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Yet another Athens font thread

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Aliaksei Syrel

Yet another Athens font thread

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.

Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Cheers,

Alex

Nicolai Hess

Re: Yet another Athens font thread

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:

Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?

I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

Aliaksei Syrel

Re: Yet another Athens font thread

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,

Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

Nicolai Hess

Re: Yet another Athens font thread

How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:

Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,
Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

Aliaksei Syrel

Re: Yet another Athens font thread

Do you remember a hack with scaling? (scaleBy: 1.0001@1.0001) It makes letters to have the same height, so no more huge ones with small fonts. But it doesn't fix a bug when letters have wrong width so there is a space between characters. The same effect can be achieved if we set font size manually after setting scaled font before drawing glyphs with cairo. It means that at some point we get wrong calculated glyphs. So if we "fix" scaled font before glyph calculation - the problem would be gone. In the patch I set scaled font, manually apply font size, retrieve "fixed" scaled font and calculate glyphs based on it.

Also after investigation I found something interesting. If we clean real font of a logical font the problem gets fixed for some period of time. I assume that FreeTypeFont gets broken after a while and logical font always returns broken real font. Setting realFont to nil forces logical font to create a new working free type font. As soon as new free type font is created cairo produces scaled font and caches it. So actual problem lies deep in FreeTypeFont...

I even opened two images: one with broken fonts and one with working. Then I compared in inspector two free type fonts - they are absolutely the same and have identical instance variable in a whole object tree, except of handler pointers to C structure which I can't inspect from pharo...

Saving image fixes fonts because of

LogicalFont>>shutDown: quitting
self allSubInstances do: [:i | i clearRealFont].

Cheers,

Alex

On Thu, Oct 8, 2015 at 5:43 PM, Nicolai Hess <[hidden email]> wrote:

How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:
Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,
Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

Aliaksei Syrel

Re: Yet another Athens font thread

Also "broken" and working scaled fonts are the same in inspector

Cheers,

Alex

On Thu, Oct 8, 2015 at 6:05 PM, Aliaksei Syrel <[hidden email]> wrote:

Do you remember a hack with scaling? (scaleBy: 1.0001@1.0001) It makes letters to have the same height, so no more huge ones with small fonts. But it doesn't fix a bug when letters have wrong width so there is a space between characters. The same effect can be achieved if we set font size manually after setting scaled font before drawing glyphs with cairo. It means that at some point we get wrong calculated glyphs. So if we "fix" scaled font before glyph calculation - the problem would be gone. In the patch I set scaled font, manually apply font size, retrieve "fixed" scaled font and calculate glyphs based on it.

Also after investigation I found something interesting. If we clean real font of a logical font the problem gets fixed for some period of time. I assume that FreeTypeFont gets broken after a while and logical font always returns broken real font. Setting realFont to nil forces logical font to create a new working free type font. As soon as new free type font is created cairo produces scaled font and caches it. So actual problem lies deep in FreeTypeFont...

I even opened two images: one with broken fonts and one with working. Then I compared in inspector two free type fonts - they are absolutely the same and have identical instance variable in a whole object tree, except of handler pointers to C structure which I can't inspect from pharo...

Saving image fixes fonts because of
LogicalFont>>shutDown: quitting
self allSubInstances do: [:i | i clearRealFont].

Cheers,
Alex

On Thu, Oct 8, 2015 at 5:43 PM, Nicolai Hess <[hidden email]> wrote:
How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:
Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,
Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

Aliaksei Syrel

Re: Yet another Athens font thread

In reply to this post by Aliaksei Syrel

No, they are needed. Because glyphs must be calculated (getGlyphs:of:) after(!) setting font size. Otherwise there are huge gaps between characters.
When font problem appears, some characters are of size 14 even if font size 10. So glyphs of big characters have larger extent as it should be. In your example you set font size and fix font, so all characters are rendered correctly, but at wrong positions. That is a source of unnecessary gaps.

Thete is a way to break font:

1) Get new pharo image
2) Get Bloc
3) Switch to bloc
4) remove all morphs
5) save and quite
6) open image
7) open nautilus

Do something to fix font. Repeat 4-7. If fix is "fake" fonts will be broken..

On Oct 9, 2015 10:31 PM, "Nicolai Hess" <[hidden email]> wrote:

2015-10-08 18:05 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Do you remember a hack with scaling? (scaleBy: 1.0001@1.0001) It makes letters to have the same height, so no more huge ones with small fonts. But it doesn't fix a bug when letters have wrong width so there is a space between characters. The same effect can be achieved if we set font size manually after setting scaled font before drawing glyphs with cairo. It means that at some point we get wrong calculated glyphs. So if we "fix" scaled font before glyph calculation - the problem would be gone. In the patch I set scaled font, manually apply font size, retrieve "fixed" scaled font and calculate glyphs based on it.

Also after investigation I found something interesting. If we clean real font of a logical font the problem gets fixed for some period of time. I assume that FreeTypeFont gets broken after a while and logical font always returns broken real font. Setting realFont to nil forces logical font to create a new working free type font. As soon as new free type font is created cairo produces scaled font and caches it. So actual problem lies deep in FreeTypeFont...

I even opened two images: one with broken fonts and one with working. Then I compared in inspector two free type fonts - they are absolutely the same and have identical instance variable in a whole object tree, except of handler pointers to C structure which I can't inspect from pharo...

Saving image fixes fonts because of
LogicalFont>>shutDown: quitting
self allSubInstances do: [:i | i clearRealFont].

Cheers,
Alex

This is great.

I looked at your change. And noticed the call to
setFontSize
this was never called until now. Maybe this was the problem.

Now, I just changed

renderGlyphs: cairoGlyphs

    font lock.
    canvas
        setPathMatrix;
        setScaledFont: font;
        setFontSize: originalFont pixelSize. "<< new "
    canvas paint loadOnCairoCanvas: canvas.

    canvas showGlyphs: cairoGlyphs address size: cairoGlyphs size.
    font unlock.

And it seems the font issue is gone. Maybe the other changes (set and get scaled font in #glyphsOf:from:to: )
isn't needed? (needs more tests)

On Thu, Oct 8, 2015 at 5:43 PM, Nicolai Hess <[hidden email]> wrote:
How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:
Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,
Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex

stepharo

Re: Yet another Athens font thread

In reply to this post by Aliaksei Syrel

Le 8/10/15 18:05, Aliaksei Syrel a écrit :

Do you remember a hack with scaling? (scaleBy: [hidden email]) It makes letters to have the same height, so no more huge ones with small fonts. But it doesn't fix a bug when letters have wrong width so there is a space between characters. The same effect can be achieved if we set font size manually after setting scaled font before drawing glyphs with cairo. It means that at some point we get wrong calculated glyphs. So if we "fix" scaled font before glyph calculation - the problem would be gone. In the patch I set scaled font, manually apply font size, retrieve "fixed" scaled font and calculate glyphs based on it.

Also after investigation I found something interesting. If we clean real font of a logical font the problem gets fixed for some period of time. I assume that FreeTypeFont gets broken after a while and logical font always returns broken real font.

Exactly.
If you have code we applied accept it.
In the pharo roadmaps on github you have a roadmap for the problems I identify.

Setting realFont to nil forces logical font to create a new working free type font. As soon as new free type font is created cairo produces scaled font and caches it. So actual problem lies deep in FreeTypeFont...

I even opened two images: one with broken fonts and one with working. Then I compared in inspector two free type fonts - they are absolutely the same and have identical instance variable in a whole object tree, except of handler pointers to C structure which I can't inspect from pharo...

Saving image fixes fonts because of

LogicalFont>>shutDown: quitting
self allSubInstances do: [:i | i clearRealFont].

Cheers,
Alex

On Thu, Oct 8, 2015 at 5:43 PM, Nicolai Hess <[hidden email]> wrote:

How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:

Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,

Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:

Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.

Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?

I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,

Alex

Nicolai Hess

Re: Yet another Athens font thread

In reply to this post by Aliaksei Syrel

2015-10-09 22:43 GMT+02:00 Aliaksei Syrel <[hidden email]>:

No, they are needed. Because glyphs must be calculated (getGlyphs:of:) after(!) setting font size. Otherwise there are huge gaps between characters.
When font problem appears, some characters are of size 14 even if font size 10. So glyphs of big characters have larger extent as it should be. In your example you set font size and fix font, so all characters are rendered correctly, but at wrong positions. That is a source of unnecessary gaps.

Ok, I understand.
In what situation do you see huge gaps between glyphs? I only know about the problem of wrong sized glyphs.

Thete is a way to break font:

1) Get new pharo image
2) Get Bloc
3) Switch to bloc
4) remove all morphs
5) save and quite
6) open image
7) open nautilus

Do something to fix font. Repeat 4-7. If fix is "fake" fonts will be broken..

On Oct 9, 2015 10:31 PM, "Nicolai Hess" <[hidden email]> wrote:

2015-10-08 18:05 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Do you remember a hack with scaling? (scaleBy: 1.0001@1.0001) It makes letters to have the same height, so no more huge ones with small fonts. But it doesn't fix a bug when letters have wrong width so there is a space between characters. The same effect can be achieved if we set font size manually after setting scaled font before drawing glyphs with cairo. It means that at some point we get wrong calculated glyphs. So if we "fix" scaled font before glyph calculation - the problem would be gone. In the patch I set scaled font, manually apply font size, retrieve "fixed" scaled font and calculate glyphs based on it.

Also after investigation I found something interesting. If we clean real font of a logical font the problem gets fixed for some period of time. I assume that FreeTypeFont gets broken after a while and logical font always returns broken real font. Setting realFont to nil forces logical font to create a new working free type font. As soon as new free type font is created cairo produces scaled font and caches it. So actual problem lies deep in FreeTypeFont...

I even opened two images: one with broken fonts and one with working. Then I compared in inspector two free type fonts - they are absolutely the same and have identical instance variable in a whole object tree, except of handler pointers to C structure which I can't inspect from pharo...

Saving image fixes fonts because of
LogicalFont>>shutDown: quitting
self allSubInstances do: [:i | i clearRealFont].

Cheers,
Alex

This is great.

I looked at your change. And noticed the call to
setFontSize
this was never called until now. Maybe this was the problem.

Now, I just changed

renderGlyphs: cairoGlyphs

    font lock.
    canvas
        setPathMatrix;
        setScaledFont: font;
        setFontSize: originalFont pixelSize. "<< new "
    canvas paint loadOnCairoCanvas: canvas.

    canvas showGlyphs: cairoGlyphs address size: cairoGlyphs size.
    font unlock.

And it seems the font issue is gone. Maybe the other changes (set and get scaled font in #glyphsOf:from:to: )
isn't needed? (needs more tests)

On Thu, Oct 8, 2015 at 5:43 PM, Nicolai Hess <[hidden email]> wrote:
How did you fix it?

Am 08.10.2015 17:06 schrieb "Aliaksei Syrel" <[hidden email]>:
Hi

It looks like I fixed that weird text rendering problem... Just get the latest Athens-Cairo.

Cheers,
Alex

On Mon, Aug 3, 2015 at 9:32 PM, Nicolai Hess <[hidden email]> wrote:

2015-06-10 12:01 GMT+02:00 Aliaksei Syrel <[hidden email]>:
Hi

I noticed that if I force use "Source Code Pro" as standard font for all elements in the image I never have problems with font rendering. In case of "Source Sans Pro" font is just not usable becasue of rendering bugs on mac, windows and linux(?). If "Lucida Sans Pro" is used - no bugs too.

Because bug is reproducable on all platform - it's platform independent bug.
Because it's reproducable only with one specific font - maybe it's not an athens issue but bug in font itself and if someone could change/update Source Sans Pro to a newly version or to a similar font the problem will be solved?

Did you try to use a new font version ?
I don't know exactly how embedded fonts are included. I tried to create the font with a newer version but it did not work ( or at least I could not see any difference).

Cheers,
Alex