Another question on the W32 port

Another question on the W32 port

[Kim F. Storm]

I was looking at glyph_rect in X and W32, and noticed that they are
significantly different due to the following change:

2002-02-18  Jason Rumney  <jasonr@gnu.org>

	* w32term.c (glyph_rect): Determine the row and glyph more precisely.


Now I wonder why that change was not back-ported to the X version?

Was there a specific W32 problem that was related to this, or can the
new W32 version be used on X too (modulo the differences in rectangle
implementation) ?

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Another question on the W32 port

[Jason Rumney]

storm@cua.dk (Kim F. Storm) writes:

> I was looking at glyph_rect in X and W32, and noticed that they are
> significantly different due to the following change:
> 
> 2002-02-18  Jason Rumney  <jasonr@gnu.org>
> 
> 	* w32term.c (glyph_rect): Determine the row and glyph more precisely.
> 
> 
> Now I wonder why that change was not back-ported to the X version?
> 
> Was there a specific W32 problem that was related to this, or can the
> new W32 version be used on X too (modulo the differences in rectangle
> implementation) ?

My memory that far back is sketchy, but I think it may have been to
do with mouse highlighting. There have long been bugs in mouse
highlighting that show up under Windows, but not X, and it has often
confused me when I have found a fix for such bugs and wondered why the
fix was not necessary on X. In such cases I decide to play it safe
and not backport the change to X.

Re: Another question on the W32 port

[Kim F. Storm]

Jason Rumney <jasonr@gnu.org> writes:

> storm@cua.dk (Kim F. Storm) writes:
> 
> > I was looking at glyph_rect in X and W32, and noticed that they are
> > significantly different due to the following change:
> > 
> > 2002-02-18  Jason Rumney  <jasonr@gnu.org>
> > 
> > 	* w32term.c (glyph_rect): Determine the row and glyph more precisely.
> > 
> > 
> > Now I wonder why that change was not back-ported to the X version?
> > 
> > Was there a specific W32 problem that was related to this, or can the
> > new W32 version be used on X too (modulo the differences in rectangle
> > implementation) ?
> 
> My memory that far back is sketchy, but I think it may have been to
> do with mouse highlighting. There have long been bugs in mouse
> highlighting that show up under Windows, but not X, and it has often
> confused me when I have found a fix for such bugs and wondered why the
> fix was not necessary on X. 

Yes, that is strange.

Maybe it can be related to cleartype as you mention in the below
W32-specific comment from get_glyph_string_clip_rect:

  /* If drawing the cursor, don't let glyph draw outside its
     advertised boundaries. Cleartype does this under some circumstances.  */


>                             In such cases I decide to play it safe
> and not backport the change to X.

I would prefer if such "improved" code was backported (or
consolidated) like I did with get_glyph_string_clip_rect, i.e. let the
additional checks be conditioned by HAVE_NTGUI.  That way, if similar
problems are seen on other platforms later on, the fix may actually be
there already.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Another question on the W32 port

[Jason Rumney]

storm@cua.dk (Kim F. Storm) writes:

> Maybe it can be related to cleartype as you mention in the below
> W32-specific comment from get_glyph_string_clip_rect:
> 
>   /* If drawing the cursor, don't let glyph draw outside its
>      advertised boundaries. Cleartype does this under some circumstances.  */

I'm pretty sure that the cleartype fix was more recent than the
change we were looking at.