/* * 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_MORX_TABLE_HH #define HB_AAT_LAYOUT_MORX_TABLE_HH #include "hb-open-type.hh" #include "hb-aat-layout-common.hh" #include "hb-ot-layout-common.hh" #include "hb-aat-map.hh" /* * morx -- Extended Glyph Metamorphosis * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6morx.html * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6mort.html */ #define HB_AAT_TAG_morx HB_TAG('m','o','r','x') #define HB_AAT_TAG_mort HB_TAG('m','o','r','t') namespace AAT { using namespace OT; template struct RearrangementSubtable { typedef typename Types::HBUINT HBUINT; typedef void EntryData; struct driver_context_t { static constexpr bool in_place = true; enum Flags { MarkFirst = 0x8000, /* If set, make the current glyph the first * glyph to be rearranged. */ DontAdvance = 0x4000, /* If set, don't advance to the next glyph * before going to the new state. This means * that the glyph index doesn't change, even * if the glyph at that index has changed. */ MarkLast = 0x2000, /* If set, make the current glyph the last * glyph to be rearranged. */ Reserved = 0x1FF0, /* These bits are reserved and should be set to 0. */ Verb = 0x000F, /* The type of rearrangement specified. */ }; driver_context_t (const RearrangementSubtable *table HB_UNUSED) : ret (false), start (0), end (0) {} bool is_actionable (StateTableDriver *driver HB_UNUSED, const Entry &entry) { return (entry.flags & Verb) && start < end; } void transition (StateTableDriver *driver, const Entry &entry) { hb_buffer_t *buffer = driver->buffer; unsigned int flags = entry.flags; if (flags & MarkFirst) start = buffer->idx; if (flags & MarkLast) end = MIN (buffer->idx + 1, buffer->len); if ((flags & Verb) && start < end) { /* The following map has two nibbles, for start-side * and end-side. Values of 0,1,2 mean move that many * to the other side. Value of 3 means move 2 and * flip them. */ const unsigned char map[16] = { 0x00, /* 0 no change */ 0x10, /* 1 Ax => xA */ 0x01, /* 2 xD => Dx */ 0x11, /* 3 AxD => DxA */ 0x20, /* 4 ABx => xAB */ 0x30, /* 5 ABx => xBA */ 0x02, /* 6 xCD => CDx */ 0x03, /* 7 xCD => DCx */ 0x12, /* 8 AxCD => CDxA */ 0x13, /* 9 AxCD => DCxA */ 0x21, /* 10 ABxD => DxAB */ 0x31, /* 11 ABxD => DxBA */ 0x22, /* 12 ABxCD => CDxAB */ 0x32, /* 13 ABxCD => CDxBA */ 0x23, /* 14 ABxCD => DCxAB */ 0x33, /* 15 ABxCD => DCxBA */ }; unsigned int m = map[flags & Verb]; unsigned int l = MIN (2, m >> 4); unsigned int r = MIN (2, m & 0x0F); bool reverse_l = 3 == (m >> 4); bool reverse_r = 3 == (m & 0x0F); if (end - start >= l + r) { buffer->merge_clusters (start, MIN (buffer->idx + 1, buffer->len)); buffer->merge_clusters (start, end); hb_glyph_info_t *info = buffer->info; hb_glyph_info_t buf[4]; memcpy (buf, info + start, l * sizeof (buf[0])); memcpy (buf + 2, info + end - r, r * sizeof (buf[0])); if (l != r) memmove (info + start + r, info + start + l, (end - start - l - r) * sizeof (buf[0])); memcpy (info + start, buf + 2, r * sizeof (buf[0])); memcpy (info + end - l, buf, l * sizeof (buf[0])); if (reverse_l) { buf[0] = info[end - 1]; info[end - 1] = info[end - 2]; info[end - 2] = buf[0]; } if (reverse_r) { buf[0] = info[start]; info[start] = info[start + 1]; info[start + 1] = buf[0]; } } } } public: bool ret; private: unsigned int start; unsigned int end; }; bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); driver_context_t dc (this); StateTableDriver driver (machine, c->buffer, c->face); driver.drive (&dc); return_trace (dc.ret); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); return_trace (machine.sanitize (c)); } protected: StateTable machine; public: DEFINE_SIZE_STATIC (16); }; template struct ContextualSubtable { typedef typename Types::HBUINT HBUINT; struct EntryData { HBUINT16 markIndex; /* Index of the substitution table for the * marked glyph (use 0xFFFF for none). */ HBUINT16 currentIndex; /* Index of the substitution table for the * current glyph (use 0xFFFF for none). */ public: DEFINE_SIZE_STATIC (4); }; struct driver_context_t { static constexpr bool in_place = true; enum Flags { SetMark = 0x8000, /* If set, make the current glyph the marked glyph. */ DontAdvance = 0x4000, /* If set, don't advance to the next glyph before * going to the new state. */ Reserved = 0x3FFF, /* These bits are reserved and should be set to 0. */ }; driver_context_t (const ContextualSubtable *table_, hb_aat_apply_context_t *c_) : ret (false), c (c_), mark_set (false), mark (0), table (table_), subs (table+table->substitutionTables) {} bool is_actionable (StateTableDriver *driver, const Entry &entry) { hb_buffer_t *buffer = driver->buffer; if (buffer->idx == buffer->len && !mark_set) return false; return entry.data.markIndex != 0xFFFF || entry.data.currentIndex != 0xFFFF; } void transition (StateTableDriver *driver, const Entry &entry) { hb_buffer_t *buffer = driver->buffer; /* Looks like CoreText applies neither mark nor current substitution for * end-of-text if mark was not explicitly set. */ if (buffer->idx == buffer->len && !mark_set) return; const GlyphID *replacement; replacement = nullptr; if (Types::extended) { if (entry.data.markIndex != 0xFFFF) { const Lookup &lookup = subs[entry.data.markIndex]; replacement = lookup.get_value (buffer->info[mark].codepoint, driver->num_glyphs); } } else { unsigned int offset = entry.data.markIndex + buffer->info[mark].codepoint; const UnsizedArrayOf &subs_old = (const UnsizedArrayOf &) subs; replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)]; if (!replacement->sanitize (&c->sanitizer) || !*replacement) replacement = nullptr; } if (replacement) { buffer->unsafe_to_break (mark, MIN (buffer->idx + 1, buffer->len)); buffer->info[mark].codepoint = *replacement; ret = true; } replacement = nullptr; unsigned int idx = MIN (buffer->idx, buffer->len - 1); if (Types::extended) { if (entry.data.currentIndex != 0xFFFF) { const Lookup &lookup = subs[entry.data.currentIndex]; replacement = lookup.get_value (buffer->info[idx].codepoint, driver->num_glyphs); } } else { unsigned int offset = entry.data.currentIndex + buffer->info[idx].codepoint; const UnsizedArrayOf &subs_old = (const UnsizedArrayOf &) subs; replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)]; if (!replacement->sanitize (&c->sanitizer) || !*replacement) replacement = nullptr; } if (replacement) { buffer->info[idx].codepoint = *replacement; ret = true; } if (entry.flags & SetMark) { mark_set = true; mark = buffer->idx; } } public: bool ret; private: hb_aat_apply_context_t *c; bool mark_set; unsigned int mark; const ContextualSubtable *table; const UnsizedOffsetListOf, HBUINT, false> &subs; }; bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); driver_context_t dc (this, c); StateTableDriver driver (machine, c->buffer, c->face); driver.drive (&dc); return_trace (dc.ret); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); unsigned int num_entries = 0; if (unlikely (!machine.sanitize (c, &num_entries))) return_trace (false); if (!Types::extended) return_trace (substitutionTables.sanitize (c, this, 0)); unsigned int num_lookups = 0; const Entry *entries = machine.get_entries (); for (unsigned int i = 0; i < num_entries; i++) { const EntryData &data = entries[i].data; if (data.markIndex != 0xFFFF) num_lookups = MAX (num_lookups, 1 + data.markIndex); if (data.currentIndex != 0xFFFF) num_lookups = MAX (num_lookups, 1 + data.currentIndex); } return_trace (substitutionTables.sanitize (c, this, num_lookups)); } protected: StateTable machine; NNOffsetTo, HBUINT, false>, HBUINT> substitutionTables; public: DEFINE_SIZE_STATIC (20); }; template struct LigatureEntry; template <> struct LigatureEntry { enum Flags { SetComponent = 0x8000, /* Push this glyph onto the component stack for * eventual processing. */ DontAdvance = 0x4000, /* Leave the glyph pointer at this glyph for the next iteration. */ PerformAction = 0x2000, /* Use the ligActionIndex to process a ligature * group. */ Reserved = 0x1FFF, /* These bits are reserved and should be set to 0. */ }; struct EntryData { HBUINT16 ligActionIndex; /* Index to the first ligActionTable entry * for processing this group, if indicated * by the flags. */ public: DEFINE_SIZE_STATIC (2); }; static bool performAction (const Entry &entry) { return entry.flags & PerformAction; } static unsigned int ligActionIndex (const Entry &entry) { return entry.data.ligActionIndex; } }; template <> struct LigatureEntry { enum Flags { SetComponent = 0x8000, /* Push this glyph onto the component stack for * eventual processing. */ DontAdvance = 0x4000, /* Leave the glyph pointer at this glyph for the next iteration. */ Offset = 0x3FFF, /* Byte offset from beginning of subtable to the * ligature action list. This value must be a * multiple of 4. */ }; typedef void EntryData; static bool performAction (const Entry &entry) { return entry.flags & Offset; } static unsigned int ligActionIndex (const Entry &entry) { return entry.flags & Offset; } }; template struct LigatureSubtable { typedef typename Types::HBUINT HBUINT; typedef LigatureEntry LigatureEntryT; typedef typename LigatureEntryT::EntryData EntryData; struct driver_context_t { static constexpr bool in_place = false; enum { DontAdvance = LigatureEntryT::DontAdvance, }; enum LigActionFlags { LigActionLast = 0x80000000, /* This is the last action in the list. This also * implies storage. */ LigActionStore = 0x40000000, /* Store the ligature at the current cumulated index * in the ligature table in place of the marked * (i.e. currently-popped) glyph. */ LigActionOffset = 0x3FFFFFFF, /* A 30-bit value which is sign-extended to 32-bits * and added to the glyph ID, resulting in an index * into the component table. */ }; driver_context_t (const LigatureSubtable *table_, hb_aat_apply_context_t *c_) : ret (false), c (c_), table (table_), ligAction (table+table->ligAction), component (table+table->component), ligature (table+table->ligature), match_length (0) {} bool is_actionable (StateTableDriver *driver HB_UNUSED, const Entry &entry) { return LigatureEntryT::performAction (entry); } void transition (StateTableDriver *driver, const Entry &entry) { hb_buffer_t *buffer = driver->buffer; DEBUG_MSG (APPLY, nullptr, "Ligature transition at %u", buffer->idx); if (entry.flags & LigatureEntryT::SetComponent) { /* Never mark same index twice, in case DontAdvance was used... */ if (match_length && match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] == buffer->out_len) match_length--; match_positions[match_length++ % ARRAY_LENGTH (match_positions)] = buffer->out_len; DEBUG_MSG (APPLY, nullptr, "Set component at %u", buffer->out_len); } if (LigatureEntryT::performAction (entry)) { DEBUG_MSG (APPLY, nullptr, "Perform action with %u", match_length); unsigned int end = buffer->out_len; if (unlikely (!match_length)) return; if (buffer->idx >= buffer->len) return; /* TODO Work on previous instead? */ unsigned int cursor = match_length; unsigned int action_idx = LigatureEntryT::ligActionIndex (entry); action_idx = Types::offsetToIndex (action_idx, table, ligAction.arrayZ); const HBUINT32 *actionData = &ligAction[action_idx]; unsigned int ligature_idx = 0; unsigned int action; do { if (unlikely (!cursor)) { /* Stack underflow. Clear the stack. */ DEBUG_MSG (APPLY, nullptr, "Stack underflow"); match_length = 0; break; } DEBUG_MSG (APPLY, nullptr, "Moving to stack position %u", cursor - 1); buffer->move_to (match_positions[--cursor % ARRAY_LENGTH (match_positions)]); if (unlikely (!actionData->sanitize (&c->sanitizer))) break; action = *actionData; uint32_t uoffset = action & LigActionOffset; if (uoffset & 0x20000000) uoffset |= 0xC0000000; /* Sign-extend. */ int32_t offset = (int32_t) uoffset; unsigned int component_idx = buffer->cur().codepoint + offset; component_idx = Types::wordOffsetToIndex (component_idx, table, component.arrayZ); const HBUINT16 &componentData = component[component_idx]; if (unlikely (!componentData.sanitize (&c->sanitizer))) break; ligature_idx += componentData; DEBUG_MSG (APPLY, nullptr, "Action store %u last %u", bool (action & LigActionStore), bool (action & LigActionLast)); if (action & (LigActionStore | LigActionLast)) { ligature_idx = Types::offsetToIndex (ligature_idx, table, ligature.arrayZ); const GlyphID &ligatureData = ligature[ligature_idx]; if (unlikely (!ligatureData.sanitize (&c->sanitizer))) break; hb_codepoint_t lig = ligatureData; DEBUG_MSG (APPLY, nullptr, "Produced ligature %u", lig); buffer->replace_glyph (lig); unsigned int lig_end = match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] + 1u; /* Now go and delete all subsequent components. */ while (match_length - 1u > cursor) { DEBUG_MSG (APPLY, nullptr, "Skipping ligature component"); buffer->move_to (match_positions[--match_length % ARRAY_LENGTH (match_positions)]); buffer->replace_glyph (DELETED_GLYPH); } buffer->move_to (lig_end); buffer->merge_out_clusters (match_positions[cursor % ARRAY_LENGTH (match_positions)], buffer->out_len); } actionData++; } while (!(action & LigActionLast)); buffer->move_to (end); } } public: bool ret; private: hb_aat_apply_context_t *c; const LigatureSubtable *table; const UnsizedArrayOf &ligAction; const UnsizedArrayOf &component; const UnsizedArrayOf &ligature; unsigned int match_length; unsigned int match_positions[HB_MAX_CONTEXT_LENGTH]; }; bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); driver_context_t dc (this, c); StateTableDriver driver (machine, c->buffer, c->face); driver.drive (&dc); return_trace (dc.ret); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); /* The rest of array sanitizations are done at run-time. */ return_trace (c->check_struct (this) && machine.sanitize (c) && ligAction && component && ligature); } protected: StateTable machine; NNOffsetTo, HBUINT> ligAction; /* Offset to the ligature action table. */ NNOffsetTo, HBUINT> component; /* Offset to the component table. */ NNOffsetTo, HBUINT> ligature; /* Offset to the actual ligature lists. */ public: DEFINE_SIZE_STATIC (28); }; template struct NoncontextualSubtable { bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); bool ret = false; unsigned int num_glyphs = c->face->get_num_glyphs (); hb_glyph_info_t *info = c->buffer->info; unsigned int count = c->buffer->len; for (unsigned int i = 0; i < count; i++) { const GlyphID *replacement = substitute.get_value (info[i].codepoint, num_glyphs); if (replacement) { info[i].codepoint = *replacement; ret = true; } } return_trace (ret); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); return_trace (substitute.sanitize (c)); } protected: Lookup substitute; public: DEFINE_SIZE_MIN (2); }; template struct InsertionSubtable { typedef typename Types::HBUINT HBUINT; struct EntryData { HBUINT16 currentInsertIndex; /* Zero-based index into the insertion glyph table. * The number of glyphs to be inserted is contained * in the currentInsertCount field in the flags. * A value of 0xFFFF indicates no insertion is to * be done. */ HBUINT16 markedInsertIndex; /* Zero-based index into the insertion glyph table. * The number of glyphs to be inserted is contained * in the markedInsertCount field in the flags. * A value of 0xFFFF indicates no insertion is to * be done. */ public: DEFINE_SIZE_STATIC (4); }; struct driver_context_t { static constexpr bool in_place = false; enum Flags { SetMark = 0x8000, /* If set, mark the current glyph. */ DontAdvance = 0x4000, /* If set, don't advance to the next glyph before * going to the new state. This does not mean * that the glyph pointed to is the same one as * before. If you've made insertions immediately * downstream of the current glyph, the next glyph * processed would in fact be the first one * inserted. */ CurrentIsKashidaLike= 0x2000, /* If set, and the currentInsertList is nonzero, * then the specified glyph list will be inserted * as a kashida-like insertion, either before or * after the current glyph (depending on the state * of the currentInsertBefore flag). If clear, and * the currentInsertList is nonzero, then the * specified glyph list will be inserted as a * split-vowel-like insertion, either before or * after the current glyph (depending on the state * of the currentInsertBefore flag). */ MarkedIsKashidaLike= 0x1000, /* If set, and the markedInsertList is nonzero, * then the specified glyph list will be inserted * as a kashida-like insertion, either before or * after the marked glyph (depending on the state * of the markedInsertBefore flag). If clear, and * the markedInsertList is nonzero, then the * specified glyph list will be inserted as a * split-vowel-like insertion, either before or * after the marked glyph (depending on the state * of the markedInsertBefore flag). */ CurrentInsertBefore= 0x0800, /* If set, specifies that insertions are to be made * to the left of the current glyph. If clear, * they're made to the right of the current glyph. */ MarkedInsertBefore= 0x0400, /* If set, specifies that insertions are to be * made to the left of the marked glyph. If clear, * they're made to the right of the marked glyph. */ CurrentInsertCount= 0x3E0, /* This 5-bit field is treated as a count of the * number of glyphs to insert at the current * position. Since zero means no insertions, the * largest number of insertions at any given * current location is 31 glyphs. */ MarkedInsertCount= 0x001F, /* This 5-bit field is treated as a count of the * number of glyphs to insert at the marked * position. Since zero means no insertions, the * largest number of insertions at any given * marked location is 31 glyphs. */ }; driver_context_t (const InsertionSubtable *table, hb_aat_apply_context_t *c_) : ret (false), c (c_), mark (0), insertionAction (table+table->insertionAction) {} bool is_actionable (StateTableDriver *driver HB_UNUSED, const Entry &entry) { return (entry.flags & (CurrentInsertCount | MarkedInsertCount)) && (entry.data.currentInsertIndex != 0xFFFF ||entry.data.markedInsertIndex != 0xFFFF); } void transition (StateTableDriver *driver, const Entry &entry) { hb_buffer_t *buffer = driver->buffer; unsigned int flags = entry.flags; unsigned mark_loc = buffer->out_len; if (entry.data.markedInsertIndex != 0xFFFF) { unsigned int count = (flags & MarkedInsertCount); unsigned int start = entry.data.markedInsertIndex; const GlyphID *glyphs = &insertionAction[start]; if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0; bool before = flags & MarkedInsertBefore; unsigned int end = buffer->out_len; buffer->move_to (mark); if (buffer->idx < buffer->len && !before) buffer->copy_glyph (); /* TODO We ignore KashidaLike setting. */ for (unsigned int i = 0; i < count; i++) buffer->output_glyph (glyphs[i]); if (buffer->idx < buffer->len && !before) buffer->skip_glyph (); buffer->move_to (end + count); buffer->unsafe_to_break_from_outbuffer (mark, MIN (buffer->idx + 1, buffer->len)); } if (flags & SetMark) mark = mark_loc; if (entry.data.currentInsertIndex != 0xFFFF) { unsigned int count = (flags & CurrentInsertCount) >> 5; unsigned int start = entry.data.currentInsertIndex; const GlyphID *glyphs = &insertionAction[start]; if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0; bool before = flags & CurrentInsertBefore; unsigned int end = buffer->out_len; if (buffer->idx < buffer->len && !before) buffer->copy_glyph (); /* TODO We ignore KashidaLike setting. */ for (unsigned int i = 0; i < count; i++) buffer->output_glyph (glyphs[i]); if (buffer->idx < buffer->len && !before) buffer->skip_glyph (); /* Humm. Not sure where to move to. There's this wording under * DontAdvance flag: * * "If set, don't update the glyph index before going to the new state. * This does not mean that the glyph pointed to is the same one as * before. If you've made insertions immediately downstream of the * current glyph, the next glyph processed would in fact be the first * one inserted." * * This suggests that if DontAdvance is NOT set, we should move to * end+count. If it *was*, then move to end, such that newly inserted * glyphs are now visible. * * https://github.com/harfbuzz/harfbuzz/issues/1224#issuecomment-427691417 */ buffer->move_to ((flags & DontAdvance) ? end : end + count); } } public: bool ret; private: hb_aat_apply_context_t *c; unsigned int mark; const UnsizedArrayOf &insertionAction; }; bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); driver_context_t dc (this, c); StateTableDriver driver (machine, c->buffer, c->face); driver.drive (&dc); return_trace (dc.ret); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); /* The rest of array sanitizations are done at run-time. */ return_trace (c->check_struct (this) && machine.sanitize (c) && insertionAction); } protected: StateTable machine; NNOffsetTo, HBUINT> insertionAction; /* Byte offset from stateHeader to the start of * the insertion glyph table. */ public: DEFINE_SIZE_STATIC (20); }; struct Feature { bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); return_trace (c->check_struct (this)); } public: HBUINT16 featureType; /* The type of feature. */ HBUINT16 featureSetting; /* The feature's setting (aka selector). */ HBUINT32 enableFlags; /* Flags for the settings that this feature * and setting enables. */ HBUINT32 disableFlags; /* Complement of flags for the settings that this * feature and setting disable. */ public: DEFINE_SIZE_STATIC (12); }; template struct ChainSubtable { typedef typename Types::HBUINT HBUINT; template friend struct Chain; unsigned int get_size () const { return length; } unsigned int get_type () const { return coverage & 0xFF; } unsigned int get_coverage () const { return coverage >> (sizeof (HBUINT) * 8 - 8); } enum Coverage { Vertical = 0x80, /* If set, this subtable will only be applied * to vertical text. If clear, this subtable * will only be applied to horizontal text. */ Backwards = 0x40, /* If set, this subtable will process glyphs * in descending order. If clear, it will * process the glyphs in ascending order. */ AllDirections = 0x20, /* If set, this subtable will be applied to * both horizontal and vertical text (i.e. * the state of bit 0x80000000 is ignored). */ Logical = 0x10, /* If set, this subtable will process glyphs * in logical order (or reverse logical order, * depending on the value of bit 0x80000000). */ }; enum Type { Rearrangement = 0, Contextual = 1, Ligature = 2, Noncontextual = 4, Insertion = 5 }; template typename context_t::return_t dispatch (context_t *c) const { unsigned int subtable_type = get_type (); TRACE_DISPATCH (this, subtable_type); switch (subtable_type) { case Rearrangement: return_trace (c->dispatch (u.rearrangement)); case Contextual: return_trace (c->dispatch (u.contextual)); case Ligature: return_trace (c->dispatch (u.ligature)); case Noncontextual: return_trace (c->dispatch (u.noncontextual)); case Insertion: return_trace (c->dispatch (u.insertion)); default: return_trace (c->default_return_value ()); } } bool apply (hb_aat_apply_context_t *c) const { TRACE_APPLY (this); hb_sanitize_with_object_t with (&c->sanitizer, this); return_trace (dispatch (c)); } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); if (!length.sanitize (c) || length <= min_size || !c->check_range (this, length)) return_trace (false); hb_sanitize_with_object_t with (c, this); return_trace (dispatch (c)); } protected: HBUINT length; /* Total subtable length, including this header. */ HBUINT coverage; /* Coverage flags and subtable type. */ HBUINT32 subFeatureFlags;/* The 32-bit mask identifying which subtable this is. */ union { RearrangementSubtable rearrangement; ContextualSubtable contextual; LigatureSubtable ligature; NoncontextualSubtable noncontextual; InsertionSubtable insertion; } u; public: DEFINE_SIZE_MIN (2 * sizeof (HBUINT) + 4); }; template struct Chain { typedef typename Types::HBUINT HBUINT; hb_mask_t compile_flags (const hb_aat_map_builder_t *map) const { hb_mask_t flags = defaultFlags; { unsigned int count = featureCount; for (unsigned i = 0; i < count; i++) { const Feature &feature = featureZ[i]; hb_aat_layout_feature_type_t type = (hb_aat_layout_feature_type_t) (unsigned int) feature.featureType; hb_aat_layout_feature_selector_t setting = (hb_aat_layout_feature_selector_t) (unsigned int) feature.featureSetting; retry: const hb_aat_map_builder_t::feature_info_t *info = map->features.bsearch (type); if (info && info->setting == setting) { flags &= feature.disableFlags; flags |= feature.enableFlags; } else if (type == HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE && setting == HB_AAT_LAYOUT_FEATURE_SELECTOR_SMALL_CAPS) { /* Deprecated. https://github.com/harfbuzz/harfbuzz/issues/1342 */ type = HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE; setting = HB_AAT_LAYOUT_FEATURE_SELECTOR_LOWER_CASE_SMALL_CAPS; goto retry; } } } return flags; } void apply (hb_aat_apply_context_t *c, hb_mask_t flags) const { const ChainSubtable *subtable = &StructAfter > (featureZ.as_array (featureCount)); unsigned int count = subtableCount; for (unsigned int i = 0; i < count; i++) { bool reverse; if (!(subtable->subFeatureFlags & flags)) goto skip; if (!(subtable->get_coverage() & ChainSubtable::AllDirections) && HB_DIRECTION_IS_VERTICAL (c->buffer->props.direction) != bool (subtable->get_coverage() & ChainSubtable::Vertical)) goto skip; /* Buffer contents is always in logical direction. Determine if * we need to reverse before applying this subtable. We reverse * back after if we did reverse indeed. * * Quoting the spac: * """ * Bits 28 and 30 of the coverage field control the order in which * glyphs are processed when the subtable is run by the layout engine. * Bit 28 is used to indicate if the glyph processing direction is * the same as logical order or layout order. Bit 30 is used to * indicate whether glyphs are processed forwards or backwards within * that order. Bit 30 Bit 28 Interpretation for Horizontal Text 0 0 The subtable is processed in layout order (the same order as the glyphs, which is always left-to-right). 1 0 The subtable is processed in reverse layout order (the order opposite that of the glyphs, which is always right-to-left). 0 1 The subtable is processed in logical order (the same order as the characters, which may be left-to-right or right-to-left). 1 1 The subtable is processed in reverse logical order (the order opposite that of the characters, which may be right-to-left or left-to-right). */ reverse = subtable->get_coverage () & ChainSubtable::Logical ? bool (subtable->get_coverage () & ChainSubtable::Backwards) : bool (subtable->get_coverage () & ChainSubtable::Backwards) != HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction); if (!c->buffer->message (c->font, "start chain subtable %d", c->lookup_index)) goto skip; if (reverse) c->buffer->reverse (); subtable->apply (c); if (reverse) c->buffer->reverse (); (void) c->buffer->message (c->font, "end chain subtable %d", c->lookup_index); if (unlikely (!c->buffer->successful)) return; skip: subtable = &StructAfter > (*subtable); c->set_lookup_index (c->lookup_index + 1); } } unsigned int get_size () const { return length; } bool sanitize (hb_sanitize_context_t *c, unsigned int version HB_UNUSED) const { TRACE_SANITIZE (this); if (!length.sanitize (c) || length < min_size || !c->check_range (this, length)) return_trace (false); if (!c->check_array (featureZ.arrayZ, featureCount)) return_trace (false); const ChainSubtable *subtable = &StructAfter > (featureZ.as_array (featureCount)); unsigned int count = subtableCount; for (unsigned int i = 0; i < count; i++) { if (!subtable->sanitize (c)) return_trace (false); subtable = &StructAfter > (*subtable); } return_trace (true); } protected: HBUINT32 defaultFlags; /* The default specification for subtables. */ HBUINT32 length; /* Total byte count, including this header. */ HBUINT featureCount; /* Number of feature subtable entries. */ HBUINT subtableCount; /* The number of subtables in the chain. */ UnsizedArrayOf featureZ; /* Features. */ /*ChainSubtable firstSubtable;*//* Subtables. */ /*subtableGlyphCoverageArray*/ /* Only if version >= 3. We don't use. */ public: DEFINE_SIZE_MIN (8 + 2 * sizeof (HBUINT)); }; /* * The 'mort'/'morx' Table */ template struct mortmorx { static constexpr hb_tag_t tableTag = HB_AAT_TAG_morx; bool has_data () const { return version != 0; } void compile_flags (const hb_aat_map_builder_t *mapper, hb_aat_map_t *map) const { const Chain *chain = &firstChain; unsigned int count = chainCount; for (unsigned int i = 0; i < count; i++) { map->chain_flags.push (chain->compile_flags (mapper)); chain = &StructAfter > (*chain); } } void apply (hb_aat_apply_context_t *c) const { if (unlikely (!c->buffer->successful)) return; c->set_lookup_index (0); const Chain *chain = &firstChain; unsigned int count = chainCount; for (unsigned int i = 0; i < count; i++) { chain->apply (c, c->plan->aat_map.chain_flags[i]); if (unlikely (!c->buffer->successful)) return; chain = &StructAfter > (*chain); } } bool sanitize (hb_sanitize_context_t *c) const { TRACE_SANITIZE (this); if (!version.sanitize (c) || !version || !chainCount.sanitize (c)) return_trace (false); const Chain *chain = &firstChain; unsigned int count = chainCount; for (unsigned int i = 0; i < count; i++) { if (!chain->sanitize (c, version)) return_trace (false); chain = &StructAfter > (*chain); } return_trace (true); } protected: HBUINT16 version; /* Version number of the glyph metamorphosis table. * 1, 2, or 3. */ HBUINT16 unused; /* Set to 0. */ HBUINT32 chainCount; /* Number of metamorphosis chains contained in this * table. */ Chain firstChain; /* Chains. */ public: DEFINE_SIZE_MIN (8); }; struct morx : mortmorx { static constexpr hb_tag_t tableTag = HB_AAT_TAG_morx; }; struct mort : mortmorx { static constexpr hb_tag_t tableTag = HB_AAT_TAG_mort; }; } /* namespace AAT */ #endif /* HB_AAT_LAYOUT_MORX_TABLE_HH */