/gfx/harfbuzz/src/hb-ot-layout-gsub-table.hh
C++ Header | 1398 lines | 1042 code | 238 blank | 118 comment | 164 complexity | aff6aee4802095f0befff2866500f960 MD5 | raw file
Possible License(s): JSON, Apache-2.0, 0BSD, LGPL-3.0, BSD-2-Clause, AGPL-1.0, MPL-2.0, GPL-2.0, LGPL-2.1, MIT, MPL-2.0-no-copyleft-exception, BSD-3-Clause
- /*
- * Copyright © 2007,2008,2009,2010 Red Hat, Inc.
- * Copyright © 2010,2012 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.
- *
- * Red Hat Author(s): Behdad Esfahbod
- * Google Author(s): Behdad Esfahbod
- */
- #ifndef HB_OT_LAYOUT_GSUB_TABLE_HH
- #define HB_OT_LAYOUT_GSUB_TABLE_HH
- #include "hb-ot-layout-gsubgpos-private.hh"
- struct SingleSubstFormat1
- {
- friend struct SingleSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- hb_codepoint_t glyph_id = iter.get_glyph ();
- if (c->glyphs->has (glyph_id))
- c->glyphs->add ((glyph_id + deltaGlyphID) & 0xFFFF);
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
- unsigned int index = (this+coverage) (glyph_id);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- /* According to the Adobe Annotated OpenType Suite, result is always
- * limited to 16bit. */
- glyph_id = (glyph_id + deltaGlyphID) & 0xFFFF;
- c->replace_glyph (glyph_id);
- return TRACE_RETURN (true);
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
- }
- protected:
- USHORT format; /* Format identifier--format = 1 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of Substitution table */
- SHORT deltaGlyphID; /* Add to original GlyphID to get
- * substitute GlyphID */
- public:
- DEFINE_SIZE_STATIC (6);
- };
- struct SingleSubstFormat2
- {
- friend struct SingleSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- if (c->glyphs->has (iter.get_glyph ()))
- c->glyphs->add (substitute[iter.get_coverage ()]);
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
- unsigned int index = (this+coverage) (glyph_id);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- if (unlikely (index >= substitute.len)) return TRACE_RETURN (false);
- glyph_id = substitute[index];
- c->replace_glyph (glyph_id);
- return TRACE_RETURN (true);
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (coverage.sanitize (c, this) && substitute.sanitize (c));
- }
- protected:
- USHORT format; /* Format identifier--format = 2 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of Substitution table */
- ArrayOf<GlyphID>
- substitute; /* Array of substitute
- * GlyphIDs--ordered by Coverage Index */
- public:
- DEFINE_SIZE_ARRAY (6, substitute);
- };
- struct SingleSubst
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- switch (u.format) {
- case 1: u.format1.closure (c); break;
- case 2: u.format2.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- switch (u.format) {
- case 1: return u.format1.get_coverage ();
- case 2: return u.format2.get_coverage ();
- default:return Null(Coverage);
- }
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.apply (c));
- case 2: return TRACE_RETURN (u.format2.apply (c));
- default:return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!u.format.sanitize (c)) return TRACE_RETURN (false);
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.sanitize (c));
- case 2: return TRACE_RETURN (u.format2.sanitize (c));
- default:return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- USHORT format; /* Format identifier */
- SingleSubstFormat1 format1;
- SingleSubstFormat2 format2;
- } u;
- };
- struct Sequence
- {
- friend struct MultipleSubstFormat1;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- unsigned int count = substitute.len;
- for (unsigned int i = 0; i < count; i++)
- c->glyphs->add (substitute[i]);
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- if (unlikely (!substitute.len)) return TRACE_RETURN (false);
- unsigned int klass = c->property & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE ? HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH : 0;
- unsigned int count = substitute.len;
- for (unsigned int i = 0; i < count; i++) {
- set_lig_props_for_component (c->buffer->cur(), i);
- c->output_glyph (substitute.array[i], klass);
- }
- c->buffer->skip_glyph ();
- return TRACE_RETURN (true);
- }
- public:
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (substitute.sanitize (c));
- }
- protected:
- ArrayOf<GlyphID>
- substitute; /* String of GlyphIDs to substitute */
- public:
- DEFINE_SIZE_ARRAY (2, substitute);
- };
- struct MultipleSubstFormat1
- {
- friend struct MultipleSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- if (c->glyphs->has (iter.get_glyph ()))
- (this+sequence[iter.get_coverage ()]).closure (c);
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- unsigned int index = (this+coverage) (c->buffer->cur().codepoint);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- return TRACE_RETURN ((this+sequence[index]).apply (c));
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (coverage.sanitize (c, this) && sequence.sanitize (c, this));
- }
- protected:
- USHORT format; /* Format identifier--format = 1 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of Substitution table */
- OffsetArrayOf<Sequence>
- sequence; /* Array of Sequence tables
- * ordered by Coverage Index */
- public:
- DEFINE_SIZE_ARRAY (6, sequence);
- };
- struct MultipleSubst
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- switch (u.format) {
- case 1: u.format1.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- switch (u.format) {
- case 1: return u.format1.get_coverage ();
- default:return Null(Coverage);
- }
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.apply (c));
- default:return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!u.format.sanitize (c)) return TRACE_RETURN (false);
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.sanitize (c));
- default:return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- USHORT format; /* Format identifier */
- MultipleSubstFormat1 format1;
- } u;
- };
- typedef ArrayOf<GlyphID> AlternateSet; /* Array of alternate GlyphIDs--in
- * arbitrary order */
- struct AlternateSubstFormat1
- {
- friend struct AlternateSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- if (c->glyphs->has (iter.get_glyph ())) {
- const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
- unsigned int count = alt_set.len;
- for (unsigned int i = 0; i < count; i++)
- c->glyphs->add (alt_set[i]);
- }
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
- unsigned int index = (this+coverage) (glyph_id);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- const AlternateSet &alt_set = this+alternateSet[index];
- if (unlikely (!alt_set.len)) return TRACE_RETURN (false);
- hb_mask_t glyph_mask = c->buffer->cur().mask;
- hb_mask_t lookup_mask = c->lookup_mask;
- /* Note: This breaks badly if two features enabled this lookup together. */
- unsigned int shift = _hb_ctz (lookup_mask);
- unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
- if (unlikely (alt_index > alt_set.len || alt_index == 0)) return TRACE_RETURN (false);
- glyph_id = alt_set[alt_index - 1];
- c->replace_glyph (glyph_id);
- return TRACE_RETURN (true);
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (coverage.sanitize (c, this) && alternateSet.sanitize (c, this));
- }
- protected:
- USHORT format; /* Format identifier--format = 1 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of Substitution table */
- OffsetArrayOf<AlternateSet>
- alternateSet; /* Array of AlternateSet tables
- * ordered by Coverage Index */
- public:
- DEFINE_SIZE_ARRAY (6, alternateSet);
- };
- struct AlternateSubst
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- switch (u.format) {
- case 1: u.format1.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- switch (u.format) {
- case 1: return u.format1.get_coverage ();
- default:return Null(Coverage);
- }
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.apply (c));
- default:return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!u.format.sanitize (c)) return TRACE_RETURN (false);
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.sanitize (c));
- default:return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- USHORT format; /* Format identifier */
- AlternateSubstFormat1 format1;
- } u;
- };
- struct Ligature
- {
- friend struct LigatureSet;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- unsigned int count = component.len;
- for (unsigned int i = 1; i < count; i++)
- if (!c->glyphs->has (component[i]))
- return;
- c->glyphs->add (ligGlyph);
- }
- inline bool would_apply (hb_would_apply_context_t *c) const
- {
- return c->len == 1 || (c->len == 2 && component.len == 2 && component[1] == c->second);
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- unsigned int count = component.len;
- if (unlikely (count < 1)) return TRACE_RETURN (false);
- hb_apply_context_t::mark_skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1);
- if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
- /*
- * This is perhaps the trickiest part of GSUB... Remarks:
- *
- * - If all components of the ligature were marks, we call this a mark ligature.
- *
- * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
- * it as a ligature glyph. Though, really, this will not really be used...
- *
- * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
- * the ligature to keep its old ligature id. This will allow it to attach to
- * a base ligature in GPOS. Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
- * and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
- * ligature id and component value of 2. Then if SHADDA,FATHA form a ligature
- * later, we don't want them to lose their ligature id/component, otherwise
- * GPOS will fail to correctly position the mark ligature on top of the
- * LAM,LAM,HEH ligature. See:
- * https://bugzilla.gnome.org/show_bug.cgi?id=676343
- *
- * - If a ligature is formed of components that some of which are also ligatures
- * themselves, and those ligature components had marks attached to *their*
- * components, we have to attach the marks to the new ligature component
- * positions! Now *that*'s tricky! And these marks may be following the
- * last component of the whole sequence, so we should loop forward looking
- * for them and update them.
- *
- * Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
- * 'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
- * id and component == 1. Now, during 'liga', the LAM and the LAM-HEH ligature
- * form a LAM-LAM-HEH ligature. We need to reassign the SHADDA and FATHA to
- * the new ligature with a component value of 2.
- *
- * This in fact happened to a font... See:
- * https://bugzilla.gnome.org/show_bug.cgi?id=437633
- *
- * - Ligatures cannot be formed across glyphs attached to different components
- * of previous ligatures. Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
- * LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
- * However, it would be wrong to ligate that SHADDA,FATHA sequence.o
- * There is an exception to this: If a ligature tries ligating with marks that
- * belong to it itself, go ahead, assuming that the font designer knows what
- * they are doing (otherwise it can break Indic stuff when a matra wants to
- * ligate with a conjunct...)
- */
- bool is_mark_ligature = !!(c->property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
- unsigned int total_component_count = 0;
- total_component_count += get_lig_num_comps (c->buffer->cur());
- unsigned int first_lig_id = get_lig_id (c->buffer->cur());
- unsigned int first_lig_comp = get_lig_comp (c->buffer->cur());
- for (unsigned int i = 1; i < count; i++)
- {
- unsigned int property;
- if (!skippy_iter.next (&property)) return TRACE_RETURN (false);
- if (likely (c->buffer->info[skippy_iter.idx].codepoint != component[i])) return TRACE_RETURN (false);
- unsigned int this_lig_id = get_lig_id (c->buffer->info[skippy_iter.idx]);
- unsigned int this_lig_comp = get_lig_comp (c->buffer->info[skippy_iter.idx]);
- if (first_lig_id && first_lig_comp) {
- /* If first component was attached to a previous ligature component,
- * all subsequent components should be attached to the same ligature
- * component, otherwise we shouldn't ligate them. */
- if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
- return TRACE_RETURN (false);
- } else {
- /* If first component was NOT attached to a previous ligature component,
- * all subsequent components should also NOT be attached to any ligature
- * component, unless they are attached to the first component itself! */
- if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
- return TRACE_RETURN (false);
- }
- is_mark_ligature = is_mark_ligature && (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
- total_component_count += get_lig_num_comps (c->buffer->info[skippy_iter.idx]);
- }
- /* Deal, we are forming the ligature. */
- c->buffer->merge_clusters (c->buffer->idx, skippy_iter.idx + 1);
- unsigned int klass = is_mark_ligature ? 0 : HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
- unsigned int lig_id = is_mark_ligature ? 0 : allocate_lig_id (c->buffer);
- unsigned int last_lig_id = get_lig_id (c->buffer->cur());
- unsigned int last_num_components = get_lig_num_comps (c->buffer->cur());
- unsigned int components_so_far = last_num_components;
- if (!is_mark_ligature)
- set_lig_props_for_ligature (c->buffer->cur(), lig_id, total_component_count);
- c->replace_glyph (ligGlyph, klass);
- for (unsigned int i = 1; i < count; i++)
- {
- while (c->should_mark_skip_current_glyph ())
- {
- if (!is_mark_ligature) {
- unsigned int new_lig_comp = components_so_far - last_num_components +
- MIN (MAX (get_lig_comp (c->buffer->cur()), 1u), last_num_components);
- set_lig_props_for_mark (c->buffer->cur(), lig_id, new_lig_comp);
- }
- c->buffer->next_glyph ();
- }
- last_lig_id = get_lig_id (c->buffer->cur());
- last_num_components = get_lig_num_comps (c->buffer->cur());
- components_so_far += last_num_components;
- /* Skip the base glyph */
- c->buffer->idx++;
- }
- if (!is_mark_ligature && last_lig_id) {
- /* Re-adjust components for any marks following. */
- for (unsigned int i = c->buffer->idx; i < c->buffer->len; i++) {
- if (last_lig_id == get_lig_id (c->buffer->info[i])) {
- unsigned int new_lig_comp = components_so_far - last_num_components +
- MIN (MAX (get_lig_comp (c->buffer->info[i]), 1u), last_num_components);
- set_lig_props_for_mark (c->buffer->info[i], lig_id, new_lig_comp);
- } else
- break;
- }
- }
- return TRACE_RETURN (true);
- }
- public:
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (ligGlyph.sanitize (c) && component.sanitize (c));
- }
- protected:
- GlyphID ligGlyph; /* GlyphID of ligature to substitute */
- HeadlessArrayOf<GlyphID>
- component; /* Array of component GlyphIDs--start
- * with the second component--ordered
- * in writing direction */
- public:
- DEFINE_SIZE_ARRAY (4, component);
- };
- struct LigatureSet
- {
- friend struct LigatureSubstFormat1;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- unsigned int num_ligs = ligature.len;
- for (unsigned int i = 0; i < num_ligs; i++)
- (this+ligature[i]).closure (c);
- }
- inline bool would_apply (hb_would_apply_context_t *c) const
- {
- unsigned int num_ligs = ligature.len;
- for (unsigned int i = 0; i < num_ligs; i++)
- {
- const Ligature &lig = this+ligature[i];
- if (lig.would_apply (c))
- return true;
- }
- return false;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- unsigned int num_ligs = ligature.len;
- for (unsigned int i = 0; i < num_ligs; i++)
- {
- const Ligature &lig = this+ligature[i];
- if (lig.apply (c)) return TRACE_RETURN (true);
- }
- return TRACE_RETURN (false);
- }
- public:
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (ligature.sanitize (c, this));
- }
- protected:
- OffsetArrayOf<Ligature>
- ligature; /* Array LigatureSet tables
- * ordered by preference */
- public:
- DEFINE_SIZE_ARRAY (2, ligature);
- };
- struct LigatureSubstFormat1
- {
- friend struct LigatureSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- if (c->glyphs->has (iter.get_glyph ()))
- (this+ligatureSet[iter.get_coverage ()]).closure (c);
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool would_apply (hb_would_apply_context_t *c) const
- {
- return (this+ligatureSet[(this+coverage) (c->first)]).would_apply (c);
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
- unsigned int index = (this+coverage) (glyph_id);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- const LigatureSet &lig_set = this+ligatureSet[index];
- return TRACE_RETURN (lig_set.apply (c));
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- return TRACE_RETURN (coverage.sanitize (c, this) && ligatureSet.sanitize (c, this));
- }
- protected:
- USHORT format; /* Format identifier--format = 1 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of Substitution table */
- OffsetArrayOf<LigatureSet>
- ligatureSet; /* Array LigatureSet tables
- * ordered by Coverage Index */
- public:
- DEFINE_SIZE_ARRAY (6, ligatureSet);
- };
- struct LigatureSubst
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- switch (u.format) {
- case 1: u.format1.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- switch (u.format) {
- case 1: return u.format1.get_coverage ();
- default:return Null(Coverage);
- }
- }
- inline bool would_apply (hb_would_apply_context_t *c) const
- {
- switch (u.format) {
- case 1: return u.format1.would_apply (c);
- default:return false;
- }
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.apply (c));
- default:return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!u.format.sanitize (c)) return TRACE_RETURN (false);
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.sanitize (c));
- default:return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- USHORT format; /* Format identifier */
- LigatureSubstFormat1 format1;
- } u;
- };
- static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index);
- static inline void closure_lookup (hb_closure_context_t *c, unsigned int lookup_index);
- struct ContextSubst : Context
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- return Context::closure (c, closure_lookup);
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- return TRACE_RETURN (Context::apply (c, substitute_lookup));
- }
- };
- struct ChainContextSubst : ChainContext
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- return ChainContext::closure (c, closure_lookup);
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- return TRACE_RETURN (ChainContext::apply (c, substitute_lookup));
- }
- };
- struct ExtensionSubst : Extension
- {
- friend struct SubstLookupSubTable;
- friend struct SubstLookup;
- private:
- inline const struct SubstLookupSubTable& get_subtable (void) const
- {
- unsigned int offset = get_offset ();
- if (unlikely (!offset)) return Null(SubstLookupSubTable);
- return StructAtOffset<SubstLookupSubTable> (this, offset);
- }
- inline void closure (hb_closure_context_t *c) const;
- inline const Coverage &get_coverage (void) const;
- inline bool would_apply (hb_would_apply_context_t *c) const;
- inline bool apply (hb_apply_context_t *c) const;
- inline bool sanitize (hb_sanitize_context_t *c);
- inline bool is_reverse (void) const;
- };
- struct ReverseChainSingleSubstFormat1
- {
- friend struct ReverseChainSingleSubst;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
- unsigned int count;
- count = backtrack.len;
- for (unsigned int i = 0; i < count; i++)
- if (!(this+backtrack[i]).intersects (c->glyphs))
- return;
- count = lookahead.len;
- for (unsigned int i = 0; i < count; i++)
- if (!(this+lookahead[i]).intersects (c->glyphs))
- return;
- const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
- Coverage::Iter iter;
- for (iter.init (this+coverage); iter.more (); iter.next ()) {
- if (c->glyphs->has (iter.get_glyph ()))
- c->glyphs->add (substitute[iter.get_coverage ()]);
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- return this+coverage;
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- if (unlikely (c->nesting_level_left != MAX_NESTING_LEVEL))
- return TRACE_RETURN (false); /* No chaining to this type */
- unsigned int index = (this+coverage) (c->buffer->cur().codepoint);
- if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
- const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
- const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
- if (match_backtrack (c,
- backtrack.len, (USHORT *) backtrack.array,
- match_coverage, this) &&
- match_lookahead (c,
- lookahead.len, (USHORT *) lookahead.array,
- match_coverage, this,
- 1))
- {
- c->replace_glyph_inplace (substitute[index]);
- c->buffer->idx--; /* Reverse! */
- return TRACE_RETURN (true);
- }
- return TRACE_RETURN (false);
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
- return TRACE_RETURN (false);
- OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
- if (!lookahead.sanitize (c, this))
- return TRACE_RETURN (false);
- ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
- return TRACE_RETURN (substitute.sanitize (c));
- }
- protected:
- USHORT format; /* Format identifier--format = 1 */
- OffsetTo<Coverage>
- coverage; /* Offset to Coverage table--from
- * beginning of table */
- OffsetArrayOf<Coverage>
- backtrack; /* Array of coverage tables
- * in backtracking sequence, in glyph
- * sequence order */
- OffsetArrayOf<Coverage>
- lookaheadX; /* Array of coverage tables
- * in lookahead sequence, in glyph
- * sequence order */
- ArrayOf<GlyphID>
- substituteX; /* Array of substitute
- * GlyphIDs--ordered by Coverage Index */
- public:
- DEFINE_SIZE_MIN (10);
- };
- struct ReverseChainSingleSubst
- {
- friend struct SubstLookupSubTable;
- private:
- inline void closure (hb_closure_context_t *c) const
- {
- TRACE_CLOSURE ();
- switch (u.format) {
- case 1: u.format1.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (void) const
- {
- switch (u.format) {
- case 1: return u.format1.get_coverage ();
- default:return Null(Coverage);
- }
- }
- inline bool apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.apply (c));
- default:return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (!u.format.sanitize (c)) return TRACE_RETURN (false);
- switch (u.format) {
- case 1: return TRACE_RETURN (u.format1.sanitize (c));
- default:return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- USHORT format; /* Format identifier */
- ReverseChainSingleSubstFormat1 format1;
- } u;
- };
- /*
- * SubstLookup
- */
- struct SubstLookupSubTable
- {
- friend struct SubstLookup;
- enum Type {
- Single = 1,
- Multiple = 2,
- Alternate = 3,
- Ligature = 4,
- Context = 5,
- ChainContext = 6,
- Extension = 7,
- ReverseChainSingle = 8
- };
- inline void closure (hb_closure_context_t *c,
- unsigned int lookup_type) const
- {
- TRACE_CLOSURE ();
- switch (lookup_type) {
- case Single: u.single.closure (c); break;
- case Multiple: u.multiple.closure (c); break;
- case Alternate: u.alternate.closure (c); break;
- case Ligature: u.ligature.closure (c); break;
- case Context: u.context.closure (c); break;
- case ChainContext: u.chainContext.closure (c); break;
- case Extension: u.extension.closure (c); break;
- case ReverseChainSingle: u.reverseChainContextSingle.closure (c); break;
- default: break;
- }
- }
- inline const Coverage &get_coverage (unsigned int lookup_type) const
- {
- switch (lookup_type) {
- case Single: return u.single.get_coverage ();
- case Multiple: return u.multiple.get_coverage ();
- case Alternate: return u.alternate.get_coverage ();
- case Ligature: return u.ligature.get_coverage ();
- case Context: return u.context.get_coverage ();
- case ChainContext: return u.chainContext.get_coverage ();
- case Extension: return u.extension.get_coverage ();
- case ReverseChainSingle: return u.reverseChainContextSingle.get_coverage ();
- default: return Null(Coverage);
- }
- }
- inline bool would_apply (hb_would_apply_context_t *c,
- unsigned int lookup_type) const
- {
- TRACE_WOULD_APPLY ();
- if (get_coverage (lookup_type).get_coverage (c->first) == NOT_COVERED) return false;
- if (c->len == 1) return true; /* Done! */
- /* Only need to look further for lookups that support substitutions
- * of input longer than 1. */
- switch (lookup_type) {
- case Ligature: return u.ligature.would_apply (c);
- case Context: return u.context.would_apply (c);
- case ChainContext: return u.chainContext.would_apply (c);
- case Extension: return u.extension.would_apply (c);
- default: return false;
- }
- }
- inline bool apply (hb_apply_context_t *c, unsigned int lookup_type) const
- {
- TRACE_APPLY ();
- switch (lookup_type) {
- case Single: return TRACE_RETURN (u.single.apply (c));
- case Multiple: return TRACE_RETURN (u.multiple.apply (c));
- case Alternate: return TRACE_RETURN (u.alternate.apply (c));
- case Ligature: return TRACE_RETURN (u.ligature.apply (c));
- case Context: return TRACE_RETURN (u.context.apply (c));
- case ChainContext: return TRACE_RETURN (u.chainContext.apply (c));
- case Extension: return TRACE_RETURN (u.extension.apply (c));
- case ReverseChainSingle: return TRACE_RETURN (u.reverseChainContextSingle.apply (c));
- default: return TRACE_RETURN (false);
- }
- }
- inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
- TRACE_SANITIZE ();
- if (!u.header.sub_format.sanitize (c))
- return TRACE_RETURN (false);
- switch (lookup_type) {
- case Single: return TRACE_RETURN (u.single.sanitize (c));
- case Multiple: return TRACE_RETURN (u.multiple.sanitize (c));
- case Alternate: return TRACE_RETURN (u.alternate.sanitize (c));
- case Ligature: return TRACE_RETURN (u.ligature.sanitize (c));
- case Context: return TRACE_RETURN (u.context.sanitize (c));
- case ChainContext: return TRACE_RETURN (u.chainContext.sanitize (c));
- case Extension: return TRACE_RETURN (u.extension.sanitize (c));
- case ReverseChainSingle: return TRACE_RETURN (u.reverseChainContextSingle.sanitize (c));
- default: return TRACE_RETURN (true);
- }
- }
- protected:
- union {
- struct {
- USHORT sub_format;
- } header;
- SingleSubst single;
- MultipleSubst multiple;
- AlternateSubst alternate;
- LigatureSubst ligature;
- ContextSubst context;
- ChainContextSubst chainContext;
- ExtensionSubst extension;
- ReverseChainSingleSubst reverseChainContextSingle;
- } u;
- public:
- DEFINE_SIZE_UNION (2, header.sub_format);
- };
- struct SubstLookup : Lookup
- {
- inline const SubstLookupSubTable& get_subtable (unsigned int i) const
- { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
- inline static bool lookup_type_is_reverse (unsigned int lookup_type)
- { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
- inline bool is_reverse (void) const
- {
- unsigned int type = get_type ();
- if (unlikely (type == SubstLookupSubTable::Extension))
- return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
- return lookup_type_is_reverse (type);
- }
- inline void closure (hb_closure_context_t *c) const
- {
- unsigned int lookup_type = get_type ();
- unsigned int count = get_subtable_count ();
- for (unsigned int i = 0; i < count; i++)
- get_subtable (i).closure (c, lookup_type);
- }
- template <typename set_t>
- inline void add_coverage (set_t *glyphs) const
- {
- const Coverage *last = NULL;
- unsigned int count = get_subtable_count ();
- for (unsigned int i = 0; i < count; i++) {
- const Coverage *c = &get_subtable (i).get_coverage (get_type ());
- if (c != last) {
- c->add_coverage (glyphs);
- last = c;
- }
- }
- }
- inline bool would_apply (hb_would_apply_context_t *c) const
- {
- if (!c->digest.may_have (c->first)) return false;
- unsigned int lookup_type = get_type ();
- unsigned int count = get_subtable_count ();
- for (unsigned int i = 0; i < count; i++)
- if (get_subtable (i).would_apply (c, lookup_type))
- return true;
- return false;
- }
- inline bool apply_once (hb_apply_context_t *c) const
- {
- unsigned int lookup_type = get_type ();
- if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props, &c->property))
- return false;
- unsigned int count = get_subtable_count ();
- for (unsigned int i = 0; i < count; i++)
- if (get_subtable (i).apply (c, lookup_type))
- return true;
- return false;
- }
- inline bool apply_string (hb_apply_context_t *c) const
- {
- bool ret = false;
- if (unlikely (!c->buffer->len))
- return false;
- c->set_lookup (*this);
- if (likely (!is_reverse ()))
- {
- /* in/out forward substitution */
- c->buffer->clear_output ();
- c->buffer->idx = 0;
- while (c->buffer->idx < c->buffer->len)
- {
- if ((c->buffer->cur().mask & c->lookup_mask) &&
- c->digest.may_have (c->buffer->cur().codepoint) &&
- apply_once (c))
- ret = true;
- else
- c->buffer->next_glyph ();
- }
- if (ret)
- c->buffer->swap_buffers ();
- }
- else
- {
- /* in-place backward substitution */
- c->buffer->idx = c->buffer->len - 1;
- do
- {
- if ((c->buffer->cur().mask & c->lookup_mask) &&
- c->digest.may_have (c->buffer->cur().codepoint) &&
- apply_once (c))
- ret = true;
- else
- c->buffer->idx--;
- }
- while ((int) c->buffer->idx >= 0);
- }
- return ret;
- }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
- OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
- if (unlikely (!list.sanitize (c, this, get_type ()))) return TRACE_RETURN (false);
- if (unlikely (get_type () == SubstLookupSubTable::Extension))
- {
- /* The spec says all subtables of an Extension lookup should
- * have the same type. This is specially important if one has
- * a reverse type!
- *
- * We just check that they are all either forward, or reverse. */
- unsigned int type = get_subtable (0).u.extension.get_type ();
- unsigned int count = get_subtable_count ();
- for (unsigned int i = 1; i < count; i++)
- if (get_subtable (i).u.extension.get_type () != type)
- return TRACE_RETURN (false);
- }
- return TRACE_RETURN (true);
- }
- };
- typedef OffsetListOf<SubstLookup> SubstLookupList;
- /*
- * GSUB -- The Glyph Substitution Table
- */
- struct GSUB : GSUBGPOS
- {
- static const hb_tag_t Tag = HB_OT_TAG_GSUB;
- inline const SubstLookup& get_lookup (unsigned int i) const
- { return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
- template <typename set_t>
- inline void add_coverage (set_t *glyphs, unsigned int lookup_index) const
- { get_lookup (lookup_index).add_coverage (glyphs); }
- inline bool would_substitute_lookup (hb_would_apply_context_t *c, unsigned int lookup_index) const
- { return get_lookup (lookup_index).would_apply (c); }
- inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index) const
- { return get_lookup (lookup_index).apply_string (c); }
- static inline void substitute_start (hb_font_t *font, hb_buffer_t *buffer);
- static inline void substitute_finish (hb_font_t *font, hb_buffer_t *buffer);
- inline void closure_lookup (hb_closure_context_t *c,
- unsigned int lookup_index) const
- { return get_lookup (lookup_index).closure (c); }
- inline bool sanitize (hb_sanitize_context_t *c) {
- TRACE_SANITIZE ();
- if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
- OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
- return TRACE_RETURN (list.sanitize (c, this));
- }
- public:
- DEFINE_SIZE_STATIC (10);
- };
- void
- GSUB::substitute_start (hb_font_t *font, hb_buffer_t *buffer)
- {
- HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
- HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
- HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
- const GDEF &gdef = *hb_ot_layout_from_face (font->face)->gdef;
- unsigned int count = buffer->len;
- for (unsigned int i = 0; i < count; i++) {
- buffer->info[i].lig_props() = buffer->info[i].syllable() = 0;
- buffer->info[i].glyph_props() = gdef.get_glyph_props (buffer->info[i].codepoint);
- }
- }
- void
- GSUB::substitute_finish (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer HB_UNUSED)
- {
- }
- /* Out-of-class implementation for methods recursing */
- inline void ExtensionSubst::closure (hb_closure_context_t *c) const
- {
- get_subtable ().closure (c, get_type ());
- }
- inline const Coverage & ExtensionSubst::get_coverage (void) const
- {
- return get_subtable ().get_coverage (get_type ());
- }
- inline bool ExtensionSubst::would_apply (hb_would_apply_context_t *c) const
- {
- return get_subtable ().would_apply (c, get_type ());
- }
- inline bool ExtensionSubst::apply (hb_apply_context_t *c) const
- {
- TRACE_APPLY ();
- return TRACE_RETURN (get_subtable ().apply (c, get_type ()));
- }
- inline bool ExtensionSubst::sanitize (hb_sanitize_context_t *c)
- {
- TRACE_SANITIZE ();
- if (unlikely (!Extension::sanitize (c))) return TRACE_RETURN (false);
- unsigned int offset = get_offset ();
- if (unlikely (!offset)) return TRACE_RETURN (true);
- return TRACE_RETURN (StructAtOffset<SubstLookupSubTable> (this, offset).sanitize (c, get_type ()));
- }
- inline bool ExtensionSubst::is_reverse (void) const
- {
- unsigned int type = get_type ();
- if (unlikely (type == SubstLookupSubTable::Extension))
- return CastR<ExtensionSubst> (get_subtable()).is_reverse ();
- return SubstLookup::lookup_type_is_reverse (type);
- }
- static inline void closure_lookup (hb_closure_context_t *c, unsigned int lookup_index)
- {
- const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
- const SubstLookup &l = gsub.get_lookup (lookup_index);
- if (unlikely (c->nesting_level_left == 0))
- return;
- c->nesting_level_left--;
- l.closure (c);
- c->nesting_level_left++;
- }
- static inline bool substitute_lookup (hb_apply_context_t *c, unsigned int lookup_index)
- {
- const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
- const SubstLookup &l = gsub.get_lookup (lookup_index);
- if (unlikely (c->nesting_level_left == 0))
- return false;
- hb_apply_context_t new_c (*c);
- new_c.nesting_level_left--;
- new_c.set_lookup (l);
- return l.apply_once (&new_c);
- }
- #endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */