1. win32lib bug in getFontSize
I posted this once in "Analyze this" but I suspect that no one probably
noticed.
I've discovered that win32lib getFontSize is wrong..at least in my opinion.
Look at this link which has a drawing of characters explaining the vars used.
http://msdn2.microsoft.com/en-us/library/ms534015.aspx
Then look at the winlib32 code below. "tmInternalLeading" is actually added
twice. It's first contained in "tmHeight" then getFontSize adds it again.
I think that "tmInternalLeading" should be removed from the char heigth.
I've rem'd it out on my copy and my list boxes have the correct height since
I'm sizing them by character heights. If I'm wrong please explain.
global function getFontSize( integer id )
-- get metrics for current font
integer width, height, maxwidth
atom tm
-- text metric structure
tm = w32acquire_mem(0, SIZEOF_TEXTMETRIC )
-- get the metrics of the font (queryFont will prepend the DC)
if not queryFont( id, xGetTextMetrics, {tm} ) then
warnErr( Err_GETFONTSIZE )
end if
-- assign values
width = w32fetch(tm,tmAveCharWidth)
maxwidth = w32fetch(tm,tmMaxCharWidth)
height = w32fetch(tm,tmHeight) +
w32fetch(tm,tmInternalLeading) + <----------- remove this
w32fetch(tm,tmExternalLeading)
-- release
w32release_mem( tm )
-- return results
return { width, height, maxwidth }
end function
2. Re: win32lib bug in getFontSize
George Walters wrote:
>
> I posted this once in "Analyze this" but I suspect that no one probably
> noticed.
>
> I've discovered that win32lib getFontSize is wrong..at least in my opinion.
>
> Look at this link which has a drawing of characters explaining the vars used.
>
> <a
> href="http://msdn2.microsoft.com/en-us/library/ms534015.aspx">http://msdn2.microsoft.com/en-us/library/ms534015.aspx</a>
>
From the illustration posted on that page, I'd replace one of the
tmInternalLeading by tmExternalLeading. But I'm not very experienced in
typesetting, so please anyone prove me wrong.
CChris
> Then look at the winlib32 code below. "tmInternalLeading" is actually added
> twice. It's first contained in "tmHeight" then getFontSize adds it again.
> I think that "tmInternalLeading" should be removed from the char heigth.
> I've rem'd it out on my copy and my list boxes have the correct height since
> I'm sizing them by character heights. If I'm wrong please explain.
>
>
> global function getFontSize( integer id )
>
> -- get metrics for current font
>
> integer width, height, maxwidth
> atom tm
>
> -- text metric structure
> tm = w32acquire_mem(0, SIZEOF_TEXTMETRIC )
>
> -- get the metrics of the font (queryFont will prepend the DC)
> if not queryFont( id, xGetTextMetrics, {tm} ) then
> warnErr( Err_GETFONTSIZE )
> end if
>
> -- assign values
> width = w32fetch(tm,tmAveCharWidth)
> maxwidth = w32fetch(tm,tmMaxCharWidth)
> height = w32fetch(tm,tmHeight) +
> w32fetch(tm,tmInternalLeading) + <----------- remove this
> w32fetch(tm,tmExternalLeading)
>
> -- release
> w32release_mem( tm )
>
> -- return results
> return { width, height, maxwidth }
>
> end function
3. Re: win32lib bug in getFontSize
What I'm saying is the the character height should read as follows:
height = w32fetch(tm,tmHeight) + w32fetch(tm,tmExternalLeading
4. Re: win32lib bug in getFontSize
- Posted by CChris <christian.cuvier at ?griculture.gouv.?r>
Nov 29, 2007
-
Last edited Nov 30, 2007
George Walters wrote:
>
> What I'm saying is the the character height should read as follows:
>
> height = w32fetch(tm,tmHeight) + w32fetch(tm,tmExternalLeading
My perception would be
height = w32fetch(tm,tmHeight) + w32fetch(tm,tmExternalLeading) +
w32fetch(tm,tmInternalLeading)
Any thoughts?
CChris
5. Re: win32lib bug in getFontSize
- Posted by George Walters <gwalters at sc?r?.com>
Nov 29, 2007
-
Last edited Nov 30, 2007
Chris, getFontSize has that now. My point is that tmHeight contains the top
(leading space) tmInternalLeading, so you only need to add tmExternalLeading
for the total height. The lower tmInternalLeading in the diagram belongs to
the lower character in the diagram.
6. Re: win32lib bug in getFontSize
- Posted by Derek Parnell <ddparnell at big?ond?com>
Nov 29, 2007
-
Last edited Nov 30, 2007
George Walters wrote:
> I've discovered that win32lib getFontSize is wrong..at least in my opinion.
I agree that it is wrong. The tmHeight value already includes the
tmInternalLeading value so the win32lib function should not add it in again.
--
Derek Parnell
Melbourne, Australia
Skype name: derek.j.parnell
