/* Pango
* pango-ot-ruleset.c: Shaping using OpenType features
*
* Copyright (C) 2000 Red Hat Software
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "pango-ot-private.h"
static void pango_ot_ruleset_finalize (GObject *object);
/**
* PangoOTRuleset:
*
* The #PangoOTRuleset structure holds a
* set of features selected from the tables in an OpenType font.
* (A feature is an operation such as adjusting glyph positioning
* that should be applied to a text feature such as a certain
* type of accent.) A #PangoOTRuleset
* is created with pango_ot_ruleset_new(), features are added
* to it with pango_ot_ruleset_add_feature(), then it is
* applied to a #PangoGlyphString with pango_ot_ruleset_shape().
*/
G_DEFINE_TYPE (PangoOTRuleset, pango_ot_ruleset, G_TYPE_OBJECT);
static void
pango_ot_ruleset_class_init (PangoOTRulesetClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = pango_ot_ruleset_finalize;
}
static void
pango_ot_ruleset_init (PangoOTRuleset *ruleset)
{
}
static void
pango_ot_ruleset_finalize (GObject *object)
{
G_OBJECT_CLASS (pango_ot_ruleset_parent_class)->finalize (object);
}
/**
* pango_ot_ruleset_get_for_description:
* @info: a #PangoOTInfo.
* @desc: a #PangoOTRulesetDescription.
*
* Returns a ruleset for the given OpenType info and ruleset
* description. Rulesets are created on demand using
* pango_ot_ruleset_new_from_description().
* The returned ruleset should not be modified or destroyed.
*
* The static feature map members of @desc should be alive as
* long as @info is.
*
* Return value: the #PangoOTRuleset for @desc. This object will have
* the same lifetime as @info.
*
* Since: 1.18
**/
const PangoOTRuleset *
pango_ot_ruleset_get_for_description (PangoOTInfo *info,
const PangoOTRulesetDescription *desc)
{
static PangoOTRuleset *ruleset; /* MT-safe */
if (g_once_init_enter (&ruleset))
g_once_init_leave (&ruleset, g_object_new (PANGO_TYPE_OT_RULESET, NULL));
return ruleset;
}
/**
* 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)
{
return g_object_new (PANGO_TYPE_OT_RULESET, NULL);
}
/**
* 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)
{
return g_object_new (PANGO_TYPE_OT_RULESET, NULL);
}
/**
* pango_ot_ruleset_new_from_description:
* @info: a #PangoOTInfo.
* @desc: a #PangoOTRulesetDescription.
*
* Creates a new #PangoOTRuleset for the given OpenType infor and
* matching the given ruleset description.
*
* This is a convenience function that calls pango_ot_ruleset_new_for() and
* adds the static GSUB/GPOS features to the resulting ruleset, followed by
* adding other features to both GSUB and GPOS.
*
* The static feature map members of @desc should be alive as
* long as @info is.
*
* Return value: the newly allocated #PangoOTRuleset, which
* should be freed with g_object_unref().
*
* Since: 1.18
**/
PangoOTRuleset *
pango_ot_ruleset_new_from_description (PangoOTInfo *info,
const PangoOTRulesetDescription *desc)
{
return g_object_new (PANGO_TYPE_OT_RULESET, NULL);
}
/**
* 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)
{
}
/**
* 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)
{
return FALSE;
}
/**
* pango_ot_ruleset_maybe_add_features:
* @ruleset: a #PangoOTRuleset.
* @table_type: the table type to add features to.
* @features: array of feature name and property bits to add.
* @n_features: number of feature records in @features array.
*
* This is a convenience function that
* for each feature in the feature map array @features
* converts the feature name to a #PangoOTTag feature tag using PANGO_OT_TAG_MAKE()
* and calls pango_ot_ruleset_maybe_add_feature() on it.
*
* Return value: The number of features in @features that were found
* and added to @ruleset.
*
* Since: 1.18
**/
guint
pango_ot_ruleset_maybe_add_features (PangoOTRuleset *ruleset,
PangoOTTableType table_type,
const PangoOTFeatureMap *features,
guint n_features)
{
return 0;
}
/**
* pango_ot_ruleset_get_feature_count:
* @ruleset: a #PangoOTRuleset.
* @n_gsub_features: (out) (optional): location to store number of
* GSUB features, or %NULL.
* @n_gpos_features: (out) (optional): location to store number of
* GPOS features, or %NULL.
*
* Gets the number of GSUB and GPOS features in the ruleset.
*
* Return value: Total number of features in the @ruleset.
*
* Since: 1.18
**/
guint
pango_ot_ruleset_get_feature_count (const PangoOTRuleset *ruleset,
guint *n_gsub_features,
guint *n_gpos_features)
{
return 0;
}
/**
* 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 (const PangoOTRuleset *ruleset,
PangoOTBuffer *buffer)
{
}
/**
* pango_ot_ruleset_position:
* @ruleset: a #PangoOTRuleset.
* @buffer: a #PangoOTBuffer.
*
* Performs the OpenType GPOS positioning on @buffer using the features
* in @ruleset
*
* Since: 1.4
**/
void
pango_ot_ruleset_position (const PangoOTRuleset *ruleset,
PangoOTBuffer *buffer)
{
}
/* ruleset descriptions */
/**
* pango_ot_ruleset_description_hash:
* @desc: a ruleset description
*
* Computes a hash of a #PangoOTRulesetDescription structure suitable
* to be used, for example, as an argument to g_hash_table_new().
*
* Return value: the hash value.
*
* Since: 1.18
**/
guint
pango_ot_ruleset_description_hash (const PangoOTRulesetDescription *desc)
{
return 0;
}
/**
* pango_ot_ruleset_description_equal:
* @desc1: a ruleset description
* @desc2: a ruleset description
*
* Compares two ruleset descriptions for equality.
* Two ruleset descriptions are considered equal if the rulesets
* they describe are provably identical. This means that their
* script, language, and all feature sets should be equal. For static feature
* sets, the array addresses are compared directly, while for other
* features, the list of features is compared one by one.
* (Two ruleset descriptions may result in identical rulesets
* being created, but still compare %FALSE.)
*
* Return value: %TRUE if two ruleset descriptions are identical,
* %FALSE otherwise.
*
* Since: 1.18
**/
gboolean
pango_ot_ruleset_description_equal (const PangoOTRulesetDescription *desc1,
const PangoOTRulesetDescription *desc2)
{
return TRUE;
}
/**
* pango_ot_ruleset_description_copy:
* @desc: ruleset description to copy
*
* Creates a copy of @desc, which should be freed with
* pango_ot_ruleset_description_free(). Primarily used internally
* by pango_ot_ruleset_get_for_description() to cache rulesets for
* ruleset descriptions.
*
* Return value: the newly allocated #PangoOTRulesetDescription, which
* should be freed with pango_ot_ruleset_description_free().
*
* Since: 1.18
**/
PangoOTRulesetDescription *
pango_ot_ruleset_description_copy (const PangoOTRulesetDescription *desc)
{
PangoOTRulesetDescription *copy;
g_return_val_if_fail (desc != NULL, NULL);
copy = g_slice_new (PangoOTRulesetDescription);
*copy = *desc;
return copy;
}
/**
* pango_ot_ruleset_description_free:
* @desc: an allocated #PangoOTRulesetDescription
*
* Frees a ruleset description allocated by
* pango_ot_ruleset_description_copy().
*
* Since: 1.18
**/
void
pango_ot_ruleset_description_free (PangoOTRulesetDescription *desc)
{
g_slice_free (PangoOTRulesetDescription, desc);
}