Re: pngcairo performance on Windows

[Allin C. <cot...@wf...>]

On Tue, 3 Nov 2009, Ethan Merritt wrote:

> On Tuesday 03 November 2009 09:39:33 Allin Cottrell wrote:
> >
> > On Mon, 2 Nov 2009, Allin Cottrell wrote:
>
> > I think I have one piece of the puzzle.
>
> I'm not convinced.  I suspect that the change you see may be an
> artifact of shifting the character position by 1 or 2 pixels.
> See comments below.
>
> More importantly...
> I have begun to wonder if the involvment of cairo may be a red herring.
> The problem may be more general than that.
> Have a look at Bug report
>
> 1918293  	 "Copy to Clipboard" on MS-Win32 clip "tails" of p,g,q and y
>
> https://sourceforge.net/tracker/?func=detail&aid=1918293&group_id=2055&atid=102055
>
> Could this be the same problem, but involving the
> windows terminal rather than the cairo terminal?
> Could it be that the real problem is with the font itself?
> Or with some very low level Windows font rendering code that is shared by
> cairo and by the windows terminal?

Yes, this could be.  I understand that pango uses FreeType for
font-handling on Linux, but uses "native" win32 font-handling on
MS Windows.  Maybe the difference lies there.  If so, I have no
idea if the bug lies in the underlying win32 font routines or in
pango's interface to them.

(As a guess, I'd be surprised if there's an outright bug in
Windows font-handling, since this seems to be a point of pride in
an OS that's otherwise cr*p, but I can well believe that the
documentation for these routines is obscure or misleading.)

Allin Cottrell