/*

 * Copyright © 2012  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Google Author(s): Behdad Esfahbod

 */

#ifndef HB_SHAPER_HH

#define HB_SHAPER_HH

#include "hb.hh"

typedef hb_bool_t hb_shape_func_t (hb_shape_plan_t    *shape_plan,

           hb_font_t          *font,

           hb_buffer_t        *buffer,

           const hb_feature_t *features,

           unsigned int        num_features);

#define HB_SHAPER_IMPLEMENT(name) \

  extern "C" HB_INTERNAL hb_shape_func_t _hb_##name##_shape;

#include "hb-shaper-list.hh"

#undef HB_SHAPER_IMPLEMENT

struct hb_shaper_pair_t {

  char name[16];

  hb_shape_func_t *func;

};

HB_INTERNAL const hb_shaper_pair_t *

_hb_shapers_get (void);

/* Means: succeeded, but don't need to keep any data. */

#define HB_SHAPER_DATA_SUCCEEDED ((void *) +1)

/* Means: tried but failed to create. */

#define HB_SHAPER_DATA_INVALID ((void *) -1)

#define HB_SHAPER_DATA_TYPE_NAME(shaper, object)  hb_##shaper##_##object##_data_t

#define HB_SHAPER_DATA_TYPE(shaper, object)   struct HB_SHAPER_DATA_TYPE_NAME(shaper, object)

#define HB_SHAPER_DATA_INSTANCE(shaper, object, instance) (* reinterpret_cast<hb_atomic_ptr_t<HB_SHAPER_DATA_TYPE(shaper, object) *> *> (&(instance)->shaper_data.shaper))

#define HB_SHAPER_DATA(shaper, object)      HB_SHAPER_DATA_INSTANCE(shaper, object, object)

#define HB_SHAPER_DATA_CREATE_FUNC(shaper, object)  _hb_##shaper##_shaper_##object##_data_create

#define HB_SHAPER_DATA_DESTROY_FUNC(shaper, object) _hb_##shaper##_shaper_##object##_data_destroy

#define HB_SHAPER_DATA_ENSURE_FUNC(shaper, object)  hb_##shaper##_shaper_##object##_data_ensure

#define HB_SHAPER_DATA_PROTOTYPE(shaper, object) \

  HB_SHAPER_DATA_TYPE (shaper, object); /* Type forward declaration. */ \

  extern "C" HB_INTERNAL HB_SHAPER_DATA_TYPE (shaper, object) * \

  HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (hb_##object##_t *object HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS); \

  extern "C" HB_INTERNAL void \

  HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (HB_SHAPER_DATA_TYPE (shaper, object) *data); \

  extern "C" HB_INTERNAL bool \

  HB_SHAPER_DATA_ENSURE_FUNC (shaper, object) (hb_##object##_t *object)

#define HB_SHAPER_DATA_DESTROY(shaper, object) \

    if (HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object).get ()) \

      if (data != HB_SHAPER_DATA_INVALID && data != HB_SHAPER_DATA_SUCCEEDED) \

        HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data);

#define HB_SHAPER_DATA_ENSURE_DEFINE(shaper, object) \

  HB_SHAPER_DATA_ENSURE_DEFINE_WITH_CONDITION(shaper, object, true)

#define HB_SHAPER_DATA_ENSURE_DEFINE_WITH_CONDITION(shaper, object, condition) \

bool \

HB_SHAPER_DATA_ENSURE_FUNC(shaper, object) (hb_##object##_t *object) \

{\

  retry: \

  HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object).get (); \

  if (likely (data) && !(condition)) { \

    /* XXX-MT-bug \

     * Note that evaluating condition above can be dangerous if another thread \

     * got here first and destructed data.  That's, as always, bad use pattern. \

     * If you modify the font (change font size), other threads must not be \

     * using it at the same time.  However, since this check is delayed to \

     * when one actually tries to shape something, this is a XXX race condition \

     * (and the only know we have that I know of) right now.  Ie. you modify the \

     * font size in one thread, then (supposedly safely) try to use it from two \

     * or more threads and BOOM!  I'm not sure how to fix this.  We want RCU. \

     * Maybe when it doesn't matter when we finally implement AAT shaping, as

     * this (condition) is currently only used by hb-coretext. */ \

    /* Drop and recreate. */ \

    /* If someone dropped it in the mean time, throw it away and don't touch it. \

     * Otherwise, destruct it. */ \

    if (likely (HB_SHAPER_DATA (shaper, object).cmpexch (data, nullptr))) \

    { \

      HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \

    } \

    goto retry; \

  } \

  if (unlikely (!data)) { \

    data = HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (object); \

    if (unlikely (!data)) \

      data = (HB_SHAPER_DATA_TYPE (shaper, object) *) HB_SHAPER_DATA_INVALID; \

    if (unlikely (!HB_SHAPER_DATA (shaper, object).cmpexch (nullptr, data))) { \

      if (data && \

    data != HB_SHAPER_DATA_INVALID && \

    data != HB_SHAPER_DATA_SUCCEEDED) \

  HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \

      goto retry; \

    } \

  } \

  return data != nullptr && (void *) data != HB_SHAPER_DATA_INVALID; \

}

Unexecuted instantiation: hb_ot_shaper_face_data_ensure

Unexecuted instantiation: hb_ot_shaper_font_data_ensure

/* For embedding in face / font / ... */

struct hb_shaper_data_t {

#define HB_SHAPER_IMPLEMENT(shaper) hb_atomic_ptr_t<void *> shaper;

#include "hb-shaper-list.hh"

#undef HB_SHAPER_IMPLEMENT

};

#define HB_SHAPERS_COUNT (sizeof (hb_shaper_data_t) / sizeof (void *))

#endif /* HB_SHAPER_HH */