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Unview!   wow, that will save me exiting the console a hundred times 
a day!!  That is a top tip & should be in a prominate place for newbies.

If you want to show a window and return to console immediately, use 
VIEW/NEW instead.

I have been looking at the library examples & noticed that some of 
them start off with something like
navigator: make object! [

The ones like this dont do anything so I am guessing I need to use 
this code in a way I have not come across yet. I have been madley 
trying things like

make a: navigator  and looking up make in the documentation, but 
not understanding the answers.

make object! is the same as making a context. If you see an entire 
script wrapped in make object! [] or context [], it is because it 
was desired to use this script with other scripts without polluting 
the global namespace.

Try this:

context [
	a: 2
	set 'b 3
	set 'c does [return a]
]

>> a
>> b
>> c

A simple way to control what's private and public.

I see, that is good.    I have seen the 'b   syntax used but not 
understood it yet.  I see in your example the set 'b 3 seems like 
b: 3 in the global context.  Thanks very much for your tips, they 
are a great help.

On the other hand, if you want 'a, 'b, 'c to be local to the context 
-- so other parts of your application can also have their own 'a. 
'b and 'c without overwriting each other:

    my-api: context [
        a: 2
        b: 3
        c: does [return a + b]
    ]

my-api/a: 5   ;; override default value
print my-api/c  ;; executes function in context

I wondered how the xxx/xxx/xxx paths to data were constructed... 
I was thinking of this sort of thing as a way to refer to valuse 
in a multi demensional array by name rather than number
house: context [
  room1: context [
      items: [bed chair table]
      ]
  room2: context [
      items: [TV sofa HiFi]
      ]
]

That's the way I do it, using 'context / make object!

Some people prefer using blocks rather than objects:
    blk: [a 4 b 5 c 6]
    blk/b
    == 5
   blk/b: 99
   probe blk
    == [a 4 b 99 c 6]

There are advantages and disadvantages to each approach.

:-) ..... You could think of it as a  type of associative array.

A question: if I want to provide a dialoge to navigate to a directory 
can I call up the ms windows file open & save dialogs, or do I have 
to do it all in rebol. I cant find any examples of this & dont have 
the skills to create my own...  I like the idea of having a GUI interface, 
but I may have to go back to command line if it is too hard for me 
:-)

oh, that was simpler than expected. Thanks very much.  I must say 
I dont think Rebol is very easy to learn, but once all these tricks 
are known it must be very easy to write things quickly.  Perl is 
like a tool shop & a tree for wood, while Rebol is like a high street 
full of all sorts of shops as well as tools.

There is a request-dir too, but it is a bit of a joke. Looks like 
the way to go is to use the request-file then extract the directory. 
 Why would request-dir even exist in such a feeble state? Sorry, 
I hope I am  not speaking out of turn, but if anyone had that pop 
up they would think it was a bit odd.

large parts of the GUI system was written in a very short time by 
Carl alone back early in this decade and has not been officially 
upgraded.

AH a string "*.txt" for the filter works   Thanks for your help

REBOL []

do %include.r
include %file-list.r


flash-wnd: flash "Finding test files..."

if file: request-file/only [
    files: read first split-path file
]
if none? file [halt]

items: collect/only item [
    foreach file files [item: reduce [file none]]
]

unview/only flash-wnd



;-------------------------------------------------------------------------------
;-- Generic functions

call*: func [cmd] [
    either find first :call /show [call/show cmd] [call cmd]
]

change-each: func [
    [throw]

    "Change each value in the series by applying a function to it"

    'word   [word!] "Word or block of words to set each time (will be 
    local)"
    series  [series!] "The series to traverse"

    body    [block!] "Block to evaluate. Return value to change current 
    item to."
    /local do-body
][
    do-body: func reduce [[throw] word] body
    forall series [change/only series do-body series/1]

    ; The newer FORALL doesn't return the series at the tail like the 
    old one

    ; did, but it will return the result of the block, which is CHANGE's 
    result,
    ; so we need to explicitly return the series here.
    series
]

collect: func [
    "Collects block evaluations." [throw]
    'word
    block [block!] "Block to evaluate."
    /into dest [block!] "Where to append results"
    /only "Insert series results as series"

    /local fn code marker at-marker? marker* mark replace-marker rules
][
    block: copy/deep block
    dest: any [dest make block! []]

    fn: func [val] compose [(pick [insert insert/only] not only) tail 
    dest get/any 'val

        get/any 'val
    ]
    code: 'fn
    marker: to set-word! word
    at-marker?: does [mark/1 = marker]
    replace-marker: does [change/part mark code 1]
    marker*: [mark: set-word! (if at-marker? [replace-marker])]
    parse block rules: [any [marker* | into rules | skip]]
    do block
    head :dest
]

edit-file: func [file] [
    ;print mold file

    call* join "notepad.exe " to-local-file file ;join test-file-dir 
    file
]

flatten: func [block [any-block!]][
    parse block [

        any [block: any-block! (change/part block first block 1) :block | 
        skip]
    ]
    head block
]

logic-to-words: func [block] [

    change-each val block [either logic? val [to word! form val] [:val]]
]

standardize: func [

    "Make sure a block contains standard key-value pairs, using a template 
    block"
    block    [block!] "Block to standardize"
    template [block!] "Key value template pairs"
][
    foreach [key val] template [
        if not found? find/skip block key 2 [
            repend block [key val]
        ]
    ]
]

tally: func [

    "Counts values in the series; returns a block of [value count] sub-blocks."
    series [series!]
    /local result blk
][
    result: make block! length? unique series

    foreach value unique series [repend result [value reduce [value 0]]]
    foreach value series [
        blk: first next find/skip result value 2
        blk/2: blk/2 + 1
    ]
    extract next result 2
]


;-------------------------------------------------------------------------------

counts: none

refresh: has [i] [
    reset-counts
    i: 0
    foreach item items [
        i: i + 1
        set-status reform ["Testing" mold item/1]
        item/2: random/only reduce [true false]
        show main-lst
        set-face f-prog i / length? items
        wait .25
    ]
    update-counts
    set-status mold counts
]

reset-counts: does [counts: copy [total 0 passed 0 failed 0]]

set-status: func [value] [set-face status form value]

update-counts: has [pass-fail] [
    counts/total: length? items

    pass-fail: logic-to-words flatten tally collect res [foreach item 
    items [res: item/2]]
    ;result (e.g.): [true 2012 false 232]
    standardize pass-fail [true 0 false 0]
    counts/passed: pass-fail/true
    counts/failed: pass-fail/false
]

;---------------------------------------------------------------


main-lst: sld: ; The list and slider faces
c-1:           ; A face we use for some sizing calculations
    none
ml-cnt:        ; Used to track the result list slider value.
visible-rows:  ; How many result items are visible at one time.
    0

lay: layout [
    origin 5x5
    space 1x0
    across

    style col-hdr text 100 center black mint - 20

    text 600 navy bold {

        This is a sample using file-list and updating progress as files are
        processed. 
    }
    return
    pad 0x10

    col-hdr "Result"  col-hdr 400 "File" col-hdr 100
    return
    pad -2x0

    ; The first block for a LIST specifies the sub-layout of a "row",

    ; which can be any valid layout, not just a simple "line" of data.

    ; The SUPPLY block for a list is the code that gets called to display

    ; data, in this case as the list is scrolled. Here COUNT tells us

    ; which ~visible~ row data is being requested for. We add that to 
    the

    ; offset (ML-CNT) set as the slider is moved. INDEX tells us which
    ; ~face~ in the sub-layout the data is going to.

    ; COUNT is defined in the list style itself, as a local variable 
    in
    ; the 'pane function.
    main-lst: list 607x300 [
        across space 1x0 origin 0x0
        style cell text 100x20 black mint + 25 center middle
        c-1: cell  cell 400 left   cell [edit-file item/1]
    ] supply [
        count: count + ml-cnt
        item: pick items count
        face/text: either item [
            switch index [
                1 [

                    face/color: switch item/2 reduce [none [gray] false [red] true [green]]
                    item/2
                ]
                2 [mold item/1]
                3 ["Edit"]
            ]
        ] [none]
    ]

    sld: scroller 16x298 [ ; use SLIDER for older versions of View

        if ml-cnt <> (val: to-integer value * subtract length? items visible-rows) 
        [
            ml-cnt: val
            show main-lst
        ]
    ]
    return
    pad 0x20
    f-prog: progress 600x16
    return
    status: text 500 return
    button 200 "Run" [refresh  show lay]
    pad 200
    button "Quit" #"^q" [quit]
]

visible-rows: to integer! (main-lst/size/y / c-1/size/y)

either visible-rows >= length? items [
    sld/step: 0
    sld/redrag 1
][
    sld/step: 1 / ((length? items) - visible-rows)
    sld/redrag (max 1 visible-rows) / length? items
]

view lay

Hi, I am trying to reduce the number of global variables I use in 
functions & so my functions return blocks, but I have not discovered 
any simple way to dereference the information in the variables, within 
the blocks..  I have written a function to do it, but I guess there 
is a built in function if I could find it. Or at least something 
a bit more elegant than this: "return_value_of_block_component" function. 
  Any tips most welcome please.

f1: func [a] [
	b: join a "-Bee"
	c: join a "-Cee"
	return [b c]
]

d: f1 {Hi}

return_value_of_block_component: func [block component] [
	foreach element block [
	if element = component [return reduce [element]]
	]
]

H: return_value_of_block_component d 'b
I: return_value_of_block_component d 'c

print H
print I

For f1, reduce the block before you return it. Then use set [a b] 
f1 "blah" to get the values.

vars: make object! [
	b: c: none
]

f1: func [a] [
	vars/b: join a "-Bee"
	vars/c: join b "-Cee"
	vars
]

Only the things you define in a function as local are local.

Each object has its own context. All variables in the object are 
local to the object's context. Only the object "variable" would be 
in the global context:

>> a: 1

== 1

>> obj: make object! [
[    a: "one"
[    b: "two"
[    c: "three"

[    ]
>> a
== 1
>> obj/a
 
== "one"

>> b

** Script Error: b has no value
** Near: b

>> obj/b
 
== "two"

Hi, I have been puzzeling over this all evening & would love a few 
tips please.

I am trying to write a single parse rule that will extract the first 
number before the "/" in each case, but my logic must be faulty I 
think.

digit: charset [#"0" - #"9"]
data1: {random 10/2}
data2: {2/33-35,2/48}

parse/all data1 [ some [[h: 1 2 digit :h copy result to "/" thru 
end] | skip]]
result

parse/all data2 [ some [[h: 1 2 digit :h copy result to "/" thru 
end] | skip]]
result

Thanks Oldes, that looks good. I didnt know I could use compliment 
in a parse like that either. I must have been doing it wrong when 
I tried as I kept getting errors. 

Thanks Steeve, I must go & study more about opt too now.   I very 
much appreciate you clever guys coming in this group to help me with 
my simple questions. I am begining to get a bit more productive with 
some of the things I am trying to do, although I am still very much 
a beginner in most areas. Thanks.

aha, that is easier to learn .. I also don't the advanced parsing 
that oldes gave you example, and I wrote a couple of finished programs 
that used "normal" parsing as a main featurea

I suppose I could add a comma to the end of the string then I would 
be able to use it as a marker.

Is there a way of applying translate to invert the y axis?

Another solution is to apply own translation function on the dialect 
block or generate the dialect block with translated coords from scratch. 
(this shouldn't be a rocket science and would work with text too)

Regarding text, maybe Graham is right and a graphics-only reverse 
would help? for diagrams. The current way is a bit complicated, until 
one gets the trick.

Looks like magic :) But should not be required to draw a line through 
some data?

So, why does the text move across the page ?

view/new layout [
		b: box 400x400 black effect [ draw []]
]

for i 0 90 5 [

 b/effect: compose/deep [ draw [ rotate (i) text vectorial "This is 
 a string of text 1" 300x75 ]]
	show b
	wait .2
]

or set up a straight line "spline" for the text ...

speaking of which, it could be fun to see a LOGO like dialect for 
DRAW. fun for the kids.

got plenty of those around, not mine though. I don't know how interested 
they would be in it yet. I spent countless hours in COMAL80 when 
I was a kid drawing with the "turtle".

Comal80 - a Danish product?

I remember I had a Comal80 interpreter for my C64.

I think it was a great drawing tool. very straight forward approach 
to drawing.

just labelling the y-axis is a problem because of the way AGG does 
the rotate vs PostScript rotate command

and there's no way to save a graphic state in AGG.

ah, yeah that could be a problem

Graham, AGG rotation: that's just an effect of the way AGG does its 
transformations which apply to the whole image. The rotate command 
is just a shortcut method of specifying just the rotation angle of 
a transformation.

I agree that it is a bit uncomfortable at first. I was also expecting 
something simpler like in flash, but I suppose this way is more powerful.

Is there a reason, why SPLINE doesn't draw anything with just two 
points?

view layout [box effect [draw [pen black spline 10x10 90x90]]]

Cyphre, it makes sense to have spline draw a line with only two points 
in a gfx application, where the user start a line with two points 
and may continue with more points or may just end the line after 
only two points.

can't the drawing application change it to a line if it ends in two 
points?

example, sliding objects on a path, connecting lines along splines, 
etc...

Maxim, maybe a Bezier curve is what, you're after? Try
do http://www.fys.ku.dk/~niclasen/rebol/fysik/bezier.r
You can find the Bezier function inside the script.

Cyphre, was has to be done for R3 IMHO is a way for us to probe values, 
just like a 3d package allows you to get point, edge, curvature info 
out of transforming and deforming geometry.

using liquid I am already able to build a draw network, which recycles 
values and allows multiple elements to cooperate.  but I can't get 
that within each element itself.

hmm, reading some of license related answers, GPL seems to prove 
itself being a cancer once again :-(

We can assume, Cairo is distributed under LGPL, right? If so, it 
becomes 
really incompatible with the GPL. For now I'd suggest you 
to keep using AGG 
2.4, at least until we can come up with a better 
legal solution. Basically, 
I want to prevent some 
commercial monster corporations" from free use of 

AGG. But I do want the Linux world to keep using it for free. I'm 
not quite 

sure how well LGPL protects from uncontrolled free commercial use; 
if it 

does, I may re-think and switch to the LGPL. But I'm not willing 
to keep 

using totally free, BSD-like licences in future versions. Ideally, 
I'd like 
to come up with some kind of a QT-like licensing scheme."

but he also adds:


We are working on a legal solution that allows us to prepare special
releases 
of AGG under a commercial license along with GPL. Currently you can
keep 
using AGG 2.4 for free, but I'll stop supporting it soon.
We are 
also working on different fee plans, to make it as flexible as
possible. 
It's hard to tell you concrete values right now, but there won't
be 
anything extraordinary. Depending on the projects and your revenue
we 
can even provide you a 
free commercial license".
We will inform you soon about possible options.

McSeem"

Does someone have a demo-script with agg-fonts on debian? I have 
no deep clue how to use 'draws deper features and dont want to spend 
some hours figuring that out^^

i read it does not work beacuse of absolute font-pathes. i give it 
a try

Yes, I have a demo that Cyphre gave me.

Is there a performance-difference in using the old face/image or 
 drawing images in the draw-block?

Is there a way in Draw/AGG to globally set TEXT rendering mode (aliased, 
antialiased, vectorial) instead of setting it each time you  call 
TEXT ?

Oldes: you could make a REBOL wrapper around the GD library (used 
by PHP for image processing).

well, it is just that we talk about R3 as of a beast, not being compatible 
more than from 30% to R2. If it is going to be nearly 100% compatible, 
than continued development of R2 after R3 release is total vaste 
of resources .....

AGG wouldn't have this effect since it does not seem to use clear 
text.  in fact, in general I find AGG font AA pretty ugly... is there 
a way to improve this?  even if its slow?  there are some situations 
which do not mind speed (generating HQ output graphics, for example) 
 or small GUIs or when converting face looks to bitmaps before display.. 
(trades speed for ram)

Maxim, I don't know. The output seems pretty similar to what is output 
with Freetype 2, but the AA is a little uneven, yes.

I find the issue is mostly with thin lines where the aa will be quite 
spectacular in its variations  especially if you look at the difference 
from 45 angle and near 0 or 90 degre angles. I know that AA should 
be an energy based repartition, which is not linear.  (gamma) such 
that two pixels at 0.5 are actually a quarter as bright as one full 
1.0 brightness pixel to our vision (obviously subjective to user 
response, applied monitor gamma and superwhite levels, etc).

for example, if you want to slide a picture of a stars, you must 
first boost the gamma of the picture by 2, do the move and then apply 
a .5 gamma.  then, the AA will have spread out according to energy 
rather than color.  which means that the 2 side-by-side pixels will 
be at much more than 0.5 of the original 1.0 single pixel brightness.

so I guess a similar operation is needed for fonts (I have no concrete 
bg in fonts, only view a similarity)

The AA is the reason, why I want bitmap fonts. With such a bitmap 
it would be very easy to create pixel fonts. If you take a look at 
Flash you can see, that most of the sites is using pixel precision 
fonts, which are made for fixed height but anyway are much more smaller. 
http://fontsforflash.com/

and if I can use such a image http://box.lebeda.ws/~hmm/rebol/projects/font-tools/latest/fonts/idea.png
to create glyphs which I can use in flash: http://box.lebeda.ws/~hmm/rebol/projects/font-tools/latest/fonts/idea.html
it would be nice to have a chance to use such a bitmap (or the vectorized 
glyphs) in Rebol as well

Is carl going to release a linux sdk with agg enabled?

never mind, I already used my rebol/flash dialect to make the chart. 
I just wanted to say, that there is probably a bug, because this 
is working:
view layout [
	box 400x400 effect [draw [
		rotate 15
		fill-pen red    arc 200x200 90x90 0   108 closed
		fill-pen green  arc 200x200 90x90 108 252 closed
	]]
]

Ach... ok my fault - the center point is in zero - that's why it 
was not visible - so it's probably not a bug

what about a library of draw snipsets handled by rebol.org ?

we could think too about a standardized form for draw animations

90+% of what you need to do that, Steeve, is already in the Library:

[1] we could (in minutes) add extra valid domains or types so a script 
could be categorised as draw-snippet


[2] the LIbrary doesn't use rebservices for an API. It has an API 
called LDS that predates rebservices (basically, the library team 
got there first). You can use it to download any script (among other 
things too)

http://www.rebol.org/cgi-bin/cgiwrap/rebol/documentation.r?script=lds-local.r#toc-50


[3] using LS to download a snippet every time it is needed would 
be slow and wasteful.....But you could easily write get-draw-snippet 
that caches results locally.
****

That would not be perfect as it would be good to have a page/pages 
showing the images the snippets produce. But if there were enough 
snippets, we could add that.....And, before we do someone else could 
beat us to it on their own website -- they could use LDS to get all 
the snippets and display the images. It'd be a neat bit of Community 
interaction.

====> Perhaps switch to Library for any detailed discussion.

Steve, I am about to release in the next few weeks a dataflow draw 
engine called glob.  its allows selectable layers of assembled draw 
blocks, can VERY easily animate too.

Yep, I wanted to make Contextfree parser  in Rebol couple of years 
ago but still don't get to it. Anyway it would be a nice PARSE/DRAW 
exercise :)

BTW, I'm working on a DRAW-based visual CAPTCHA for web forms. I 
guess that if these commands are buggy, I'll have to  do it the old-fashion 
way, making all the calculations in REBOL (instead of letting DRAW 
do the maths).

To clarify it have a look at result this example:

view layout [
	box 600x400 effect [
		draw [ 
			fill-pen blue box 50x50 150x150
			translate 50x50 fill-pen red box 50x50 150x150
			reset-matrix
			translate 70x70 fill-pen yellow box 0x0 100x100
		]
		draw [
			translate 200x0 
			fill-pen blue box 50x50 150x150
			translate 50x50 fill-pen red box 50x50 150x150
			translate 70x70 fill-pen yellow box 0x0 100x100
		]
	]
]

Yes, the example is a bit confusing :) I hope we will have better 
DRAW docs for R3.

ive experimented with various values and don't have a clue - please 
enlighten me :)

Maybe this give a clue?

view layout [b: box 400x400 white effect [draw [shape [move 0x200 
arc 90 200x400 false true]]] at 300x20 slider [b/effect/draw/shape/arc: 
to-integer value * 360 show b]]

Yes, the ARC shape command is a bit confusing....we need to improve 
the syntax or make at least clear docs on it.

is it possible to add viewport rendering into AGG?  eg virtual boundary 
limits - this would save using additional gobs/faces and simplify 
things a lot

no for clipping on retangular regions.. there is a command for that 
already and ive missed it havent I? ;)

so I guess after all that I still do want a viewport ;P

altho i can be munged with a translate after teh clip i suppose

it would be a nice effect

yeah - but im worried about event hit detection - or is it a pre-composited?

or even have a single event function as event awake (you can do this 
in R2 too)

basically... the event gives you the window gob and the offset in 
it. then there's a native that can map an offset inside the window 
to the gob it belongs too. so the mezz code just uses that, then 
maps the gob to the feel, eg via gob/data (user data field)

if you had a game that was operated by keys only, for example, you 
would not need to do any of this, so it's even faster than R2

since gob/data can be whatever... you can map any gob to any feel, 
gob b inside gob a may map to gob c which is elsewhere.

or you don't map the offset to the gob at all, but use a bitmap to 
map the offset to something else, like max does in elixir etc.

it was a joke ;-)

faces are higher level... they have a feel, other info needed for 
eg for vid, etc.

but you don't need to use "faces" at all, you can just use gobs in 
a game for eg. and handle events your own way... maybe gob/data maps 
to the player object :)

how that gob/data points to face/feel/on-click? is there a mezz code 
in gob/data?

hmm, it would be coold, if you could post any simple actual code 
as a spoiler - we can already learn from studying :-)

wait a month (less actually... it's 4 already)

id rather wait a month and have to docs out :)

or just adding a fill-at command

fill-at - that's a problem with anti-alias

normally you set a tolerance