src/hb-shape-plan.cc - third_party/harfbuzz - Git at Google

 /*
  * 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
  */

 #include "hb.hh"
 #include "hb-shape-plan.hh"
 #include "hb-shaper.hh"
 #include "hb-font.hh"
 #include "hb-buffer.hh"


 static void
 hb_shape_plan_plan (hb_shape_plan_t    *shape_plan,
 		    const hb_feature_t *user_features,
 		    unsigned int        num_user_features,
 		    const int          *coords,
 		    unsigned int        num_coords,
 		    const char * const *shaper_list)
 {
   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
 		  "num_features=%d num_coords=%d shaper_list=%p",
 		  num_user_features,
 		  num_coords,
 		  shaper_list);

   const hb_shaper_pair_t *shapers = _hb_shapers_get ();

 #define HB_SHAPER_PLAN(shaper) \
 	HB_STMT_START { \
 	  if (hb_##shaper##_shaper_face_data_ensure (shape_plan->face_unsafe)) \
 	  { \
 	    /* XXX-MT-bug What happened to *ensure*ing this?!!!! */ \
 	    HB_SHAPER_DATA (shaper, shape_plan).set_relaxed ( \
 	      HB_SHAPER_DATA_CREATE_FUNC (shaper, shape_plan) (shape_plan, \
 							       user_features, num_user_features, \
 							       coords, num_coords)); \
 	    shape_plan->shaper_func = _hb_##shaper##_shape; \
 	    shape_plan->shaper_name = #shaper; \
 	    return; \
 	  } \
 	} HB_STMT_END

   if (likely (!shaper_list)) {
     for (unsigned int i = 0; i < HB_SHAPERS_COUNT; i++)
       if (false)
 	;
 #define HB_SHAPER_IMPLEMENT(shaper) \
       else if (shapers[i].func == _hb_##shaper##_shape) \
 	HB_SHAPER_PLAN (shaper);
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT
   } else {
     for (; *shaper_list; shaper_list++)
       if (false)
 	;
 #define HB_SHAPER_IMPLEMENT(shaper) \
       else if (0 == strcmp (*shaper_list, #shaper)) \
 	HB_SHAPER_PLAN (shaper);
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT
   }

 #undef HB_SHAPER_PLAN
 }


 /*
  * hb_shape_plan_t
  */

 DEFINE_NULL_INSTANCE (hb_shape_plan_t) =
 {
   HB_OBJECT_HEADER_STATIC,

   true, /* default_shaper_list */
   nullptr, /* face */
   HB_SEGMENT_PROPERTIES_DEFAULT, /* props */

   nullptr, /* shaper_func */
   nullptr, /* shaper_name */

   nullptr, /* user_features */
   0,    /* num_user_featurs */

   nullptr, /* coords */
   0,    /* num_coords */

   {
 #define HB_SHAPER_IMPLEMENT(shaper) HB_ATOMIC_PTR_INIT (HB_SHAPER_DATA_INVALID),
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT
   },
 };


 /**
  * hb_shape_plan_create: (Xconstructor)
  * @face:
  * @props:
  * @user_features: (array length=num_user_features):
  * @num_user_features:
  * @shaper_list: (array zero-terminated=1):
  *
  *
  *
  * Return value: (transfer full):
  *
  * Since: 0.9.7
  **/
 hb_shape_plan_t *
 hb_shape_plan_create (hb_face_t                     *face,
 		      const hb_segment_properties_t *props,
 		      const hb_feature_t            *user_features,
 		      unsigned int                   num_user_features,
 		      const char * const            *shaper_list)
 {
   return hb_shape_plan_create2 (face, props,
 				user_features, num_user_features,
 				nullptr, 0,
 				shaper_list);
 }

 hb_shape_plan_t *
 hb_shape_plan_create2 (hb_face_t                     *face,
 		       const hb_segment_properties_t *props,
 		       const hb_feature_t            *user_features,
 		       unsigned int                   num_user_features,
 		       const int                     *orig_coords,
 		       unsigned int                   num_coords,
 		       const char * const            *shaper_list)
 {
   DEBUG_MSG_FUNC (SHAPE_PLAN, nullptr,
 		  "face=%p num_features=%d num_coords=%d shaper_list=%p",
 		  face,
 		  num_user_features,
 		  num_coords,
 		  shaper_list);

   hb_shape_plan_t *shape_plan;
   hb_feature_t *features = nullptr;
   int *coords = nullptr;

   if (unlikely (!face))
     face = hb_face_get_empty ();
   if (unlikely (!props))
     return hb_shape_plan_get_empty ();
   if (num_user_features && !(features = (hb_feature_t *) calloc (num_user_features, sizeof (hb_feature_t))))
     return hb_shape_plan_get_empty ();
   if (num_coords && !(coords = (int *) calloc (num_coords, sizeof (int))))
   {
     free (features);
     return hb_shape_plan_get_empty ();
   }
   if (!(shape_plan = hb_object_create<hb_shape_plan_t> ()))
   {
     free (coords);
     free (features);
     return hb_shape_plan_get_empty ();
   }

   assert (props->direction != HB_DIRECTION_INVALID);

   hb_face_make_immutable (face);
   shape_plan->default_shaper_list = !shaper_list;
   shape_plan->face_unsafe = face;
   shape_plan->props = *props;
   shape_plan->num_user_features = num_user_features;
   shape_plan->user_features = features;
   if (num_user_features)
     memcpy (features, user_features, num_user_features * sizeof (hb_feature_t));
   shape_plan->num_coords = num_coords;
   shape_plan->coords = coords;
   if (num_coords)
     memcpy (coords, orig_coords, num_coords * sizeof (int));

   hb_shape_plan_plan (shape_plan,
 		      user_features, num_user_features,
 		      coords, num_coords,
 		      shaper_list);

   return shape_plan;
 }

 /**
  * hb_shape_plan_get_empty:
  *
  *
  *
  * Return value: (transfer full):
  *
  * Since: 0.9.7
  **/
 hb_shape_plan_t *
 hb_shape_plan_get_empty (void)
 {
   return const_cast<hb_shape_plan_t *> (&Null(hb_shape_plan_t));
 }

 /**
  * hb_shape_plan_reference: (skip)
  * @shape_plan: a shape plan.
  *
  *
  *
  * Return value: (transfer full):
  *
  * Since: 0.9.7
  **/
 hb_shape_plan_t *
 hb_shape_plan_reference (hb_shape_plan_t *shape_plan)
 {
   return hb_object_reference (shape_plan);
 }

 /**
  * hb_shape_plan_destroy: (skip)
  * @shape_plan: a shape plan.
  *
  *
  *
  * Since: 0.9.7
  **/
 void
 hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
 {
   if (!hb_object_destroy (shape_plan)) return;

 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, shape_plan);
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT

   free (shape_plan->user_features);
   free (shape_plan->coords);

   free (shape_plan);
 }

 /**
  * hb_shape_plan_set_user_data: (skip)
  * @shape_plan: a shape plan.
  * @key:
  * @data:
  * @destroy:
  * @replace:
  *
  *
  *
  * Return value:
  *
  * Since: 0.9.7
  **/
 hb_bool_t
 hb_shape_plan_set_user_data (hb_shape_plan_t    *shape_plan,
 			     hb_user_data_key_t *key,
 			     void *              data,
 			     hb_destroy_func_t   destroy,
 			     hb_bool_t           replace)
 {
   return hb_object_set_user_data (shape_plan, key, data, destroy, replace);
 }

 /**
  * hb_shape_plan_get_user_data: (skip)
  * @shape_plan: a shape plan.
  * @key:
  *
  *
  *
  * Return value: (transfer none):
  *
  * Since: 0.9.7
  **/
 void *
 hb_shape_plan_get_user_data (hb_shape_plan_t    *shape_plan,
 			     hb_user_data_key_t *key)
 {
   return hb_object_get_user_data (shape_plan, key);
 }


 /**
  * hb_shape_plan_execute:
  * @shape_plan: a shape plan.
  * @font: a font.
  * @buffer: a buffer.
  * @features: (array length=num_features):
  * @num_features:
  *
  *
  *
  * Return value:
  *
  * Since: 0.9.7
  **/
 hb_bool_t
 hb_shape_plan_execute (hb_shape_plan_t    *shape_plan,
 		       hb_font_t          *font,
 		       hb_buffer_t        *buffer,
 		       const hb_feature_t *features,
 		       unsigned int        num_features)
 {
   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
 		  "num_features=%d shaper_func=%p, shaper_name=%s",
 		  num_features,
 		  shape_plan->shaper_func,
 		  shape_plan->shaper_name);

   if (unlikely (!buffer->len))
     return true;

   assert (!hb_object_is_inert (buffer));
   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE);

   if (unlikely (hb_object_is_inert (shape_plan)))
     return false;

   assert (shape_plan->face_unsafe == font->face);
   assert (hb_segment_properties_equal (&shape_plan->props, &buffer->props));

 #define HB_SHAPER_EXECUTE(shaper) \
 	HB_STMT_START { \
 	  return HB_SHAPER_DATA (shaper, shape_plan).get () && \
 		 hb_##shaper##_shaper_font_data_ensure (font) && \
 		 _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
 	} HB_STMT_END

   if (false)
     ;
 #define HB_SHAPER_IMPLEMENT(shaper) \
   else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
     HB_SHAPER_EXECUTE (shaper);
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT

 #undef HB_SHAPER_EXECUTE

   return false;
 }


 /*
  * caching
  */

 #if 0
 static unsigned int
 hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
 {
   return hb_segment_properties_hash (&shape_plan->props) +
 	 shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
 }
 #endif

 /* User-feature caching is currently somewhat dumb:
  * it only finds matches where the feature array is identical,
  * not cases where the feature lists would be compatible for plan purposes
  * but have different ranges, for example.
  */
 struct hb_shape_plan_proposal_t
 {
   const hb_segment_properties_t  props;
   const char * const            *shaper_list;
   const hb_feature_t            *user_features;
   unsigned int                   num_user_features;
   const int                     *coords;
   unsigned int                   num_coords;
   hb_shape_func_t               *shaper_func;
 };

 static inline hb_bool_t
 hb_shape_plan_user_features_match (const hb_shape_plan_t          *shape_plan,
 				   const hb_shape_plan_proposal_t *proposal)
 {
   if (proposal->num_user_features != shape_plan->num_user_features)
     return false;
   for (unsigned int i = 0, n = proposal->num_user_features; i < n; i++)
     if (proposal->user_features[i].tag   != shape_plan->user_features[i].tag   ||
         proposal->user_features[i].value != shape_plan->user_features[i].value ||
         proposal->user_features[i].start != shape_plan->user_features[i].start ||
         proposal->user_features[i].end   != shape_plan->user_features[i].end)
       return false;
   return true;
 }

 static inline hb_bool_t
 hb_shape_plan_coords_match (const hb_shape_plan_t          *shape_plan,
 			    const hb_shape_plan_proposal_t *proposal)
 {
   if (proposal->num_coords != shape_plan->num_coords)
     return false;
   for (unsigned int i = 0, n = proposal->num_coords; i < n; i++)
     if (proposal->coords[i] != shape_plan->coords[i])
       return false;
   return true;
 }

 static hb_bool_t
 hb_shape_plan_matches (const hb_shape_plan_t          *shape_plan,
 		       const hb_shape_plan_proposal_t *proposal)
 {
   return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
 	 hb_shape_plan_user_features_match (shape_plan, proposal) &&
 	 hb_shape_plan_coords_match (shape_plan, proposal) &&
 	 ((shape_plan->default_shaper_list && !proposal->shaper_list) ||
 	  (shape_plan->shaper_func == proposal->shaper_func));
 }

 static inline hb_bool_t
 hb_non_global_user_features_present (const hb_feature_t *user_features,
 				     unsigned int        num_user_features)
 {
   while (num_user_features) {
     if (user_features->start != 0 || user_features->end != (unsigned int) -1)
       return true;
     num_user_features--;
     user_features++;
   }
   return false;
 }

 static inline hb_bool_t
 hb_coords_present (const int *coords,
 		   unsigned int num_coords)
 {
   return num_coords != 0;
 }

 /**
  * hb_shape_plan_create_cached:
  * @face:
  * @props:
  * @user_features: (array length=num_user_features):
  * @num_user_features:
  * @shaper_list: (array zero-terminated=1):
  *
  *
  *
  * Return value: (transfer full):
  *
  * Since: 0.9.7
  **/
 hb_shape_plan_t *
 hb_shape_plan_create_cached (hb_face_t                     *face,
 			     const hb_segment_properties_t *props,
 			     const hb_feature_t            *user_features,
 			     unsigned int                   num_user_features,
 			     const char * const            *shaper_list)
 {
   return hb_shape_plan_create_cached2 (face, props,
 				       user_features, num_user_features,
 				       nullptr, 0,
 				       shaper_list);
 }

 hb_shape_plan_t *
 hb_shape_plan_create_cached2 (hb_face_t                     *face,
 			      const hb_segment_properties_t *props,
 			      const hb_feature_t            *user_features,
 			      unsigned int                   num_user_features,
 			      const int                     *coords,
 			      unsigned int                   num_coords,
 			      const char * const            *shaper_list)
 {
   DEBUG_MSG_FUNC (SHAPE_PLAN, nullptr,
 		  "face=%p num_features=%d shaper_list=%p",
 		  face,
 		  num_user_features,
 		  shaper_list);

   hb_shape_plan_proposal_t proposal = {
     *props,
     shaper_list,
     user_features,
     num_user_features,
     nullptr
   };

   if (shaper_list) {
     /* Choose shaper.  Adapted from hb_shape_plan_plan().
      * Must choose shaper exactly the same way as that function. */
     for (const char * const *shaper_item = shaper_list; *shaper_item; shaper_item++)
       if (false)
 	;
 #define HB_SHAPER_IMPLEMENT(shaper) \
       else if (0 == strcmp (*shaper_item, #shaper) && \
 	       hb_##shaper##_shaper_face_data_ensure (face)) \
       { \
 	proposal.shaper_func = _hb_##shaper##_shape; \
 	break; \
       }
 #include "hb-shaper-list.hh"
 #undef HB_SHAPER_IMPLEMENT

     if (unlikely (!proposal.shaper_func))
       return hb_shape_plan_get_empty ();
   }


 retry:
   hb_face_t::plan_node_t *cached_plan_nodes = face->shape_plans.get ();

   /* Don't look for plan in the cache if there were variation coordinates XXX Fix me. */
   if (!hb_coords_present (coords, num_coords))
     for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
       if (hb_shape_plan_matches (node->shape_plan, &proposal))
       {
         DEBUG_MSG_FUNC (SHAPE_PLAN, node->shape_plan, "fulfilled from cache");
         return hb_shape_plan_reference (node->shape_plan);
       }

   /* Not found. */
   hb_shape_plan_t *shape_plan = hb_shape_plan_create2 (face, props,
 						       user_features, num_user_features,
 						       coords, num_coords,
 						       shaper_list);

   /* Don't add to the cache if face is inert. */
   if (unlikely (hb_object_is_inert (face)))
     return shape_plan;

   /* Don't add the plan to the cache if there were user features with non-global ranges */
   if (hb_non_global_user_features_present (user_features, num_user_features))
     return shape_plan;
   /* Don't add the plan to the cache if there were variation coordinates XXX Fix me. */
   if (hb_coords_present (coords, num_coords))
     return shape_plan;

   hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) calloc (1, sizeof (hb_face_t::plan_node_t));
   if (unlikely (!node))
     return shape_plan;

   node->shape_plan = shape_plan;
   node->next = cached_plan_nodes;

   if (unlikely (!face->shape_plans.cmpexch (cached_plan_nodes, node)))
   {
     hb_shape_plan_destroy (shape_plan);
     free (node);
     goto retry;
   }
   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan, "inserted into cache");

   return hb_shape_plan_reference (shape_plan);
 }

 /**
  * hb_shape_plan_get_shaper:
  * @shape_plan: a shape plan.
  *
  *
  *
  * Return value: (transfer none):
  *
  * Since: 0.9.7
  **/
 const char *
 hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
 {
   return shape_plan->shaper_name;
 }
	/*
	* 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
	*/

	#include "hb.hh"
	#include "hb-shape-plan.hh"
	#include "hb-shaper.hh"
	#include "hb-font.hh"
	#include "hb-buffer.hh"


	static void
	hb_shape_plan_plan (hb_shape_plan_t *shape_plan,
	const hb_feature_t *user_features,
	unsigned int num_user_features,
	const int *coords,
	unsigned int num_coords,
	const char * const *shaper_list)
	{
	DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
	"num_features=%d num_coords=%d shaper_list=%p",
	num_user_features,
	num_coords,
	shaper_list);

	const hb_shaper_pair_t *shapers = _hb_shapers_get ();

	#define HB_SHAPER_PLAN(shaper) \
	HB_STMT_START { \
	if (hb_##shaper##_shaper_face_data_ensure (shape_plan->face_unsafe)) \
	{ \
	/* XXX-MT-bug What happened to ensureing this?!!!! */ \
	HB_SHAPER_DATA (shaper, shape_plan).set_relaxed ( \
	HB_SHAPER_DATA_CREATE_FUNC (shaper, shape_plan) (shape_plan, \
	user_features, num_user_features, \
	coords, num_coords)); \
	shape_plan->shaper_func = _hb_##shaper##_shape; \
	shape_plan->shaper_name = #shaper; \
	return; \
	} \
	} HB_STMT_END

	if (likely (!shaper_list)) {
	for (unsigned int i = 0; i < HB_SHAPERS_COUNT; i++)
	if (false)
	;
	#define HB_SHAPER_IMPLEMENT(shaper) \
	else if (shapers[i].func == _hb_##shaper##_shape) \
	HB_SHAPER_PLAN (shaper);
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT
	} else {
	for (; *shaper_list; shaper_list++)
	if (false)
	;
	#define HB_SHAPER_IMPLEMENT(shaper) \
	else if (0 == strcmp (*shaper_list, #shaper)) \
	HB_SHAPER_PLAN (shaper);
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT
	}

	#undef HB_SHAPER_PLAN
	}


	/*
	* hb_shape_plan_t
	*/

	DEFINE_NULL_INSTANCE (hb_shape_plan_t) =
	{
	HB_OBJECT_HEADER_STATIC,

	true, /* default_shaper_list */
	nullptr, /* face */
	HB_SEGMENT_PROPERTIES_DEFAULT, /* props */

	nullptr, /* shaper_func */
	nullptr, /* shaper_name */

	nullptr, /* user_features */
	0, /* num_user_featurs */

	nullptr, /* coords */
	0, /* num_coords */

	{
	#define HB_SHAPER_IMPLEMENT(shaper) HB_ATOMIC_PTR_INIT (HB_SHAPER_DATA_INVALID),
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT
	},
	};


	/**
	* hb_shape_plan_create: (Xconstructor)
	* @face:
	* @props:
	* @user_features: (array length=num_user_features):
	* @num_user_features:
	* @shaper_list: (array zero-terminated=1):
	*
	*
	*
	* Return value: (transfer full):
	*
	* Since: 0.9.7
	**/
	hb_shape_plan_t *
	hb_shape_plan_create (hb_face_t *face,
	const hb_segment_properties_t *props,
	const hb_feature_t *user_features,
	unsigned int num_user_features,
	const char * const *shaper_list)
	{
	return hb_shape_plan_create2 (face, props,
	user_features, num_user_features,
	nullptr, 0,
	shaper_list);
	}

	hb_shape_plan_t *
	hb_shape_plan_create2 (hb_face_t *face,
	const hb_segment_properties_t *props,
	const hb_feature_t *user_features,
	unsigned int num_user_features,
	const int *orig_coords,
	unsigned int num_coords,
	const char * const *shaper_list)
	{
	DEBUG_MSG_FUNC (SHAPE_PLAN, nullptr,
	"face=%p num_features=%d num_coords=%d shaper_list=%p",
	face,
	num_user_features,
	num_coords,
	shaper_list);

	hb_shape_plan_t *shape_plan;
	hb_feature_t *features = nullptr;
	int *coords = nullptr;

	if (unlikely (!face))
	face = hb_face_get_empty ();
	if (unlikely (!props))
	return hb_shape_plan_get_empty ();
	if (num_user_features && !(features = (hb_feature_t *) calloc (num_user_features, sizeof (hb_feature_t))))
	return hb_shape_plan_get_empty ();
	if (num_coords && !(coords = (int *) calloc (num_coords, sizeof (int))))
	{
	free (features);
	return hb_shape_plan_get_empty ();
	}
	if (!(shape_plan = hb_object_create<hb_shape_plan_t> ()))
	{
	free (coords);
	free (features);
	return hb_shape_plan_get_empty ();
	}

	assert (props->direction != HB_DIRECTION_INVALID);

	hb_face_make_immutable (face);
	shape_plan->default_shaper_list = !shaper_list;
	shape_plan->face_unsafe = face;
	shape_plan->props = *props;
	shape_plan->num_user_features = num_user_features;
	shape_plan->user_features = features;
	if (num_user_features)
	memcpy (features, user_features, num_user_features * sizeof (hb_feature_t));
	shape_plan->num_coords = num_coords;
	shape_plan->coords = coords;
	if (num_coords)
	memcpy (coords, orig_coords, num_coords * sizeof (int));

	hb_shape_plan_plan (shape_plan,
	user_features, num_user_features,
	coords, num_coords,
	shaper_list);

	return shape_plan;
	}

	/**
	* hb_shape_plan_get_empty:
	*
	*
	*
	* Return value: (transfer full):
	*
	* Since: 0.9.7
	**/
	hb_shape_plan_t *
	hb_shape_plan_get_empty (void)
	{
	return const_cast<hb_shape_plan_t *> (&Null(hb_shape_plan_t));
	}

	/**
	* hb_shape_plan_reference: (skip)
	* @shape_plan: a shape plan.
	*
	*
	*
	* Return value: (transfer full):
	*
	* Since: 0.9.7
	**/
	hb_shape_plan_t *
	hb_shape_plan_reference (hb_shape_plan_t *shape_plan)
	{
	return hb_object_reference (shape_plan);
	}

	/**
	* hb_shape_plan_destroy: (skip)
	* @shape_plan: a shape plan.
	*
	*
	*
	* Since: 0.9.7
	**/
	void
	hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
	{
	if (!hb_object_destroy (shape_plan)) return;

	#define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, shape_plan);
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT

	free (shape_plan->user_features);
	free (shape_plan->coords);

	free (shape_plan);
	}

	/**
	* hb_shape_plan_set_user_data: (skip)
	* @shape_plan: a shape plan.
	* @key:
	* @data:
	* @destroy:
	* @replace:
	*
	*
	*
	* Return value:
	*
	* Since: 0.9.7
	**/
	hb_bool_t
	hb_shape_plan_set_user_data (hb_shape_plan_t *shape_plan,
	hb_user_data_key_t *key,
	void * data,
	hb_destroy_func_t destroy,
	hb_bool_t replace)
	{
	return hb_object_set_user_data (shape_plan, key, data, destroy, replace);
	}

	/**
	* hb_shape_plan_get_user_data: (skip)
	* @shape_plan: a shape plan.
	* @key:
	*
	*
	*
	* Return value: (transfer none):
	*
	* Since: 0.9.7
	**/
	void *
	hb_shape_plan_get_user_data (hb_shape_plan_t *shape_plan,
	hb_user_data_key_t *key)
	{
	return hb_object_get_user_data (shape_plan, key);
	}


	/**
	* hb_shape_plan_execute:
	* @shape_plan: a shape plan.
	* @font: a font.
	* @buffer: a buffer.
	* @features: (array length=num_features):
	* @num_features:
	*
	*
	*
	* Return value:
	*
	* Since: 0.9.7
	**/
	hb_bool_t
	hb_shape_plan_execute (hb_shape_plan_t *shape_plan,
	hb_font_t *font,
	hb_buffer_t *buffer,
	const hb_feature_t *features,
	unsigned int num_features)
	{
	DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
	"num_features=%d shaper_func=%p, shaper_name=%s",
	num_features,
	shape_plan->shaper_func,
	shape_plan->shaper_name);

	if (unlikely (!buffer->len))
	return true;

	assert (!hb_object_is_inert (buffer));
	assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE);

	if (unlikely (hb_object_is_inert (shape_plan)))
	return false;

	assert (shape_plan->face_unsafe == font->face);
	assert (hb_segment_properties_equal (&shape_plan->props, &buffer->props));

	#define HB_SHAPER_EXECUTE(shaper) \
	HB_STMT_START { \
	return HB_SHAPER_DATA (shaper, shape_plan).get () && \
	hb_##shaper##_shaper_font_data_ensure (font) && \
	_hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
	} HB_STMT_END

	if (false)
	;
	#define HB_SHAPER_IMPLEMENT(shaper) \
	else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
	HB_SHAPER_EXECUTE (shaper);
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT

	#undef HB_SHAPER_EXECUTE

	return false;
	}


	/*
	* caching
	*/

	#if 0
	static unsigned int
	hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
	{
	return hb_segment_properties_hash (&shape_plan->props) +
	shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
	}
	#endif

	/* User-feature caching is currently somewhat dumb:
	* it only finds matches where the feature array is identical,
	* not cases where the feature lists would be compatible for plan purposes
	* but have different ranges, for example.
	*/
	struct hb_shape_plan_proposal_t
	{
	const hb_segment_properties_t props;
	const char * const *shaper_list;
	const hb_feature_t *user_features;
	unsigned int num_user_features;
	const int *coords;
	unsigned int num_coords;
	hb_shape_func_t *shaper_func;
	};

	static inline hb_bool_t
	hb_shape_plan_user_features_match (const hb_shape_plan_t *shape_plan,
	const hb_shape_plan_proposal_t *proposal)
	{
	if (proposal->num_user_features != shape_plan->num_user_features)
	return false;
	for (unsigned int i = 0, n = proposal->num_user_features; i < n; i++)
	if (proposal->user_features[i].tag != shape_plan->user_features[i].tag \|\|
	proposal->user_features[i].value != shape_plan->user_features[i].value \|\|
	proposal->user_features[i].start != shape_plan->user_features[i].start \|\|
	proposal->user_features[i].end != shape_plan->user_features[i].end)
	return false;
	return true;
	}

	static inline hb_bool_t
	hb_shape_plan_coords_match (const hb_shape_plan_t *shape_plan,
	const hb_shape_plan_proposal_t *proposal)
	{
	if (proposal->num_coords != shape_plan->num_coords)
	return false;
	for (unsigned int i = 0, n = proposal->num_coords; i < n; i++)
	if (proposal->coords[i] != shape_plan->coords[i])
	return false;
	return true;
	}

	static hb_bool_t
	hb_shape_plan_matches (const hb_shape_plan_t *shape_plan,
	const hb_shape_plan_proposal_t *proposal)
	{
	return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
	hb_shape_plan_user_features_match (shape_plan, proposal) &&
	hb_shape_plan_coords_match (shape_plan, proposal) &&
	((shape_plan->default_shaper_list && !proposal->shaper_list) \|\|
	(shape_plan->shaper_func == proposal->shaper_func));
	}

	static inline hb_bool_t
	hb_non_global_user_features_present (const hb_feature_t *user_features,
	unsigned int num_user_features)
	{
	while (num_user_features) {
	if (user_features->start != 0 \|\| user_features->end != (unsigned int) -1)
	return true;
	num_user_features--;
	user_features++;
	}
	return false;
	}

	static inline hb_bool_t
	hb_coords_present (const int *coords,
	unsigned int num_coords)
	{
	return num_coords != 0;
	}

	/**
	* hb_shape_plan_create_cached:
	* @face:
	* @props:
	* @user_features: (array length=num_user_features):
	* @num_user_features:
	* @shaper_list: (array zero-terminated=1):
	*
	*
	*
	* Return value: (transfer full):
	*
	* Since: 0.9.7
	**/
	hb_shape_plan_t *
	hb_shape_plan_create_cached (hb_face_t *face,
	const hb_segment_properties_t *props,
	const hb_feature_t *user_features,
	unsigned int num_user_features,
	const char * const *shaper_list)
	{
	return hb_shape_plan_create_cached2 (face, props,
	user_features, num_user_features,
	nullptr, 0,
	shaper_list);
	}

	hb_shape_plan_t *
	hb_shape_plan_create_cached2 (hb_face_t *face,
	const hb_segment_properties_t *props,
	const hb_feature_t *user_features,
	unsigned int num_user_features,
	const int *coords,
	unsigned int num_coords,
	const char * const *shaper_list)
	{
	DEBUG_MSG_FUNC (SHAPE_PLAN, nullptr,
	"face=%p num_features=%d shaper_list=%p",
	face,
	num_user_features,
	shaper_list);

	hb_shape_plan_proposal_t proposal = {
	*props,
	shaper_list,
	user_features,
	num_user_features,
	nullptr
	};

	if (shaper_list) {
	/* Choose shaper. Adapted from hb_shape_plan_plan().
	* Must choose shaper exactly the same way as that function. */
	for (const char * const shaper_item = shaper_list; shaper_item; shaper_item++)
	if (false)
	;
	#define HB_SHAPER_IMPLEMENT(shaper) \
	else if (0 == strcmp (*shaper_item, #shaper) && \
	hb_##shaper##_shaper_face_data_ensure (face)) \
	{ \
	proposal.shaper_func = _hb_##shaper##_shape; \
	break; \
	}
	#include "hb-shaper-list.hh"
	#undef HB_SHAPER_IMPLEMENT

	if (unlikely (!proposal.shaper_func))
	return hb_shape_plan_get_empty ();
	}


	retry:
	hb_face_t::plan_node_t *cached_plan_nodes = face->shape_plans.get ();

	/* Don't look for plan in the cache if there were variation coordinates XXX Fix me. */
	if (!hb_coords_present (coords, num_coords))
	for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
	if (hb_shape_plan_matches (node->shape_plan, &proposal))
	{
	DEBUG_MSG_FUNC (SHAPE_PLAN, node->shape_plan, "fulfilled from cache");
	return hb_shape_plan_reference (node->shape_plan);
	}

	/* Not found. */
	hb_shape_plan_t *shape_plan = hb_shape_plan_create2 (face, props,
	user_features, num_user_features,
	coords, num_coords,
	shaper_list);

	/* Don't add to the cache if face is inert. */
	if (unlikely (hb_object_is_inert (face)))
	return shape_plan;

	/* Don't add the plan to the cache if there were user features with non-global ranges */
	if (hb_non_global_user_features_present (user_features, num_user_features))
	return shape_plan;
	/* Don't add the plan to the cache if there were variation coordinates XXX Fix me. */
	if (hb_coords_present (coords, num_coords))
	return shape_plan;

	hb_face_t::plan_node_t node = (hb_face_t::plan_node_t ) calloc (1, sizeof (hb_face_t::plan_node_t));
	if (unlikely (!node))
	return shape_plan;

	node->shape_plan = shape_plan;
	node->next = cached_plan_nodes;

	if (unlikely (!face->shape_plans.cmpexch (cached_plan_nodes, node)))
	{
	hb_shape_plan_destroy (shape_plan);
	free (node);
	goto retry;
	}
	DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan, "inserted into cache");

	return hb_shape_plan_reference (shape_plan);
	}

	/**
	* hb_shape_plan_get_shaper:
	* @shape_plan: a shape plan.
	*
	*
	*
	* Return value: (transfer none):
	*
	* Since: 0.9.7
	**/
	const char *
	hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
	{
	return shape_plan->shaper_name;
	}