diff options
Diffstat (limited to 'gfx/harfbuzz/src/OT/Layout/GSUB/ReverseChainSingleSubstFormat1.hh')
-rw-r--r-- | gfx/harfbuzz/src/OT/Layout/GSUB/ReverseChainSingleSubstFormat1.hh | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/OT/Layout/GSUB/ReverseChainSingleSubstFormat1.hh b/gfx/harfbuzz/src/OT/Layout/GSUB/ReverseChainSingleSubstFormat1.hh new file mode 100644 index 0000000000..2c2e1aa44f --- /dev/null +++ b/gfx/harfbuzz/src/OT/Layout/GSUB/ReverseChainSingleSubstFormat1.hh @@ -0,0 +1,244 @@ +#ifndef OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH +#define OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH + +#include "Common.hh" + +namespace OT { +namespace Layout { +namespace GSUB_impl { + +struct ReverseChainSingleSubstFormat1 +{ + protected: + HBUINT16 format; /* Format identifier--format = 1 */ + Offset16To<Coverage> + coverage; /* Offset to Coverage table--from + * beginning of table */ + Array16OfOffset16To<Coverage> + backtrack; /* Array of coverage tables + * in backtracking sequence, in glyph + * sequence order */ + Array16OfOffset16To<Coverage> + lookaheadX; /* Array of coverage tables + * in lookahead sequence, in glyph + * sequence order */ + Array16Of<HBGlyphID16> + substituteX; /* Array of substitute + * GlyphIDs--ordered by Coverage Index */ + public: + DEFINE_SIZE_MIN (10); + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this))) + return_trace (false); + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + if (!lookahead.sanitize (c, this)) + return_trace (false); + const auto &substitute = StructAfter<decltype (substituteX)> (lookahead); + return_trace (substitute.sanitize (c)); + } + + bool intersects (const hb_set_t *glyphs) const + { + if (!(this+coverage).intersects (glyphs)) + return false; + + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + + unsigned int count; + + count = backtrack.len; + for (unsigned int i = 0; i < count; i++) + if (!(this+backtrack[i]).intersects (glyphs)) + return false; + + count = lookahead.len; + for (unsigned int i = 0; i < count; i++) + if (!(this+lookahead[i]).intersects (glyphs)) + return false; + + return true; + } + + bool may_have_non_1to1 () const + { return false; } + + void closure (hb_closure_context_t *c) const + { + if (!intersects (c->glyphs)) return; + + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + const auto &substitute = StructAfter<decltype (substituteX)> (lookahead); + + + hb_zip (this+coverage, substitute) + | hb_filter (c->parent_active_glyphs (), hb_first) + | hb_map (hb_second) + | hb_sink (c->output) + ; + } + + void closure_lookups (hb_closure_lookups_context_t *c) const {} + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + if (unlikely (!(this+coverage).collect_coverage (c->input))) return; + + unsigned int count; + + count = backtrack.len; + for (unsigned int i = 0; i < count; i++) + if (unlikely (!(this+backtrack[i]).collect_coverage (c->before))) return; + + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + count = lookahead.len; + for (unsigned int i = 0; i < count; i++) + if (unlikely (!(this+lookahead[i]).collect_coverage (c->after))) return; + + const auto &substitute = StructAfter<decltype (substituteX)> (lookahead); + count = substitute.len; + c->output->add_array (substitute.arrayZ, substitute.len); + } + + const Coverage &get_coverage () const { return this+coverage; } + + bool would_apply (hb_would_apply_context_t *c) const + { return c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + if (unlikely (c->nesting_level_left != HB_MAX_NESTING_LEVEL)) + return_trace (false); /* No chaining to this type */ + + unsigned int index = (this+coverage).get_coverage (c->buffer->cur ().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + const auto &substitute = StructAfter<decltype (substituteX)> (lookahead); + + if (unlikely (index >= substitute.len)) return_trace (false); + + unsigned int start_index = 0, end_index = 0; + if (match_backtrack (c, + backtrack.len, (HBUINT16 *) backtrack.arrayZ, + match_coverage, this, + &start_index) && + match_lookahead (c, + lookahead.len, (HBUINT16 *) lookahead.arrayZ, + match_coverage, this, + c->buffer->idx + 1, &end_index)) + { + c->buffer->unsafe_to_break_from_outbuffer (start_index, end_index); + + if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ()) + { + c->buffer->message (c->font, + "replacing glyph at %u (reverse chaining substitution)", + c->buffer->idx); + } + + c->replace_glyph_inplace (substitute[index]); + + if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ()) + { + c->buffer->message (c->font, + "replaced glyph at %u (reverse chaining substitution)", + c->buffer->idx); + } + + /* Note: We DON'T decrease buffer->idx. The main loop does it + * for us. This is useful for preventing surprises if someone + * calls us through a Context lookup. */ + return_trace (true); + } + else + { + c->buffer->unsafe_to_concat_from_outbuffer (start_index, end_index); + return_trace (false); + } + } + + template<typename Iterator, + hb_requires (hb_is_iterator (Iterator))> + bool serialize_coverage_offset_array (hb_subset_context_t *c, Iterator it) const + { + TRACE_SERIALIZE (this); + auto *out = c->serializer->start_embed<Array16OfOffset16To<Coverage>> (); + + if (unlikely (!c->serializer->allocate_size<HBUINT16> (HBUINT16::static_size))) + return_trace (false); + + for (auto& offset : it) { + auto *o = out->serialize_append (c->serializer); + if (unlikely (!o) || !o->serialize_subset (c, offset, this)) + return_trace (false); + } + + return_trace (true); + } + + template<typename Iterator, typename BacktrackIterator, typename LookaheadIterator, + hb_requires (hb_is_sorted_source_of (Iterator, hb_codepoint_pair_t)), + hb_requires (hb_is_iterator (BacktrackIterator)), + hb_requires (hb_is_iterator (LookaheadIterator))> + bool serialize (hb_subset_context_t *c, + Iterator coverage_subst_iter, + BacktrackIterator backtrack_iter, + LookaheadIterator lookahead_iter) const + { + TRACE_SERIALIZE (this); + + auto *out = c->serializer->start_embed (this); + if (unlikely (!c->serializer->check_success (out))) return_trace (false); + if (unlikely (!c->serializer->embed (this->format))) return_trace (false); + if (unlikely (!c->serializer->embed (this->coverage))) return_trace (false); + + if (!serialize_coverage_offset_array (c, backtrack_iter)) return_trace (false); + if (!serialize_coverage_offset_array (c, lookahead_iter)) return_trace (false); + + auto *substitute_out = c->serializer->start_embed<Array16Of<HBGlyphID16>> (); + auto substitutes = + + coverage_subst_iter + | hb_map (hb_second) + ; + + auto glyphs = + + coverage_subst_iter + | hb_map_retains_sorting (hb_first) + ; + if (unlikely (! c->serializer->check_success (substitute_out->serialize (c->serializer, substitutes)))) + return_trace (false); + + if (unlikely (!out->coverage.serialize_serialize (c->serializer, glyphs))) + return_trace (false); + return_trace (true); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + const hb_set_t &glyphset = *c->plan->glyphset_gsub (); + const hb_map_t &glyph_map = *c->plan->glyph_map; + + const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack); + const auto &substitute = StructAfter<decltype (substituteX)> (lookahead); + + auto it = + + hb_zip (this+coverage, substitute) + | hb_filter (glyphset, hb_first) + | hb_filter (glyphset, hb_second) + | hb_map_retains_sorting ([&] (hb_pair_t<hb_codepoint_t, const HBGlyphID16 &> p) -> hb_codepoint_pair_t + { return hb_pair (glyph_map[p.first], glyph_map[p.second]); }) + ; + + return_trace (bool (it) && serialize (c, it, backtrack.iter (), lookahead.iter ())); + } +}; + +} +} +} + +#endif /* HB_OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH */ |