[HarfBuzz] Graphite

[Jonathan Kew]

On 27 May 2010, at 16:01, Behdad Esfahbod wrote:

> Hi Martin,
> 
> I'm leaning towards disabling Graphite by default.  In my testing:
> 
>  - A very simple test case with Doulos SIL shows wrong glyphs on the screen
> as I showed you during the hackfest,
> 
>  - My Firefox has been crashing insie Graphite consistently.

That's not good. :( I wonder, though, if it's at least partly due to limitations of the Gecko/harfbuzz integration patches - in particular, they don't currently provide full glyph metrics to HB, as the OpenType code doesn't need them, but Graphite does. I fixed this last week in an experimental tree, and then Graphite seemed to be working nicely within Firefox, but I haven't merged this to the main Gecko/harfbuzz patch queue yet; my priority there is to get the OpenType-based stuff landed and into wider testing.

It would help us move forward if you could modify the OpenType-based code to use a new hb_get_glyph_advance() callback instead of ...metrics() where possible, so that we can implement a more complete metrics callback (as needed for Graphite) without risking a performance impact on the OpenType code path.

JK