[Etoys] [Fwd: [squeak-dev] Fwd: A little font rendering speedup]

[Karl Ramberg]

Maybe for Etoys, too?
I saw a speedup from 8026 to  7558 with about 10 windows open.
What do others think ?
Karl

-------- Original Message --------
Subject: 	[squeak-dev] Fwd: A little font rendering speedup
Date: 	Sun, 19 Apr 2009 16:36:19 +0300
From: 	Igor Stasenko <siguctua at gmail.com>
Reply-To: 	The general-purpose Squeak developers list 
<squeak-dev at lists.squeakfoundation.org>
To: 	The general-purpose Squeak developers list 
<squeak-dev at lists.squeakfoundation.org>, Pharo Development 
<Pharo-project at lists.gforge.inria.fr>



I put this on mantis, since i'm sure this applies to squeak3.10 and Pharo both.

http://bugs.squeak.org/view.php?id=7338


---------- Forwarded message ----------
From: Igor Stasenko<siguctua at gmail.com>
Date: 2009/4/19
Subject: A little font rendering speedup
To: Pharo Development<Pharo-project at lists.gforge.inria.fr>


This is an image-side change, which makes a primitiveDisplayString to
not fail because StrikeFontSet returns nil for (font
characterToGlyphMap).

Since the code, which using fast primitive looks like following:

        self primDisplayString: aString from: startIndex to: stopIndex
                        map: font characterToGlyphMap xTable: font xTable
                        kern: kernDelta

I thought, why one would return nil in ( font characterToGlyphMap ).
Since #xTable in StrikeFontSet implemented as following:

xTable
        "Answer an Array of the left x-coordinate of characters in glyphs."

        ^ (fontArray  at: 1) xTable.

i think it is safe to do similar in characterToGlyphMap ,
this allows the primitive to work w/o failure, because otherwise, if
you look at implementation of

primDisplayString: aString from: startIndex to: stopIndex map:
glyphMap xTable: xTable kern: kernDelta

in fallback code it does same thing again (and ignoring glyphMap at all, btw).


To bench a difference, leave a couple of windows with text in world and then do:

[10 timesRepeat: [World fullDrawOn: World assuredCanvas] ] timeToRun

before change:

  645

after change:

  545




-- 
Best regards,
Igor Stasenko AKA sig.


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