World: r3wp

so clearly, the rebol event engine is capable of much higher throughput 
than its allowing.

he can but it's a design limit.

the rate you enter on a face is not taken in account. 
Time events are always throwed at the same rate.

Then there is some internal counter for each face which have a rate 
value, to know when the time events must be dispatched to them.
I don't know if i'm clear...

the rate is taken into account if you set it before opening the window, 
but cannot be changed after.

but beyond 5 / second, is progressively gets off by the above percentages. 
 up to a maximum of 15/s when you put it at 24

but I am now building a precise timed function which is taking 1% 
cpu and can go up to  60 frames/second consistently.

wrong, it can be, but you must do a refresh on the face, after changing 
his rate

beyond that and the wait goes into madness mode and consumes 100% 
(of one core)

What i mean, is that, there is 2 rates.

One for the inner event handler which is always the same (the limit 
you pointed 15 ev/sec)
And the rate of the face, wich is basically a counter

this might have been fixed in a later view, cause it didn't update 
before.

ah ok.

So even if you fix a low rate 1 ev/minutes on a face, The time events 
continue to be send at a rate of 15 ev/sec in the inner event handler.
It can be the reason why it consumes so much time

i got the problem in area-tc

and there is another one problem, It consumes time and memory, you 
have to to do frequent recycles.

I've never had any memory issues with recycling...
do you put recycle to off?

(when rate is used)

no, but i saw that when the time rate is activated it consumes memory, 
some mega, i don't like that

seems the lack of resolution from the /precise flag is the source 
of the offset in what you ask and what you get.  I bet on a linux 
box, it would be much more precise.

Max rate of 15/s sounds a bit low to me. When I was on WinXP it was 
48/s maximum rate.

if I put rate at or anything above 30 I only ever get 15, and when 
I do tests with my more precise timing function it seems that by 
using wait 0.001 I can go  at 65 frames / second.  


ironicaly, rounding and IEEE math errors give me the same 66% - 75% 
offset between desired rate and actual rate... seems I'm using the 
same algorythm than REBOL internally.

this is on a winxp with 1.5GHz core2 duo.

(and good nvidia gfx card)

I have a strange reaction in some AGG code...  calling show on the 
face is actually appending the new AGG drawing to previous such that 
the image is the result of all prior draws... but the draw stroke 
(verified) isn't growing!


anyone know what is causing this... AFAFIK I am not using the draw 
command, but setting the face/effect and calling to-image on the 
face.

DOH!  never mind... just found it... I was setting the face/image 
to that new image  ...  heheheh  obvious.

anyone have some spline (bezier, nurbs, anything) math converted 
to rebol code?


I want do to some point on spline stuff, using control vertices to 
orient the curve.

if it has tangent functions for the points that would even be better!

did you check rebol.org ?

yep.. didn't find anything with spline or curve in it... is there 
something there?

but I could have done more searching...

you can"t use draw dialect ?

how do I get the x,y coordinate on the curve from a spline I draw 
with AGG?

I need the math, the main use isn't for AGG, but it will eventually 
have to be displayed anyways.

well i've done some smouth functions to interpolates coordinates, 
but i don't know if it's your need.
What is your input and what output are you expecting ?

you're starting from some points i guess, and you want to construct 
a smouth curve with them...

yes... bezier, b-spline, or nurbs, if possible... cause I can easily 
match them with other applications if I need to eventually.

ok, i give you a hint

i download a script wait...

the most common know function (i guess) to interpolate 2 points is 
to use this cosine function.

(1 - cosine a * 180) / 2

i use it in my plasma script

a is a value between 0,1

I know bezier really is just an iterated break up of an algorythm 
between control points..  I could implement the math, but if you've 
got some stuff all done  ;-)

all the algorythms are available on the web via siggraph and other 
sources, but coding that stuff usually isn't very fun.

I was asking, cause I saw a demo once of someone rebuilding the AGG 
spline manually right over the AGG one.. so some code definitely 
exists.

no, i use it to interpolate colors, not coordinates, so it is no 
use as it is in my script.

But it's easy to figure how to interpolate coordinates instead of 
colors gradiants, i gues...

Giving 2 points as input , i can write it if you want, but give me 
the paremeters you want and the result expected (an image, a block 
of coordinates ?).
Give the specs

for linear interpolation its pretty easy.
  
this is the complicated use...

give me the (x.y)  at length z of (bezier, nurbs, quadratic, etc) 
spline defined by points  p1, p2, p3, p4, pn

We wrote our own spline (arc function for a Paint program we did). 
 

DPaint had this, which implies John's RPaint has this code too, no?

ho i see, your input is a length and you want the coordinates in 
return ?

tricky need

The nice thing is that it works backwards, which is, you give it 
XY, and a control point, and it draws thorugh the control point.

Of note, if you want another way to think of an arc.

Think of drawing 3 points A B C (C is the "pull")

Now, you have what looks like a triangle.


If you make a tic halfway between A and C, and B and C, and draw 
a line been these tics, then keep doing this, you will eventually 
make an Arc.

The last tic is where your Mouse cursor would end up.

That is why Arc in RPaint is "backwards".

Cool, eh?