harfbuzz/src/hb-subset-plan.cc

275 lines
7.6 KiB
C++

/*
* 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-plan.hh"
#include "hb-map.hh"
#include "hb-set.hh"
#include "hb-ot-cmap-table.hh"
#include "hb-ot-glyf-table.hh"
#include "hb-ot-cff1-table.hh"
#include "hb-ot-var-fvar-table.hh"
#include "hb-ot-stat-table.hh"
static inline 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());
}
}
#ifndef HB_NO_SUBSET_CFF
static inline void
_add_cff_seac_components (const OT::cff1::accelerator_t &cff,
hb_codepoint_t gid,
hb_set_t *gids_to_retain)
{
hb_codepoint_t base_gid, accent_gid;
if (cff.get_seac_components (gid, &base_gid, &accent_gid))
{
hb_set_add (gids_to_retain, base_gid);
hb_set_add (gids_to_retain, accent_gid);
}
}
#endif
#ifndef HB_NO_SUBSET_LAYOUT
static inline void
_gsub_closure (hb_face_t *face, hb_set_t *gids_to_retain)
{
hb_set_t lookup_indices;
hb_ot_layout_collect_lookups (face,
HB_OT_TAG_GSUB,
nullptr,
nullptr,
nullptr,
&lookup_indices);
hb_ot_layout_lookups_substitute_closure (face,
&lookup_indices,
gids_to_retain);
}
#endif
static inline void
_remove_invalid_gids (hb_set_t *glyphs,
unsigned int num_glyphs)
{
hb_codepoint_t gid = HB_SET_VALUE_INVALID;
while (glyphs->next (&gid))
{
if (gid >= num_glyphs)
glyphs->del (gid);
}
}
static void
_populate_gids_to_retain (hb_subset_plan_t* plan,
const hb_set_t *unicodes,
const hb_set_t *input_glyphs_to_retain,
bool close_over_gsub)
{
OT::cmap::accelerator_t cmap;
OT::glyf::accelerator_t glyf;
OT::cff1::accelerator_t cff;
cmap.init (plan->source);
glyf.init (plan->source);
cff.init (plan->source);
plan->_glyphset_gsub->add (0); // Not-def
hb_set_union (plan->_glyphset_gsub, input_glyphs_to_retain);
hb_codepoint_t cp = HB_SET_VALUE_INVALID;
while (unicodes->next (&cp))
{
hb_codepoint_t gid;
if (!cmap.get_nominal_glyph (cp, &gid))
{
DEBUG_MSG(SUBSET, nullptr, "Drop U+%04X; no gid", cp);
continue;
}
plan->unicodes->add (cp);
plan->codepoint_to_glyph->set (cp, gid);
plan->_glyphset_gsub->add (gid);
}
#ifndef HB_NO_SUBSET_LAYOUT
if (close_over_gsub)
// Add all glyphs needed for GSUB substitutions.
_gsub_closure (plan->source, plan->_glyphset_gsub);
#endif
_remove_invalid_gids (plan->_glyphset_gsub, plan->source->get_num_glyphs ());
// Populate a full set of glyphs to retain by adding all referenced
// composite glyphs.
hb_codepoint_t gid = HB_SET_VALUE_INVALID;
while (plan->_glyphset_gsub->next (&gid))
{
_add_gid_and_children (glyf, gid, plan->_glyphset);
#ifndef HB_NO_SUBSET_CFF
if (cff.is_valid ())
_add_cff_seac_components (cff, gid, plan->_glyphset);
#endif
}
_remove_invalid_gids (plan->_glyphset, plan->source->get_num_glyphs ());
cff.fini ();
glyf.fini ();
cmap.fini ();
}
static void
_create_old_gid_to_new_gid_map (const hb_face_t *face,
bool retain_gids,
const hb_set_t *all_gids_to_retain,
hb_map_t *glyph_map, /* OUT */
hb_map_t *reverse_glyph_map, /* OUT */
unsigned int *num_glyphs /* OUT */)
{
if (!retain_gids)
{
+ hb_enumerate (hb_iter (all_gids_to_retain), (hb_codepoint_t) 0)
| hb_sink (reverse_glyph_map)
;
*num_glyphs = reverse_glyph_map->get_population ();
} else {
+ hb_iter (all_gids_to_retain)
| hb_map ([] (hb_codepoint_t _) {
return hb_pair_t<hb_codepoint_t, hb_codepoint_t> (_, _);
})
| hb_sink (reverse_glyph_map)
;
unsigned max_glyph =
+ hb_iter (all_gids_to_retain)
| hb_reduce (hb_max, 0)
;
*num_glyphs = max_glyph + 1;
}
+ reverse_glyph_map->iter ()
| hb_map (&hb_pair_t<hb_codepoint_t, hb_codepoint_t>::reverse)
| hb_sink (glyph_map)
;
}
static void
_nameid_closure (hb_face_t *face,
hb_set_t *nameids)
{
#ifndef HB_NO_STAT
face->table.STAT->collect_name_ids (nameids);
#endif
#ifndef HB_NO_VAR
face->table.fvar->collect_name_ids (nameids);
#endif
}
/**
* hb_subset_plan_create:
* Computes a plan for subsetting the supplied face according
* to a provided 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_input_t *input)
{
hb_subset_plan_t *plan = hb_object_create<hb_subset_plan_t> ();
plan->drop_hints = input->drop_hints;
plan->desubroutinize = input->desubroutinize;
plan->retain_gids = input->retain_gids;
plan->unicodes = hb_set_create ();
plan->name_ids = hb_set_reference (input->name_ids);
_nameid_closure (face, plan->name_ids);
plan->drop_tables = hb_set_reference (input->drop_tables);
plan->source = hb_face_reference (face);
plan->dest = hb_face_builder_create ();
plan->_glyphset = hb_set_create ();
plan->_glyphset_gsub = hb_set_create ();
plan->codepoint_to_glyph = hb_map_create ();
plan->glyph_map = hb_map_create ();
plan->reverse_glyph_map = hb_map_create ();
_populate_gids_to_retain (plan,
input->unicodes,
input->glyphs,
!input->drop_tables->has (HB_OT_TAG_GSUB));
_create_old_gid_to_new_gid_map (face,
input->retain_gids,
plan->_glyphset,
plan->glyph_map,
plan->reverse_glyph_map,
&plan->_num_output_glyphs);
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;
hb_set_destroy (plan->unicodes);
hb_set_destroy (plan->name_ids);
hb_set_destroy (plan->drop_tables);
hb_face_destroy (plan->source);
hb_face_destroy (plan->dest);
hb_map_destroy (plan->codepoint_to_glyph);
hb_map_destroy (plan->glyph_map);
hb_map_destroy (plan->reverse_glyph_map);
hb_set_destroy (plan->_glyphset);
hb_set_destroy (plan->_glyphset_gsub);
free (plan);
}