[openbeos] Re: openbeos Digest V8 #104

  • From: "Stefano Ceccherini" <stefano.ceccherini@xxxxxxxxx>
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Thu, 26 Jun 2008 16:37:15 +0200

2008/6/26 Stephan Assmus <superstippi@xxxxxx>:

> Makes a lot of sense. Please do create enhencement tickets, so that these
> remarks don't get lost. Even BTextView uses a "width cache buffer" to avoid
> too many calls for getting the width of glyphs. Maybe this can be done on
> the BFont level instead of on the individual view class level.

I thought about that too. But there is a problem:
That kind of caching can only be done if the font spacing used is
B_CHAR_SPACING, because it's the only mode where the width of a string
is the sum of the widths of the single characters (IOW: "abc" has the
same width as "cab" or "acb"), so caching the width of the single
characters is all you have to do. In B_STRING_SPACING, the width of a
string also depends on the position of the characters, so that there
is no simple way of caching like it's done in in the width cache
buffer used by BTextView.

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