/**
* pango_ot_ruleset_maybe_add_feature:
* @ruleset: a #PangoOTRuleset.
* @table_type: the table type to add a feature to.
* @feature_tag: the tag of the feature to add.
* @property_bit: the property bit to use for this feature. Used to identify
* the glyphs that this feature should be applied to, or
* %PANGO_OT_ALL_GLYPHS if it should be applied to all glyphs.
*
* This is a convenience function that first tries to find the feature
* using pango_ot_info_find_feature() and the ruleset script and language
* passed to pango_ot_ruleset_new_for(),
* and if the feature is found, adds it to the ruleset.
*
* If @ruleset was not created using pango_ot_ruleset_new_for(), this function
* does nothing.
*
* Return value: %TRUE if the feature was found and added to ruleset,
* %FALSE otherwise.
*
* Since: 1.18
**/
gboolean
pango_ot_ruleset_maybe_add_feature (PangoOTRuleset *ruleset,
PangoOTTableType table_type,
PangoOTTag feature_tag,
gulong property_bit)
{
guint feature_index;
g_return_val_if_fail (PANGO_IS_OT_RULESET (ruleset), FALSE);
g_return_val_if_fail (ruleset->info != NULL, FALSE);
pango_ot_info_find_feature (ruleset->info, table_type,
feature_tag,
ruleset->script_index[table_type],
ruleset->language_index[table_type],
&feature_index);
if (feature_index != PANGO_OT_NO_FEATURE)
{
pango_ot_ruleset_add_feature (ruleset, table_type,
feature_index, property_bit);
return TRUE;
}
return FALSE;
}
static void
maybe_add_GPOS_feature (PangoOTRuleset *ruleset,
PangoOTInfo *info,
guint script_index,
PangoOTTag tag,
gulong property_bit)
{
guint feature_index;
/* 0xffff == default language system */
if (pango_ot_info_find_feature (info, PANGO_OT_TABLE_GPOS,
tag, script_index, 0xffff, &feature_index))
pango_ot_ruleset_add_feature (ruleset, PANGO_OT_TABLE_GPOS, feature_index,
property_bit);
}
static void
maybe_add_GPOS_feature (PangoOTRuleset *ruleset,
PangoOTInfo *info,
guint script_index,
PangoOTTag feature_tag,
gulong property_bit)
{
guint feature_index;
if (pango_ot_info_find_feature (info, PANGO_OT_TABLE_GPOS,
feature_tag,script_index, 0xffff, &feature_index))
{
/*
printf("Added GPOS feature '%c%c%c%c' = %8.8X\n", feature_tag>>24, feature_tag>>16&0xFF, feature_tag>>8&0xFF, feature_tag&0xFF, property_bit);
*/
pango_ot_ruleset_add_feature (ruleset, PANGO_OT_TABLE_GPOS, feature_index,
property_bit);
}
}
/**
* pango_ot_ruleset_new_for:
* @info: a #PangoOTInfo.
* @script: a #PangoScript.
* @language: a #PangoLanguage.
*
* Creates a new #PangoOTRuleset for the given OpenType info, script, and
* language.
*
* This function is part of a convenience scheme that highly simplifies
* using a #PangoOTRuleset to represent features for a specific pair of script
* and language. So one can use this function passing in the script and
* language of interest, and later try to add features to the ruleset by just
* specifying the feature name or tag, without having to deal with finding
* script, language, or feature indices manually.
*
* In excess to what pango_ot_ruleset_new() does, this function will:
* <itemizedlist>
* <listitem>
* Find the #PangoOTTag script and language tags associated with
* @script and @language using pango_ot_tag_from_script() and
* pango_ot_tag_from_language(),
* </listitem>
* <listitem>
* For each of table types %PANGO_OT_TABLE_GSUB and %PANGO_OT_TABLE_GPOS,
* find the script index of the script tag found and the language
* system index of the language tag found in that script system, using
* pango_ot_info_find_script() and pango_ot_info_find_language(),
* </listitem>
* <listitem>
* For found language-systems, if they have required feature
* index, add that feature to the ruleset using
* pango_ot_ruleset_add_feature(),
* </listitem>
* <listitem>
* Remember found script and language indices for both table types,
* and use them in future pango_ot_ruleset_maybe_add_feature() and
* pango_ot_ruleset_maybe_add_features().
* </listitem>
* </itemizedlist>
*
* Because of the way return values of pango_ot_info_find_script() and
* pango_ot_info_find_language() are ignored, this function automatically
* finds and uses the 'DFLT' script and the default language-system.
*
* Return value: the newly allocated #PangoOTRuleset, which
* should be freed with g_object_unref().
*
* Since: 1.18
**/
PangoOTRuleset *
pango_ot_ruleset_new_for (PangoOTInfo *info,
PangoScript script,
PangoLanguage *language)
{
PangoOTRuleset *ruleset;
PangoOTTag script_tag, language_tag;
PangoOTTableType table_type;
g_return_val_if_fail (PANGO_IS_OT_INFO (info), NULL);
ruleset = pango_ot_ruleset_new (info);
script_tag = pango_ot_tag_from_script (script);
language_tag = pango_ot_tag_from_language (language);
for (table_type = PANGO_OT_TABLE_GSUB; table_type <= PANGO_OT_TABLE_GPOS; table_type++)
{
guint script_index, language_index, feature_index;
pango_ot_info_find_script (ruleset->info, table_type,
script_tag, &script_index);
pango_ot_info_find_language (ruleset->info, table_type, script_index,
language_tag, &language_index,
&feature_index);
ruleset->script_index[table_type] = script_index;
ruleset->language_index[table_type] = language_index;
/* add required feature of the language */
pango_ot_ruleset_add_feature (ruleset, table_type,
feature_index, PANGO_OT_ALL_GLYPHS);
}
return ruleset;
}
