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

 /*
  * Copyright © 2018  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): Garret Rieger, Roderick Sheeter
  */

 #include "hb-subset-private.hh"

 #include "hb-subset-plan.hh"
 #include "hb-ot-cmap-table.hh"
 #include "hb-ot-glyf-table.hh"

 static int
 _hb_codepoint_t_cmp (const void *pa, const void *pb)
 {
   hb_codepoint_t a = * (hb_codepoint_t *) pa;
   hb_codepoint_t b = * (hb_codepoint_t *) pb;

   return a < b ? -1 : a > b ? +1 : 0;
 }

 hb_bool_t
 hb_subset_plan_new_gid_for_codepoint (hb_subset_plan_t *plan,
                                       hb_codepoint_t codepoint,
                                       hb_codepoint_t *new_gid)
 {
   // TODO actual map, delete this garbage.
   for (unsigned int i = 0; i < plan->codepoints.len; i++)
   {
     if (plan->codepoints[i] != codepoint) continue;
     if (!hb_subset_plan_new_gid_for_old_id(plan, plan->gids_to_retain[i], new_gid))
     {
       return false;
     }
     return true;
   }
   return false;
 }

 hb_bool_t
 hb_subset_plan_new_gid_for_old_id (hb_subset_plan_t *plan,
                                    hb_codepoint_t old_gid,
                                    hb_codepoint_t *new_gid)
 {
   // the index in old_gids is the new gid; only up to codepoints.len are valid
   for (unsigned int i = 0; i < plan->gids_to_retain_sorted.len; i++)
   {
     if (plan->gids_to_retain_sorted[i] == old_gid)
     {
       *new_gid = i;
       return true;
     }
   }
   return false;
 }

 hb_bool_t
 hb_subset_plan_add_table (hb_subset_plan_t *plan,
                           hb_tag_t tag,
                           hb_blob_t *contents)
 {
   return hb_subset_face_add_table(plan->dest, tag, contents);
 }

 static void
 _populate_codepoints (hb_set_t *input_codepoints,
                       hb_prealloced_array_t<hb_codepoint_t>& plan_codepoints)
 {
   plan_codepoints.alloc (hb_set_get_population (input_codepoints));
   hb_codepoint_t cp = -1;
   while (hb_set_next (input_codepoints, &cp)) {
     hb_codepoint_t *wr = plan_codepoints.push();
     *wr = cp;
   }
   plan_codepoints.qsort (_hb_codepoint_t_cmp);
 }

 static void
 _add_gid_and_children (const OT::glyf::accelerator_t &glyf,
 		       hb_codepoint_t gid,
 		       hb_set_t *gids_to_retain)
 {
   if (hb_set_has (gids_to_retain, gid))
     // Already visited this gid, ignore.
     return;

   hb_set_add (gids_to_retain, gid);

   OT::glyf::CompositeGlyphHeader::Iterator composite;
   if (glyf.get_composite (gid, &composite))
   {
     do
     {
       _add_gid_and_children (glyf, (hb_codepoint_t) composite.current->glyphIndex, gids_to_retain);
     } while (composite.move_to_next());
   }
 }

 static void
 _populate_gids_to_retain (hb_face_t *face,
                           hb_prealloced_array_t<hb_codepoint_t>& codepoints,
                           hb_prealloced_array_t<hb_codepoint_t>& old_gids,
                           hb_prealloced_array_t<hb_codepoint_t>& old_gids_sorted)
 {
   OT::cmap::accelerator_t cmap;
   OT::glyf::accelerator_t glyf;
   cmap.init (face);
   glyf.init (face);

   hb_auto_array_t<unsigned int> bad_indices;

   old_gids.alloc (codepoints.len);
   for (unsigned int i = 0; i < codepoints.len; i++)
   {
     hb_codepoint_t gid;
     if (!cmap.get_nominal_glyph (codepoints[i], &gid))
     {
       gid = -1;
       *(bad_indices.push ()) = i;
     }
     *(old_gids.push ()) = gid;
   }

   /* Generally there shouldn't be any */
   while (bad_indices.len > 0)
   {
     unsigned int i = bad_indices[bad_indices.len - 1];
     bad_indices.pop ();
     DEBUG_MSG(SUBSET, nullptr, "Drop U+%04X; no gid", codepoints[i]);
     codepoints.remove (i);
     old_gids.remove (i);
   }

   // Populate a full set of glyphs to retain by adding all referenced
   // composite glyphs.
   // TODO expand with glyphs reached by G*
   hb_set_t * all_gids_to_retain = hb_set_create ();
   _add_gid_and_children (glyf, 0, all_gids_to_retain);
   for (unsigned int i = 0; i < old_gids.len; i++)
     _add_gid_and_children (glyf, old_gids[i], all_gids_to_retain);

   // Transfer to a sorted list.
   old_gids_sorted.alloc (hb_set_get_population (all_gids_to_retain));
   hb_codepoint_t gid = HB_SET_VALUE_INVALID;
   while (hb_set_next (all_gids_to_retain, &gid))
     *(old_gids_sorted.push ()) = gid;

   hb_set_destroy (all_gids_to_retain);
   glyf.fini ();
   cmap.fini ();
 }

 /**
  * hb_subset_plan_create:
  * Computes a plan for subsetting the supplied face according
  * to a provide profile and input. The plan describes
  * which tables and glyphs should be retained.
  *
  * Return value: New subset plan.
  *
  * Since: 1.7.5
  **/
 hb_subset_plan_t *
 hb_subset_plan_create (hb_face_t           *face,
                        hb_subset_profile_t *profile,
                        hb_subset_input_t   *input)
 {
   hb_subset_plan_t *plan = hb_object_create<hb_subset_plan_t> ();

   plan->codepoints.init();
   plan->gids_to_retain.init();
   plan->gids_to_retain_sorted.init();
   plan->source = hb_face_reference (face);
   plan->dest = hb_subset_face_create ();

   _populate_codepoints (input->unicodes, plan->codepoints);
   _populate_gids_to_retain (face,
                             plan->codepoints,
                             plan->gids_to_retain,
                             plan->gids_to_retain_sorted);

   return plan;
 }

 /**
  * hb_subset_plan_destroy:
  *
  * Since: 1.7.5
  **/
 void
 hb_subset_plan_destroy (hb_subset_plan_t *plan)
 {
   if (!hb_object_destroy (plan)) return;

   plan->codepoints.finish ();
   plan->gids_to_retain.finish ();
   plan->gids_to_retain_sorted.finish ();

   hb_face_destroy (plan->source);
   hb_face_destroy (plan->dest);

   free (plan);
 }
	/*
	* Copyright © 2018 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): Garret Rieger, Roderick Sheeter
	*/

	#include "hb-subset-private.hh"

	#include "hb-subset-plan.hh"
	#include "hb-ot-cmap-table.hh"
	#include "hb-ot-glyf-table.hh"

	static int
	_hb_codepoint_t_cmp (const void pa, const void pb)
	{
	hb_codepoint_t a = * (hb_codepoint_t *) pa;
	hb_codepoint_t b = * (hb_codepoint_t *) pb;

	return a < b ? -1 : a > b ? +1 : 0;
	}

	hb_bool_t
	hb_subset_plan_new_gid_for_codepoint (hb_subset_plan_t *plan,
	hb_codepoint_t codepoint,
	hb_codepoint_t *new_gid)
	{
	// TODO actual map, delete this garbage.
	for (unsigned int i = 0; i < plan->codepoints.len; i++)
	{
	if (plan->codepoints[i] != codepoint) continue;
	if (!hb_subset_plan_new_gid_for_old_id(plan, plan->gids_to_retain[i], new_gid))
	{
	return false;
	}
	return true;
	}
	return false;
	}

	hb_bool_t
	hb_subset_plan_new_gid_for_old_id (hb_subset_plan_t *plan,
	hb_codepoint_t old_gid,
	hb_codepoint_t *new_gid)
	{
	// the index in old_gids is the new gid; only up to codepoints.len are valid
	for (unsigned int i = 0; i < plan->gids_to_retain_sorted.len; i++)
	{
	if (plan->gids_to_retain_sorted[i] == old_gid)
	{
	*new_gid = i;
	return true;
	}
	}
	return false;
	}

	hb_bool_t
	hb_subset_plan_add_table (hb_subset_plan_t *plan,
	hb_tag_t tag,
	hb_blob_t *contents)
	{
	return hb_subset_face_add_table(plan->dest, tag, contents);
	}

	static void
	_populate_codepoints (hb_set_t *input_codepoints,
	hb_prealloced_array_t<hb_codepoint_t>& plan_codepoints)
	{
	plan_codepoints.alloc (hb_set_get_population (input_codepoints));
	hb_codepoint_t cp = -1;
	while (hb_set_next (input_codepoints, &cp)) {
	hb_codepoint_t *wr = plan_codepoints.push();
	*wr = cp;
	}
	plan_codepoints.qsort (_hb_codepoint_t_cmp);
	}

	static void
	_add_gid_and_children (const OT::glyf::accelerator_t &glyf,
	hb_codepoint_t gid,
	hb_set_t *gids_to_retain)
	{
	if (hb_set_has (gids_to_retain, gid))
	// Already visited this gid, ignore.
	return;

	hb_set_add (gids_to_retain, gid);

	OT::glyf::CompositeGlyphHeader::Iterator composite;
	if (glyf.get_composite (gid, &composite))
	{
	do
	{
	_add_gid_and_children (glyf, (hb_codepoint_t) composite.current->glyphIndex, gids_to_retain);
	} while (composite.move_to_next());
	}
	}

	static void
	_populate_gids_to_retain (hb_face_t *face,
	hb_prealloced_array_t<hb_codepoint_t>& codepoints,
	hb_prealloced_array_t<hb_codepoint_t>& old_gids,
	hb_prealloced_array_t<hb_codepoint_t>& old_gids_sorted)
	{
	OT::cmap::accelerator_t cmap;
	OT::glyf::accelerator_t glyf;
	cmap.init (face);
	glyf.init (face);

	hb_auto_array_t<unsigned int> bad_indices;

	old_gids.alloc (codepoints.len);
	for (unsigned int i = 0; i < codepoints.len; i++)
	{
	hb_codepoint_t gid;
	if (!cmap.get_nominal_glyph (codepoints[i], &gid))
	{
	gid = -1;
	*(bad_indices.push ()) = i;
	}
	*(old_gids.push ()) = gid;
	}

	/* Generally there shouldn't be any */
	while (bad_indices.len > 0)
	{
	unsigned int i = bad_indices[bad_indices.len - 1];
	bad_indices.pop ();
	DEBUG_MSG(SUBSET, nullptr, "Drop U+%04X; no gid", codepoints[i]);
	codepoints.remove (i);
	old_gids.remove (i);
	}

	// Populate a full set of glyphs to retain by adding all referenced
	// composite glyphs.
	// TODO expand with glyphs reached by G*
	hb_set_t * all_gids_to_retain = hb_set_create ();
	_add_gid_and_children (glyf, 0, all_gids_to_retain);
	for (unsigned int i = 0; i < old_gids.len; i++)
	_add_gid_and_children (glyf, old_gids[i], all_gids_to_retain);

	// Transfer to a sorted list.
	old_gids_sorted.alloc (hb_set_get_population (all_gids_to_retain));
	hb_codepoint_t gid = HB_SET_VALUE_INVALID;
	while (hb_set_next (all_gids_to_retain, &gid))
	*(old_gids_sorted.push ()) = gid;

	hb_set_destroy (all_gids_to_retain);
	glyf.fini ();
	cmap.fini ();
	}

	/**
	* hb_subset_plan_create:
	* Computes a plan for subsetting the supplied face according
	* to a provide profile and input. The plan describes
	* which tables and glyphs should be retained.
	*
	* Return value: New subset plan.
	*
	* Since: 1.7.5
	**/
	hb_subset_plan_t *
	hb_subset_plan_create (hb_face_t *face,
	hb_subset_profile_t *profile,
	hb_subset_input_t *input)
	{
	hb_subset_plan_t *plan = hb_object_create<hb_subset_plan_t> ();

	plan->codepoints.init();
	plan->gids_to_retain.init();
	plan->gids_to_retain_sorted.init();
	plan->source = hb_face_reference (face);
	plan->dest = hb_subset_face_create ();

	_populate_codepoints (input->unicodes, plan->codepoints);
	_populate_gids_to_retain (face,
	plan->codepoints,
	plan->gids_to_retain,
	plan->gids_to_retain_sorted);

	return plan;
	}

	/**
	* hb_subset_plan_destroy:
	*
	* Since: 1.7.5
	**/
	void
	hb_subset_plan_destroy (hb_subset_plan_t *plan)
	{
	if (!hb_object_destroy (plan)) return;

	plan->codepoints.finish ();
	plan->gids_to_retain.finish ();
	plan->gids_to_retain_sorted.finish ();

	hb_face_destroy (plan->source);
	hb_face_destroy (plan->dest);

	free (plan);
	}