831687 - hook up hinted-glyph-advances callback in the graphite shaper

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect)

Description

[Jonathan Kew [:jfkthame]]

(From bug 831277 comment 4.)

gfxGraphiteShaper includes code to use hinted glyph widths via a callback, but it fails to actually set the mUseFontGlyphWidths flag when appropriate and hence this option never actually gets used. This is why graphite rendering on windows tends to vary from opentype rendering even where no shaping/layout difference would be expected, more substantially than on other platforms (as windows may hint glyph advances pretty aggressively, depending on the cleartype mode).

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: make graphite shaping use hinted widths if implemented by the font

With this fix, the graphite and harfbuzz renderings of Charis SIL (see http://people.mozilla.org/~jkew/charis-test.html) now match on Windows.

Comment 2

[Jonathan Kew [:jfkthame]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/0ac50fa858a7

Comment 3

[(no longer active)]

https://hg.mozilla.org/mozilla-central/rev/0ac50fa858a7