Bug 253967

Summary: Incorrect font scaling when using system weight synthesis
Product: WebKit Reporter: Ridvanovskyy V. <ridvanovskyy>
Component: TextAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Major CC: mmaxfield, ridvanovskyy, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: iPhone / iPad   
OS: iOS 16   
Attachments:
Description Flags
Here is screenshot with issue
none
Alfa Slab One metadata none

Ridvanovskyy V.
Reported 2023-03-15 08:42:25 PDT
Created attachment 465447 [details] Here is screenshot with issue Issue description: when synthesized works, we can see not correct result(text duplicates in 3 layers), this result create issue with for example text-shadows. 100% reproduce. Here is case description: Font "Alfa Slab One — Regular 400" - https://fonts.google.com/share?selection.family=Alfa+Slab+One Font metadata: family name - Alfa Slab One weight class - Regular 400 width class - Normal Monospaced slope class - Plain style name - Regular full name - "Alfa Slab One Regular" postScript - AlfaSlabOne-Regular style group - "Alfa Slab One" Regular master name - Regular Font converted from ttf to woff, woff2 with fontLab8. // css file with @font-face @font-face { font-family: 'Alfa Slab One'; src: url("path/alfa-slab-one.woff2") format("woff2"), url("path/alfa-slab-one.woff") format("woff"); font-weight: 400; font-style: normal; } // css file with font usage without defect .component { font-family: 'Alfa Slab One'; font-weight: 400; } // css file with font usage with defect .component { font-family: 'Alfa Slab One'; font-weight: 900; // here is working synthesized by Safari browser, because it can't find font-weight in @font-face } Additional info: I tested more that 20 fonts from different services, i try to convert with different tools (fontLab8, TransType4, fontsquirrel.com) and try to use different formats(ttf, woff, woff2) - issue always reproduced. font-synthesis: none; - fixed this issue, but it's not normal that browser synthesis create such ui issues. https://codepen.io/Ridi/pen/QWVrMQy - codepen, where you can check code and fork. https://codepen.io/Ridi/full/QWVrMQy - this codepen in fullscreen mode, you can open from real device, browserstack or xcode emulator.
Attachments
Here is screenshot with issue (39.07 KB, image/jpeg)
2023-03-15 08:42 PDT, Ridvanovskyy V.
no flags
Alfa Slab One metadata (113.29 KB, image/png)
2023-03-15 08:44 PDT, Ridvanovskyy V.
no flags
Ridvanovskyy V.
Comment 1 2023-03-15 08:44:16 PDT
Created attachment 465448 [details] Alfa Slab One metadata Alfa Slab One metadata
Radar WebKit Bug Importer
Comment 2 2023-03-22 08:43:14 PDT
Ridvanovskyy V.
Comment 3 2023-06-17 13:01:37 PDT
The issue is still present. Are there any updates, information about the issue?
Myles C. Maxfield
Comment 4 2023-06-17 13:50:16 PDT
Hrm. At a glance, this looks like synthetic bold. But let me check deeper today.
Myles C. Maxfield
Comment 5 2023-06-17 14:02:39 PDT
Oh, you already said "font-synthesis: none; - fixed this issue" So, yes, this is due to synthetic bold.
Myles C. Maxfield
Comment 6 2023-06-17 14:20:23 PDT
*** This bug has been marked as a duplicate of bug 215559 ***
Ridvanovskyy V.
Comment 7 2023-06-17 14:54:00 PDT
Yes, I agree that this is a duplicate, but I would suggest using the description from this task as a basis or even making it the main task. Why? It has a broader description here, with examples of fonts, link to font source, css, a;; font data description, playgrounds and screenshots. Otherwise, all of that will be lost.
Ridvanovskyy V.
Comment 8 2023-06-17 16:54:20 PDT
(In reply to Myles C. Maxfield from comment #6) > > *** This bug has been marked as a duplicate of bug 215559 *** Sorry for message duplication, i don't do reply in previous. Yes, I agree that this is a duplicate, but I would suggest using the description from this task as a basis or even making it the main task. Why? It has a broader description here, with examples of fonts, link to font source, css, font data description, playgrounds and screenshots. Otherwise, all of that will be lost.
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