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Groups > comp.sys.acorn.programmer > #931

Re: FontV information

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In message <j8693u$laa$1@dont-email.me>
          John Tytgat <this@is.invalid> wrote:

> On 10/25/2011 10:23 AM, Martin Wuerthner wrote:
>> Yes. It is unclear to me why Sprite and Draw calls are vectored, but
>> Font calls are not.

> I always thought this was because of performance reasons (but no proof
> for that).  [...]

I do not think that can have been the reason because there is no 
substantial difference between FontV and SpriteV in terms of the 
number of calls and the complexity of a single call. Both are 
relatively high-level and therefore ideal for vectoring. There are 
lots of SWIs that are called much more often and do less per call 
(which means the overhead of vectoring is more noticeable) and they 
are still vectored, e.g., WrchV. Looking at David Ruck's VecStat, the 
number of times WrchV, ByteV, MouseV, ChangeEnvV are called dwarves 
the number of SpriteV calls, and FontV would probably be similar.

Interestingly, in a typical desktop environment, it is RemV that is 
called most often (around 9 million times in the 10 minutes I spent 
writing this message), followed by MouseV, ByteV (5 million), 
ChangeEnvV (3 million), WrchV (1.2 million). The number of SpriteV 
calls is negligible at 33,000 and FontV would be in that region, too.

-- 
Martin
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Martin Wuerthner         MW Software      http://www.mw-software.com/
        RISC OS Software for Design, Printing and Publishing
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Thread

FontV information wpb <w.blatchley@yahoo.com> - 2011-10-24 06:05 -0700
  Re: FontV information Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-24 19:14 +0200
    Re: FontV information wpb <w.blatchley@yahoo.com> - 2011-10-24 10:31 -0700
      Re: FontV information Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-25 10:23 +0200
        Re: FontV information John Tytgat <this@is.invalid> - 2011-10-25 14:12 +0200
          Re: FontV information Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-26 13:01 +0200
            Re: FontV information druck <news@druck.org.uk> - 2011-10-27 11:08 +0100
              Re: FontV information wpb <w.blatchley@yahoo.com> - 2011-10-31 00:53 -0700
                Re: FontV information John Tytgat <this@is.invalid> - 2011-10-31 11:51 +0100
                Re: FontV information Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-31 12:01 +0100
                Re: FontV information wpb <w.blatchley@yahoo.com> - 2011-11-07 07:53 -0800

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