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From: mears@hpindda.HP.COM (David Mears)
Newsgroups: comp.windows.x
Subject: Determining font size values:  R2 vs. R3
Message-ID: <3630008@hpindda.HP.COM>
Date: 20 Feb 90 23:45:30 GMT
Organization: HP Information Networks, Cupertino, CA
Lines: 27

I have an application which needs to compute the size of an enclosing
box around a block of text that will be put into a widget.  To determine
the size, I determine the max width and height of the font being used
and then multiply those values by the number of characters in the
widest line, and by the number of lines in the block.  My calculations
came out fine when used with R2 based fonts, but do not work right with
an R3 font.  Apparently there was some small change made in the way
that the sizing information is stored in the R3 fonts.  I would
appreciate it if someone could show me how to modify my calculations so
they will give the correct results with either an R2 or an R3 font.

Right now I determine the font character width and height by the
following formulas:

	TFheight = font->max_bounds.ascent + font->max_bounds.descent;
	TFwidth = font->max_bounds.rbearing - font->min_bounds.lbearing;

BTW, using these formulas tends to give me a value which is slightly
small for the R3 fonts.

Thanks.

David B. Mears
Hewlett-Packard
Cupertino CA
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