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Re: setstrokeadjust: what's the disadvantage?

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In article <6068d7ca-fef2-46db-8c2c-cb97fefed43d@googlegroups.com>, 
jdawiseman@gmail.com says...
> 
> From 'Emulation of the setstrokeadjust Operator', Adobe Technical Note #5111, 31 March 1992, §2.3 on page 9:
> 
> http://partners.adobe.com/public/developer/en/ps/sdk/5111.Stroke_Adj.pdf
> 
> Both PostScript Level 2 systems and Display PostScript(tm) systems are able to perform an automatic adjustment to paths that causes them to be rendered at uniform widths. This automatic stroke adjustment can be turned on and off with the setstrokeadjust operator. Stroke adjusted paths are actually rendered slightly faster on Level 2 systems than non-stroke adjusted paths, so that you might want to stroke adjust paths for performance reasons alone, even when the improved 
appearance is not a consideration.
> 
> Does Adobe's 
> > Stroke adjusted paths are actually rendered slightly 
> > faster on Level 2 systems than non-stroke adjusted paths
> 
> suggest that the arguments about speed are mistaken?

As I said, implementations vary, and it might be that an already slow 
scan conversion is not slower (and indeed may even be faster) with 
stroke adjustment turned on.

The only way to tell, I believe, is to actually try it and measure the 
performance. If it truly is faster on Adobe interpreers then I would 
expect Adobe to have it turned on permanently (I certainly would in 
their place).

Bear in mind that many early level 2 implementations were hardware RIPs 
and may have had custom ASICs to improve rendering. Adobe's Emerald and 
Jade RIPs did I believe, and the early CPSI RIPS (which initially ran on 
Sun SPARC) had optional hardware assist in the form of expansion cards. 
So those *might* have been faster because of hardware acceleration. Or 
maybe not, it was all a long time ago and while I remember that the 
ColorBurst board accelerated colour handling I don't recall what the 
PixelBurst board did. It might only have been screening.

Another possibility is that there are two implementations (on level 2 
Adobe RIPS), an older one for compatibility with level 1 and a newer one 
only used when stroke adjustment is turned on. Then it may be that the 
newer impleemntation (which does not have to care about backward 
compatibility) is faster. This is the sort of thing we do in Ghostscript 
quite frequently, eventually the deprecated system is removed, if no 
problems show up.

If you can gather performance figures from several different 
manufacturers, and show that the various interpreters don't simply 
ignore the operator, I would be interested in seeing it, just for 
curiosity.


				Ken

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setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-04-27 03:25 -0700
  Re: setstrokeadjust: what's the disadvantage? ken <ken@spamcop.net> - 2015-04-27 14:29 +0100
    Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-04-27 08:56 -0700
      Re: setstrokeadjust: what's the disadvantage? tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2015-04-27 14:59 -0400
        Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-04-27 13:29 -0700
          Re: setstrokeadjust: what's the disadvantage? tlvp <mPiOsUcB.EtLlLvEp@att.net> - 2015-04-27 22:43 -0400
      Re: setstrokeadjust: what's the disadvantage? ken <ken@spamcop.net> - 2015-04-28 07:54 +0100
        Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-04-28 02:01 -0700
          Re: setstrokeadjust: what's the disadvantage? ken <ken@spamcop.net> - 2015-04-28 11:27 +0100
            Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-04-28 04:02 -0700
        Re: setstrokeadjust: what's the disadvantage? Mark Carroll <mtbc@bcs.org> - 2015-04-28 10:43 +0100
  Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-05-01 15:16 -0700
    Re: setstrokeadjust: what's the disadvantage? ken <ken@spamcop.net> - 2015-05-02 09:13 +0100
      Re: setstrokeadjust: what's the disadvantage? jdaw1 <jdawiseman@gmail.com> - 2015-05-02 03:29 -0700

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