+/*
+ * 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ return (this+coverage) (glyph_id) != NOT_COVERED;
+ }
+
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ return (this+coverage) (glyph_id) != NOT_COVERED;
+ }
+
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ switch (u.format) {
+ case 1: return u.format1.would_apply (glyph_id);
+ case 2: return u.format2.would_apply (glyph_id);
+ 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));
+ 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);
+ }
+ }
+
+ private:
+ 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;
+ c->replace_glyphs_be16 (1, substitute.len, (const uint16_t *) substitute.array, klass);
+
+ return TRACE_RETURN (true);
+ }
+
+ public:
+ inline bool sanitize (hb_sanitize_context_t *c) {
+ TRACE_SANITIZE ();
+ return TRACE_RETURN (substitute.sanitize (c));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ return (this+coverage) (glyph_id) != NOT_COVERED;
+ }
+
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ switch (u.format) {
+ case 1: return u.format1.would_apply (glyph_id);
+ 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);
+ }
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ return (this+coverage) (glyph_id) != NOT_COVERED;
+ }
+
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ switch (u.format) {
+ case 1: return u.format1.would_apply (glyph_id);
+ 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);
+ }
+ }
+
+ private:
+ 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_codepoint_t second) const
+ {
+ return component.len == 2 && component[1] == second;
+ }
+
+ inline bool apply (hb_apply_context_t *c) const
+ {
+ TRACE_APPLY ();
+ unsigned int count = component.len;
+ if (unlikely (count < 2)) 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);
+
+ bool first_was_mark = (c->property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
+ bool found_non_mark = false;
+
+ for (unsigned int i = 1; i < count; i++)
+ {
+ unsigned int property;
+
+ if (!skippy_iter.next (&property)) return TRACE_RETURN (false);
+
+ found_non_mark |= !(property & HB_OT_LAYOUT_GLYPH_CLASS_MARK);
+
+ if (likely (c->buffer->info[skippy_iter.idx].codepoint != component[i])) return TRACE_RETURN (false);
+ }
+
+ unsigned int klass = first_was_mark && found_non_mark ? HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE : 0;
+
+ /* Allocate new ligature id */
+ unsigned int lig_id = allocate_lig_id (c->buffer);
+ set_lig_props (c->buffer->cur(), lig_id, 0);
+
+ if (skippy_iter.idx < c->buffer->idx + count) /* No input glyphs skipped */
+ {
+ c->replace_glyphs_be16 (count, 1, (const uint16_t *) &ligGlyph, klass);
+ }
+ else
+ {
+ c->replace_glyph (ligGlyph);
+
+ /* Now we must do a second loop to copy the skipped glyphs to
+ `out' and assign component values to it. We start with the
+ glyph after the first component. Glyphs between component
+ i and i+1 belong to component i. Together with the lig_id
+ value it is later possible to check whether a specific
+ component value really belongs to a given ligature. */
+
+ for (unsigned int i = 1; i < count; i++)
+ {
+ while (c->should_mark_skip_current_glyph ())
+ {
+ set_lig_props (c->buffer->cur(), lig_id, i);
+ c->replace_glyph (c->buffer->cur().codepoint);
+ }
+
+ /* Skip the base glyph */
+ c->buffer->idx++;
+ }
+ }
+
+ return TRACE_RETURN (true);
+ }
+
+ public:
+ inline bool sanitize (hb_sanitize_context_t *c) {
+ TRACE_SANITIZE ();
+ return TRACE_RETURN (ligGlyph.sanitize (c) && component.sanitize (c));
+ }
+
+ private:
+ 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_codepoint_t second) 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 (second))
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const
+ {
+ unsigned int index;
+ return (index = (this+coverage) (first)) != NOT_COVERED &&
+ (this+ligatureSet[index]).would_apply (second);
+ }
+
+ 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));
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const
+ {
+ switch (u.format) {
+ case 1: return u.format1.would_apply (first, second);
+ 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);
+ }
+ }
+
+ private:
+ 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 bool would_apply (hb_codepoint_t glyph_id) const;
+ inline bool would_apply (hb_codepoint_t first, hb_codepoint_t second) 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 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->buffer->cur().codepoint = 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));
+ }
+
+ private:
+ 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 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);
+ }
+ }
+
+ private:
+ 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.c.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 bool would_apply (hb_codepoint_t glyph_id,
+ unsigned int lookup_type) const
+ {
+ switch (lookup_type) {
+ case Single: return u.single.would_apply (glyph_id);
+ case Multiple: return u.multiple.would_apply (glyph_id);
+ case Alternate: return u.alternate.would_apply (glyph_id);
+ case Extension: return u.extension.would_apply (glyph_id);
+ default: return false;
+ }
+ }
+ inline bool would_apply (hb_codepoint_t first,
+ hb_codepoint_t second,
+ unsigned int lookup_type) const
+ {
+ switch (lookup_type) {
+ case Ligature: return u.ligature.would_apply (first, second);
+ case Extension: return u.extension.would_apply (first, second);
+ 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.c.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 ();
+ 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.c.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);
+ }
+ }
+
+ private:
+ union {
+ USHORT sub_format;
+ SingleSubst single;
+ MultipleSubst multiple;
+ AlternateSubst alternate;
+ LigatureSubst ligature;
+ ContextSubst c;
+ ChainContextSubst chainContext;
+ ExtensionSubst extension;
+ ReverseChainSingleSubst reverseChainContextSingle;
+ } u;
+ public:
+ DEFINE_SIZE_UNION (2, 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);
+ }
+
+ inline bool would_apply (hb_codepoint_t glyph_id) const
+ {
+ 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 (glyph_id, lookup_type))
+ return true;
+ return false;
+ }
+ inline bool would_apply (hb_codepoint_t first, hb_codepoint_t second) const
+ {
+ 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 (first, second, lookup_type))
+ return true;
+ return false;
+ }
+
+ inline bool apply_once (hb_apply_context_t *c) const
+ {
+ unsigned int lookup_type = get_type ();
+
+ if (!_hb_ot_layout_check_glyph_property (c->face, &c->buffer->cur(), c->lookup_props, &c->property))
+ return false;
+
+ if (unlikely (lookup_type == SubstLookupSubTable::Extension))
+ {
+ /* The spec says all subtables should have the same type.
+ * This is specially important if one has a reverse type!
+ *
+ * This is rather slow to do this here for every glyph,
+ * but it's easiest, and who uses extension lookups anyway?!*/
+ 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 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) && 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) && 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);
+ return TRACE_RETURN (list.sanitize (c, this, get_type ()));
+ }
+};
+
+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)); }
+
+ 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_buffer_t *buffer);
+ static inline void substitute_finish (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_buffer_t *buffer)
+{
+ HB_BUFFER_ALLOCATE_VAR (buffer, props_cache);
+ HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
+ HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
+
+ unsigned int count = buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ buffer->info[i].props_cache() = buffer->info[i].lig_props() = buffer->info[i].syllable() = 0;
+}
+
+void
+GSUB::substitute_finish (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 bool ExtensionSubst::would_apply (hb_codepoint_t glyph_id) const
+{
+ return get_subtable ().would_apply (glyph_id, get_type ());
+}
+
+inline bool ExtensionSubst::would_apply (hb_codepoint_t first, hb_codepoint_t second) const
+{
+ return get_subtable ().would_apply (first, second, 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 = *(c->face->ot_layout->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 = *(c->face->ot_layout->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 */