Tk: non-default font 16 x slower

[Wybo Dekker]

When I use the default fonts in my Ruby-Tk application it takes
400 milliseconds to start up. When I use Helvetica or other fonts it takes
6400 seconds. Is there something I can do about that? Perl does not have
that problem.

 

[Hidetoshi NAGAI]

Hi,

From: Wybo Dekker <[email protected]>
Subject: Tk: non-default font 16 x slower
Date: Mon, 18 Aug 2003 19:52:35 +0900

When I use the default fonts in my Ruby-Tk application it takes
400 milliseconds to start up. When I use Helvetica or other fonts it takes
6400 seconds. Is there something I can do about that? Perl does not have
that problem.

Could you tell me your environment ( Ruby version, Tcl/Tk version, OS,
and so on ) and send me your script?

Maybe the problem depends on auto-creation of font objects.
If you use the same font for many widgets, please create a TkFont
object for the font and try to give the font object to the font option
of each widgets.

 

[Kero van Gelder]

When I use the default fonts in my Ruby-Tk application it takes
400 milliseconds to start up. When I use Helvetica or other fonts it takes
6400 seconds. Is there something I can do about that? Perl does not have
that problem.

Use a font explicitely, not only string references (which causes the font
to be built over and over again), like:

font = TkFont.new('courier')
widget.font(font)

hth,
Kero.

 

[Richard Zidlicky]

Use a font explicitely, not only string references (which causes the font
to be built over and over again), like:

font = TkFont.new('courier')

very good tip, but why is font creation so exceedingly slow
anyway?
On a Pentium 100 it used to take a few seconds with a font
that was already cached by xfs.

Richard

 

[Hidetoshi NAGAI]

Hi,

From: Richard Zidlicky <[email protected]>
Subject: Re: Tk: non-default font 16 x slower
Date: Tue, 19 Aug 2003 20:40:55 +0900

very good tip, but why is font creation so exceedingly slow
anyway?

Ruby/Tk recommends to distinguish between (1) widgets have the
*SAME* font, and (2) widgets coincidentally have the fonts with
same properties. That is the reason of creating a named font
when a font name is given to 'font' option. When properties of
a TkFont object are changed, displayed font images of all widgets
given the TkFont object are changed. However, it needs large cost
to create a new named font. So, Ruby/Tk is slow if you give the
'font' option with a font name to each of many widgets.

 

[Kero van Gelder]

When I use the default fonts in my Ruby-Tk application it takes

very good tip, but why is font creation so exceedingly slow
anyway?
On a Pentium 100 it used to take a few seconds with a font
that was already cached by xfs.

It is "created" in Tk. Probably some "extra" things happen.
The answer to what happens, would be in some Tk manual or newsgroup

Bye,
Kero.