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[Postscript] Emitting Postscript from REBOL

Geomol
20-Apr-2008
[1583x3]
Remember what kind of language, PS is.
There is no information about font (other than Times 40) in my example.
The 0x421 and 595 comes from the papersize, which is 595x842 when 
using A4.
Henrik
20-Apr-2008
[1586x2]
ok, tell me then the algorithm for calculating the font height inside 
REBOL. :-) you cannot possibly know without reading and parsing the 
.PFM files yourself.
and as mentioned at first, I already tried the font size... doesn't 
work.
Geomol
20-Apr-2008
[1588]
Why would I need the font height? I didn't need that in my example 
to center the text.
Henrik
20-Apr-2008
[1589]
no, because you probably were eyeballing it.
Geomol
20-Apr-2008
[1590]
No, I didn't! :)
Henrik
20-Apr-2008
[1591]
center the text
 ... are you talking about _horizontally_ centered text?
Geomol
20-Apr-2008
[1592x2]
When you do things like:
at 100x200 "some text"

the character origin of the first character in the text is at position 
100x200.
No, horiz and vert!
Henrik
20-Apr-2008
[1594]
where did you get 0x421 from?
Geomol
20-Apr-2008
[1595x2]
0 is left side of paper. 421 is height of paper divided by 2. 842 
/ 2 = 421.
Then it's centered.
Henrik
20-Apr-2008
[1597x3]
if that's the case, let me test the theory
what?...
why doesn't that work for smaller cells?
Geomol
20-Apr-2008
[1600x2]
PageSize A4
page [
	font [Times 18]
	at 60x421 "abcdefg"
	font [Times 36]
	at 130x421 "abcdefg"
	font [Times 96]
	at 260x421 "abcdefg"
]
In my example, the baseline of all the text is vertical centered 
on the page.
Henrik
20-Apr-2008
[1602x3]
now I'm reallly confused. it would mean the height of the paper is 
somehow misleading. I tried your method in the table cells and get 
top-aligned text as I expected.
sorry
not top-aligned text, but text where the baseline is the center.
Geomol
20-Apr-2008
[1605x2]
Ok, if it does, what you need. :-)
Do you have the psrefman.pdf document for PS second edition? Seciton 
5.4 has a drawing of font positioning.
Henrik
20-Apr-2008
[1607]
I. Need. Vertically. Centered. Text. :-) Is that so hard to understand? 
:-)
Geomol
20-Apr-2008
[1608]
LOL :)
Henrik
20-Apr-2008
[1609x2]
Your method produces this:

http://hmkdesign.dk/rebol/postscript/testsheet.ps
That is _not_ vertically centered text. That is text that is vertically 
centered around the baseline.
Geomol
20-Apr-2008
[1611]
Eh, the baseline is centered in each cell, right? And you're asking 
each word to be centered within its cell with equal space above and 
below the text?
Henrik
20-Apr-2008
[1612]
... yes :-)
Geomol
20-Apr-2008
[1613]
Because if you want that, then it'll look strange, because each line 
in the table will have text jumping up and down, depending on whether 
you have letters like 'g' and 't' or you just have letters like 'a'. 
And that will look less nice to me.
Henrik
20-Apr-2008
[1614]
sigh... I've already said 4 times that I use the alphabet to prevent 
this! :-)
Geomol
20-Apr-2008
[1615]
But you're right, that if you really want that, then you need to 
get info from each letter in the font.
Henrik
20-Apr-2008
[1616]
yes! now you get it
Geomol
20-Apr-2008
[1617]
:) In REBOL/View, there is things like offsets to position text within 
field and so. Couldn't you go with something like that? Just subtract 
a little from each vertical position to get the text a little down, 
if you want?
Henrik
20-Apr-2008
[1618]
then I have to do that for each single individual case. with the 
deadline I have to produce this table, that may be my option for 
now, but that is definitely not optimal.
Geomol
20-Apr-2008
[1619x2]
If you have different fontsizes in your tables, you could do something 
like:
y-pos: y-pos - (fontsize / 10)
Then adjust the 10 factor, until you're satisfied. And that should 
then work for all fontsizes.
Henrik
20-Apr-2008
[1621]
well, possibly. I'll see if that works for now.
Geomol
20-Apr-2008
[1622]
Sorry, that I find it hard to understand, what you mean from time 
to time, my fault. I get you now. I would put things like margins, 
linespace, vertical position within tables, etc. in a dialect above 
the postscript dialect level. Doing it that way, the same postscript 
dialect can be used for all sorts of layout engines, because it has 
little restriction.
Henrik
20-Apr-2008
[1623]
for the syntax and input yes, but if you need accuracy, you need 
to get the information via postscript.
Geomol
20-Apr-2008
[1624]
ok
Henrik
20-Apr-2008
[1625]
because we are already doing it correctly using stringwidth, namely 
by calculating the text size accurately inside postscript. the same 
should count for the vertical size. it's strange that information 
is so hard to get.
Geomol
20-Apr-2008
[1626]
Don't you think, it already is centered, if you take underline into 
consideration? It seems weird to me, that Adobe would position text 
being off some amount, either up or down.
Henrik
20-Apr-2008
[1627x2]
it is not centered, because the baseline is not at the center of 
the text. if only it were :-)
and the position calculation is around the baseline.
Geomol
20-Apr-2008
[1629]
That is the reason, that they put the baseline as they did?
Henrik
20-Apr-2008
[1630x3]
the baseline is a typographical tool. it is the place where your 
letters are "resting" against, just like when you were learning to 
write in school, you had a guide line to write characters on. but 
the baseline itself is completely useless for vertical centering 
of text.
adobe didn't invent the baseline
but I do wish that each char in a font had a center point that indicates 
the absolute center of a character both horizontally and vertically. 
horizontally, that would be individual for each char, but vertically 
it has to be identical for all chars, like the baseline is.