/**
* pango_ot_ruleset_substitute:
* @ruleset: a #PangoOTRuleset.
* @buffer: a #PangoOTBuffer.
*
* Performs the OpenType GSUB substitution on @buffer using the features
* in @ruleset
*
* Since: 1.4
**/
void
pango_ot_ruleset_substitute (PangoOTRuleset *ruleset,
PangoOTBuffer *buffer)
{
unsigned int i;
HB_GSUB gsub = NULL;
g_return_if_fail (PANGO_IS_OT_RULESET (ruleset));
g_return_if_fail (PANGO_IS_OT_INFO (ruleset->info));
for (i = 0; i < ruleset->rules->len; i++)
{
PangoOTRule *rule = &g_array_index (ruleset->rules, PangoOTRule, i);
if (rule->table_type != PANGO_OT_TABLE_GSUB)
continue;
if (!gsub)
{
gsub = pango_ot_info_get_gsub (ruleset->info);
if (gsub)
HB_GSUB_Clear_Features (gsub);
else
return;
}
HB_GSUB_Add_Feature (gsub, rule->feature_index, rule->property_bit);
}
HB_GSUB_Apply_String (gsub, buffer->buffer);
}
/**
* pango_ot_ruleset_new:
* @info: a #PangoOTInfo.
*
* Creates a new #PangoOTRuleset for the given OpenType info.
*
* Return value: the newly allocated #PangoOTRuleset, which
* should be freed with g_object_unref().
**/
PangoOTRuleset *
pango_ot_ruleset_new (PangoOTInfo *info)
{
PangoOTRuleset *ruleset;
g_return_val_if_fail (PANGO_IS_OT_INFO (info), NULL);
ruleset = g_object_new (PANGO_TYPE_OT_RULESET, NULL);
ruleset->info = info;
g_object_add_weak_pointer (G_OBJECT (ruleset->info), (gpointer *)(void*)&ruleset->info);
return ruleset;
}
/**
* pango_ot_ruleset_add_feature:
* @ruleset: a #PangoOTRuleset.
* @table_type: the table type to add a feature to.
* @feature_index: the index 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.
*
* Adds a feature to the ruleset.
**/
void
pango_ot_ruleset_add_feature (PangoOTRuleset *ruleset,
PangoOTTableType table_type,
guint feature_index,
gulong property_bit)
{
PangoOTRule tmp_rule;
g_return_if_fail (PANGO_IS_OT_RULESET (ruleset));
g_return_if_fail (PANGO_IS_OT_INFO (ruleset->info));
tmp_rule.table_type = table_type;
tmp_rule.feature_index = feature_index;
tmp_rule.property_bit = property_bit;
g_array_append_val (ruleset->rules, tmp_rule);
}
/**
* 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;
}
/**
* pango_ot_ruleset_position:
* @ruleset: a #PangoOTRuleset.
* @buffer: a #PangoOTBuffer.
*
* Performs the OpenType GPOS positionoing on @buffer using the features
* in @ruleset
*
* Since: 1.4
**/
void
pango_ot_ruleset_position (PangoOTRuleset *ruleset,
PangoOTBuffer *buffer)
{
unsigned int i;
HB_GPOS gpos = NULL;
g_return_if_fail (PANGO_IS_OT_RULESET (ruleset));
g_return_if_fail (PANGO_IS_OT_INFO (ruleset->info));
for (i = 0; i < ruleset->rules->len; i++)
{
PangoOTRule *rule = &g_array_index (ruleset->rules, PangoOTRule, i);
if (rule->table_type != PANGO_OT_TABLE_GPOS)
continue;
if (!gpos)
{
gpos = pango_ot_info_get_gpos (ruleset->info);
if (gpos)
HB_GPOS_Clear_Features (gpos);
else
return;
}
HB_GPOS_Add_Feature (gpos, rule->feature_index, rule->property_bit);
}
if (HB_GPOS_Apply_String (ruleset->info->face, gpos, 0, buffer->buffer,
FALSE /* enable device-dependant values */,
buffer->rtl) == FT_Err_Ok)
buffer->applied_gpos = TRUE;
}
