1299903 - Specific Fonts look different with Skia

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect)

Description

[Mason Chang [Inactive] [:mchang]]

Skia on Windows 7 with Consolas and Segoe UI fonts specifically look thicker than when rendered with cairo.

Skia on Windows 10 with Courier New looks thinner. This I suspect would be related to GDI fonts vs DWrite and maybe not respecting the GDI tweaks here [1]

[1] http://searchfox.org/mozilla-central/source/modules/libpref/init/all.js#3364

Comment 1

[Mason Chang [Inactive] [:mchang]]

Attachment: Small Test case

Comment 2

[Mason Chang [Inactive] [:mchang]]

Attachment: Skia rendering Segoe UI

Comment 3

[Mason Chang [Inactive] [:mchang]]

Attachment: Cairo rendering Segoe UI

Comment 4

[Mason Chang [Inactive] [:mchang]]

I should know, Consolas and Segoe UI only look different with cleartype disabled system wide.

Comment 5

[Jorg K (CEST = GMT+2)]

What about "Courier New"? I tried removing it from
gfx.font_rendering.cleartype_params.force_gdi_classic_for_families
but it didn't make a difference.

Comment 6

[Mason Chang [Inactive] [:mchang]]

(In reply to Jorg K (GMT+2, PTO during summer) from comment #5)
> What about "Courier New"? I tried removing it from
> gfx.font_rendering.cleartype_params.force_gdi_classic_for_families
> but it didn't make a difference.

Still looking.

Comment 7

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

[Tracking Requested - why for this release]: Regresion

Comment 8

[Mason Chang [Inactive] [:mchang]]

This isn't going to ship in 51 and I'm not sure this is considered a real regression yet.

Comment 9

[Mason Chang [Inactive] [:mchang]]

I'm not sure this bug will fix the lightness issue, but it will solve some of the characters actually rendering differently with courier new. On a side note, found this https://bugs.chromium.org/p/chromium/issues/detail?id=356823  comment 20 - "On the positive side, Googling this bug lead me to learn that I should never, ever use courier/courier new ever and apparently God kills a kitten each time I do."

Comment 10

[Jorg K (CEST = GMT+2)]

<off topic>
That will be a lot of dead cats then ;-( - I tried consolas, I don't like the "g". What's the font used here on BMO? Or on bugs.chromium.org?
</off topic>

Comment 11

[Mason Chang [Inactive] [:mchang]]

Attachment: Force GDI Type rendering with Skia

Cairo would force TEXT_RENDERING_GDI_CLASSIC [1] for specific fonts if we detected we should force GDI classic mode on some fonts [2]. This passes down that decision into Skia so that we can disable subpixel text positioning and enable bitmap fonts for these specific cases, which uses TEXT_RENDERING_GDI_CLASSIC as well [3].

[1] http://searchfox.org/mozilla-central/source/gfx/cairo/cairo/src/cairo-dwrite-font.cpp#1105
[2] http://searchfox.org/mozilla-central/source/gfx/thebes/gfxDWriteFontList.cpp#1001
[3] http://searchfox.org/mozilla-central/source/gfx/skia/skia/src/ports/SkScalerContext_win_dw.cpp#283

Comment 12

[Mason Chang [Inactive] [:mchang]]

(In reply to Jorg K (GMT+2, PTO during summer) from comment #10)
> <off topic>
> That will be a lot of dead cats then ;-( - I tried consolas, I don't like
> the "g". What's the font used here on BMO? Or on bugs.chromium.org?
> </off topic>

The font im seeing on BMO is "13px/1.2 "Droid Sans Mono", Menlo, Monaco, "Courier New", Courier, monospace"

Comment 13

[Jorg K (CEST = GMT+2)]

Since I don't have "Droid Sans Mono", Menlo, Monaco (they are native to Linux, Mac, Mac), I'm producing a lot of dead cats ;-)

Comment 14

[Mason Chang [Inactive] [:mchang]]

Try - https://treeherder.mozilla.org/#/jobs?repo=try&revision=77e909db7bc9

Comment 15

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/72d223d9dec0
Force GDI Classic rendering for specific fonts with skia on windows. r=lsalzman

Comment 16

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/72d223d9dec0

Comment 17

[Gerry Chang [:gchang]]

No need to track for 51 as this is fixed.

Comment 18

[Jorg K (CEST = GMT+2)]

(In reply to Mason Chang PTO 10/3 [:mchang] from comment #6)
> (In reply to Jorg K (GMT+2, PTO during summer) from comment #5)
> > What about "Courier New"? I tried removing it from
> > gfx.font_rendering.cleartype_params.force_gdi_classic_for_families
> > but it didn't make a difference.
> Still looking.

Now that Skia has landed again for Windows and this bug has landed as well, I must say that "Courier New" still looks pretty bad when rendered with Skia, particularly the number "2" as detailed in bug 1007702 comment #19. I need to switch Skia off, since "Courier New" which is the *default* monospace font on Windows just looks so bad.

Any plans fixing this? If this gets shipped in FF release one day, you'll get and outcry.

Comment 19

[Jorg K (CEST = GMT+2)]

Please ignore the previous comment. I tried with a FF Nightly and a TB Daily both on a new profile and "Courier New" looks thin but acceptable, just like in Chrome. No bad "2".

Note: When I wrote comment #18, I had some messed-up gfx.* preferences, so the "2" did look bad. After rectifying that, it's all good.

Thanks a lot for your work, patience and support!

Comment 20

[Milan Sreckovic [:milan] (needinfo for best results)]

Thanks Jorg - do you recall which of the gfx.* preferences caused the bad font display?

Comment 21

[Jorg K (CEST = GMT+2)]

Yes, I had foolishly removed "Courier New" from gfx.font_rendering.cleartype_params.force_gdi_classic_for_families. I can't even remember why. It must have happened earlier on when I turned all possible screws to see what made a difference. I mentioned it in comment #5. Sorry about the confusion, it's all good now ;-)