World: r3wp

Guest: this is not a bug. Try this code:

img: draw 50x50 [fill-pen green box 0x0 49x49]
view layout [image img]

it seems to be bug to me

you have to take in mind that the coordinate system starts from 0x0 
not 1x1. The white border is a 'stroke'  rendered by PEN (which is 
set to white by default). So if you want just plain box you have 
to write:


 view layout [box 50x50 effect [draw [pen none fill-pen red box 0x0 
 49x49]]]

hmm

ups, the last line should be:


view layout [box 50x50 effect [draw [pen none fill-pen red box 0x0 
50x50]]]

(because the stroke line is not rendered in that case)

thanks. I can't wait to use draw/AGG effects !

Is there a replacement for key effect? my trials are not what I expected 
regarding that...

keying at level of DRAW is not supported in the latest alpha of Rebol 
with AGG. You can yse the KEY command in the EFFECT blocku though. 
I'm looking into this so this feature will be hopefully back in the 
betaversion of Rebol/AGG release.

will native matrix operations be exposed with AGG?  if so which ones?

yes,  AGG will support 2D affine transformation matrices. So you 
can apply translation, rotation, scaling and inversion on  the actual 
matrix.

You will be able to define the matrix content directy using block! 
of 6 values.(this is more for advanced users or useful with some 
kind of vectorial format conversions)

You will be able to use also matrix stack and PUSH/POP different 
statest of matrix. This will allow nested(hierarchical)  transformations.

so how about matrix multiplication and transpose -- non-graphics 
specialized maths

general matrix operation? I am not sure it belongs to AGG, but we 
asked for it long time ago :-)

I want to thank Cyphre for all his test scripts in REBOL/View/tests/. 
Very a good good source of inspiration  and a perfect show room for 
the AGG capabilities ...

Agreed. Has anyone done (or is working on) an AGG based SVG renderer? 
Or an SVG2DRAW converter? If so, there's a wealth of SVG content 
out there that we could use ...

I'm thinking SVG icon sets for a start.

we made a start a couple of years ago but didn't get far
http://www.compkarori.com/vanilla/display/SVG+Dialect

ashley: IIRC, Cyphre has a SVG parser that outputs a draw block. 
but i think it was unfinished.

Yes he has. The Tiger head was "stolen" from an SVG source ;-)

Cyphre, or others - I am curious. I just read latest blogs about 
Mozilla technology - they will switch rendering to Cairo open source 
library. It will handle svg as well as the rest of rendering too. 
IIRC Cairo was already mentioned here. I wonder how AGG compares?

All I know is that the classic SVG Tiger demo ( Viewtop/Tests/View/Tiger.r 
) looks better than any others that I've seen...

Ammon - was it you who once talked about Shake compositing etc.? 
Some of you guys once suggested kind of "caching" for already-rendered 
stuff (nodes) etc. I wonder what Carl has in ming with min-face, 
but maybe we could be even faster :-)

Cairo seems to be ahead a bit though - buffered imaging, hw usage. 
I do remember that Carl wanted to introduce kind of view plug-ins, 
which should allow faster rendering/blitting?

Close.  It was actually Maxim who talked about Shake.  He's done 
some work with it which involves REBOL...

Hmm, Maxim - haven't seen him for ages her. Is he still around? :-)

her=here

Maxim is around.  I've been communicating with him mostly via email 
as he hasn't actually logged into AltME in a while...

I have SVG viewer called SVG-LITE in works...

It is in early state of developement..the source has actually about 
7,5Kb and it is not optimized.

If my tries are good, ARC command use "time" direction !! I would 
better think in "Trigonometric" one, no ?

I have 2 "not so good" behaviour with 'ARC command.

1) Drawing an Arc with big line-width at rectangular angle (0, 90, 
180, 270) does not give an edge as I would. Try :

n: 1
plot: [
	pen black line-width n
	arc 190x130 60x60 90 270
	arc 390x130 60x60 180 270
	arc 190x330 60x60 0 270
	arc 390x330 60x60 270 270
]
							
view center-face layout [
	bx: box 580x450 effect [draw plot]
	sl: slider 580x20 [
		n: 1 + (sl/data * 70)
		show bx
	]
]

...move the slider and see.

2) closed ARC does not work if angle goes up to 0° angle. Try :

n: 0
plot: [
	pen black line-width 2
	arc 190x130 60x60 90 n closed
	arc 390x130 60x60 180 n closed
	arc 190x330 60x60 0 n closed
	arc 390x330 60x60 270 n closed
]
							
view center-face layout [
	bx: box 580x450 effect [draw plot]
	sl: slider 580x20 [
		n: 1 + (sl/data * 360)
		show bx
	]
]

...move the slider slowly and see.

This one looks like a bug :-(

Easier to see with filled arcs :

n: 0
plot: [
	fill-pen red pen black line-width 5
	arc 190x130 60x60 90 n closed
	arc 390x130 60x60 180 n closed
	arc 190x330 60x60 0 n closed
	arc 390x330 60x60 270 n closed
]
							
view center-face layout [
	bx: box 580x450 effect [draw plot]
	sl: slider 580x20 [
		n: 1 + (sl/data * 360)
		show bx
	]
]

There is a missing STOP-ANGLE: STOP-ANGLE // 360 or something like 
that in the calculation.

Sorry to feed. A more complete test script :

rebol [title: "ARC's Draw command test"]

begin: angle: 0
lines?: 'closed
plot: [
	fill-pen red pen black line-width 5
	arc 100x100 90x90 begin angle lines?
]
							
view center-face layout [
	bx: box 200x200 effect [draw plot]
	across
	style vt vtext 60 right

 vt "Start:" scroller 392x16 [angle: face/data * 360 show bx] return

 vt "Angle:" scroller 392x16 [begin: face/data * 360 show bx] return

 vt "Type :" toggle "open it" "closed it" [either face/data [lines?: 
 none] [lines?: 'closed] show bx]
]

Pretty cool DideC

DideC: thanks for the report, please add it to the RAMBO. This will 
be fixed in 1.3.1

Ok, done.

What do you thinka of the first test (this group, yesterday 20:25) 
?

It looks like some rounding or stroke generator problem. I need to 
investigate more soon.

ok