Re: [PATCH 2/2] fonts: Increase the Em size to fix a build failure with freetype 2.8.1

[Dmitry Timoshkov]

Michael Stefaniuc  wrote:
> -UnderlinePosition: -100
> -UnderlineWidth: 50
> -Ascent: 11
> -Descent: 2
> +UnderlinePosition: -15753.8
> +UnderlineWidth: 7876.92
> +Ascent: 1733
> +Descent: 315
> +InvalidEm: 0
>  LayerCount: 2
>  Layer: 0 0 "Back" 1
>  Layer: 1 0 "Fore" 0
> @@ -21,7 +22,7 @@ OS2_UseTypoMetrics: 0
>  PfmFamily: 49
>  TTFWeight: 400
>  TTFWidth: 5
> -LineGap: 1
> +LineGap: 158
>  VLineGap: 0
>  Panose: 2 0 6 9 0 0 0 0 0 0
>  OS2TypoAscent: 0
> @@ -56,770 +57,770 @@ BeginChars: 65536 498
>
> StartChar: space
>  Encoding: 32 32 0
> -Width: 8
> +Width: 1260
>  Flags: W
>  LayerCount: 2
>  EndChar
>
> StartChar: exclam
>  Encoding: 33 33 1
> -Width: 8
> +Width: 1260
>  Flags: W
>  LayerCount: 2
>  EndChar

Did you test that after this patch font and glyph metrics still stay the same?

[PATCH 2/2] fonts: Increase the Em size to fix a build failure with freetype 2.8.1

[Michael Stefaniuc]

On 09/28/2017 06:53 AM, Dmitry Timoshkov wrote:
> Michael Stefaniuc  wrote:
> > -UnderlinePosition: -100
> > -UnderlineWidth: 50
> > -Ascent: 11
> > -Descent: 2
> > +UnderlinePosition: -15753.8
> > +UnderlineWidth: 7876.92
> > +Ascent: 1733
> > +Descent: 315
> > +InvalidEm: 0
> >  LayerCount: 2
> >  Layer: 0 0 "Back" 1
> >  Layer: 1 0 "Fore" 0
> > @@ -21,7 +22,7 @@ OS2_UseTypoMetrics: 0
> >  PfmFamily: 49
> >  TTFWeight: 400
> >  TTFWidth: 5
> > -LineGap: 1
> > +LineGap: 158
> >  VLineGap: 0
> >  Panose: 2 0 6 9 0 0 0 0 0 0
> >  OS2TypoAscent: 0
> > @@ -56,770 +57,770 @@ BeginChars: 65536 498
> >
> > StartChar: space
> >  Encoding: 32 32 0
> > -Width: 8
> > +Width: 1260
> >  Flags: W
> >  LayerCount: 2
> >  EndChar
> >
> > StartChar: exclam
> >  Encoding: 33 33 1
> > -Width: 8
> > +Width: 1260
> >  Flags: W
> >  LayerCount: 2
> >  EndChar
>
> Did you test that after this patch font and glyph metrics still stay the same?

To find the relevant changes I have verified that the numbers increased
by the factor of 2048 divided by the old Em size (11 or 13 or 15). Of
course as 11, 13, 15 aren't factors of 2048 there are rounding errors.

But it doesn't matter as:
a) Those are bitmap only fonts.
b) Only the *.fon files are installed but not the corresponding *.ttf files.
c) The generated *.fon files are bit by bit identical (sha1sum) before
and after this commit.

bye
    michael

[PATCH 2/2] fonts: Increase the Em size to fix a build failure with freetype 2.8.1

[Dmitry Timoshkov]

Michael Stefaniuc  wrote:
> > Did you test that after this patch font and glyph metrics still stay the same?
>
> To find the relevant changes I have verified that the numbers increased
> by the factor of 2048 divided by the old Em size (11 or 13 or 15). Of
> course as 11, 13, 15 aren't factors of 2048 there are rounding errors.
>
> But it doesn't matter as:
> a) Those are bitmap only fonts.
> b) Only the *.fon files are installed but not the corresponding *.ttf files.

That's true, but it's sometimes useful to be able to load and test .ttf
files as well, although it looks like after some Windows update intermediate
Wine bitmap-only .ttf fonts is no longer possible to load under Windows, and
since freetype 2.8.1 Linux started to behave same way.
> c) The generated *.fon files are bit by bit identical (sha1sum) before
> and after this commit.

Great, that's the key point.

[PATCH 2/2] fonts: Increase the Em size to fix a build failure with freetype 2.8.1

[Michael Stefaniuc]

On 09/28/2017 10:07 AM, Dmitry Timoshkov wrote:
> Michael Stefaniuc  wrote:
> > > Did you test that after this patch font and glyph metrics still stay the same?
> >
> > To find the relevant changes I have verified that the numbers increased
> > by the factor of 2048 divided by the old Em size (11 or 13 or 15). Of
> > course as 11, 13, 15 aren't factors of 2048 there are rounding errors.
> >
> > But it doesn't matter as:
> > a) Those are bitmap only fonts.
> > b) Only the *.fon files are installed but not the corresponding *.ttf files.
>
> That's true, but it's sometimes useful to be able to load and test .ttf
> files as well, although it looks like after some Windows update intermediate
> Wine bitmap-only .ttf fonts is no longer possible to load under Windows, and
> since freetype 2.8.1 Linux started to behave same way.

Seems the Em increase fixed that on Windows too:
<nsivov> puk, with fixed em field ttfs open now on windows too
> > c) The generated *.fon files are bit by bit identical (sha1sum) before
> > and after this commit.
>
> Great, that's the key point.

Right, that's why I have included that info in my patch submission ;)
https://www.winehq.org/pipermail/wine-patches/2017-September/165357.html

"With this two patches applied I always get the exact same fon files for
all possible combinations:
- freetype 2.6.5 and unpatched Wine
- freetype 2.6.5 and this two patches applied
- freetype 2.8.1 and this two patches applied"

bye
    michael