hb_shape() now accepts a shaper_options and a shaper_list argument.
Both can be set to NULL to emulate previous API. And in most situations
they are expected to be set to NULL.
hb_shape() also returns a boolean for now. If shaper_list is NULL, the
return value can be ignored.
shaper_options is ignored for now, but otherwise it should be a
NULL-terminated list of strings.
shaper_list is a NULL-terminated list of strings. Currently recognized
strings are "ot" for native OpenType Layout implementation, "uniscribe"
for the Uniscribe backend, and "fallback" for the non-complex backend
(that will be implemented shortly). The fallback backend never fails.
The env var HB_SHAPER_LIST is also parsed and honored. It's a
colon-separated list of shaper names. The fallback shaper is invoked if
none of the env-listed shapers succeed.
New API hb_buffer_guess_properties() added.
Add compose() and decompose() unicode funcs. These implement
pair-wise canonical composition/decomposition.
The glib/icu implementations are lacking for now. We are adding
API for this to glib, but I cannot find any useful API in ICU.
May end of implementing these in-house.
Changed all unicode_funcs callback names to remove the "_get" part.
Eg, hb_unicode_get_script_func_t is now hb_unicode_script_func_t,
and hb_unicode_get_script() is hb_unicode_script() now.
We don't cache any metrics internally, so the correct way to add more
glyph metrics items is to add new callbacks for them. We already have
separeate callbacks for advance vs extents.
Previously if a default global feature was overrided by a non-global
user feature, we were not setting any default mask for the feature,
essentially disabling the feature by default. Fix that.
