't remember the architecture 
corectly.