1267180 - Apple Color Emoji font fails to display at large sizes when using Skia content rendering

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect)

Description

[Alex]

Attachment: 4 Pizza slice emojis

When using Skia content rendering, emoji characters in the Apple Color Emoji font fail to display over a certain size (128px on retina, 256px on non-retina), when using the CoreGraphics backend they show correctly.

In the attached file there should be 4 emoji characters showing, the top row has 2 characters straddling the 128/129px boundary, the bottom row 256/257px. On my retina display only the top left one displays. If I zoom out to 50% then both characters on the top row show, but only the left most one on the bottom row shows.

Comment 1

[Alex]

Attachment: Broken emoji

I didn't realize Bugzilla actually forced windows-1252, this should work.

Comment 2

[Mason Chang [Inactive] [:mchang]]

This is because Skia doesn't render some fonts if they are too big. The failure also occurs in Chrome, but not Safari.

Comment 3

[Mason Chang [Inactive] [:mchang]]

Attachment: colorglyph.patch

Big fonts will be rendered as paths[1], and Skia would try to get the path from CG [2], which would return null, so we'd render nothing. This patch tells Skia to draw the glyph as a normal glyph and not a path if it has color glyphs. Also a good possible candidate for upstream as chrome fails too.

[1] https://dxr.mozilla.org/mozilla-central/source/gfx/skia/skia/src/core/SkDraw.cpp?case=true&from=SkDraw.cpp#1412
[2] https://dxr.mozilla.org/mozilla-central/source/gfx/skia/skia/src/ports/SkFontHost_mac.cpp?from=SkFontHost_mac.cpp#1393

Comment 4

[Mason Chang [Inactive] [:mchang]]

Try looks good - https://treeherder.mozilla.org/#/jobs?repo=try&revision=3e3895576d96

Comment 5

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/57e54fef9cf2

Comment 6

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/57e54fef9cf2