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From: wdh@well.UUCP (Bill Hofmann)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Quickdraw efficiency question
Message-ID: <12676@well.UUCP>
Date: 12 Jul 89 23:17:27 GMT
References: <1681@neoucom.UUCP> <7943@hoptoad.uucp>
Reply-To: wdh@well.UUCP (Bill Hofmann)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 17

In article <7943@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes:
>In article <1681@neoucom.UUCP> sam@neoucom.UUCP (Scott A. Mason) writes:
>>Question:
>>Which would be faster when drawing multiple characters to a window?
>>  1) repeated calls to DrawChar
>>  2) building a string and calling DrawString.
>DrawString.  Smaller trap overhead, fewer internal calls to the Font
>Manager, some built-in heuristics to speed things up.  DrawText is
>even better,m supposedly.
Only by a few instructions for each call, since what DrawString does
is pop the length byte and jump to the DrawText code.  If efficiency is
the object here, DrawText (or DrawString) is a very good candidate for
doing a GetTrapAddress at the beginning of your application and doing
a direct jump to it. I've clocked ~10% speed improvement in my app's
redraw just from this optimization.

-Bill