[cairo] cairo_show_text and Chinese

Bill Spitzak spitzak at thefoundry.co.uk
Fri Oct 3 19:33:15 PDT 2008

Another thing that would be very useful in this FAQ is an indication as 
to how long Pango objects can/should live.

If the user wants to draw the same text more than once, should they keep 
the PangoLayout object? What if they want to draw different pieces of 
text, should they call set_text more than once? What if they want to 
change the font, can they call set_font_description more than once? If 
any of these are true is it more efficient to test for changes and not 
call if the font/text is the same?

Or perhaps Pango has been purposly designed so that creating/destroying 
these is really cheap (ie maybe they are in a freelist so malloc/free is 
not done). That would be ideal but unless you clearly state it, most 
programmers are not going to believe it.

Whatever the answer, it would help a lot if the FAQ answered these 
questions. A log of people are going to start from this FAQ and never 
study Pango enough to find out the answer (and in fact it is likely the 
answer cannot be figured out from Pango's documentation). Programmers 
guessing what is best will probably mean that 50% of them will guess 
wrong about how Pango is implemented and produce a slower program.

Bill Spitzak, Senior Software Engineer
The Foundry, 618 Hampton Drive, Venice, CA, 90291, USA
Tel: +1 310 399-4555 * Fax: +1 310 450-4516 * Web: www.thefoundry.co.uk
The Foundry Visionmongers Ltd * Registered in England and Wales No: 4642027

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