World: r3wp

window: layout [i: image rate 5 load %gtfo.jpg key escape [halt]]

zoom-in: does [i/size: i/size * 5 / 4]
zoom-out: does [i/size: i/size * 4 / 5]
down: false
alt-down: false

insert-event-func [
	probe event/type
	switch/all event/type [
		down [down: true]
		up [down: false]
		time [if down [zoom-in]]		
		alt-down [alt-down: true]
		alt-up [alt-down: false]
		time [if down [zoom-in] if alt-down [zoom-out]]
	]
	center-face i
	show window
	event
]

view/options window [resize]

REBOL []


window: layout [i: image rate 5 load http://rebol.com/graphics/kits.jpg
key escape [halt]]

zoom-in: does [i/size: i/size * 5 / 4]
zoom-out: does [i/size: i/size * 4 / 5]
down: false
alt-down: false

insert-event-func [
	probe event/type
	switch/all event/type [
		down [down: true]
		up [down: false]
		time [if down [zoom-in]]		
		alt-down [alt-down: true]
		alt-up [alt-down: false]
		time [if down [zoom-in] if alt-down [zoom-out]]
	]
	center-face i
	show window
	event
]

view/options window [resize]

Can comments be deleted?

I guess they can't. Anyway, thanks for your help!

comments here in Altme? No - they can't be deleted ...

This is the first step to creating a zooming user interface

What do you mostly use rebol for?

as for me - simple CGI stuff, some automatition tasks, few GUI utils 
....

In easy-vid, Carl creates layouts of a fixed size, and fits all his 
text accordingly.  Hypernotes creates layouts that are variable in 
height.  How is this done?

ie. control the width and let the height expand to as necessary.

set the width and then use size-text

If you use unview/only window, why should any other windows close 
down as well?

they shouldn't

I wonder if it's the Z order that is the problem

Maybe it's just a rebgui issue ...

It's also occuring if I use the close gadget at the top right ..

Yes, it seems to be a result of using rebgui's display/parent ...

Can't find the DRAW group anymore, so I'm posting here.

Does anyone know if IMAGE-FILTER BILINEAR is working in Draw? I see 
no differences with NEAREST mode (which looks horrible when scaling 
down a big image, even with preserved aspect ratio).

If BILINEAR filter is not working or not implemented (while being 
documented), that would be really a pity to have to code my own bilinear 
filter in REBOL which would be probably too slow to use, or install 
a 10MB library like ImageMagic...

bilinear only works with scaling up

forget making smooth thumbnails with R2 :-)

I'm finishing attached files management for CureCode with thumbnails 
generation....too bad, you'll have horrible thumbnails...


Once again with REBOL, stuck at 95% of the goal and no (simple) way 
to workaround. That's how I usually loose all the time gained by 
using REBOL instead of another language...Where's that Rant channel? 
:-)

Fortunately R3 has no problem with this.

Nice, so now could you port Cheyenne + CureCode to R3 in one night? 
If not, I can't see how R3 can help me.

Just trying to help :-) I could see the use here for launching r3 
processes from Cheyenne for limited special functions. I assume the 
thumbnails are generated once?

Yes, I know, I'm really pissed off by the misleading Draw documentation...

there are wrappers to image-magick, no? Or - you could use nconvert 
from xnview package from command line too ...

just workarounds too ... before Cyphre fixes/extends Draw ... but 
I doubt any native changes are going to be backported to R2.

Yes, once only, I guess CALL would be ok, just need to install ImageMagic 
on Windows, test it, then install it on Linux server, test again, 
then add this package to the list of dependencies to maintain...cool!

get used to what other environments do ;-)

... well, just kidding ... I thought it is a one-time job ....

Well, the point in using REBOL+my own closely integrated frameworks 
is to avoid third-party dependencies...

Try contact Cyphre ... or I will ask him ...

If R2/Draw is not going to be updated, there's no point in bothering 
him.

Doc, I might have a resizer to make thumbs...

can't you call R3 from R2 ?

Ah nice! I started looking at http://en.wikipedia.org/wiki/Lanczos_resampling
to see if a REBOL implementation would be fast enough.

Just a test:

set 'resize func [img /local sz c1 c3 i2] [
	if file? img [img: load-image img]

	scale: img/size/x / 160
	sz: as-pair 160 round img/size/y / scale
	c1: 1x0 * sz
	c3: 0x1 * sz


 i2: to-image layout [origin 0 box sz effect [draw [image img 0x0 
 c1 sz c3]]]
	save/png %img.png i2
]

Call RESIZE with a loaded image. It'll save the img.png file, that'll 
have x-size of 160. It looks ok here.

Change the 160 to some other value, if you need other size.

That's almost the code I've made already. The issue is not having 
BILINEAR or any other good enough filter for thumbnails.

(or give it as an argument)

I'm working with 64x64

It seems to be ok without the filter, so maybe some default filter 
is in action. Let me check...

Lanczos (IrfanView) is giving incredible good results.

couldn't convolve filter be used somehow?

I use lanczos in XnView by default ...

you can blur the image before downscaling, but it can smear it more 
and the image isn't as clear.

How do you access CONVOLVE operator? (can't see it in Draw documentation)