tor-browser

hb-shape-plan.cc (16466B)

---

/*
* 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"


#ifndef HB_NO_SHAPER

/**
* SECTION:hb-shape-plan
* @title: hb-shape-plan
* @short_description: Object representing a shaping plan
* @include: hb.h
*
* Shape plans are an internal mechanism. Each plan contains state
* describing how HarfBuzz will shape a particular text segment, based on
* the combination of segment properties and the capabilities in the
* font face in use.
*
* Shape plans are not used for shaping directly, but can be queried to
* access certain information about how shaping will perform, given a set
* of specific input parameters (script, language, direction, features,
* etc.).
*
* Most client programs will not need to deal with shape plans directly.
**/


/*
* hb_shape_plan_key_t
*/

bool
hb_shape_plan_key_t::init (bool                           copy,
		   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)
{
 hb_feature_t *features = nullptr;
 if (copy && num_user_features && !(features = (hb_feature_t *) hb_calloc (num_user_features, sizeof (hb_feature_t))))
   goto bail;

 this->props = *props;
 this->num_user_features = num_user_features;
 this->user_features = copy ? features : user_features;
 if (copy && num_user_features)
 {
   hb_memcpy (features, user_features, num_user_features * sizeof (hb_feature_t));
   /* Make start/end uniform to easier catch bugs. */
   for (unsigned int i = 0; i < num_user_features; i++)
   {
     if (features[0].start != HB_FEATURE_GLOBAL_START)
features[0].start = 1;
     if (features[0].end   != HB_FEATURE_GLOBAL_END)
features[0].end   = 2;
   }
 }
 this->shaper_func = nullptr;
 this->shaper_name = nullptr;
#ifndef HB_NO_OT_SHAPE
 this->ot.init (face, coords, num_coords);
#endif

 /*
  * Choose shaper.
  */

#define HB_SHAPER_PLAN(shaper) \
HB_STMT_START { \
  if (face->data.shaper) \
  { \
    this->shaper_func = _hb_##shaper##_shape; \
    this->shaper_name = #shaper; \
    return true; \
  } \
} HB_STMT_END

 if (unlikely (shaper_list))
 {
   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
 }
 else
 {
   const HB_UNUSED hb_shaper_entry_t *shapers = _hb_shapers_get ();
   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
 }
#undef HB_SHAPER_PLAN

bail:
 ::hb_free (features);
 return false;
}

bool
hb_shape_plan_key_t::user_features_match (const hb_shape_plan_key_t *other)
{
 if (this->num_user_features != other->num_user_features)
   return false;
 for (unsigned int i = 0; i < num_user_features; i++)
 {
   if (this->user_features[i].tag   != other->user_features[i].tag   ||
this->user_features[i].value != other->user_features[i].value ||
(this->user_features[i].start == HB_FEATURE_GLOBAL_START &&
 this->user_features[i].end   == HB_FEATURE_GLOBAL_END) !=
(other->user_features[i].start == HB_FEATURE_GLOBAL_START &&
 other->user_features[i].end   == HB_FEATURE_GLOBAL_END))
     return false;
 }
 return true;
}

bool
hb_shape_plan_key_t::equal (const hb_shape_plan_key_t *other)
{
 return hb_segment_properties_equal (&this->props, &other->props) &&
 this->user_features_match (other) &&
#ifndef HB_NO_OT_SHAPE
 this->ot.equal (&other->ot) &&
#endif
 this->shaper_func == other->shaper_func;
}


/*
* hb_shape_plan_t
*/


/**
* hb_shape_plan_create:
* @face: #hb_face_t to use
* @props: The #hb_segment_properties_t of the segment
* @user_features: (array length=num_user_features): The list of user-selected features
* @num_user_features: The number of user-selected features
* @shaper_list: (array zero-terminated=1): List of shapers to try
*
* Constructs a shaping plan for a combination of @face, @user_features, @props,
* and @shaper_list.
*
* Return value: (transfer full): The shaping plan
*
* 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_create2:
* @face: #hb_face_t to use
* @props: The #hb_segment_properties_t of the segment
* @user_features: (array length=num_user_features): The list of user-selected features
* @num_user_features: The number of user-selected features
* @coords: (array length=num_coords): The list of variation-space coordinates
* @num_coords: The number of variation-space coordinates
* @shaper_list: (array zero-terminated=1): List of shapers to try
*
* The variable-font version of #hb_shape_plan_create.
* Constructs a shaping plan for a combination of @face, @user_features, @props,
* and @shaper_list, plus the variation-space coordinates @coords.
*
* Return value: (transfer full): The shaping plan
*
* Since: 1.4.0
**/
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                     *coords,
	       unsigned int                   num_coords,
	       const char * const            *shaper_list)
{
 DEBUG_MSG_FUNC (SHAPE_PLAN, nullptr,
	  "face=%p num_features=%u num_coords=%u shaper_list=%p",
	  face,
	  num_user_features,
	  num_coords,
	  shaper_list);

 if (unlikely (!HB_DIRECTION_IS_VALID (props->direction)))
   return hb_shape_plan_get_empty ();

 hb_shape_plan_t *shape_plan;

 if (unlikely (!props))
   goto bail;
 if (!(shape_plan = hb_object_create<hb_shape_plan_t> ()))
   goto bail;

 if (unlikely (!face))
   face = hb_face_get_empty ();
 hb_face_make_immutable (face);
 shape_plan->face_unsafe = face;

 if (unlikely (!shape_plan->key.init (true,
			       face,
			       props,
			       user_features,
			       num_user_features,
			       coords,
			       num_coords,
			       shaper_list)))
   goto bail2;
#ifndef HB_NO_OT_SHAPE
 if (unlikely (!shape_plan->ot.init0 (face, &shape_plan->key)))
   goto bail3;
#endif

 return shape_plan;

#ifndef HB_NO_OT_SHAPE
bail3:
#endif
 shape_plan->key.fini ();
bail2:
 hb_free (shape_plan);
bail:
 return hb_shape_plan_get_empty ();
}

/**
* hb_shape_plan_get_empty:
*
* Fetches the singleton empty shaping plan.
*
* Return value: (transfer full): The empty shaping plan
*
* Since: 0.9.7
**/
hb_shape_plan_t *
hb_shape_plan_get_empty ()
{
 return const_cast<hb_shape_plan_t *> (&Null (hb_shape_plan_t));
}

/**
* hb_shape_plan_reference: (skip)
* @shape_plan: A shaping plan
*
* Increases the reference count on the given shaping plan.
*
* Return value: (transfer full): @shape_plan
*
* 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 shaping plan
*
* Decreases the reference count on the given shaping plan. When the
* reference count reaches zero, the shaping plan is destroyed,
* freeing all memory.
*
* Since: 0.9.7
**/
void
hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
{
 if (!hb_object_destroy (shape_plan)) return;

 hb_free (shape_plan);
}

/**
* hb_shape_plan_set_user_data: (skip)
* @shape_plan: A shaping plan
* @key: The user-data key to set
* @data: A pointer to the user data
* @destroy: (nullable): A callback to call when @data is not needed anymore
* @replace: Whether to replace an existing data with the same key
*
* Attaches a user-data key/data pair to the given shaping plan.
*
* Return value: `true` if success, `false` otherwise.
*
* 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 shaping plan
* @key: The user-data key to query
*
* Fetches the user data associated with the specified key,
* attached to the specified shaping plan.
*
* Return value: (transfer none): A pointer to the user data
*
* Since: 0.9.7
**/
void *
hb_shape_plan_get_user_data (const hb_shape_plan_t *shape_plan,
		     hb_user_data_key_t    *key)
{
 return hb_object_get_user_data (shape_plan, key);
}

/**
* hb_shape_plan_get_shaper:
* @shape_plan: A shaping plan
*
* Fetches the shaper from a given shaping plan.
*
* Return value: (transfer none): The shaper
*
* Since: 0.9.7
**/
const char *
hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
{
 return shape_plan->key.shaper_name;
}


static bool
_hb_shape_plan_execute_internal (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=%u shaper_func=%p, shaper_name=%s",
	  num_features,
	  shape_plan->key.shaper_func,
	  shape_plan->key.shaper_name);

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

 assert (!hb_object_is_immutable (buffer));

 buffer->assert_unicode ();

 if (unlikely (!hb_object_is_valid (shape_plan)))
   return false;

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

#define HB_SHAPER_EXECUTE(shaper) \
HB_STMT_START { \
  return font->data.shaper && \
	 _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
} HB_STMT_END

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

#undef HB_SHAPER_EXECUTE

 return false;
}
/**
* hb_shape_plan_execute:
* @shape_plan: A shaping plan
* @font: The #hb_font_t to use
* @buffer: The #hb_buffer_t to work upon
* @features: (array length=num_features): Features to enable
* @num_features: The number of features to enable
*
* Executes the given shaping plan on the specified buffer, using
* the given @font and @features.
*
* Return value: `true` if success, `false` otherwise.
*
* 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)
{
 bool ret = _hb_shape_plan_execute_internal (shape_plan, font, buffer,
				      features, num_features);

 if (ret && buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE)
   buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;

 return ret;
}


/*
* Caching
*/

/**
* hb_shape_plan_create_cached:
* @face: #hb_face_t to use
* @props: The #hb_segment_properties_t of the segment
* @user_features: (array length=num_user_features): The list of user-selected features
* @num_user_features: The number of user-selected features
* @shaper_list: (array zero-terminated=1): List of shapers to try
*
* Creates a cached shaping plan suitable for reuse, for a combination
* of @face, @user_features, @props, and @shaper_list.
*
* Return value: (transfer full): The shaping plan
*
* 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_create_cached2:
* @face: #hb_face_t to use
* @props: The #hb_segment_properties_t of the segment
* @user_features: (array length=num_user_features): The list of user-selected features
* @num_user_features: The number of user-selected features
* @coords: (array length=num_coords): The list of variation-space coordinates
* @num_coords: The number of variation-space coordinates
* @shaper_list: (array zero-terminated=1): List of shapers to try
*
* The variable-font version of #hb_shape_plan_create_cached.
* Creates a cached shaping plan suitable for reuse, for a combination
* of @face, @user_features, @props, and @shaper_list, plus the
* variation-space coordinates @coords.
*
* Return value: (transfer full): The shaping plan
*
* Since: 1.4.0
**/
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=%u shaper_list=%p",
	  face,
	  num_user_features,
	  shaper_list);

retry:
 hb_face_t::plan_node_t *cached_plan_nodes = face->shape_plans;

 bool dont_cache = !hb_object_is_valid (face);

 if (likely (!dont_cache))
 {
   hb_shape_plan_key_t key;
   if (!key.init (false,
	   face,
	   props,
	   user_features,
	   num_user_features,
	   coords,
	   num_coords,
	   shaper_list))
     return hb_shape_plan_get_empty ();

   for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
     if (node->shape_plan->key.equal (&key))
     {
DEBUG_MSG_FUNC (SHAPE_PLAN, node->shape_plan, "fulfilled from cache");
return hb_shape_plan_reference (node->shape_plan);
     }
 }

 hb_shape_plan_t *shape_plan = hb_shape_plan_create2 (face, props,
					       user_features, num_user_features,
					       coords, num_coords,
					       shaper_list);

 if (unlikely (dont_cache))
   return shape_plan;

 hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) hb_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);
   hb_free (node);
   goto retry;
 }
 DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan, "inserted into cache");

 return hb_shape_plan_reference (shape_plan);
}


#endif