/* 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);

}