Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.postscript > #307 > unrolled thread

What's postscript's basic algorithm?

Back to article view | Back to comp.lang.postscript

Contents

  What's postscript's basic algorithm? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-08-25 11:37 +0200
    Re: What's postscript's basic algorithm? bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-08-25 11:25 +0100
    Re: What's postscript's basic algorithm? luser- -droog <mijoryx@yahoo.com> - 2011-08-26 19:51 -0700
      Re: What's postscript's basic algorithm? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-09-14 09:49 +0200
        Re: What's postscript's basic algorithm? rodd@panix.com (Rod Dorman) - 2011-09-14 18:21 +0000
        Re: What's postscript's basic algorithm? bonomi@host122.r-bonomi.com (Robert Bonomi) - 2011-09-20 05:12 -0500
          Re: What's postscript's basic algorithm? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-09-20 20:52 +0200
            Re: What's postscript's basic algorithm? bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-09-22 15:40 +0100
              Re: What's postscript's basic algorithm? tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2011-09-22 12:15 -0400
            Re: What's postscript's basic algorithm? bonomi@host122.r-bonomi.com (Robert Bonomi) - 2011-09-25 01:03 -0500
    Re: What's postscript's basic algorithm? Don Lancaster <don@tinaja.com> - 2011-11-08 18:18 -0700

#307 — What's postscript's basic algorithm?

Is the rendering of 'text' which originates from `pdftops` written
one char at a time, or is it rendered one-row-of-pixel at a time
or what?

If the syntax is forth-like, does it also multilevel compose
compound <views/pictures> from a set/library of primitives/glyphs?

== TIA
 

[toc] | [next] | [standalone]

#308

NoHtmlMailsPlease wrote:
> Is the rendering of 'text' which originates from `pdftops` written
> one char at a time, or is it rendered one-row-of-pixel at a time
> or what?

It's unspecified. Postscript specifies an image, the rendering
engine can implement this as it wishes.

It is likely that a screen-driving renderer, a framebuffer (e.g. laser print)
driving engine, and a typesetter (driving a very high resolution output)
would all work differently.

  BugBear

[toc] | [prev] | [next] | [standalone]

#311

On Aug 25, 4:37 am, "NoHtmlMailsPlease" <UsePlainT...@dog.edu> wrote:
> Is the rendering of 'text' which originates from `pdftops` written
> one char at a time, or is it rendered one-row-of-pixel at a time
> or what?

The 1st-edition manual describes two basic device-rendering modes:
framebuffer device or band-device. Some of the algorithms will be
different for different modes, but they all use the Weiler-Atherton
clipping algorithm. A screen-based renderer may choose to use
dithering
instead of halftone screens.

> If the syntax is forth-like, does it also multilevel compose
> compound <views/pictures> from a set/library of primitives/glyphs?

Mu. Syntax just describes how the source-code "looks". It is not
related
to what the language "does".

You might find a general overview like wikipedia.com/Postscript
useful.
Also the "blue book", Adobe's very nice tutorial is available free
online.

[toc] | [prev] | [next] | [standalone]

#330

"luser- -droog" <mijoryx@yahoo.com> wrote in message 
news:9528d930-4e45-45ae-9d44-74045726388e@o26g2000vbi.googlegroups.com...
> On Aug 25, 4:37 am, "NoHtmlMailsPlease" <UsePlainT...@dog.edu> wrote:
>> Is the rendering of 'text' which originates from `pdftops` written
>> one char at a time, or is it rendered one-row-of-pixel at a time
>> or what?
>
> The 1st-edition manual describes two basic device-rendering modes:
> framebuffer device or band-device. Some of the algorithms will be
> different for different modes, but they all use the Weiler-Atherton
> clipping algorithm. A screen-based renderer may choose to use
> dithering
> instead of halftone screens.
>
>> If the syntax is forth-like, does it also multilevel compose
>> compound <views/pictures> from a set/library of primitives/glyphs?
>
> Mu. Syntax just describes how the source-code "looks". It is not
> related
> to what the language "does".
>
> You might find a general overview like wikipedia.com/Postscript
> useful.
> Also the "blue book", Adobe's very nice tutorial is available free
> online.
>
OK, there's a LOT on line.
I'm trying to have my pdf-text do page-breaks at paragraph-breaks.
And experimenting with `gs <my ps file> `  gets my stuck at
<position x,y to new-line> where, working from 1st principles leads to:
lineStart -> Xcoodinate ; CurrentY - FontSizePlusextra -> Ycoordinate
which seems absurdly "indirect".

So far I haven't found the <relative move Y down to next line based
on currentFontSize>

This stuff looks like a canOworms which could consume a lot of time
if allowed to.

== Chris Glur
 

[toc] | [prev] | [next] | [standalone]

#332

In article <j4pppg$4i0$1@dont-email.me>,
NoHtmlMailsPlease <UsePlainText@dog.edu> wrote:
>  ...
>I'm trying to have my pdf-text do page-breaks at paragraph-breaks.
>And experimenting with `gs <my ps file> `  gets my stuck at
><position x,y to new-line> where, working from 1st principles leads to:
>lineStart -> Xcoodinate ; CurrentY - FontSizePlusextra -> Ycoordinate
>which seems absurdly "indirect".
>
>So far I haven't found the <relative move Y down to next line based
>on currentFontSize>

And its quite possible there isn't any. Most word processing and page
layout programs allow you to set the leading to something other than
the font size.

Column balancing is another case where vertical positioning won't be
simple.

>This stuff looks like a canOworms which could consume a lot of time
>if allowed to.

Well sure, PostScript is a programming language and like most of them
theres more than one way of writing the program so it ain't gonna be
easy to analyze the program to figure out what's a 'paragraph'.

-- 
					-- Rod --
rodd(at)polylogics(dot)com

[toc] | [prev] | [next] | [standalone]

#335

In article <j4pppg$4i0$1@dont-email.me>,
NoHtmlMailsPlease <UsePlainText@dog.edu> wrote:
>
>
>So far I haven't found the <relative move Y down to next line based
>on currentFontSize>

There's a reason you haven't found it.  It *doesn't* exist.

It is the responsibility of whatever generates the postscript to
keep track of the font size and generate the rmove based on what
_it_ thinks is the right amount for that font size.  (This is usually
*not* the actual font height.)

>This stuff looks like a canOworms which could consume a lot of time
>if allowed to.
>
>== Chris Glur

Oh.  *you*.

IF you can't be bothered to learn the theory first, you will waste a
lot of time banging your head against the wall, trying to make it fit
your erroneous expectations.

Postscript simply *doesn't* work the way _you_ "think it ought to".

You have to adapt to the way it works, not the other way around.

When you can't find something that matches your expectations, that is
a positive indicator that *your*expectations* are wrong, and need to be
revised.

Dollars to donuts, based on a couple of _decades_ of watching your blind
insistence that the world change to work _your_ way, you _won't_ take this
advice.

[toc] | [prev] | [next] | [standalone]

#342

"Robert Bonomi" <bonomi@host122.r-bonomi.com> wrote in message 
news:BfCdnbPbKoeI-uXTnZ2dnUVZ_j2dnZ2d@posted.nuvoxcommunications...
> In article <j4pppg$4i0$1@dont-email.me>,
> NoHtmlMailsPlease <UsePlainText@dog.edu> wrote:
>>
>>
>>So far I haven't found the <relative move Y down to next line based
>>on currentFontSize>
>
> There's a reason you haven't found it.  It *doesn't* exist.
>
> It is the responsibility of whatever generates the postscript to
> keep track of the font size and generate the rmove based on what
> _it_ thinks is the right amount for that font size.  (This is usually
> *not* the actual font height.)
>
>>This stuff looks like a canOworms which could consume a lot of time
>>if allowed to.
>>
>>== Chris Glur
>
> Oh.  *you*.
>
Play the ball, not the player.
Stay on topic: technology, else join the Oprah Winfree forum.

> IF you can't be bothered to learn the theory first, you will waste a
> lot of time banging your head against the wall, trying to make it fit
> your erroneous expectations.
>
> Postscript simply *doesn't* work the way _you_ "think it ought to".
>
> You have to adapt to the way it works, not the other way around.
>
> When you can't find something that matches your expectations, that is
> a positive indicator that *your*expectations* are wrong, and need to be
> revised.
>
> Dollars to donuts, based on a couple of _decades_ of watching your blind
> insistence that the world change to work _your_ way, you _won't_ take this
> advice.
>
Technology is designed to fit human needs, as far as possible.
 

[toc] | [prev] | [next] | [standalone]

#343

NoHtmlMailsPlease wrote:
>

>> Dollars to donuts, based on a couple of _decades_ of watching your blind
>> insistence that the world change to work _your_ way, you _won't_ take
>> this
>> advice.
>>
> Technology is designed to fit human needs, as far as possible.

What a lovely, boldy stated assertion.

On current evidence, PostScript is a counterexample.

  BugBear

[toc] | [prev] | [next] | [standalone]

#344

On Thu, 22 Sep 2011 15:40:58 +0100, bugbear wrote:

>  ... boldy ...

Sorry: was that meant to be baldy? moldy? bilky? boldly? :-) 

Cheers, -- tlvp
-- 
Avant de repondre, jeter la poubelle, SVP.

[toc] | [prev] | [next] | [standalone]

#349

In article <j5fbbg$1fk$1@dont-email.me>,
NoHtmlMailsPlease <UsePlainText@dog.edu> wrote:
>
>
>"Robert Bonomi" <bonomi@host122.r-bonomi.com> wrote in message 
>news:BfCdnbPbKoeI-uXTnZ2dnUVZ_j2dnZ2d@posted.nuvoxcommunications...
>> In article <j4pppg$4i0$1@dont-email.me>,
>> NoHtmlMailsPlease <UsePlainText@dog.edu> wrote:
>>>
>>>
>>>So far I haven't found the <relative move Y down to next line based
>>>on currentFontSize>
>>
>> There's a reason you haven't found it.  It *doesn't* exist.
>>
>> It is the responsibility of whatever generates the postscript to
>> keep track of the font size and generate the rmove based on what
>> _it_ thinks is the right amount for that font size.  (This is usually
>> *not* the actual font height.)
>>
>>>This stuff looks like a canOworms which could consume a lot of time
>>>if allowed to.
>>>
>>>== Chris Glur
>>
>> Oh.  *you*.
>>
>Play the ball, not the player.
>Stay on topic: technology, else join the Oprah Winfree forum.

To the self-proclaimed "do as I say, not as I do" net-nanny who is too
much of a coward to post with a real name on the From line, too incompetent
to deal with using a real email address,  and too much of a chicken to
put his name on his "advice" --

Chris Glur, in accordance with your 'rules', please confine your future
activities to the Oprah Winfree[sic] forum.


>> IF you can't be bothered to learn the theory first, you will waste a
>> lot of time banging your head against the wall, trying to make it fit
>> your erroneous expectations.
>>
>> Postscript simply *doesn't* work the way _you_ "think it ought to".
>>
>> You have to adapt to the way it works, not the other way around.
>>
>> When you can't find something that matches your expectations, that is
>> a positive indicator that *your*expectations* are wrong, and need to be
>> revised.
>>
>> Dollars to donuts, based on a couple of _decades_ of watching your blind
>> insistence that the world change to work _your_ way, you _won't_ take this
>> advice.
>>
>Technology is designed to fit human needs, as far as possible.

You demonstrate that you "don't know what you don't know".

I repeat: Postscript simply *doesn't* work the way _you_ "think it ought to".

You can argue about it.

You can try to impose your idea of 'how it ought to work' on how at actually
works -- and be forever frustrated and doomed to failure.

*OR*, you can set aside your assumptions, biases, and prejudices, and *LEARN*
how it is _designed_ to work.

Knowing your history, I'll bet money, at long odds, *against* that last.

[toc] | [prev] | [next] | [standalone]

#441

On 8/25/2011 2:37 AM, NoHtmlMailsPlease wrote:
> Is the rendering of 'text' which originates from `pdftops` written
> one char at a time, or is it rendered one-row-of-pixel at a time
> or what?
>
> If the syntax is forth-like, does it also multilevel compose
> compound <views/pictures> from a set/library of primitives/glyphs?
>
> == TIA
>


Depends entirely on the algorithm chosen.

Some text coding sets character at a time, some word at a time, and some 
full lines at a time.

Much more at < http://www.tinaja.com/pssamp1.asp >

-- 
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU's LAIR web site at http://www.tinaja.com

[toc] | [prev] | [standalone]

Back to top | Article view | comp.lang.postscript

csiph-web