Bug 185675 - Canvas text with middle baseline alignment does not match vertically centered table cell text in certain languages
Summary: Canvas text with middle baseline alignment does not match vertically centered...
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Canvas (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2018-05-16 01:11 PDT by Jon Lee
Modified: 2018-07-05 10:13 PDT (History)
5 users (show)

See Also:

Attachments
Test (2.65 KB, text/html)
2018-05-16 01:11 PDT, Jon Lee 		no flags Details
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Description Jon Lee 2018-05-16 01:11:10 PDT 
Created attachment 340475 [details]
Test

See test page.

For each section I have a table cell that covers the full colored div. In the cell is vertically centered text.

On top of the cell is a canvas that covers the full colored div. I render the same text with textAlign center and textBaseline middle. The text animates side to side to show alignment.

For English, Cyrillic, Chinese, Japanese, Hebrew and Tamil, the alignment is pretty spot on.

For Korean and Tamil, the alignment is off by at most one point.

For Arabic, the alignment is off by more than one point.
Comment 1 Radar WebKit Bug Importer 2018-05-16 01:11:59 PDT 
<rdar://problem/40287413>
Comment 2 Jon Lee 2018-07-05 10:13:09 PDT 
FWIW, Chrome and Firefox also do not align perfectly on all languages either, but which languages differ and how they differ are not the same as Safari.