Add a new API, hb_ot_layout_get_feature_name_ids (#976)

This new API returns cvXX and ssXX related NameId, things like
featUiLabelNameId, featUiTooltipTextNameId, sampleTextNameId, ... of cvXX
and UINameId of ssXX, in a unified way.

However HarfBuzz currently doesn't expose an API for retrieving the actual
information associated with NameId from the `name` table and that should be
done separately.
This commit is contained in:
Ebrahim Byagowi 2018-07-21 21:14:48 +04:30 committed by GitHub
parent 93b65d9fe3
commit 0c1b287b72
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4 changed files with 109 additions and 0 deletions

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@ -450,6 +450,7 @@ hb_ot_layout_collect_lookups
hb_ot_layout_feature_get_lookups
hb_ot_layout_feature_with_variations_get_lookups
hb_ot_layout_get_attach_points
hb_ot_layout_get_feature_name_ids
hb_ot_layout_get_glyph_class
hb_ot_layout_get_glyphs_in_class
hb_ot_layout_get_ligature_carets

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@ -478,6 +478,20 @@ struct FeatureParams
return Null(FeatureParamsSize);
}
inline const FeatureParamsStylisticSet& get_stylistic_set_params (hb_tag_t tag) const
{
if ((tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
return u.stylisticSet;
return Null(FeatureParamsStylisticSet);
}
inline const FeatureParamsCharacterVariants& get_character_variants_params (hb_tag_t tag) const
{
if ((tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
return u.characterVariants;
return Null(FeatureParamsCharacterVariants);
}
private:
union {
FeatureParamsSize size;

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@ -1016,6 +1016,24 @@ hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
OT::GPOS::position_finish_offsets (font, buffer);
}
static const OT::FeatureParams&
_get_gsubgpos_matched_feature_params (hb_face_t *face, hb_tag_t feature)
{
const OT::GSUB &gsub = _get_gsub (face);
unsigned int gsub_num_features = gsub.get_feature_count ();
for (unsigned int i = 0; i < gsub_num_features; i++)
if (feature == gsub.get_feature_tag (i))
return gsub.get_feature (i).get_feature_params ();
const OT::GPOS &gpos = _get_gpos (face);
unsigned int gpos_num_features = gpos.get_feature_count ();
for (unsigned int i = 0; i < gpos_num_features; i++)
if (feature == gpos.get_feature_tag (i))
return gpos.get_feature (i).get_feature_params ();
return Null (OT::FeatureParams);
}
/**
* hb_ot_layout_get_size_params:
*
@ -1066,6 +1084,74 @@ hb_ot_layout_get_size_params (hb_face_t *face,
return false;
}
/**
* hb_ot_layout_get_feature_name_ids:
* @face: #hb_face_t to work upon
* @feature: ssXX and cvXX tag
* @label_id: (out) (allow-none): The name table name ID that specifies a string
* for a user-interface label for this feature. (May be NULL.)
* @tooltip_id: (out) (allow-none): The name table name ID that specifies a string
* that an application can use for tooltip text for this
* feature. (May be NULL.)
* @sample_id: (out) (allow-none): The name table name ID that specifies sample text
* that illustrates the effect of this feature. (May be NULL.)
* @num_named_parameters: (out) (allow-none): Number of named parameters. (May be zero.)
* @first_param_id: (out) (allow-none): The first name table name ID used to specify
* strings for user-interface labels for the feature
* parameters. (Must be zero if numParameters is zero.)
*
* Return value: true if could find any feature with the tag, false otherwise
*
* Since: REPLACEME
**/
hb_bool_t
hb_ot_layout_get_feature_name_ids (hb_face_t *face,
hb_tag_t feature,
unsigned int *label_id, /* OUT. May be nullptr */
unsigned int *tooltip_id, /* OUT. May be nullptr */
unsigned int *sample_id, /* OUT. May be nullptr */
unsigned int *num_named_parameters, /* OUT. May be nullptr */
unsigned int *first_param_id /* OUT. May be nullptr */)
{
const OT::FeatureParams &feature_params =
_get_gsubgpos_matched_feature_params (face, feature);
if (&feature_params != &Null (OT::FeatureParams))
{
const OT::FeatureParamsStylisticSet& ss_params =
feature_params.get_stylistic_set_params (feature);
if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
{
#define PARAM(a, A) if (a) *a = A
PARAM(label_id, ss_params.uiNameID);
// ssXX features don't have the rest
PARAM(tooltip_id, 0);
PARAM(sample_id, 0);
PARAM(num_named_parameters, 0);
PARAM(first_param_id, 0);
return true;
}
const OT::FeatureParamsCharacterVariants& cv_params =
feature_params.get_character_variants_params (feature);
if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
{
PARAM(label_id, cv_params.featUILableNameID);
PARAM(tooltip_id, cv_params.featUITooltipTextNameID);
PARAM(sample_id, cv_params.sampleTextNameID);
PARAM(num_named_parameters, cv_params.numNamedParameters);
PARAM(first_param_id, cv_params.firstParamUILabelNameID);
return true;
}
}
PARAM(label_id, 0);
PARAM(tooltip_id, 0);
PARAM(sample_id, 0);
PARAM(num_named_parameters, 0);
PARAM(first_param_id, 0);
#undef PARAM
return false;
}
/*
* Parts of different types are implemented here such that they have direct

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@ -322,6 +322,14 @@ hb_ot_layout_get_size_params (hb_face_t *face,
unsigned int *range_start, /* OUT. May be NULL */
unsigned int *range_end /* OUT. May be NULL */);
HB_EXTERN hb_bool_t
hb_ot_layout_get_feature_name_ids (hb_face_t *face,
hb_tag_t feature,
unsigned int *label_id /* OUT. May be NULL */,
unsigned int *tooltip_id /* OUT. May be NULL */,
unsigned int *sample_id /* OUT. May be NULL */,
unsigned int *num_named_parameters /* OUT. May be NULL */,
unsigned int *first_param_id /* OUT. May be NULL */);
/*
* BASE