| /* | |
| * Copyright © 2017 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): Behdad Esfahbod | |
| */ | |
| #ifndef HB_AAT_LAYOUT_COMMON_HH | |
| #define HB_AAT_LAYOUT_COMMON_HH | |
| #include "hb-aat-layout.hh" | |
| #include "hb-aat-map.hh" | |
| #include "hb-ot-layout-common.hh" | |
| #include "hb-ot-layout-gdef-table.hh" | |
| #include "hb-open-type.hh" | |
| #include "hb-cache.hh" | |
| #include "hb-bit-set.hh" | |
| #include "hb-bit-page.hh" | |
| namespace OT { | |
| struct GDEF; | |
| }; | |
| namespace AAT { | |
| using namespace OT; | |
| struct ankr; | |
| using hb_aat_class_cache_t = hb_ot_layout_mapping_cache_t; | |
| /* The state-machine subtables' transition functions are called once per | |
| * transition from the drive loop, but are big enough that the compiler | |
| * declines to inline them, leaving a call in the hottest loop of AAT | |
| * shaping. Forcing them inline is worth 3-10% instructions on | |
| * morx/kerx-heavy fonts, for about 16KB of code. */ | |
| #ifndef HB_OPTIMIZE_SIZE | |
| #define HB_AAT_TRANSITION_INLINE HB_ALWAYS_INLINE | |
| #else | |
| #define HB_AAT_TRANSITION_INLINE | |
| #endif | |
| struct hb_aat_scratch_t | |
| { | |
| hb_aat_scratch_t () = default; | |
| hb_aat_scratch_t (const hb_aat_scratch_t &) = delete; | |
| hb_aat_scratch_t (hb_aat_scratch_t &&o) | |
| { | |
| buffer_glyph_set.set_relaxed (o.buffer_glyph_set.get_relaxed ()); | |
| o.buffer_glyph_set.set_relaxed (nullptr); | |
| } | |
| hb_aat_scratch_t & operator = (hb_aat_scratch_t &&o) | |
| { | |
| buffer_glyph_set.set_relaxed (o.buffer_glyph_set.get_relaxed ()); | |
| o.buffer_glyph_set.set_relaxed (nullptr); | |
| return *this; | |
| } | |
| ~hb_aat_scratch_t () | |
| { | |
| auto *s = buffer_glyph_set.get_relaxed (); | |
| if (unlikely (!s)) | |
| return; | |
| s->fini (); | |
| hb_free (s); | |
| } | |
| hb_bit_set_t *create_buffer_glyph_set () const | |
| { | |
| hb_bit_set_t *s = buffer_glyph_set.get_acquire (); | |
| if (s && buffer_glyph_set.cmpexch (s, nullptr)) | |
| { | |
| s->clear (); | |
| return s; | |
| } | |
| s = (hb_bit_set_t *) hb_calloc (1, sizeof (hb_bit_set_t)); | |
| if (unlikely (!s)) | |
| return nullptr; | |
| s->init (); | |
| return s; | |
| } | |
| void destroy_buffer_glyph_set (hb_bit_set_t *s) const | |
| { | |
| if (unlikely (!s)) | |
| return; | |
| if (buffer_glyph_set.cmpexch (nullptr, s)) | |
| return; | |
| s->fini (); | |
| hb_free (s); | |
| } | |
| mutable hb_atomic_t<hb_bit_set_t *> buffer_glyph_set; | |
| }; | |
| enum { DELETED_GLYPH = 0xFFFF }; | |
| #define HB_BUFFER_SCRATCH_FLAG_AAT_HAS_DELETED HB_BUFFER_SCRATCH_FLAG_SHAPER0 | |
| struct hb_aat_apply_context_t : | |
| hb_dispatch_context_t<hb_aat_apply_context_t, bool, HB_DEBUG_APPLY> | |
| { | |
| const char *get_name () { return "APPLY"; } | |
| template <typename T, typename ...Ts> | |
| return_t dispatch (const T &obj, Ts&&... ds) | |
| { return obj.apply (this, std::forward<Ts> (ds)...); } | |
| static return_t default_return_value () { return false; } | |
| bool stop_sublookup_iteration (return_t r) const { return r; } | |
| const hb_ot_shape_plan_t *plan; | |
| hb_font_t *font; | |
| hb_face_t *face; | |
| hb_buffer_t *buffer; | |
| hb_sanitize_context_t sanitizer; | |
| const ankr *ankr_table; | |
| const OT::GDEF &gdef; | |
| bool has_glyph_classes; | |
| const hb_sorted_vector_t<hb_aat_map_t::range_flags_t> *range_flags = nullptr; | |
| hb_mask_t subtable_flags = 0; | |
| bool buffer_is_reversed = false; | |
| // Caches | |
| bool using_buffer_glyph_set = false; | |
| hb_bit_set_t *buffer_glyph_set = nullptr; | |
| const hb_bit_set_t *first_set = nullptr; | |
| const hb_bit_set_t *second_set = nullptr; | |
| hb_aat_class_cache_t *machine_class_cache = nullptr; | |
| /* Unused. For debug tracing only. */ | |
| unsigned int lookup_index; | |
| HB_INTERNAL hb_aat_apply_context_t (const hb_ot_shape_plan_t *plan_, | |
| hb_font_t *font_, | |
| hb_buffer_t *buffer_, | |
| hb_blob_t *blob = const_cast<hb_blob_t *> (&Null (hb_blob_t))); | |
| HB_INTERNAL ~hb_aat_apply_context_t (); | |
| HB_INTERNAL void set_ankr_table (const AAT::ankr *ankr_table_); | |
| void set_lookup_index (unsigned int i) { lookup_index = i; } | |
| void reverse_buffer () | |
| { | |
| buffer->reverse (); | |
| buffer_is_reversed = !buffer_is_reversed; | |
| } | |
| void setup_buffer_glyph_set () | |
| { | |
| using_buffer_glyph_set = buffer->len >= 4 && buffer_glyph_set; | |
| if (likely (using_buffer_glyph_set)) | |
| buffer->collect_codepoints (*buffer_glyph_set); | |
| } | |
| bool buffer_intersects_machine () const | |
| { | |
| if (likely (using_buffer_glyph_set)) | |
| return buffer_glyph_set->intersects (*first_set); | |
| // Faster for shorter buffers. | |
| for (unsigned i = 0; i < buffer->len; i++) | |
| if (first_set->has (buffer->info[i].codepoint)) | |
| return true; | |
| return false; | |
| } | |
| template <typename T> | |
| HB_NODISCARD bool output_glyphs (unsigned int count, | |
| const T *glyphs) | |
| { | |
| if (likely (using_buffer_glyph_set)) | |
| buffer_glyph_set->add_array (glyphs, count); | |
| for (unsigned int i = 0; i < count; i++) | |
| { | |
| bool at_end_of_text = buffer->idx == buffer->len; | |
| if (at_end_of_text) | |
| if (unlikely (!buffer->output_glyph (glyphs[i]))) return false; | |
| hb_glyph_info_t &info = at_end_of_text ? buffer->prev () : buffer->cur (); | |
| if (glyphs[i] == DELETED_GLYPH) | |
| { | |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_AAT_HAS_DELETED; | |
| _hb_glyph_info_set_aat_deleted (&info); | |
| } | |
| else | |
| { | |
| #ifndef HB_NO_OT_LAYOUT | |
| if (has_glyph_classes) | |
| _hb_glyph_info_set_glyph_props (&info, | |
| gdef.get_glyph_props (glyphs[i])); | |
| #endif | |
| } | |
| if (!at_end_of_text) | |
| if (unlikely (!buffer->output_glyph (glyphs[i]))) return false; | |
| } | |
| return true; | |
| } | |
| HB_NODISCARD bool replace_glyph (hb_codepoint_t glyph) | |
| { | |
| if (glyph == DELETED_GLYPH) | |
| { | |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_AAT_HAS_DELETED; | |
| _hb_glyph_info_set_aat_deleted (&buffer->cur()); | |
| } | |
| if (likely (using_buffer_glyph_set)) | |
| buffer_glyph_set->add (glyph); | |
| #ifndef HB_NO_OT_LAYOUT | |
| if (has_glyph_classes) | |
| _hb_glyph_info_set_glyph_props (&buffer->cur(), | |
| gdef.get_glyph_props (glyph)); | |
| #endif | |
| return buffer->replace_glyph (glyph); | |
| } | |
| HB_NODISCARD bool delete_glyph () | |
| { | |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_AAT_HAS_DELETED; | |
| _hb_glyph_info_set_aat_deleted (&buffer->cur()); | |
| return buffer->replace_glyph (DELETED_GLYPH); | |
| } | |
| void replace_glyph_inplace (unsigned i, hb_codepoint_t glyph) | |
| { | |
| buffer->info[i].codepoint = glyph; | |
| if (glyph == DELETED_GLYPH) | |
| { | |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_AAT_HAS_DELETED; | |
| _hb_glyph_info_set_aat_deleted (&buffer->info[i]); | |
| } | |
| if (likely (using_buffer_glyph_set)) | |
| buffer_glyph_set->add (glyph); | |
| #ifndef HB_NO_OT_LAYOUT | |
| if (has_glyph_classes) | |
| _hb_glyph_info_set_glyph_props (&buffer->info[i], | |
| gdef.get_glyph_props (glyph)); | |
| #endif | |
| } | |
| }; | |
| /* | |
| * Lookup Table | |
| */ | |
| template <typename T> struct Lookup; | |
| template <typename T> | |
| struct LookupFormat0 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const | |
| { | |
| if (unlikely (glyph_id >= num_glyphs)) return nullptr; | |
| return &arrayZ[glyph_id]; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs, unsigned num_glyphs) const | |
| { | |
| glyphs.add_range (0, num_glyphs - 1); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, unsigned num_glyphs, const filter_t &filter) const | |
| { | |
| for (unsigned i = 0; i < num_glyphs; i++) | |
| if (filter (arrayZ[i])) | |
| glyphs.add (i); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (arrayZ.sanitize (c, c->get_num_glyphs ())); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (arrayZ.sanitize (c, c->get_num_glyphs (), base)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 0 */ | |
| UnsizedArrayOf<T> | |
| arrayZ; /* Array of lookup values, indexed by glyph index. */ | |
| public: | |
| DEFINE_SIZE_UNBOUNDED (2); | |
| }; | |
| template <typename T> | |
| struct LookupSegmentSingle | |
| { | |
| static constexpr unsigned TerminationWordCount = 2u; | |
| int cmp (hb_codepoint_t g) const | |
| { return g < first ? -1 : g <= last ? 0 : +1 ; } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| if (first == DELETED_GLYPH) return; | |
| glyphs.add_range (first, last); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| if (first == DELETED_GLYPH) return; | |
| if (!filter (value)) return; | |
| glyphs.add_range (first, last); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && value.sanitize (c)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && value.sanitize (c, base)); | |
| } | |
| HBGlyphID16 last; /* Last GlyphID in this segment */ | |
| HBGlyphID16 first; /* First GlyphID in this segment */ | |
| T value; /* The lookup value (only one) */ | |
| public: | |
| DEFINE_SIZE_STATIC (4 + T::static_size); | |
| }; | |
| template <typename T> | |
| struct LookupFormat2 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const T* get_value (hb_codepoint_t glyph_id) const | |
| { | |
| const LookupSegmentSingle<T> *v = segments.bsearch (glyph_id); | |
| return v ? &v->value : nullptr; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| unsigned count = segments.get_length (); | |
| for (unsigned int i = 0; i < count; i++) | |
| segments[i].collect_glyphs (glyphs); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| unsigned count = segments.get_length (); | |
| for (unsigned int i = 0; i < count; i++) | |
| segments[i].collect_glyphs_filtered (glyphs, filter); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (segments.sanitize (c)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (segments.sanitize (c, base)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 2 */ | |
| VarSizedBinSearchArrayOf<LookupSegmentSingle<T>> | |
| segments; /* The actual segments. These must already be sorted, | |
| * according to the first word in each one (the last | |
| * glyph in each segment). */ | |
| public: | |
| DEFINE_SIZE_ARRAY (8, segments); | |
| }; | |
| template <typename T> | |
| struct LookupSegmentArray | |
| { | |
| static constexpr unsigned TerminationWordCount = 2u; | |
| const T* get_value (hb_codepoint_t glyph_id, const void *base) const | |
| { | |
| return first <= glyph_id && glyph_id <= last ? &(base+valuesZ)[glyph_id - first] : nullptr; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| if (first == DELETED_GLYPH) return; | |
| glyphs.add_range (first, last); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const void *base, const filter_t &filter) const | |
| { | |
| if (first == DELETED_GLYPH) return; | |
| const auto &values = base+valuesZ; | |
| for (hb_codepoint_t i = first; i <= last; i++) | |
| if (filter (values[i - first])) | |
| glyphs.add (i); | |
| } | |
| int cmp (hb_codepoint_t g) const | |
| { return g < first ? -1 : g <= last ? 0 : +1; } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && | |
| hb_barrier () && | |
| first <= last && | |
| valuesZ.sanitize (c, base, last - first + 1)); | |
| } | |
| template <typename ...Ts> | |
| bool sanitize (hb_sanitize_context_t *c, const void *base, Ts&&... ds) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && | |
| hb_barrier () && | |
| first <= last && | |
| valuesZ.sanitize (c, base, last - first + 1, std::forward<Ts> (ds)...)); | |
| } | |
| HBGlyphID16 last; /* Last GlyphID in this segment */ | |
| HBGlyphID16 first; /* First GlyphID in this segment */ | |
| NNOffset16To<UnsizedArrayOf<T>> | |
| valuesZ; /* A 16-bit offset from the start of | |
| * the table to the data. */ | |
| public: | |
| DEFINE_SIZE_STATIC (6); | |
| }; | |
| template <typename T> | |
| struct LookupFormat4 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const T* get_value (hb_codepoint_t glyph_id) const | |
| { | |
| const LookupSegmentArray<T> *v = segments.bsearch (glyph_id); | |
| return v ? v->get_value (glyph_id, this) : nullptr; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| unsigned count = segments.get_length (); | |
| for (unsigned i = 0; i < count; i++) | |
| segments[i].collect_glyphs (glyphs); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| unsigned count = segments.get_length (); | |
| for (unsigned i = 0; i < count; i++) | |
| segments[i].collect_glyphs_filtered (glyphs, this, filter); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (segments.sanitize (c, this)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (segments.sanitize (c, this, base)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 4 */ | |
| VarSizedBinSearchArrayOf<LookupSegmentArray<T>> | |
| segments; /* The actual segments. These must already be sorted, | |
| * according to the first word in each one (the last | |
| * glyph in each segment). */ | |
| public: | |
| DEFINE_SIZE_ARRAY (8, segments); | |
| }; | |
| template <typename T> | |
| struct LookupSingle | |
| { | |
| static constexpr unsigned TerminationWordCount = 1u; | |
| int cmp (hb_codepoint_t g) const { return glyph.cmp (g); } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| if (glyph == DELETED_GLYPH) return; | |
| glyphs.add (glyph); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| if (glyph == DELETED_GLYPH) return; | |
| if (!filter (value)) return; | |
| glyphs.add (glyph); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && value.sanitize (c)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && value.sanitize (c, base)); | |
| } | |
| HBGlyphID16 glyph; /* Last GlyphID */ | |
| T value; /* The lookup value (only one) */ | |
| public: | |
| DEFINE_SIZE_STATIC (2 + T::static_size); | |
| }; | |
| template <typename T> | |
| struct LookupFormat6 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const T* get_value (hb_codepoint_t glyph_id) const | |
| { | |
| const LookupSingle<T> *v = entries.bsearch (glyph_id); | |
| return v ? &v->value : nullptr; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| unsigned count = entries.get_length (); | |
| for (unsigned i = 0; i < count; i++) | |
| entries[i].collect_glyphs (glyphs); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| unsigned count = entries.get_length (); | |
| for (unsigned i = 0; i < count; i++) | |
| entries[i].collect_glyphs_filtered (glyphs, filter); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (entries.sanitize (c)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (entries.sanitize (c, base)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 6 */ | |
| VarSizedBinSearchArrayOf<LookupSingle<T>> | |
| entries; /* The actual entries, sorted by glyph index. */ | |
| public: | |
| DEFINE_SIZE_ARRAY (8, entries); | |
| }; | |
| template <typename T> | |
| struct LookupFormat8 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const T* get_value (hb_codepoint_t glyph_id) const | |
| { | |
| return firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount ? | |
| &valueArrayZ[glyph_id - firstGlyph] : nullptr; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| if (unlikely (!glyphCount)) return; | |
| if (firstGlyph == DELETED_GLYPH) return; | |
| glyphs.add_range (firstGlyph, firstGlyph + glyphCount - 1); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| if (unlikely (!glyphCount)) return; | |
| if (firstGlyph == DELETED_GLYPH) return; | |
| const T *p = valueArrayZ.arrayZ; | |
| for (unsigned i = 0; i < glyphCount; i++) | |
| if (filter (p[i])) | |
| glyphs.add (firstGlyph + i); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount)); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && valueArrayZ.sanitize (c, glyphCount, base)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 8 */ | |
| HBGlyphID16 firstGlyph; /* First glyph index included in the trimmed array. */ | |
| HBUINT16 glyphCount; /* Total number of glyphs (equivalent to the last | |
| * glyph minus the value of firstGlyph plus 1). */ | |
| UnsizedArrayOf<T> | |
| valueArrayZ; /* The lookup values (indexed by the glyph index | |
| * minus the value of firstGlyph). */ | |
| public: | |
| DEFINE_SIZE_ARRAY (6, valueArrayZ); | |
| }; | |
| template <typename T> | |
| struct LookupFormat10 | |
| { | |
| friend struct Lookup<T>; | |
| private: | |
| const typename T::type get_value_or_null (hb_codepoint_t glyph_id) const | |
| { | |
| if (!(firstGlyph <= glyph_id && glyph_id - firstGlyph < glyphCount)) | |
| return Null (T); | |
| const HBUINT8 *p = &valueArrayZ[(glyph_id - firstGlyph) * valueSize]; | |
| unsigned int v = 0; | |
| unsigned int count = valueSize; | |
| for (unsigned int i = 0; i < count; i++) | |
| v = (v << 8) | *p++; | |
| return v; | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs) const | |
| { | |
| if (unlikely (!glyphCount)) return; | |
| if (firstGlyph == DELETED_GLYPH) return; | |
| glyphs.add_range (firstGlyph, firstGlyph + glyphCount - 1); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, const filter_t &filter) const | |
| { | |
| if (unlikely (!glyphCount)) return; | |
| if (firstGlyph == DELETED_GLYPH) return; | |
| const HBUINT8 *p = valueArrayZ.arrayZ; | |
| for (unsigned i = 0; i < glyphCount; i++) | |
| { | |
| unsigned int v = 0; | |
| unsigned int count = valueSize; | |
| for (unsigned int j = 0; j < count; j++) | |
| v = (v << 8) | *p++; | |
| if (filter (v)) | |
| glyphs.add (firstGlyph + i); | |
| } | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && | |
| hb_barrier () && | |
| valueSize <= 4 && | |
| valueArrayZ.sanitize (c, glyphCount * valueSize)); | |
| } | |
| protected: | |
| HBUINT16 format; /* Format identifier--format = 8 */ | |
| HBUINT16 valueSize; /* Byte size of each value. */ | |
| HBGlyphID16 firstGlyph; /* First glyph index included in the trimmed array. */ | |
| HBUINT16 glyphCount; /* Total number of glyphs (equivalent to the last | |
| * glyph minus the value of firstGlyph plus 1). */ | |
| UnsizedArrayOf<HBUINT8> | |
| valueArrayZ; /* The lookup values (indexed by the glyph index | |
| * minus the value of firstGlyph). */ | |
| public: | |
| DEFINE_SIZE_ARRAY (8, valueArrayZ); | |
| }; | |
| template <typename T> | |
| struct Lookup | |
| { | |
| const T* get_value (hb_codepoint_t glyph_id, unsigned int num_glyphs) const | |
| { | |
| switch (u.format.v) { | |
| case 0: hb_barrier (); return u.format0.get_value (glyph_id, num_glyphs); | |
| case 2: hb_barrier (); return u.format2.get_value (glyph_id); | |
| case 4: hb_barrier (); return u.format4.get_value (glyph_id); | |
| case 6: hb_barrier (); return u.format6.get_value (glyph_id); | |
| case 8: hb_barrier (); return u.format8.get_value (glyph_id); | |
| default:return nullptr; | |
| } | |
| } | |
| const typename T::type get_value_or_null (hb_codepoint_t glyph_id, unsigned int num_glyphs) const | |
| { | |
| switch (u.format.v) { | |
| /* Format 10 cannot return a pointer. */ | |
| case 10: hb_barrier (); return u.format10.get_value_or_null (glyph_id); | |
| default: | |
| const T *v = get_value (glyph_id, num_glyphs); | |
| return v ? *v : Null (T); | |
| } | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs, unsigned int num_glyphs) const | |
| { | |
| switch (u.format.v) { | |
| case 0: hb_barrier (); u.format0.collect_glyphs (glyphs, num_glyphs); return; | |
| case 2: hb_barrier (); u.format2.collect_glyphs (glyphs); return; | |
| case 4: hb_barrier (); u.format4.collect_glyphs (glyphs); return; | |
| case 6: hb_barrier (); u.format6.collect_glyphs (glyphs); return; | |
| case 8: hb_barrier (); u.format8.collect_glyphs (glyphs); return; | |
| case 10: hb_barrier (); u.format10.collect_glyphs (glyphs); return; | |
| default:return; | |
| } | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, unsigned num_glyphs, const filter_t &filter) const | |
| { | |
| switch (u.format.v) { | |
| case 0: hb_barrier (); u.format0.collect_glyphs_filtered (glyphs, num_glyphs, filter); return; | |
| case 2: hb_barrier (); u.format2.collect_glyphs_filtered (glyphs, filter); return; | |
| case 4: hb_barrier (); u.format4.collect_glyphs_filtered (glyphs, filter); return; | |
| case 6: hb_barrier (); u.format6.collect_glyphs_filtered (glyphs, filter); return; | |
| case 8: hb_barrier (); u.format8.collect_glyphs_filtered (glyphs, filter); return; | |
| case 10: hb_barrier (); u.format10.collect_glyphs_filtered (glyphs, filter); return; | |
| default:return; | |
| } | |
| } | |
| typename T::type get_class (hb_codepoint_t glyph_id, | |
| unsigned int num_glyphs, | |
| unsigned int outOfRange) const | |
| { | |
| const T *v = get_value (glyph_id, num_glyphs); | |
| return v ? *v : outOfRange; | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| if (!u.format.v.sanitize (c)) return_trace (false); | |
| hb_barrier (); | |
| switch (u.format.v) { | |
| case 0: hb_barrier (); return_trace (u.format0.sanitize (c)); | |
| case 2: hb_barrier (); return_trace (u.format2.sanitize (c)); | |
| case 4: hb_barrier (); return_trace (u.format4.sanitize (c)); | |
| case 6: hb_barrier (); return_trace (u.format6.sanitize (c)); | |
| case 8: hb_barrier (); return_trace (u.format8.sanitize (c)); | |
| case 10: hb_barrier (); return_trace (u.format10.sanitize (c)); | |
| default:return_trace (true); | |
| } | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, const void *base) const | |
| { | |
| TRACE_SANITIZE (this); | |
| if (!u.format.v.sanitize (c)) return_trace (false); | |
| hb_barrier (); | |
| switch (u.format.v) { | |
| case 0: hb_barrier (); return_trace (u.format0.sanitize (c, base)); | |
| case 2: hb_barrier (); return_trace (u.format2.sanitize (c, base)); | |
| case 4: hb_barrier (); return_trace (u.format4.sanitize (c, base)); | |
| case 6: hb_barrier (); return_trace (u.format6.sanitize (c, base)); | |
| case 8: hb_barrier (); return_trace (u.format8.sanitize (c, base)); | |
| case 10: return_trace (false); /* We don't support format10 here currently. */ | |
| default:return_trace (true); | |
| } | |
| } | |
| protected: | |
| union { | |
| struct { HBUINT16 v; } format; /* Format identifier */ | |
| LookupFormat0<T> format0; | |
| LookupFormat2<T> format2; | |
| LookupFormat4<T> format4; | |
| LookupFormat6<T> format6; | |
| LookupFormat8<T> format8; | |
| LookupFormat10<T> format10; | |
| } u; | |
| public: | |
| DEFINE_SIZE_UNION (2, format.v); | |
| }; | |
| DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1 (AAT, Lookup, 13); | |
| /* | |
| * (Extended) State Table | |
| */ | |
| template <typename T> | |
| struct Entry | |
| { | |
| // This doesn't seem like it's ever called. | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| /* Note, we don't recurse-sanitize data because we don't access it. | |
| * That said, in our DEFINE_SIZE_STATIC we access T::static_size, | |
| * which ensures that data has a simple sanitize(). To be determined | |
| * if I need to remove that as well. | |
| * | |
| * HOWEVER! Because we are a template, our DEFINE_SIZE_STATIC | |
| * assertion wouldn't be checked, hence the line below. */ | |
| static_assert (T::static_size, ""); | |
| return_trace (c->check_struct (this)); | |
| } | |
| public: | |
| HBUINT16 newState; /* Byte offset from beginning of state table | |
| * to the new state. Really?!?! Or just state | |
| * number? The latter in morx for sure. */ | |
| HBUINT16 flags; /* Table specific. */ | |
| T data; /* Optional offsets to per-glyph tables. */ | |
| public: | |
| DEFINE_SIZE_STATIC (4 + T::static_size); | |
| }; | |
| template <> | |
| struct Entry<void> | |
| { | |
| // This does seem like it's ever called. | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this)); | |
| } | |
| public: | |
| HBUINT16 newState; /* Byte offset from beginning of state table to the new state. */ | |
| HBUINT16 flags; /* Table specific. */ | |
| public: | |
| DEFINE_SIZE_STATIC (4); | |
| }; | |
| enum Class | |
| { | |
| CLASS_END_OF_TEXT = 0, | |
| CLASS_OUT_OF_BOUNDS = 1, | |
| CLASS_DELETED_GLYPH = 2, | |
| CLASS_END_OF_LINE = 3, | |
| }; | |
| template <typename Types, typename Extra> | |
| struct StateTable | |
| { | |
| typedef typename Types::HBUINT HBUINT; | |
| typedef typename Types::HBUSHORT HBUSHORT; | |
| typedef typename Types::ClassTypeNarrow ClassType; | |
| enum State | |
| { | |
| STATE_START_OF_TEXT = 0, | |
| STATE_START_OF_LINE = 1, | |
| }; | |
| template <typename set_t, typename table_t> | |
| void collect_initial_glyphs (set_t &glyphs, unsigned num_glyphs, const table_t &table) const | |
| { | |
| unsigned num_classes = nClasses; | |
| if (unlikely (num_classes > hb_bit_page_t::BITS)) | |
| { | |
| (this+classTable).collect_glyphs (glyphs, num_glyphs); | |
| return; | |
| } | |
| // Collect all classes going out from the start state. | |
| hb_bit_page_t filter; | |
| for (unsigned i = 0; i < num_classes; i++) | |
| { | |
| const auto &entry = get_entry (STATE_START_OF_TEXT, i); | |
| if (new_state (entry.newState) == STATE_START_OF_TEXT && | |
| !table.is_action_initiable (entry) && !table.is_actionable (entry)) | |
| continue; | |
| filter.add (i); | |
| } | |
| // And glyphs in those classes. | |
| if (filter (CLASS_DELETED_GLYPH)) | |
| glyphs.add (DELETED_GLYPH); | |
| (this+classTable).collect_glyphs_filtered (glyphs, num_glyphs, filter); | |
| } | |
| int new_state (unsigned int newState) const | |
| { return Types::extended ? newState : ((int) newState - (int) stateArrayTable) / (int) nClasses; } | |
| unsigned int get_class (hb_codepoint_t glyph_id, | |
| unsigned int num_glyphs, | |
| hb_aat_class_cache_t *cache = nullptr) const | |
| { | |
| unsigned klass; | |
| if (cache && cache->get (glyph_id, &klass)) return klass; | |
| if (unlikely (glyph_id == DELETED_GLYPH)) return CLASS_DELETED_GLYPH; | |
| klass = (this+classTable).get_class (glyph_id, num_glyphs, CLASS_OUT_OF_BOUNDS); | |
| if (cache) cache->set (glyph_id, klass); | |
| return klass; | |
| } | |
| const Entry<Extra> *get_entries () const | |
| { return (this+entryTable).arrayZ; } | |
| const Entry<Extra> &get_entry (int state, unsigned int klass) const | |
| { | |
| unsigned n_classes = nClasses; | |
| if (unlikely (klass >= n_classes)) | |
| klass = CLASS_OUT_OF_BOUNDS; | |
| const HBUSHORT *states = (this+stateArrayTable).arrayZ; | |
| const Entry<Extra> *entries = (this+entryTable).arrayZ; | |
| unsigned int entry = states[state * n_classes + klass]; | |
| DEBUG_MSG (APPLY, nullptr, "e%u", entry); | |
| return entries[entry]; | |
| } | |
| bool sanitize (hb_sanitize_context_t *c, | |
| unsigned int *num_entries_out = nullptr) const | |
| { | |
| TRACE_SANITIZE (this); | |
| if (unlikely (!(c->check_struct (this) && | |
| hb_barrier () && | |
| nClasses >= 4 /* Ensure pre-defined classes fit. */ && | |
| classTable.sanitize (c, this)))) return_trace (false); | |
| const HBUSHORT *states = (this+stateArrayTable).arrayZ; | |
| const Entry<Extra> *entries = (this+entryTable).arrayZ; | |
| unsigned int num_classes = nClasses; | |
| if (unlikely (hb_unsigned_mul_overflows (num_classes, states[0].static_size))) | |
| return_trace (false); | |
| unsigned int row_stride = num_classes * states[0].static_size; | |
| /* Apple 'kern' table has this peculiarity: | |
| * | |
| * "Because the stateTableOffset in the state table header is (strictly | |
| * speaking) redundant, some 'kern' tables use it to record an initial | |
| * state where that should not be StartOfText. To determine if this is | |
| * done, calculate what the stateTableOffset should be. If it's different | |
| * from the actual stateTableOffset, use it as the initial state." | |
| * | |
| * We implement this by calling the initial state zero, but allow *negative* | |
| * states if the start state indeed was not the first state. Since the code | |
| * is shared, this will also apply to 'mort' table. The 'kerx' / 'morx' | |
| * tables are not affected since those address states by index, not offset. | |
| */ | |
| int min_state = 0; | |
| int max_state = 0; | |
| unsigned int num_entries = 0; | |
| int state_pos = 0; | |
| int state_neg = 0; | |
| unsigned int entry = 0; | |
| while (min_state < state_neg || state_pos <= max_state) | |
| { | |
| if (min_state < state_neg) | |
| { | |
| /* Negative states. */ | |
| if (unlikely (hb_unsigned_mul_overflows (min_state, num_classes))) | |
| return_trace (false); | |
| if (unlikely (!c->check_range (&states[min_state * num_classes], | |
| -min_state, | |
| row_stride))) | |
| return_trace (false); | |
| if ((c->max_ops -= state_neg - min_state) <= 0) | |
| return_trace (false); | |
| { /* Sweep new states. */ | |
| const HBUSHORT *stop = &states[min_state * num_classes]; | |
| if (unlikely (stop > states)) | |
| return_trace (false); | |
| for (const HBUSHORT *p = states; stop < p; p--) | |
| num_entries = hb_max (num_entries, *(p - 1) + 1u); | |
| state_neg = min_state; | |
| } | |
| } | |
| if (state_pos <= max_state) | |
| { | |
| /* Positive states. */ | |
| if (unlikely (!c->check_range (states, | |
| max_state + 1, | |
| row_stride))) | |
| return_trace (false); | |
| if ((c->max_ops -= max_state - state_pos + 1) <= 0) | |
| return_trace (false); | |
| { /* Sweep new states. */ | |
| if (unlikely (hb_unsigned_mul_overflows ((max_state + 1), num_classes))) | |
| return_trace (false); | |
| const HBUSHORT *stop = &states[(max_state + 1) * num_classes]; | |
| if (unlikely (stop < states)) | |
| return_trace (false); | |
| for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++) | |
| num_entries = hb_max (num_entries, *p + 1u); | |
| state_pos = max_state + 1; | |
| } | |
| } | |
| if (unlikely (!c->check_array (entries, num_entries))) | |
| return_trace (false); | |
| if ((c->max_ops -= num_entries - entry) <= 0) | |
| return_trace (false); | |
| { /* Sweep new entries. */ | |
| const Entry<Extra> *stop = &entries[num_entries]; | |
| for (const Entry<Extra> *p = &entries[entry]; p < stop; p++) | |
| { | |
| int newState = new_state (p->newState); | |
| min_state = hb_min (min_state, newState); | |
| max_state = hb_max (max_state, newState); | |
| } | |
| entry = num_entries; | |
| } | |
| } | |
| if (num_entries_out) | |
| *num_entries_out = num_entries; | |
| return_trace (true); | |
| } | |
| protected: | |
| HBUINT nClasses; /* Number of classes, which is the number of indices | |
| * in a single line in the state array. */ | |
| NNOffsetTo<ClassType, HBUINT> | |
| classTable; /* Offset to the class table. */ | |
| NNOffsetTo<UnsizedArrayOf<HBUSHORT>, HBUINT> | |
| stateArrayTable;/* Offset to the state array. */ | |
| NNOffsetTo<UnsizedArrayOf<Entry<Extra>>, HBUINT> | |
| entryTable; /* Offset to the entry array. */ | |
| public: | |
| DEFINE_SIZE_STATIC (4 * sizeof (HBUINT)); | |
| }; | |
| template <typename HBUCHAR> | |
| struct ClassTable | |
| { | |
| unsigned int get_class (hb_codepoint_t glyph_id, unsigned int outOfRange) const | |
| { | |
| unsigned int i = glyph_id - firstGlyph; | |
| return i >= classArray.len ? outOfRange : classArray.arrayZ[i]; | |
| } | |
| unsigned int get_class (hb_codepoint_t glyph_id, | |
| unsigned int num_glyphs HB_UNUSED, | |
| unsigned int outOfRange) const | |
| { | |
| return get_class (glyph_id, outOfRange); | |
| } | |
| template <typename set_t> | |
| void collect_glyphs (set_t &glyphs, unsigned num_glyphs) const | |
| { | |
| for (unsigned i = 0; i < classArray.len; i++) | |
| if (classArray.arrayZ[i] != CLASS_OUT_OF_BOUNDS) | |
| glyphs.add (firstGlyph + i); | |
| } | |
| template <typename set_t, typename filter_t> | |
| void collect_glyphs_filtered (set_t &glyphs, unsigned num_glyphs, const filter_t &filter) const | |
| { | |
| for (unsigned i = 0; i < classArray.len; i++) | |
| if (filter (classArray.arrayZ[i])) | |
| glyphs.add (firstGlyph + i); | |
| } | |
| bool sanitize (hb_sanitize_context_t *c) const | |
| { | |
| TRACE_SANITIZE (this); | |
| return_trace (c->check_struct (this) && classArray.sanitize (c)); | |
| } | |
| protected: | |
| HBGlyphID16 firstGlyph; /* First glyph index included in the trimmed array. */ | |
| Array16Of<HBUCHAR> classArray; /* The class codes (indexed by glyph index minus | |
| * firstGlyph). */ | |
| public: | |
| DEFINE_SIZE_ARRAY (4, classArray); | |
| }; | |
| struct SubtableGlyphCoverage | |
| { | |
| bool sanitize (hb_sanitize_context_t *c, unsigned subtable_count) const | |
| { | |
| TRACE_SANITIZE (this); | |
| if (unlikely (!c->check_array (&subtableOffsets, subtable_count))) | |
| return_trace (false); | |
| unsigned bytes = (c->get_num_glyphs () + CHAR_BIT - 1) / CHAR_BIT; | |
| for (unsigned i = 0; i < subtable_count; i++) | |
| { | |
| uint32_t offset = (uint32_t) subtableOffsets[i]; | |
| // A font file called SFNSDisplay.ttf has value 0xFFFFFFFF in the offsets. | |
| // Just ignore it. | |
| if (offset == 0 || offset == 0xFFFFFFFF) | |
| continue; | |
| if (unlikely (!subtableOffsets[i].sanitize (c, this, bytes))) | |
| return_trace (false); | |
| } | |
| return_trace (true); | |
| } | |
| protected: | |
| UnsizedArrayOf<NNOffset32To<UnsizedArrayOf<HBUINT8>>> subtableOffsets; | |
| /* Array of offsets from the beginning of the | |
| * subtable glyph coverage table to the glyph | |
| * coverage bitfield for a given subtable; there | |
| * is one offset for each subtable in the chain */ | |
| /* UnsizedArrayOf<HBUINT8> coverageBitfields; *//* The individual coverage bitfields. */ | |
| public: | |
| DEFINE_SIZE_ARRAY (0, subtableOffsets); | |
| }; | |
| struct ObsoleteTypes | |
| { | |
| static constexpr bool extended = false; | |
| typedef HBUINT16 HBUINT; | |
| typedef HBUINT8 HBUSHORT; | |
| typedef ClassTable<HBUINT8> ClassTypeNarrow; | |
| typedef ClassTable<HBUINT16> ClassTypeWide; | |
| template <typename T> | |
| static int offsetToIndex (int64_t offset, | |
| const void *base, | |
| const T *array) | |
| { | |
| int64_t array_offset = (const char *) array - (const char *) base; | |
| int bad_index = INT_MAX / T::static_size; | |
| /* https://github.com/harfbuzz/harfbuzz/issues/3483 */ | |
| /* If offset is less than base, return an offset that would | |
| * result in an address half a 32bit address-space away, | |
| * to make sure sanitize fails even on 32bit builds. */ | |
| if (unlikely (offset < array_offset)) | |
| return bad_index; | |
| /* https://github.com/harfbuzz/harfbuzz/issues/2816 */ | |
| int64_t index = (offset - array_offset) / T::static_size; | |
| if (unlikely (index > bad_index)) | |
| return bad_index; | |
| return index; | |
| } | |
| template <typename T> | |
| static int byteOffsetToIndex (int64_t offset, | |
| const void *base, | |
| const T *array) | |
| { | |
| return offsetToIndex (offset, base, array); | |
| } | |
| template <typename T> | |
| static int wordOffsetToIndex (int64_t offset, | |
| const void *base, | |
| const T *array) | |
| { | |
| return offsetToIndex (2 * offset, base, array); | |
| } | |
| }; | |
| struct ExtendedTypes | |
| { | |
| static constexpr bool extended = true; | |
| typedef HBUINT32 HBUINT; | |
| typedef HBUINT16 HBUSHORT; | |
| typedef Lookup<HBUINT16> ClassTypeNarrow; | |
| typedef Lookup<HBUINT16> ClassTypeWide; | |
| template <typename T> | |
| static unsigned int offsetToIndex (unsigned int offset, | |
| const void *base HB_UNUSED, | |
| const T *array HB_UNUSED) | |
| { | |
| return offset; | |
| } | |
| template <typename T> | |
| static unsigned int byteOffsetToIndex (unsigned int offset, | |
| const void *base HB_UNUSED, | |
| const T *array HB_UNUSED) | |
| { | |
| return offset / 2; | |
| } | |
| template <typename T> | |
| static unsigned int wordOffsetToIndex (unsigned int offset, | |
| const void *base HB_UNUSED, | |
| const T *array HB_UNUSED) | |
| { | |
| return offset; | |
| } | |
| }; | |
| template <typename Types, typename EntryData, typename Flags> | |
| struct StateTableDriver | |
| { | |
| using StateTableT = StateTable<Types, EntryData>; | |
| using EntryT = Entry<EntryData>; | |
| StateTableDriver (const StateTableT &machine_, | |
| hb_face_t *face_) : | |
| machine (machine_), | |
| num_glyphs (face_->get_num_glyphs ()) {} | |
| template <typename context_t> | |
| void drive (context_t *c, hb_aat_apply_context_t *ac) | |
| { | |
| hb_buffer_t *buffer = ac->buffer; | |
| if (!c->in_place) | |
| buffer->clear_output (); | |
| int state = StateTableT::STATE_START_OF_TEXT; | |
| // If there's only one range, we already checked the flag. | |
| auto *last_range = ac->range_flags && (ac->range_flags->length > 1) ? &(*ac->range_flags)[0] : nullptr; | |
| const bool start_state_safe_to_break_eot = | |
| !c->table->is_actionable (machine.get_entry (StateTableT::STATE_START_OF_TEXT, CLASS_END_OF_TEXT)); | |
| for (buffer->idx = 0; buffer->successful;) | |
| { | |
| unsigned int klass = likely (buffer->idx < buffer->len) ? | |
| machine.get_class (buffer->cur().codepoint, num_glyphs, ac->machine_class_cache) : | |
| (unsigned) CLASS_END_OF_TEXT; | |
| resume: | |
| DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx); | |
| const EntryT &entry = machine.get_entry (state, klass); | |
| const int next_state = machine.new_state (entry.newState); | |
| bool is_not_epsilon_transition = !(entry.flags & Flags::DontAdvance); | |
| bool is_not_actionable = !c->table->is_actionable (entry); | |
| if (unlikely (last_range)) | |
| { | |
| /* This block is copied in NoncontextualSubtable::apply. Keep in sync. */ | |
| auto *range = last_range; | |
| if (buffer->idx < buffer->len) | |
| { | |
| unsigned cluster = buffer->cur().cluster; | |
| while (cluster < range->cluster_first) | |
| range--; | |
| while (cluster > range->cluster_last) | |
| range++; | |
| last_range = range; | |
| } | |
| if (!(range->flags & ac->subtable_flags)) | |
| { | |
| if (buffer->idx == buffer->len) | |
| break; | |
| state = StateTableT::STATE_START_OF_TEXT; | |
| (void) buffer->next_glyph (); | |
| continue; | |
| } | |
| } | |
| else | |
| { | |
| // Fast path for when transitioning from start-state to start-state with | |
| // no action and advancing. Do so as long as the class remains the same. | |
| // This is common with runs of non-actionable glyphs. | |
| bool is_null_transition = state == StateTableT::STATE_START_OF_TEXT && | |
| next_state == StateTableT::STATE_START_OF_TEXT && | |
| start_state_safe_to_break_eot && | |
| is_not_actionable && | |
| is_not_epsilon_transition; | |
| if (is_null_transition) | |
| { | |
| unsigned old_klass = klass; | |
| do | |
| { | |
| c->transition (buffer, this, entry); | |
| if (buffer->idx == buffer->len || !buffer->successful) | |
| break; | |
| (void) buffer->next_glyph (); | |
| klass = likely (buffer->idx < buffer->len) ? | |
| machine.get_class (buffer->cur().codepoint, num_glyphs, ac->machine_class_cache) : | |
| (unsigned) CLASS_END_OF_TEXT; | |
| } while (klass == old_klass); | |
| if (buffer->idx == buffer->len || !buffer->successful) | |
| break; | |
| goto resume; | |
| } | |
| } | |
| /* Conditions under which it's guaranteed safe-to-break before current glyph: | |
| * | |
| * 1. There was no action in this transition; and | |
| * | |
| * 2. If we break before current glyph, the results will be the same. That | |
| * is guaranteed if: | |
| * | |
| * 2a. We were already in start-of-text state; or | |
| * | |
| * 2b. We are epsilon-transitioning to start-of-text state; or | |
| * | |
| * 2c. Starting from start-of-text state seeing current glyph: | |
| * | |
| * 2c'. There won't be any actions; and | |
| * | |
| * 2c". We would end up in the same state that we were going to end up | |
| * in now, including whether epsilon-transitioning. | |
| * | |
| * and | |
| * | |
| * 3. If we break before current glyph, there won't be any end-of-text action | |
| * after previous glyph. | |
| * | |
| * This triples the transitions we need to look up, but is worth returning | |
| * granular unsafe-to-break results. See eg.: | |
| * | |
| * https://github.com/harfbuzz/harfbuzz/issues/2860 | |
| */ | |
| const EntryT *wouldbe_entry; | |
| bool is_safe_to_break = | |
| ( | |
| /* 1. */ | |
| !c->table->is_actionable (entry) && | |
| /* 2. */ | |
| // This one is meh, I know... | |
| ( | |
| state == StateTableT::STATE_START_OF_TEXT | |
| || ((entry.flags & Flags::DontAdvance) && next_state == StateTableT::STATE_START_OF_TEXT) | |
| || ( | |
| /* 2c. */ | |
| wouldbe_entry = &machine.get_entry(StateTableT::STATE_START_OF_TEXT, klass) | |
| , | |
| /* 2c'. */ | |
| !c->table->is_actionable (*wouldbe_entry) && | |
| /* 2c". */ | |
| ( | |
| next_state == machine.new_state(wouldbe_entry->newState) && | |
| (entry.flags & Flags::DontAdvance) == (wouldbe_entry->flags & Flags::DontAdvance) | |
| ) | |
| ) | |
| ) && | |
| /* 3. */ | |
| !c->table->is_actionable (machine.get_entry (state, CLASS_END_OF_TEXT)) | |
| ); | |
| if (!is_safe_to_break && buffer->backtrack_len () && buffer->idx < buffer->len) | |
| buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1); | |
| c->transition (buffer, this, entry); | |
| state = next_state; | |
| DEBUG_MSG (APPLY, nullptr, "s%d", state); | |
| if (buffer->idx == buffer->len) | |
| break; | |
| if (is_not_epsilon_transition || buffer->max_ops-- <= 0) | |
| (void) buffer->next_glyph (); | |
| } | |
| if (!c->in_place) | |
| buffer->sync (); | |
| } | |
| public: | |
| const StateTableT &machine; | |
| unsigned int num_glyphs; | |
| }; | |
| } /* namespace AAT */ | |
| #endif /* HB_AAT_LAYOUT_COMMON_HH */ |