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Diffstat (limited to 'src/hb-ot-layout-gsubgpos.hh')
| -rw-r--r-- | src/hb-ot-layout-gsubgpos.hh | 2779 |
1 files changed, 2779 insertions, 0 deletions
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh new file mode 100644 index 0000000..88d834d --- /dev/null +++ b/src/hb-ot-layout-gsubgpos.hh @@ -0,0 +1,2779 @@ +/* + * 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_GSUBGPOS_HH +#define HB_OT_LAYOUT_GSUBGPOS_HH + +#include "hb.hh" +#include "hb-buffer.hh" +#include "hb-map.hh" +#include "hb-set.hh" +#include "hb-ot-map.hh" +#include "hb-ot-layout-common.hh" +#include "hb-ot-layout-gdef-table.hh" + + +namespace OT { + + +struct hb_intersects_context_t : + hb_dispatch_context_t<hb_intersects_context_t, bool, 0> +{ + const char *get_name () { return "INTERSECTS"; } + template <typename T> + return_t dispatch (const T &obj) { return obj.intersects (this->glyphs); } + static return_t default_return_value () { return false; } + bool stop_sublookup_iteration (return_t r) const { return r; } + + const hb_set_t *glyphs; + unsigned int debug_depth; + + hb_intersects_context_t (const hb_set_t *glyphs_) : + glyphs (glyphs_), + debug_depth (0) {} +}; + +struct hb_closure_context_t : + hb_dispatch_context_t<hb_closure_context_t, hb_void_t, 0> +{ + const char *get_name () { return "CLOSURE"; } + typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index); + template <typename T> + return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; } + static return_t default_return_value () { return HB_VOID; } + void recurse (unsigned int lookup_index) + { + if (unlikely (nesting_level_left == 0 || !recurse_func)) + return; + + nesting_level_left--; + recurse_func (this, lookup_index); + nesting_level_left++; + } + + bool should_visit_lookup (unsigned int lookup_index) + { + if (is_lookup_done (lookup_index)) + return false; + done_lookups->set (lookup_index, glyphs->get_population ()); + return true; + } + + bool is_lookup_done (unsigned int lookup_index) + { + /* Have we visited this lookup with the current set of glyphs? */ + return done_lookups->get (lookup_index) == glyphs->get_population (); + } + + hb_face_t *face; + hb_set_t *glyphs; + hb_set_t out[1]; + recurse_func_t recurse_func; + unsigned int nesting_level_left; + unsigned int debug_depth; + + hb_closure_context_t (hb_face_t *face_, + hb_set_t *glyphs_, + hb_map_t *done_lookups_, + unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) : + face (face_), + glyphs (glyphs_), + recurse_func (nullptr), + nesting_level_left (nesting_level_left_), + debug_depth (0), + done_lookups (done_lookups_) {} + + ~hb_closure_context_t () { flush (); } + + void set_recurse_func (recurse_func_t func) { recurse_func = func; } + + void flush () + { + hb_set_union (glyphs, out); + hb_set_clear (out); + } + + private: + hb_map_t *done_lookups; +}; + + +struct hb_would_apply_context_t : + hb_dispatch_context_t<hb_would_apply_context_t, bool, HB_DEBUG_WOULD_APPLY> +{ + const char *get_name () { return "WOULD_APPLY"; } + template <typename T> + return_t dispatch (const T &obj) { return obj.would_apply (this); } + static return_t default_return_value () { return false; } + bool stop_sublookup_iteration (return_t r) const { return r; } + + hb_face_t *face; + const hb_codepoint_t *glyphs; + unsigned int len; + bool zero_context; + unsigned int debug_depth; + + hb_would_apply_context_t (hb_face_t *face_, + const hb_codepoint_t *glyphs_, + unsigned int len_, + bool zero_context_) : + face (face_), + glyphs (glyphs_), + len (len_), + zero_context (zero_context_), + debug_depth (0) {} +}; + + +struct hb_collect_glyphs_context_t : + hb_dispatch_context_t<hb_collect_glyphs_context_t, hb_void_t, 0> +{ + const char *get_name () { return "COLLECT_GLYPHS"; } + typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index); + template <typename T> + return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; } + static return_t default_return_value () { return HB_VOID; } + void recurse (unsigned int lookup_index) + { + if (unlikely (nesting_level_left == 0 || !recurse_func)) + return; + + /* Note that GPOS sets recurse_func to nullptr already, so it doesn't get + * past the previous check. For GSUB, we only want to collect the output + * glyphs in the recursion. If output is not requested, we can go home now. + * + * Note further, that the above is not exactly correct. A recursed lookup + * is allowed to match input that is not matched in the context, but that's + * not how most fonts are built. It's possible to relax that and recurse + * with all sets here if it proves to be an issue. + */ + + if (output == hb_set_get_empty ()) + return; + + /* Return if new lookup was recursed to before. */ + if (recursed_lookups->has (lookup_index)) + return; + + hb_set_t *old_before = before; + hb_set_t *old_input = input; + hb_set_t *old_after = after; + before = input = after = hb_set_get_empty (); + + nesting_level_left--; + recurse_func (this, lookup_index); + nesting_level_left++; + + before = old_before; + input = old_input; + after = old_after; + + recursed_lookups->add (lookup_index); + } + + hb_face_t *face; + hb_set_t *before; + hb_set_t *input; + hb_set_t *after; + hb_set_t *output; + recurse_func_t recurse_func; + hb_set_t *recursed_lookups; + unsigned int nesting_level_left; + unsigned int debug_depth; + + hb_collect_glyphs_context_t (hb_face_t *face_, + hb_set_t *glyphs_before, /* OUT. May be NULL */ + hb_set_t *glyphs_input, /* OUT. May be NULL */ + hb_set_t *glyphs_after, /* OUT. May be NULL */ + hb_set_t *glyphs_output, /* OUT. May be NULL */ + unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) : + face (face_), + before (glyphs_before ? glyphs_before : hb_set_get_empty ()), + input (glyphs_input ? glyphs_input : hb_set_get_empty ()), + after (glyphs_after ? glyphs_after : hb_set_get_empty ()), + output (glyphs_output ? glyphs_output : hb_set_get_empty ()), + recurse_func (nullptr), + recursed_lookups (hb_set_create ()), + nesting_level_left (nesting_level_left_), + debug_depth (0) {} + ~hb_collect_glyphs_context_t () { hb_set_destroy (recursed_lookups); } + + void set_recurse_func (recurse_func_t func) { recurse_func = func; } +}; + + + +template <typename set_t> +struct hb_add_coverage_context_t : + hb_dispatch_context_t<hb_add_coverage_context_t<set_t>, const Coverage &, HB_DEBUG_GET_COVERAGE> +{ + const char *get_name () { return "GET_COVERAGE"; } + typedef const Coverage &return_t; + template <typename T> + return_t dispatch (const T &obj) { return obj.get_coverage (); } + static return_t default_return_value () { return Null(Coverage); } + bool stop_sublookup_iteration (return_t r) const + { + r.add_coverage (set); + return false; + } + + hb_add_coverage_context_t (set_t *set_) : + set (set_), + debug_depth (0) {} + + set_t *set; + unsigned int debug_depth; +}; + + +struct hb_ot_apply_context_t : + hb_dispatch_context_t<hb_ot_apply_context_t, bool, HB_DEBUG_APPLY> +{ + struct matcher_t + { + matcher_t () : + lookup_props (0), + ignore_zwnj (false), + ignore_zwj (false), + mask (-1), +#define arg1(arg) (arg) /* Remove the macro to see why it's needed! */ + syllable arg1(0), +#undef arg1 + match_func (nullptr), + match_data (nullptr) {} + + typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data); + + void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; } + void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; } + void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; } + void set_mask (hb_mask_t mask_) { mask = mask_; } + void set_syllable (uint8_t syllable_) { syllable = syllable_; } + void set_match_func (match_func_t match_func_, + const void *match_data_) + { match_func = match_func_; match_data = match_data_; } + + enum may_match_t { + MATCH_NO, + MATCH_YES, + MATCH_MAYBE + }; + + may_match_t may_match (const hb_glyph_info_t &info, + const HBUINT16 *glyph_data) const + { + if (!(info.mask & mask) || + (syllable && syllable != info.syllable ())) + return MATCH_NO; + + if (match_func) + return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO; + + return MATCH_MAYBE; + } + + enum may_skip_t { + SKIP_NO, + SKIP_YES, + SKIP_MAYBE + }; + + may_skip_t may_skip (const hb_ot_apply_context_t *c, + const hb_glyph_info_t &info) const + { + if (!c->check_glyph_property (&info, lookup_props)) + return SKIP_YES; + + if (unlikely (_hb_glyph_info_is_default_ignorable_and_not_hidden (&info) && + (ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) && + (ignore_zwj || !_hb_glyph_info_is_zwj (&info)))) + return SKIP_MAYBE; + + return SKIP_NO; + } + + protected: + unsigned int lookup_props; + bool ignore_zwnj; + bool ignore_zwj; + hb_mask_t mask; + uint8_t syllable; + match_func_t match_func; + const void *match_data; + }; + + struct skipping_iterator_t + { + void init (hb_ot_apply_context_t *c_, bool context_match = false) + { + c = c_; + match_glyph_data = nullptr; + matcher.set_match_func (nullptr, nullptr); + matcher.set_lookup_props (c->lookup_props); + /* Ignore ZWNJ if we are matching GPOS, or matching GSUB context and asked to. */ + matcher.set_ignore_zwnj (c->table_index == 1 || (context_match && c->auto_zwnj)); + /* Ignore ZWJ if we are matching context, or asked to. */ + matcher.set_ignore_zwj (context_match || c->auto_zwj); + matcher.set_mask (context_match ? -1 : c->lookup_mask); + } + void set_lookup_props (unsigned int lookup_props) + { + matcher.set_lookup_props (lookup_props); + } + void set_match_func (matcher_t::match_func_t match_func_, + const void *match_data_, + const HBUINT16 glyph_data[]) + { + matcher.set_match_func (match_func_, match_data_); + match_glyph_data = glyph_data; + } + + void reset (unsigned int start_index_, + unsigned int num_items_) + { + idx = start_index_; + num_items = num_items_; + end = c->buffer->len; + matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0); + } + + void reject () { num_items++; match_glyph_data--; } + + matcher_t::may_skip_t + may_skip (const hb_glyph_info_t &info) const + { return matcher.may_skip (c, info); } + + bool next () + { + assert (num_items > 0); + while (idx + num_items < end) + { + idx++; + const hb_glyph_info_t &info = c->buffer->info[idx]; + + matcher_t::may_skip_t skip = matcher.may_skip (c, info); + if (unlikely (skip == matcher_t::SKIP_YES)) + continue; + + matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data); + if (match == matcher_t::MATCH_YES || + (match == matcher_t::MATCH_MAYBE && + skip == matcher_t::SKIP_NO)) + { + num_items--; + match_glyph_data++; + return true; + } + + if (skip == matcher_t::SKIP_NO) + return false; + } + return false; + } + bool prev () + { + assert (num_items > 0); + while (idx > num_items - 1) + { + idx--; + const hb_glyph_info_t &info = c->buffer->out_info[idx]; + + matcher_t::may_skip_t skip = matcher.may_skip (c, info); + if (unlikely (skip == matcher_t::SKIP_YES)) + continue; + + matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data); + if (match == matcher_t::MATCH_YES || + (match == matcher_t::MATCH_MAYBE && + skip == matcher_t::SKIP_NO)) + { + num_items--; + match_glyph_data++; + return true; + } + + if (skip == matcher_t::SKIP_NO) + return false; + } + return false; + } + + unsigned int idx; + protected: + hb_ot_apply_context_t *c; + matcher_t matcher; + const HBUINT16 *match_glyph_data; + + unsigned int num_items; + unsigned int end; + }; + + + const char *get_name () { return "APPLY"; } + typedef return_t (*recurse_func_t) (hb_ot_apply_context_t *c, unsigned int lookup_index); + template <typename T> + return_t dispatch (const T &obj) { return obj.apply (this); } + static return_t default_return_value () { return false; } + bool stop_sublookup_iteration (return_t r) const { return r; } + return_t recurse (unsigned int sub_lookup_index) + { + if (unlikely (nesting_level_left == 0 || !recurse_func || buffer->max_ops-- <= 0)) + return default_return_value (); + + nesting_level_left--; + bool ret = recurse_func (this, sub_lookup_index); + nesting_level_left++; + return ret; + } + + skipping_iterator_t iter_input, iter_context; + + hb_font_t *font; + hb_face_t *face; + hb_buffer_t *buffer; + recurse_func_t recurse_func; + const GDEF &gdef; + const VariationStore &var_store; + + hb_direction_t direction; + hb_mask_t lookup_mask; + unsigned int table_index; /* GSUB/GPOS */ + unsigned int lookup_index; + unsigned int lookup_props; + unsigned int nesting_level_left; + unsigned int debug_depth; + + bool has_glyph_classes; + bool auto_zwnj; + bool auto_zwj; + bool random; + + uint32_t random_state; + + + hb_ot_apply_context_t (unsigned int table_index_, + hb_font_t *font_, + hb_buffer_t *buffer_) : + iter_input (), iter_context (), + font (font_), face (font->face), buffer (buffer_), + recurse_func (nullptr), + gdef (*face->table.GDEF->table), + var_store (gdef.get_var_store ()), + direction (buffer_->props.direction), + lookup_mask (1), + table_index (table_index_), + lookup_index ((unsigned int) -1), + lookup_props (0), + nesting_level_left (HB_MAX_NESTING_LEVEL), + debug_depth (0), + has_glyph_classes (gdef.has_glyph_classes ()), + auto_zwnj (true), + auto_zwj (true), + random (false), + random_state (1) { init_iters (); } + + void init_iters () + { + iter_input.init (this, false); + iter_context.init (this, true); + } + + void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; init_iters (); } + void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; init_iters (); } + void set_auto_zwnj (bool auto_zwnj_) { auto_zwnj = auto_zwnj_; init_iters (); } + void set_random (bool random_) { random = random_; } + void set_recurse_func (recurse_func_t func) { recurse_func = func; } + void set_lookup_index (unsigned int lookup_index_) { lookup_index = lookup_index_; } + void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; init_iters (); } + + uint32_t random_number () + { + /* http://www.cplusplus.com/reference/random/minstd_rand/ */ + random_state = random_state * 48271 % 2147483647; + return random_state; + } + + bool match_properties_mark (hb_codepoint_t glyph, + unsigned int glyph_props, + unsigned int match_props) const + { + /* If using mark filtering sets, the high short of + * match_props has the set index. + */ + if (match_props & LookupFlag::UseMarkFilteringSet) + return gdef.mark_set_covers (match_props >> 16, glyph); + + /* The second byte of match_props has the meaning + * "ignore marks of attachment type different than + * the attachment type specified." + */ + if (match_props & LookupFlag::MarkAttachmentType) + return (match_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType); + + return true; + } + + bool check_glyph_property (const hb_glyph_info_t *info, + unsigned int match_props) const + { + hb_codepoint_t glyph = info->codepoint; + unsigned int glyph_props = _hb_glyph_info_get_glyph_props (info); + + /* Not covered, if, for example, glyph class is ligature and + * match_props includes LookupFlags::IgnoreLigatures + */ + if (glyph_props & match_props & LookupFlag::IgnoreFlags) + return false; + + if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK)) + return match_properties_mark (glyph, glyph_props, match_props); + + return true; + } + + void _set_glyph_props (hb_codepoint_t glyph_index, + unsigned int class_guess = 0, + bool ligature = false, + bool component = false) const + { + unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) & + HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE; + add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED; + if (ligature) + { + add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED; + /* In the only place that the MULTIPLIED bit is used, Uniscribe + * seems to only care about the "last" transformation between + * Ligature and Multiple substitutions. Ie. if you ligate, expand, + * and ligate again, it forgives the multiplication and acts as + * if only ligation happened. As such, clear MULTIPLIED bit. + */ + add_in &= ~HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED; + } + if (component) + add_in |= HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED; + if (likely (has_glyph_classes)) + _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index)); + else if (class_guess) + _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess); + } + + void replace_glyph (hb_codepoint_t glyph_index) const + { + _set_glyph_props (glyph_index); + buffer->replace_glyph (glyph_index); + } + void replace_glyph_inplace (hb_codepoint_t glyph_index) const + { + _set_glyph_props (glyph_index); + buffer->cur().codepoint = glyph_index; + } + void replace_glyph_with_ligature (hb_codepoint_t glyph_index, + unsigned int class_guess) const + { + _set_glyph_props (glyph_index, class_guess, true); + buffer->replace_glyph (glyph_index); + } + void output_glyph_for_component (hb_codepoint_t glyph_index, + unsigned int class_guess) const + { + _set_glyph_props (glyph_index, class_guess, false, true); + buffer->output_glyph (glyph_index); + } +}; + + +struct hb_get_subtables_context_t : + hb_dispatch_context_t<hb_get_subtables_context_t, hb_void_t, HB_DEBUG_APPLY> +{ + template <typename Type> + static bool apply_to (const void *obj, OT::hb_ot_apply_context_t *c) + { + const Type *typed_obj = (const Type *) obj; + return typed_obj->apply (c); + } + + typedef bool (*hb_apply_func_t) (const void *obj, OT::hb_ot_apply_context_t *c); + + struct hb_applicable_t + { + template <typename T> + void init (const T &obj_, hb_apply_func_t apply_func_) + { + obj = &obj_; + apply_func = apply_func_; + digest.init (); + obj_.get_coverage ().add_coverage (&digest); + } + + bool apply (OT::hb_ot_apply_context_t *c) const + { + return digest.may_have (c->buffer->cur().codepoint) && apply_func (obj, c); + } + + private: + const void *obj; + hb_apply_func_t apply_func; + hb_set_digest_t digest; + }; + + typedef hb_vector_t<hb_applicable_t> array_t; + + /* Dispatch interface. */ + const char *get_name () { return "GET_SUBTABLES"; } + template <typename T> + return_t dispatch (const T &obj) + { + hb_applicable_t *entry = array.push(); + entry->init (obj, apply_to<T>); + return HB_VOID; + } + static return_t default_return_value () { return HB_VOID; } + + hb_get_subtables_context_t (array_t &array_) : + array (array_), + debug_depth (0) {} + + array_t &array; + unsigned int debug_depth; +}; + + + + +typedef bool (*intersects_func_t) (const hb_set_t *glyphs, const HBUINT16 &value, const void *data); +typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const HBUINT16 &value, const void *data); +typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data); + +struct ContextClosureFuncs +{ + intersects_func_t intersects; +}; +struct ContextCollectGlyphsFuncs +{ + collect_glyphs_func_t collect; +}; +struct ContextApplyFuncs +{ + match_func_t match; +}; + + +static inline bool intersects_glyph (const hb_set_t *glyphs, const HBUINT16 &value, const void *data HB_UNUSED) +{ + return glyphs->has (value); +} +static inline bool intersects_class (const hb_set_t *glyphs, const HBUINT16 &value, const void *data) +{ + const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data); + return class_def.intersects_class (glyphs, value); +} +static inline bool intersects_coverage (const hb_set_t *glyphs, const HBUINT16 &value, const void *data) +{ + const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value; + return (data+coverage).intersects (glyphs); +} + +static inline bool intersects_array (const hb_set_t *glyphs, + unsigned int count, + const HBUINT16 values[], + intersects_func_t intersects_func, + const void *intersects_data) +{ + for (unsigned int i = 0; i < count; i++) + if (likely (!intersects_func (glyphs, values[i], intersects_data))) + return false; + return true; +} + + +static inline void collect_glyph (hb_set_t *glyphs, const HBUINT16 &value, const void *data HB_UNUSED) +{ + glyphs->add (value); +} +static inline void collect_class (hb_set_t *glyphs, const HBUINT16 &value, const void *data) +{ + const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data); + class_def.add_class (glyphs, value); +} +static inline void collect_coverage (hb_set_t *glyphs, const HBUINT16 &value, const void *data) +{ + const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value; + (data+coverage).add_coverage (glyphs); +} +static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED, + hb_set_t *glyphs, + unsigned int count, + const HBUINT16 values[], + collect_glyphs_func_t collect_func, + const void *collect_data) +{ + for (unsigned int i = 0; i < count; i++) + collect_func (glyphs, values[i], collect_data); +} + + +static inline bool match_glyph (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data HB_UNUSED) +{ + return glyph_id == value; +} +static inline bool match_class (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data) +{ + const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data); + return class_def.get_class (glyph_id) == value; +} +static inline bool match_coverage (hb_codepoint_t glyph_id, const HBUINT16 &value, const void *data) +{ + const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value; + return (data+coverage).get_coverage (glyph_id) != NOT_COVERED; +} + +static inline bool would_match_input (hb_would_apply_context_t *c, + unsigned int count, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + match_func_t match_func, + const void *match_data) +{ + if (count != c->len) + return false; + + for (unsigned int i = 1; i < count; i++) + if (likely (!match_func (c->glyphs[i], input[i - 1], match_data))) + return false; + + return true; +} +static inline bool match_input (hb_ot_apply_context_t *c, + unsigned int count, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + match_func_t match_func, + const void *match_data, + unsigned int *end_offset, + unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], + unsigned int *p_total_component_count = nullptr) +{ + TRACE_APPLY (nullptr); + + if (unlikely (count > HB_MAX_CONTEXT_LENGTH)) return_trace (false); + + hb_buffer_t *buffer = c->buffer; + + hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input; + skippy_iter.reset (buffer->idx, count - 1); + skippy_iter.set_match_func (match_func, match_data, input); + + /* + * This is perhaps the trickiest part of OpenType... Remarks: + * + * - If all components of the ligature were marks, we call this a mark ligature. + * + * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize + * it as a ligature glyph. + * + * - Ligatures cannot be formed across glyphs attached to different components + * of previous ligatures. Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and + * LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother. + * However, it would be wrong to ligate that SHADDA,FATHA sequence. + * There are a couple of exceptions to this: + * + * o If a ligature tries ligating with marks that belong to it itself, go ahead, + * assuming that the font designer knows what they are doing (otherwise it can + * break Indic stuff when a matra wants to ligate with a conjunct, + * + * o If two marks want to ligate and they belong to different components of the + * same ligature glyph, and said ligature glyph is to be ignored according to + * mark-filtering rules, then allow. + * https://github.com/harfbuzz/harfbuzz/issues/545 + */ + + unsigned int total_component_count = 0; + total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur()); + + unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur()); + unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur()); + + enum { + LIGBASE_NOT_CHECKED, + LIGBASE_MAY_NOT_SKIP, + LIGBASE_MAY_SKIP + } ligbase = LIGBASE_NOT_CHECKED; + + match_positions[0] = buffer->idx; + for (unsigned int i = 1; i < count; i++) + { + if (!skippy_iter.next ()) return_trace (false); + + match_positions[i] = skippy_iter.idx; + + unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]); + unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]); + + if (first_lig_id && first_lig_comp) + { + /* If first component was attached to a previous ligature component, + * all subsequent components should be attached to the same ligature + * component, otherwise we shouldn't ligate them... */ + if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp) + { + /* ...unless, we are attached to a base ligature and that base + * ligature is ignorable. */ + if (ligbase == LIGBASE_NOT_CHECKED) + { + bool found = false; + const hb_glyph_info_t *out = buffer->out_info; + unsigned int j = buffer->out_len; + while (j && _hb_glyph_info_get_lig_id (&out[j - 1]) == first_lig_id) + { + if (_hb_glyph_info_get_lig_comp (&out[j - 1]) == 0) + { + j--; + found = true; + break; + } + j--; + } + + if (found && skippy_iter.may_skip (out[j]) == hb_ot_apply_context_t::matcher_t::SKIP_YES) + ligbase = LIGBASE_MAY_SKIP; + else + ligbase = LIGBASE_MAY_NOT_SKIP; + } + + if (ligbase == LIGBASE_MAY_NOT_SKIP) + return_trace (false); + } + } + else + { + /* If first component was NOT attached to a previous ligature component, + * all subsequent components should also NOT be attached to any ligature + * component, unless they are attached to the first component itself! */ + if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id)) + return_trace (false); + } + + total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]); + } + + *end_offset = skippy_iter.idx - buffer->idx + 1; + + if (p_total_component_count) + *p_total_component_count = total_component_count; + + return_trace (true); +} +static inline bool ligate_input (hb_ot_apply_context_t *c, + unsigned int count, /* Including the first glyph */ + const unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */ + unsigned int match_length, + hb_codepoint_t lig_glyph, + unsigned int total_component_count) +{ + TRACE_APPLY (nullptr); + + hb_buffer_t *buffer = c->buffer; + + buffer->merge_clusters (buffer->idx, buffer->idx + match_length); + + /* - If a base and one or more marks ligate, consider that as a base, NOT + * ligature, such that all following marks can still attach to it. + * https://github.com/harfbuzz/harfbuzz/issues/1109 + * + * - If all components of the ligature were marks, we call this a mark ligature. + * If it *is* a mark ligature, we don't allocate a new ligature id, and leave + * the ligature to keep its old ligature id. This will allow it to attach to + * a base ligature in GPOS. Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH, + * and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA with a + * ligature id and component value of 2. Then if SHADDA,FATHA form a ligature + * later, we don't want them to lose their ligature id/component, otherwise + * GPOS will fail to correctly position the mark ligature on top of the + * LAM,LAM,HEH ligature. See: + * https://bugzilla.gnome.org/show_bug.cgi?id=676343 + * + * - If a ligature is formed of components that some of which are also ligatures + * themselves, and those ligature components had marks attached to *their* + * components, we have to attach the marks to the new ligature component + * positions! Now *that*'s tricky! And these marks may be following the + * last component of the whole sequence, so we should loop forward looking + * for them and update them. + * + * Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a + * 'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature + * id and component == 1. Now, during 'liga', the LAM and the LAM-HEH ligature + * form a LAM-LAM-HEH ligature. We need to reassign the SHADDA and FATHA to + * the new ligature with a component value of 2. + * + * This in fact happened to a font... See: + * https://bugzilla.gnome.org/show_bug.cgi?id=437633 + */ + + bool is_base_ligature = _hb_glyph_info_is_base_glyph (&buffer->info[match_positions[0]]); + bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->info[match_positions[0]]); + for (unsigned int i = 1; i < count; i++) + if (!_hb_glyph_info_is_mark (&buffer->info[match_positions[i]])) + { + is_base_ligature = false; + is_mark_ligature = false; + break; + } + bool is_ligature = !is_base_ligature && !is_mark_ligature; + + unsigned int klass = is_ligature ? HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE : 0; + unsigned int lig_id = is_ligature ? _hb_allocate_lig_id (buffer) : 0; + unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur()); + unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur()); + unsigned int components_so_far = last_num_components; + + if (is_ligature) + { + _hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count); + if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) + { + _hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER); + } + } + c->replace_glyph_with_ligature (lig_glyph, klass); + + for (unsigned int i = 1; i < count; i++) + { + while (buffer->idx < match_positions[i] && buffer->successful) + { + if (is_ligature) + { + unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->cur()); + if (this_comp == 0) + this_comp = last_num_components; + unsigned int new_lig_comp = components_so_far - last_num_components + + MIN (this_comp, last_num_components); + _hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp); + } + buffer->next_glyph (); + } + + last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur()); + last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur()); + components_so_far += last_num_components; + + /* Skip the base glyph */ + buffer->idx++; + } + + if (!is_mark_ligature && last_lig_id) { + /* Re-adjust components for any marks following. */ + for (unsigned int i = buffer->idx; i < buffer->len; i++) { + if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) { + unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->info[i]); + if (!this_comp) + break; + unsigned int new_lig_comp = components_so_far - last_num_components + + MIN (this_comp, last_num_components); + _hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp); + } else + break; + } + } + return_trace (true); +} + +static inline bool match_backtrack (hb_ot_apply_context_t *c, + unsigned int count, + const HBUINT16 backtrack[], + match_func_t match_func, + const void *match_data, + unsigned int *match_start) +{ + TRACE_APPLY (nullptr); + + hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context; + skippy_iter.reset (c->buffer->backtrack_len (), count); + skippy_iter.set_match_func (match_func, match_data, backtrack); + + for (unsigned int i = 0; i < count; i++) + if (!skippy_iter.prev ()) + return_trace (false); + + *match_start = skippy_iter.idx; + + return_trace (true); +} + +static inline bool match_lookahead (hb_ot_apply_context_t *c, + unsigned int count, + const HBUINT16 lookahead[], + match_func_t match_func, + const void *match_data, + unsigned int offset, + unsigned int *end_index) +{ + TRACE_APPLY (nullptr); + + hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context; + skippy_iter.reset (c->buffer->idx + offset - 1, count); + skippy_iter.set_match_func (match_func, match_data, lookahead); + + for (unsigned int i = 0; i < count; i++) + if (!skippy_iter.next ()) + return_trace (false); + + *end_index = skippy_iter.idx + 1; + + return_trace (true); +} + + + +struct LookupRecord +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this)); + } + + HBUINT16 sequenceIndex; /* Index into current glyph + * sequence--first glyph = 0 */ + HBUINT16 lookupListIndex; /* Lookup to apply to that + * position--zero--based */ + public: + DEFINE_SIZE_STATIC (4); +}; + +template <typename context_t> +static inline void recurse_lookups (context_t *c, + unsigned int lookupCount, + const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */) +{ + for (unsigned int i = 0; i < lookupCount; i++) + c->recurse (lookupRecord[i].lookupListIndex); +} + +static inline bool apply_lookup (hb_ot_apply_context_t *c, + unsigned int count, /* Including the first glyph */ + unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */ + unsigned int lookupCount, + const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */ + unsigned int match_length) +{ + TRACE_APPLY (nullptr); + + hb_buffer_t *buffer = c->buffer; + int end; + + /* All positions are distance from beginning of *output* buffer. + * Adjust. */ + { + unsigned int bl = buffer->backtrack_len (); + end = bl + match_length; + + int delta = bl - buffer->idx; + /* Convert positions to new indexing. */ + for (unsigned int j = 0; j < count; j++) + match_positions[j] += delta; + } + + for (unsigned int i = 0; i < lookupCount && buffer->successful; i++) + { + unsigned int idx = lookupRecord[i].sequenceIndex; + if (idx >= count) + continue; + + /* Don't recurse to ourself at same position. + * Note that this test is too naive, it doesn't catch longer loops. */ + if (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index) + continue; + + if (unlikely (!buffer->move_to (match_positions[idx]))) + break; + + if (unlikely (buffer->max_ops <= 0)) + break; + + unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len (); + if (!c->recurse (lookupRecord[i].lookupListIndex)) + continue; + + unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len (); + int delta = new_len - orig_len; + + if (!delta) + continue; + + /* Recursed lookup changed buffer len. Adjust. + * + * TODO: + * + * Right now, if buffer length increased by n, we assume n new glyphs + * were added right after the current position, and if buffer length + * was decreased by n, we assume n match positions after the current + * one where removed. The former (buffer length increased) case is + * fine, but the decrease case can be improved in at least two ways, + * both of which are significant: + * + * - If recursed-to lookup is MultipleSubst and buffer length + * decreased, then it's current match position that was deleted, + * NOT the one after it. + * + * - If buffer length was decreased by n, it does not necessarily + * mean that n match positions where removed, as there might + * have been marks and default-ignorables in the sequence. We + * should instead drop match positions between current-position + * and current-position + n instead. + * + * It should be possible to construct tests for both of these cases. + */ + + end += delta; + if (end <= int (match_positions[idx])) + { + /* End might end up being smaller than match_positions[idx] if the recursed + * lookup ended up removing many items, more than we have had matched. + * Just never rewind end back and get out of here. + * https://bugs.chromium.org/p/chromium/issues/detail?id=659496 */ + end = match_positions[idx]; + /* There can't be any further changes. */ + break; + } + + unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */ + + if (delta > 0) + { + if (unlikely (delta + count > HB_MAX_CONTEXT_LENGTH)) + break; + } + else + { + /* NOTE: delta is negative. */ + delta = MAX (delta, (int) next - (int) count); + next -= delta; + } + + /* Shift! */ + memmove (match_positions + next + delta, match_positions + next, + (count - next) * sizeof (match_positions[0])); + next += delta; + count += delta; + + /* Fill in new entries. */ + for (unsigned int j = idx + 1; j < next; j++) + match_positions[j] = match_positions[j - 1] + 1; + + /* And fixup the rest. */ + for (; next < count; next++) + match_positions[next] += delta; + } + + buffer->move_to (end); + + return_trace (true); +} + + + +/* Contextual lookups */ + +struct ContextClosureLookupContext +{ + ContextClosureFuncs funcs; + const void *intersects_data; +}; + +struct ContextCollectGlyphsLookupContext +{ + ContextCollectGlyphsFuncs funcs; + const void *collect_data; +}; + +struct ContextApplyLookupContext +{ + ContextApplyFuncs funcs; + const void *match_data; +}; + +static inline bool context_intersects (const hb_set_t *glyphs, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + ContextClosureLookupContext &lookup_context) +{ + return intersects_array (glyphs, + inputCount ? inputCount - 1 : 0, input, + lookup_context.funcs.intersects, lookup_context.intersects_data); +} + +static inline void context_closure_lookup (hb_closure_context_t *c, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ContextClosureLookupContext &lookup_context) +{ + if (context_intersects (c->glyphs, + inputCount, input, + lookup_context)) + recurse_lookups (c, + lookupCount, lookupRecord); +} + +static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ContextCollectGlyphsLookupContext &lookup_context) +{ + collect_array (c, c->input, + inputCount ? inputCount - 1 : 0, input, + lookup_context.funcs.collect, lookup_context.collect_data); + recurse_lookups (c, + lookupCount, lookupRecord); +} + +static inline bool context_would_apply_lookup (hb_would_apply_context_t *c, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookupCount HB_UNUSED, + const LookupRecord lookupRecord[] HB_UNUSED, + ContextApplyLookupContext &lookup_context) +{ + return would_match_input (c, + inputCount, input, + lookup_context.funcs.match, lookup_context.match_data); +} +static inline bool context_apply_lookup (hb_ot_apply_context_t *c, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ContextApplyLookupContext &lookup_context) +{ + unsigned int match_length = 0; + unsigned int match_positions[HB_MAX_CONTEXT_LENGTH]; + return match_input (c, + inputCount, input, + lookup_context.funcs.match, lookup_context.match_data, + &match_length, match_positions) + && (c->buffer->unsafe_to_break (c->buffer->idx, c->buffer->idx + match_length), + apply_lookup (c, + inputCount, match_positions, + lookupCount, lookupRecord, + match_length)); +} + +struct Rule +{ + bool intersects (const hb_set_t *glyphs, ContextClosureLookupContext &lookup_context) const + { + return context_intersects (glyphs, + inputCount, inputZ.arrayZ, + lookup_context); + } + + void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const + { + const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> > + (inputZ.as_array ((inputCount ? inputCount - 1 : 0))); + context_closure_lookup (c, + inputCount, inputZ.arrayZ, + lookupCount, lookupRecord.arrayZ, + lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c, + ContextCollectGlyphsLookupContext &lookup_context) const + { + const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> > + (inputZ.as_array (inputCount ? inputCount - 1 : 0)); + context_collect_glyphs_lookup (c, + inputCount, inputZ.arrayZ, + lookupCount, lookupRecord.arrayZ, + lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c, + ContextApplyLookupContext &lookup_context) const + { + TRACE_WOULD_APPLY (this); + const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> > + (inputZ.as_array (inputCount ? inputCount - 1 : 0)); + return_trace (context_would_apply_lookup (c, inputCount, inputZ.arrayZ, lookupCount, lookupRecord.arrayZ, lookup_context)); + } + + bool apply (hb_ot_apply_context_t *c, + ContextApplyLookupContext &lookup_context) const + { + TRACE_APPLY (this); + const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord> > + (inputZ.as_array (inputCount ? inputCount - 1 : 0)); + return_trace (context_apply_lookup (c, inputCount, inputZ.arrayZ, lookupCount, lookupRecord.arrayZ, lookup_context)); + } + + public: + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (inputCount.sanitize (c) && + lookupCount.sanitize (c) && + c->check_range (inputZ.arrayZ, + inputZ.item_size * (inputCount ? inputCount - 1 : 0) + + LookupRecord::static_size * lookupCount)); + } + + protected: + HBUINT16 inputCount; /* Total number of glyphs in input + * glyph sequence--includes the first + * glyph */ + HBUINT16 lookupCount; /* Number of LookupRecords */ + UnsizedArrayOf<HBUINT16> + inputZ; /* Array of match inputs--start with + * second glyph */ +/*UnsizedArrayOf<LookupRecord> + lookupRecordX;*/ /* Array of LookupRecords--in + * design order */ + public: + DEFINE_SIZE_ARRAY (4, inputZ); +}; + +struct RuleSet +{ + bool intersects (const hb_set_t *glyphs, + ContextClosureLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + if ((this+rule[i]).intersects (glyphs, lookup_context)) + return true; + return false; + } + + void closure (hb_closure_context_t *c, + ContextClosureLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + (this+rule[i]).closure (c, lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c, + ContextCollectGlyphsLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + (this+rule[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c, + ContextApplyLookupContext &lookup_context) const + { + TRACE_WOULD_APPLY (this); + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + { + if ((this+rule[i]).would_apply (c, lookup_context)) + return_trace (true); + } + return_trace (false); + } + + bool apply (hb_ot_apply_context_t *c, + ContextApplyLookupContext &lookup_context) const + { + TRACE_APPLY (this); + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + { + if ((this+rule[i]).apply (c, lookup_context)) + return_trace (true); + } + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (rule.sanitize (c, this)); + } + + protected: + OffsetArrayOf<Rule> + rule; /* Array of Rule tables + * ordered by preference */ + public: + DEFINE_SIZE_ARRAY (2, rule); +}; + + +struct ContextFormat1 +{ + bool intersects (const hb_set_t *glyphs) const + { + struct ContextClosureLookupContext lookup_context = { + {intersects_glyph}, + nullptr + }; + + unsigned int count = ruleSet.len; + for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ()) + { + if (unlikely (iter.get_coverage () >= count)) + break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */ + if (glyphs->has (iter.get_glyph ()) && + (this+ruleSet[iter.get_coverage ()]).intersects (glyphs, lookup_context)) + return true; + } + return false; + } + + void closure (hb_closure_context_t *c) const + { + struct ContextClosureLookupContext lookup_context = { + {intersects_glyph}, + nullptr + }; + + unsigned int count = ruleSet.len; + for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ()) + { + if (unlikely (iter.get_coverage () >= count)) + break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */ + if (c->glyphs->has (iter.get_glyph ())) + (this+ruleSet[iter.get_coverage ()]).closure (c, lookup_context); + } + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + (this+coverage).add_coverage (c->input); + + struct ContextCollectGlyphsLookupContext lookup_context = { + {collect_glyph}, + nullptr + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + (this+ruleSet[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])]; + struct ContextApplyLookupContext lookup_context = { + {match_glyph}, + nullptr + }; + return_trace (rule_set.would_apply (c, lookup_context)); + } + + const Coverage &get_coverage () const { return this+coverage; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) + return_trace (false); + + const RuleSet &rule_set = this+ruleSet[index]; + struct ContextApplyLookupContext lookup_context = { + {match_glyph}, + nullptr + }; + return_trace (rule_set.apply (c, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 1 */ + OffsetTo<Coverage> + coverage; /* Offset to Coverage table--from + * beginning of table */ + OffsetArrayOf<RuleSet> + ruleSet; /* Array of RuleSet tables + * ordered by Coverage Index */ + public: + DEFINE_SIZE_ARRAY (6, ruleSet); +}; + + +struct ContextFormat2 +{ + bool intersects (const hb_set_t *glyphs) const + { + if (!(this+coverage).intersects (glyphs)) + return false; + + const ClassDef &class_def = this+classDef; + + struct ContextClosureLookupContext lookup_context = { + {intersects_class}, + &class_def + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + if (class_def.intersects_class (glyphs, i) && + (this+ruleSet[i]).intersects (glyphs, lookup_context)) + return true; + + return false; + } + + void closure (hb_closure_context_t *c) const + { + if (!(this+coverage).intersects (c->glyphs)) + return; + + const ClassDef &class_def = this+classDef; + + struct ContextClosureLookupContext lookup_context = { + {intersects_class}, + &class_def + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + if (class_def.intersects_class (c->glyphs, i)) { + const RuleSet &rule_set = this+ruleSet[i]; + rule_set.closure (c, lookup_context); + } + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + (this+coverage).add_coverage (c->input); + + const ClassDef &class_def = this+classDef; + struct ContextCollectGlyphsLookupContext lookup_context = { + {collect_class}, + &class_def + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + (this+ruleSet[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const ClassDef &class_def = this+classDef; + unsigned int index = class_def.get_class (c->glyphs[0]); + const RuleSet &rule_set = this+ruleSet[index]; + struct ContextApplyLookupContext lookup_context = { + {match_class}, + &class_def + }; + return_trace (rule_set.would_apply (c, lookup_context)); + } + + const Coverage &get_coverage () const { return this+coverage; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const ClassDef &class_def = this+classDef; + index = class_def.get_class (c->buffer->cur().codepoint); + const RuleSet &rule_set = this+ruleSet[index]; + struct ContextApplyLookupContext lookup_context = { + {match_class}, + &class_def + }; + return_trace (rule_set.apply (c, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 2 */ + OffsetTo<Coverage> + coverage; /* Offset to Coverage table--from + * beginning of table */ + OffsetTo<ClassDef> + classDef; /* Offset to glyph ClassDef table--from + * beginning of table */ + OffsetArrayOf<RuleSet> + ruleSet; /* Array of RuleSet tables + * ordered by class */ + public: + DEFINE_SIZE_ARRAY (8, ruleSet); +}; + + +struct ContextFormat3 +{ + bool intersects (const hb_set_t *glyphs) const + { + if (!(this+coverageZ[0]).intersects (glyphs)) + return false; + + struct ContextClosureLookupContext lookup_context = { + {intersects_coverage}, + this + }; + return context_intersects (glyphs, + glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), + lookup_context); + } + + void closure (hb_closure_context_t *c) const + { + if (!(this+coverageZ[0]).intersects (c->glyphs)) + return; + + const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount)); + struct ContextClosureLookupContext lookup_context = { + {intersects_coverage}, + this + }; + context_closure_lookup (c, + glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), + lookupCount, lookupRecord, + lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + (this+coverageZ[0]).add_coverage (c->input); + + const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount)); + struct ContextCollectGlyphsLookupContext lookup_context = { + {collect_coverage}, + this + }; + + context_collect_glyphs_lookup (c, + glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), + lookupCount, lookupRecord, + lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount)); + struct ContextApplyLookupContext lookup_context = { + {match_coverage}, + this + }; + return_trace (context_would_apply_lookup (c, glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), lookupCount, lookupRecord, lookup_context)); + } + + const Coverage &get_coverage () const { return this+coverageZ[0]; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount)); + struct ContextApplyLookupContext lookup_context = { + {match_coverage}, + this + }; + return_trace (context_apply_lookup (c, glyphCount, (const HBUINT16 *) (coverageZ.arrayZ + 1), lookupCount, lookupRecord, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (!c->check_struct (this)) return_trace (false); + unsigned int count = glyphCount; + if (!count) return_trace (false); /* We want to access coverageZ[0] freely. */ + if (!c->check_array (coverageZ.arrayZ, count)) return_trace (false); + for (unsigned int i = 0; i < count; i++) + if (!coverageZ[i].sanitize (c, this)) return_trace (false); + const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount)); + return_trace (c->check_array (lookupRecord, lookupCount)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 3 */ + HBUINT16 glyphCount; /* Number of glyphs in the input glyph + * sequence */ + HBUINT16 lookupCount; /* Number of LookupRecords */ + UnsizedArrayOf<OffsetTo<Coverage> > + coverageZ; /* Array of offsets to Coverage + * table in glyph sequence order */ +/*UnsizedArrayOf<LookupRecord> + lookupRecordX;*/ /* Array of LookupRecords--in + * design order */ + public: + DEFINE_SIZE_ARRAY (6, coverageZ); +}; + +struct Context +{ + template <typename context_t> + typename context_t::return_t dispatch (context_t *c) const + { + TRACE_DISPATCH (this, u.format); + if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ()); + switch (u.format) { + case 1: return_trace (c->dispatch (u.format1)); + case 2: return_trace (c->dispatch (u.format2)); + case 3: return_trace (c->dispatch (u.format3)); + default:return_trace (c->default_return_value ()); + } + } + + protected: + union { + HBUINT16 format; /* Format identifier */ + ContextFormat1 format1; + ContextFormat2 format2; + ContextFormat3 format3; + } u; +}; + + +/* Chaining Contextual lookups */ + +struct ChainContextClosureLookupContext +{ + ContextClosureFuncs funcs; + const void *intersects_data[3]; +}; + +struct ChainContextCollectGlyphsLookupContext +{ + ContextCollectGlyphsFuncs funcs; + const void *collect_data[3]; +}; + +struct ChainContextApplyLookupContext +{ + ContextApplyFuncs funcs; + const void *match_data[3]; +}; + +static inline bool chain_context_intersects (const hb_set_t *glyphs, + unsigned int backtrackCount, + const HBUINT16 backtrack[], + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookaheadCount, + const HBUINT16 lookahead[], + ChainContextClosureLookupContext &lookup_context) +{ + return intersects_array (glyphs, + backtrackCount, backtrack, + lookup_context.funcs.intersects, lookup_context.intersects_data[0]) + && intersects_array (glyphs, + inputCount ? inputCount - 1 : 0, input, + lookup_context.funcs.intersects, lookup_context.intersects_data[1]) + && intersects_array (glyphs, + lookaheadCount, lookahead, + lookup_context.funcs.intersects, lookup_context.intersects_data[2]); +} + +static inline void chain_context_closure_lookup (hb_closure_context_t *c, + unsigned int backtrackCount, + const HBUINT16 backtrack[], + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookaheadCount, + const HBUINT16 lookahead[], + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ChainContextClosureLookupContext &lookup_context) +{ + if (chain_context_intersects (c->glyphs, + backtrackCount, backtrack, + inputCount, input, + lookaheadCount, lookahead, + lookup_context)) + recurse_lookups (c, + lookupCount, lookupRecord); +} + +static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c, + unsigned int backtrackCount, + const HBUINT16 backtrack[], + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookaheadCount, + const HBUINT16 lookahead[], + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ChainContextCollectGlyphsLookupContext &lookup_context) +{ + collect_array (c, c->before, + backtrackCount, backtrack, + lookup_context.funcs.collect, lookup_context.collect_data[0]); + collect_array (c, c->input, + inputCount ? inputCount - 1 : 0, input, + lookup_context.funcs.collect, lookup_context.collect_data[1]); + collect_array (c, c->after, + lookaheadCount, lookahead, + lookup_context.funcs.collect, lookup_context.collect_data[2]); + recurse_lookups (c, + lookupCount, lookupRecord); +} + +static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c, + unsigned int backtrackCount, + const HBUINT16 backtrack[] HB_UNUSED, + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookaheadCount, + const HBUINT16 lookahead[] HB_UNUSED, + unsigned int lookupCount HB_UNUSED, + const LookupRecord lookupRecord[] HB_UNUSED, + ChainContextApplyLookupContext &lookup_context) +{ + return (c->zero_context ? !backtrackCount && !lookaheadCount : true) + && would_match_input (c, + inputCount, input, + lookup_context.funcs.match, lookup_context.match_data[1]); +} + +static inline bool chain_context_apply_lookup (hb_ot_apply_context_t *c, + unsigned int backtrackCount, + const HBUINT16 backtrack[], + unsigned int inputCount, /* Including the first glyph (not matched) */ + const HBUINT16 input[], /* Array of input values--start with second glyph */ + unsigned int lookaheadCount, + const HBUINT16 lookahead[], + unsigned int lookupCount, + const LookupRecord lookupRecord[], + ChainContextApplyLookupContext &lookup_context) +{ + unsigned int start_index = 0, match_length = 0, end_index = 0; + unsigned int match_positions[HB_MAX_CONTEXT_LENGTH]; + return match_input (c, + inputCount, input, + lookup_context.funcs.match, lookup_context.match_data[1], + &match_length, match_positions) + && match_backtrack (c, + backtrackCount, backtrack, + lookup_context.funcs.match, lookup_context.match_data[0], + &start_index) + && match_lookahead (c, + lookaheadCount, lookahead, + lookup_context.funcs.match, lookup_context.match_data[2], + match_length, &end_index) + && (c->buffer->unsafe_to_break_from_outbuffer (start_index, end_index), + apply_lookup (c, + inputCount, match_positions, + lookupCount, lookupRecord, + match_length)); +} + +struct ChainRule +{ + bool intersects (const hb_set_t *glyphs, ChainContextClosureLookupContext &lookup_context) const + { + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + return chain_context_intersects (glyphs, + backtrack.len, backtrack.arrayZ, + input.lenP1, input.arrayZ, + lookahead.len, lookahead.arrayZ, + lookup_context); + } + + void closure (hb_closure_context_t *c, + ChainContextClosureLookupContext &lookup_context) const + { + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + chain_context_closure_lookup (c, + backtrack.len, backtrack.arrayZ, + input.lenP1, input.arrayZ, + lookahead.len, lookahead.arrayZ, + lookup.len, lookup.arrayZ, + lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c, + ChainContextCollectGlyphsLookupContext &lookup_context) const + { + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + chain_context_collect_glyphs_lookup (c, + backtrack.len, backtrack.arrayZ, + input.lenP1, input.arrayZ, + lookahead.len, lookahead.arrayZ, + lookup.len, lookup.arrayZ, + lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c, + ChainContextApplyLookupContext &lookup_context) const + { + TRACE_WOULD_APPLY (this); + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + return_trace (chain_context_would_apply_lookup (c, + backtrack.len, backtrack.arrayZ, + input.lenP1, input.arrayZ, + lookahead.len, lookahead.arrayZ, lookup.len, + lookup.arrayZ, lookup_context)); + } + + bool apply (hb_ot_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const + { + TRACE_APPLY (this); + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + return_trace (chain_context_apply_lookup (c, + backtrack.len, backtrack.arrayZ, + input.lenP1, input.arrayZ, + lookahead.len, lookahead.arrayZ, lookup.len, + lookup.arrayZ, lookup_context)); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (!backtrack.sanitize (c)) return_trace (false); + const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16> > (backtrack); + if (!input.sanitize (c)) return_trace (false); + const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16> > (input); + if (!lookahead.sanitize (c)) return_trace (false); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + return_trace (lookup.sanitize (c)); + } + + protected: + ArrayOf<HBUINT16> + backtrack; /* Array of backtracking values + * (to be matched before the input + * sequence) */ + HeadlessArrayOf<HBUINT16> + inputX; /* Array of input values (start with + * second glyph) */ + ArrayOf<HBUINT16> + lookaheadX; /* Array of lookahead values's (to be + * matched after the input sequence) */ + ArrayOf<LookupRecord> + lookupX; /* Array of LookupRecords--in + * design order) */ + public: + DEFINE_SIZE_MIN (8); +}; + +struct ChainRuleSet +{ + bool intersects (const hb_set_t *glyphs, ChainContextClosureLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + if ((this+rule[i]).intersects (glyphs, lookup_context)) + return true; + return false; + } + void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + (this+rule[i]).closure (c, lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const + { + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + (this+rule[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const + { + TRACE_WOULD_APPLY (this); + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + if ((this+rule[i]).would_apply (c, lookup_context)) + return_trace (true); + + return_trace (false); + } + + bool apply (hb_ot_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const + { + TRACE_APPLY (this); + unsigned int num_rules = rule.len; + for (unsigned int i = 0; i < num_rules; i++) + if ((this+rule[i]).apply (c, lookup_context)) + return_trace (true); + + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (rule.sanitize (c, this)); + } + + protected: + OffsetArrayOf<ChainRule> + rule; /* Array of ChainRule tables + * ordered by preference */ + public: + DEFINE_SIZE_ARRAY (2, rule); +}; + +struct ChainContextFormat1 +{ + bool intersects (const hb_set_t *glyphs) const + { + struct ChainContextClosureLookupContext lookup_context = { + {intersects_glyph}, + {nullptr, nullptr, nullptr} + }; + + unsigned int count = ruleSet.len; + for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ()) + { + if (unlikely (iter.get_coverage () >= count)) + break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */ + if (glyphs->has (iter.get_glyph ()) && + (this+ruleSet[iter.get_coverage ()]).intersects (glyphs, lookup_context)) + return true; + } + return false; + } + + void closure (hb_closure_context_t *c) const + { + struct ChainContextClosureLookupContext lookup_context = { + {intersects_glyph}, + {nullptr, nullptr, nullptr} + }; + + unsigned int count = ruleSet.len; + for (Coverage::Iter iter (this+coverage); iter.more (); iter.next ()) + { + if (unlikely (iter.get_coverage () >= count)) + break; /* Work around malicious fonts. https://github.com/harfbuzz/harfbuzz/issues/363 */ + if (c->glyphs->has (iter.get_glyph ())) + (this+ruleSet[iter.get_coverage ()]).closure (c, lookup_context); + } + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + (this+coverage).add_coverage (c->input); + + struct ChainContextCollectGlyphsLookupContext lookup_context = { + {collect_glyph}, + {nullptr, nullptr, nullptr} + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + (this+ruleSet[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])]; + struct ChainContextApplyLookupContext lookup_context = { + {match_glyph}, + {nullptr, nullptr, nullptr} + }; + return_trace (rule_set.would_apply (c, lookup_context)); + } + + const Coverage &get_coverage () const { return this+coverage; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const ChainRuleSet &rule_set = this+ruleSet[index]; + struct ChainContextApplyLookupContext lookup_context = { + {match_glyph}, + {nullptr, nullptr, nullptr} + }; + return_trace (rule_set.apply (c, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 1 */ + OffsetTo<Coverage> + coverage; /* Offset to Coverage table--from + * beginning of table */ + OffsetArrayOf<ChainRuleSet> + ruleSet; /* Array of ChainRuleSet tables + * ordered by Coverage Index */ + public: + DEFINE_SIZE_ARRAY (6, ruleSet); +}; + +struct ChainContextFormat2 +{ + bool intersects (const hb_set_t *glyphs) const + { + if (!(this+coverage).intersects (glyphs)) + return false; + + const ClassDef &backtrack_class_def = this+backtrackClassDef; + const ClassDef &input_class_def = this+inputClassDef; + const ClassDef &lookahead_class_def = this+lookaheadClassDef; + + struct ChainContextClosureLookupContext lookup_context = { + {intersects_class}, + {&backtrack_class_def, + &input_class_def, + &lookahead_class_def} + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + if (input_class_def.intersects_class (glyphs, i) && + (this+ruleSet[i]).intersects (glyphs, lookup_context)) + return true; + + return false; + } + void closure (hb_closure_context_t *c) const + { + if (!(this+coverage).intersects (c->glyphs)) + return; + + const ClassDef &backtrack_class_def = this+backtrackClassDef; + const ClassDef &input_class_def = this+inputClassDef; + const ClassDef &lookahead_class_def = this+lookaheadClassDef; + + struct ChainContextClosureLookupContext lookup_context = { + {intersects_class}, + {&backtrack_class_def, + &input_class_def, + &lookahead_class_def} + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + if (input_class_def.intersects_class (c->glyphs, i)) { + const ChainRuleSet &rule_set = this+ruleSet[i]; + rule_set.closure (c, lookup_context); + } + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + (this+coverage).add_coverage (c->input); + + const ClassDef &backtrack_class_def = this+backtrackClassDef; + const ClassDef &input_class_def = this+inputClassDef; + const ClassDef &lookahead_class_def = this+lookaheadClassDef; + + struct ChainContextCollectGlyphsLookupContext lookup_context = { + {collect_class}, + {&backtrack_class_def, + &input_class_def, + &lookahead_class_def} + }; + + unsigned int count = ruleSet.len; + for (unsigned int i = 0; i < count; i++) + (this+ruleSet[i]).collect_glyphs (c, lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const ClassDef &backtrack_class_def = this+backtrackClassDef; + const ClassDef &input_class_def = this+inputClassDef; + const ClassDef &lookahead_class_def = this+lookaheadClassDef; + + unsigned int index = input_class_def.get_class (c->glyphs[0]); + const ChainRuleSet &rule_set = this+ruleSet[index]; + struct ChainContextApplyLookupContext lookup_context = { + {match_class}, + {&backtrack_class_def, + &input_class_def, + &lookahead_class_def} + }; + return_trace (rule_set.would_apply (c, lookup_context)); + } + + const Coverage &get_coverage () const { return this+coverage; } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const ClassDef &backtrack_class_def = this+backtrackClassDef; + const ClassDef &input_class_def = this+inputClassDef; + const ClassDef &lookahead_class_def = this+lookaheadClassDef; + + index = input_class_def.get_class (c->buffer->cur().codepoint); + const ChainRuleSet &rule_set = this+ruleSet[index]; + struct ChainContextApplyLookupContext lookup_context = { + {match_class}, + {&backtrack_class_def, + &input_class_def, + &lookahead_class_def} + }; + return_trace (rule_set.apply (c, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (coverage.sanitize (c, this) && + backtrackClassDef.sanitize (c, this) && + inputClassDef.sanitize (c, this) && + lookaheadClassDef.sanitize (c, this) && + ruleSet.sanitize (c, this)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 2 */ + OffsetTo<Coverage> + coverage; /* Offset to Coverage table--from + * beginning of table */ + OffsetTo<ClassDef> + backtrackClassDef; /* Offset to glyph ClassDef table + * containing backtrack sequence + * data--from beginning of table */ + OffsetTo<ClassDef> + inputClassDef; /* Offset to glyph ClassDef + * table containing input sequence + * data--from beginning of table */ + OffsetTo<ClassDef> + lookaheadClassDef; /* Offset to glyph ClassDef table + * containing lookahead sequence + * data--from beginning of table */ + OffsetArrayOf<ChainRuleSet> + ruleSet; /* Array of ChainRuleSet tables + * ordered by class */ + public: + DEFINE_SIZE_ARRAY (12, ruleSet); +}; + +struct ChainContextFormat3 +{ + bool intersects (const hb_set_t *glyphs) const + { + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + + if (!(this+input[0]).intersects (glyphs)) + return false; + + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + struct ChainContextClosureLookupContext lookup_context = { + {intersects_coverage}, + {this, this, this} + }; + return chain_context_intersects (glyphs, + backtrack.len, (const HBUINT16 *) backtrack.arrayZ, + input.len, (const HBUINT16 *) input.arrayZ + 1, + lookahead.len, (const HBUINT16 *) lookahead.arrayZ, + lookup_context); + } + + void closure (hb_closure_context_t *c) const + { + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + + if (!(this+input[0]).intersects (c->glyphs)) + return; + + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + struct ChainContextClosureLookupContext lookup_context = { + {intersects_coverage}, + {this, this, this} + }; + chain_context_closure_lookup (c, + backtrack.len, (const HBUINT16 *) backtrack.arrayZ, + input.len, (const HBUINT16 *) input.arrayZ + 1, + lookahead.len, (const HBUINT16 *) lookahead.arrayZ, + lookup.len, lookup.arrayZ, + lookup_context); + } + + void collect_glyphs (hb_collect_glyphs_context_t *c) const + { + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + + (this+input[0]).add_coverage (c->input); + + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + struct ChainContextCollectGlyphsLookupContext lookup_context = { + {collect_coverage}, + {this, this, this} + }; + chain_context_collect_glyphs_lookup (c, + backtrack.len, (const HBUINT16 *) backtrack.arrayZ, + input.len, (const HBUINT16 *) input.arrayZ + 1, + lookahead.len, (const HBUINT16 *) lookahead.arrayZ, + lookup.len, lookup.arrayZ, + lookup_context); + } + + bool would_apply (hb_would_apply_context_t *c) const + { + TRACE_WOULD_APPLY (this); + + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + struct ChainContextApplyLookupContext lookup_context = { + {match_coverage}, + {this, this, this} + }; + return_trace (chain_context_would_apply_lookup (c, + backtrack.len, (const HBUINT16 *) backtrack.arrayZ, + input.len, (const HBUINT16 *) input.arrayZ + 1, + lookahead.len, (const HBUINT16 *) lookahead.arrayZ, + lookup.len, lookup.arrayZ, lookup_context)); + } + + const Coverage &get_coverage () const + { + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + return this+input[0]; + } + + bool apply (hb_ot_apply_context_t *c) const + { + TRACE_APPLY (this); + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + + unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint); + if (likely (index == NOT_COVERED)) return_trace (false); + + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + struct ChainContextApplyLookupContext lookup_context = { + {match_coverage}, + {this, this, this} + }; + return_trace (chain_context_apply_lookup (c, + backtrack.len, (const HBUINT16 *) backtrack.arrayZ, + input.len, (const HBUINT16 *) input.arrayZ + 1, + lookahead.len, (const HBUINT16 *) lookahead.arrayZ, + lookup.len, lookup.arrayZ, lookup_context)); + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + // TODO(subset) + return_trace (false); + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (!backtrack.sanitize (c, this)) return_trace (false); + const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); + if (!input.sanitize (c, this)) return_trace (false); + if (!input.len) return_trace (false); /* To be consistent with Context. */ + const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); + if (!lookahead.sanitize (c, this)) return_trace (false); + const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); + return_trace (lookup.sanitize (c)); + } + + protected: + HBUINT16 format; /* Format identifier--format = 3 */ + OffsetArrayOf<Coverage> + backtrack; /* Array of coverage tables + * in backtracking sequence, in glyph + * sequence order */ + OffsetArrayOf<Coverage> + inputX ; /* Array of coverage + * tables in input sequence, in glyph + * sequence order */ + OffsetArrayOf<Coverage> + lookaheadX; /* Array of coverage tables + * in lookahead sequence, in glyph + * sequence order */ + ArrayOf<LookupRecord> + lookupX; /* Array of LookupRecords--in + * design order) */ + public: + DEFINE_SIZE_MIN (10); +}; + +struct ChainContext +{ + template <typename context_t> + typename context_t::return_t dispatch (context_t *c) const + { + TRACE_DISPATCH (this, u.format); + if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ()); + switch (u.format) { + case 1: return_trace (c->dispatch (u.format1)); + case 2: return_trace (c->dispatch (u.format2)); + case 3: return_trace (c->dispatch (u.format3)); + default:return_trace (c->default_return_value ()); + } + } + + protected: + union { + HBUINT16 format; /* Format identifier */ + ChainContextFormat1 format1; + ChainContextFormat2 format2; + ChainContextFormat3 format3; + } u; +}; + + +template <typename T> +struct ExtensionFormat1 +{ + unsigned int get_type () const { return extensionLookupType; } + + template <typename X> + const X& get_subtable () const + { + unsigned int offset = extensionOffset; + if (unlikely (!offset)) return Null(typename T::SubTable); + return StructAtOffset<typename T::SubTable> (this, offset); + } + + template <typename context_t> + typename context_t::return_t dispatch (context_t *c) const + { + TRACE_DISPATCH (this, format); + if (unlikely (!c->may_dispatch (this, this))) return_trace (c->no_dispatch_return_value ()); + return_trace (get_subtable<typename T::SubTable> ().dispatch (c, get_type ())); + } + + /* This is called from may_dispatch() above with hb_sanitize_context_t. */ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this) && + extensionOffset != 0 && + extensionLookupType != T::SubTable::Extension); + } + + protected: + HBUINT16 format; /* Format identifier. Set to 1. */ + HBUINT16 extensionLookupType; /* Lookup type of subtable referenced + * by ExtensionOffset (i.e. the + * extension subtable). */ + HBUINT32 extensionOffset; /* Offset to the extension subtable, + * of lookup type subtable. */ + public: + DEFINE_SIZE_STATIC (8); +}; + +template <typename T> +struct Extension +{ + unsigned int get_type () const + { + switch (u.format) { + case 1: return u.format1.get_type (); + default:return 0; + } + } + template <typename X> + const X& get_subtable () const + { + switch (u.format) { + case 1: return u.format1.template get_subtable<typename T::SubTable> (); + default:return Null(typename T::SubTable); + } + } + + template <typename context_t> + typename context_t::return_t dispatch (context_t *c) const + { + TRACE_DISPATCH (this, u.format); + if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ()); + switch (u.format) { + case 1: return_trace (u.format1.dispatch (c)); + default:return_trace (c->default_return_value ()); + } + } + + protected: + union { + HBUINT16 format; /* Format identifier */ + ExtensionFormat1<T> format1; + } u; +}; + + +/* + * GSUB/GPOS Common + */ + +struct hb_ot_layout_lookup_accelerator_t +{ + template <typename TLookup> + void init (const TLookup &lookup) + { + digest.init (); + lookup.add_coverage (&digest); + + subtables.init (); + OT::hb_get_subtables_context_t c_get_subtables (subtables); + lookup.dispatch (&c_get_subtables); + } + void fini () { subtables.fini (); } + + bool may_have (hb_codepoint_t g) const + { return digest.may_have (g); } + + bool apply (hb_ot_apply_context_t *c) const + { + for (unsigned int i = 0; i < subtables.length; i++) + if (subtables[i].apply (c)) + return true; + return false; + } + + private: + hb_set_digest_t digest; + hb_get_subtables_context_t::array_t subtables; +}; + +struct GSUBGPOS +{ + bool has_data () const { return version.to_int (); } + unsigned int get_script_count () const + { return (this+scriptList).len; } + const Tag& get_script_tag (unsigned int i) const + { return (this+scriptList).get_tag (i); } + unsigned int get_script_tags (unsigned int start_offset, + unsigned int *script_count /* IN/OUT */, + hb_tag_t *script_tags /* OUT */) const + { return (this+scriptList).get_tags (start_offset, script_count, script_tags); } + const Script& get_script (unsigned int i) const + { return (this+scriptList)[i]; } + bool find_script_index (hb_tag_t tag, unsigned int *index) const + { return (this+scriptList).find_index (tag, index); } + + unsigned int get_feature_count () const + { return (this+featureList).len; } + hb_tag_t get_feature_tag (unsigned int i) const + { return i == Index::NOT_FOUND_INDEX ? HB_TAG_NONE : (this+featureList).get_tag (i); } + unsigned int get_feature_tags (unsigned int start_offset, + unsigned int *feature_count /* IN/OUT */, + hb_tag_t *feature_tags /* OUT */) const + { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); } + const Feature& get_feature (unsigned int i) const + { return (this+featureList)[i]; } + bool find_feature_index (hb_tag_t tag, unsigned int *index) const + { return (this+featureList).find_index (tag, index); } + + unsigned int get_lookup_count () const + { return (this+lookupList).len; } + const Lookup& get_lookup (unsigned int i) const + { return (this+lookupList)[i]; } + + bool find_variations_index (const int *coords, unsigned int num_coords, + unsigned int *index) const + { return (version.to_int () >= 0x00010001u ? this+featureVars : Null(FeatureVariations)) + .find_index (coords, num_coords, index); } + const Feature& get_feature_variation (unsigned int feature_index, + unsigned int variations_index) const + { + if (FeatureVariations::NOT_FOUND_INDEX != variations_index && + version.to_int () >= 0x00010001u) + { + const Feature *feature = (this+featureVars).find_substitute (variations_index, + feature_index); + if (feature) + return *feature; + } + return get_feature (feature_index); + } + + template <typename TLookup> + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + struct GSUBGPOS *out = c->serializer->embed (*this); + if (unlikely (!out)) return_trace (false); + + out->scriptList.serialize_subset (c, this+scriptList, out); + out->featureList.serialize_subset (c, this+featureList, out); + + typedef OffsetListOf<TLookup> TLookupList; + /* TODO Use intersects() to count how many subtables survive? */ + CastR<OffsetTo<TLookupList> > (out->lookupList) + .serialize_subset (c, + this+CastR<const OffsetTo<TLookupList> > (lookupList), + out); + + if (version.to_int () >= 0x00010001u) + out->featureVars.serialize_subset (c, this+featureVars, out); + + return_trace (true); + } + + unsigned int get_size () const + { + return min_size + + (version.to_int () >= 0x00010001u ? featureVars.static_size : 0); + } + + template <typename TLookup> + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + typedef OffsetListOf<TLookup> TLookupList; + return_trace (version.sanitize (c) && + likely (version.major == 1) && + scriptList.sanitize (c, this) && + featureList.sanitize (c, this) && + CastR<OffsetTo<TLookupList> > (lookupList).sanitize (c, this) && + (version.to_int () < 0x00010001u || featureVars.sanitize (c, this))); + } + + template <typename T> + struct accelerator_t + { + void init (hb_face_t *face) + { + this->table = hb_sanitize_context_t().reference_table<T> (face); + if (unlikely (this->table->is_blacklisted (this->table.get_blob (), face))) + { + hb_blob_destroy (this->table.get_blob ()); + this->table = hb_blob_get_empty (); + } + + this->lookup_count = table->get_lookup_count (); + + this->accels = (hb_ot_layout_lookup_accelerator_t *) calloc (this->lookup_count, sizeof (hb_ot_layout_lookup_accelerator_t)); + if (unlikely (!this->accels)) + this->lookup_count = 0; + + for (unsigned int i = 0; i < this->lookup_count; i++) + this->accels[i].init (table->get_lookup (i)); + } + + void fini () + { + for (unsigned int i = 0; i < this->lookup_count; i++) + this->accels[i].fini (); + free (this->accels); + this->table.destroy (); + } + + hb_blob_ptr_t<T> table; + unsigned int lookup_count; + hb_ot_layout_lookup_accelerator_t *accels; + }; + + protected: + FixedVersion<>version; /* Version of the GSUB/GPOS table--initially set + * to 0x00010000u */ + OffsetTo<ScriptList> + scriptList; /* ScriptList table */ + OffsetTo<FeatureList> + featureList; /* FeatureList table */ + OffsetTo<LookupList> + lookupList; /* LookupList table */ + LOffsetTo<FeatureVariations> + featureVars; /* Offset to Feature Variations + table--from beginning of table + * (may be NULL). Introduced + * in version 0x00010001. */ + public: + DEFINE_SIZE_MIN (10); +}; + + +} /* namespace OT */ + + +#endif /* HB_OT_LAYOUT_GSUBGPOS_HH */ |