diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-layout-private.hh')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-layout-private.hh | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-layout-private.hh b/gfx/harfbuzz/src/hb-ot-layout-private.hh new file mode 100644 index 000000000..a4272de63 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-layout-private.hh @@ -0,0 +1,621 @@ +/* + * Copyright © 2007,2008,2009 Red Hat, Inc. + * Copyright © 2012,2013 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_PRIVATE_HH +#define HB_OT_LAYOUT_PRIVATE_HH + +#include "hb-private.hh" + +#include "hb-font-private.hh" +#include "hb-buffer-private.hh" +#include "hb-set-private.hh" + + +/* Private API corresponding to hb-ot-layout.h: */ + +HB_INTERNAL hb_bool_t +hb_ot_layout_table_find_feature (hb_face_t *face, + hb_tag_t table_tag, + hb_tag_t feature_tag, + unsigned int *feature_index); + + +/* + * GDEF + */ + +enum hb_ot_layout_glyph_props_flags_t +{ + /* The following three match LookupFlags::Ignore* numbers. */ + HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH = 0x02u, + HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE = 0x04u, + HB_OT_LAYOUT_GLYPH_PROPS_MARK = 0x08u, + + /* The following are used internally; not derived from GDEF. */ + HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED = 0x10u, + HB_OT_LAYOUT_GLYPH_PROPS_LIGATED = 0x20u, + HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED = 0x40u, + + HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED | + HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | + HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED +}; +HB_MARK_AS_FLAG_T (hb_ot_layout_glyph_props_flags_t); + + +/* + * GSUB/GPOS + */ + +HB_INTERNAL hb_bool_t +hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face, + unsigned int lookup_index, + const hb_codepoint_t *glyphs, + unsigned int glyphs_length, + hb_bool_t zero_context); + + +/* Should be called before all the substitute_lookup's are done. */ +HB_INTERNAL void +hb_ot_layout_substitute_start (hb_font_t *font, + hb_buffer_t *buffer); + + +struct hb_ot_layout_lookup_accelerator_t; + +namespace OT { + struct hb_apply_context_t; + struct SubstLookup; +} + +HB_INTERNAL void +hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c, + const OT::SubstLookup &lookup, + const hb_ot_layout_lookup_accelerator_t &accel); + + +/* Should be called before all the position_lookup's are done. */ +HB_INTERNAL void +hb_ot_layout_position_start (hb_font_t *font, + hb_buffer_t *buffer); + +/* Should be called after all the position_lookup's are done, to finish advances. */ +HB_INTERNAL void +hb_ot_layout_position_finish_advances (hb_font_t *font, + hb_buffer_t *buffer); + +/* Should be called after hb_ot_layout_position_finish_advances, to finish offsets. */ +HB_INTERNAL void +hb_ot_layout_position_finish_offsets (hb_font_t *font, + hb_buffer_t *buffer); + + + +/* + * hb_ot_layout_t + */ + +namespace OT { + struct GDEF; + struct GSUB; + struct GPOS; + struct MATH; +} + +struct hb_ot_layout_lookup_accelerator_t +{ + template <typename TLookup> + inline void init (const TLookup &lookup) + { + digest.init (); + lookup.add_coverage (&digest); + } + + inline void fini (void) + { + } + + inline bool may_have (hb_codepoint_t g) const { + return digest.may_have (g); + } + + private: + hb_set_digest_t digest; +}; + +struct hb_ot_layout_t +{ + hb_blob_t *gdef_blob; + hb_blob_t *gsub_blob; + hb_blob_t *gpos_blob; + hb_blob_t *math_blob; + + const struct OT::GDEF *gdef; + const struct OT::GSUB *gsub; + const struct OT::GPOS *gpos; + const struct OT::MATH *math; + + unsigned int gsub_lookup_count; + unsigned int gpos_lookup_count; + + hb_ot_layout_lookup_accelerator_t *gsub_accels; + hb_ot_layout_lookup_accelerator_t *gpos_accels; +}; + + +HB_INTERNAL hb_ot_layout_t * +_hb_ot_layout_create (hb_face_t *face); + +HB_INTERNAL void +_hb_ot_layout_destroy (hb_ot_layout_t *layout); + + +#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot) + + +/* + * Buffer var routines. + */ + +/* buffer var allocations, used during the entire shaping process */ +#define unicode_props() var2.u16[0] + +/* buffer var allocations, used during the GSUB/GPOS processing */ +#define glyph_props() var1.u16[0] /* GDEF glyph properties */ +#define lig_props() var1.u8[2] /* GSUB/GPOS ligature tracking */ +#define syllable() var1.u8[3] /* GSUB/GPOS shaping boundaries */ + + +/* loop over syllables */ + +#define foreach_syllable(buffer, start, end) \ + for (unsigned int \ + _count = buffer->len, \ + start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \ + start < _count; \ + start = end, end = _next_syllable (buffer, start)) + +static inline unsigned int +_next_syllable (hb_buffer_t *buffer, unsigned int start) +{ + hb_glyph_info_t *info = buffer->info; + unsigned int count = buffer->len; + + unsigned int syllable = info[start].syllable(); + while (++start < count && syllable == info[start].syllable()) + ; + + return start; +} + + +/* unicode_props */ + +/* Design: + * unicode_props() is a two-byte number. The low byte includes: + * - General_Category: 5 bits. + * - A bit each for: + * * Is it Default_Ignorable(); we have a modified Default_Ignorable(). + * * Whether it's one of the three Mongolian Free Variation Selectors. + * * One free bit right now. + * + * The high-byte has different meanings, switched by the Gen-Cat: + * - For Mn,Mc,Me: the modified Combining_Class. + * - For Cf: whether it's ZWJ, ZWNJ, or something else. + * - For Ws: index of which space character this is, if space fallback + * is needed, ie. we don't set this by default, only if asked to. + */ + +enum hb_unicode_props_flags_t { + UPROPS_MASK_GEN_CAT = 0x001Fu, + UPROPS_MASK_IGNORABLE = 0x0020u, + UPROPS_MASK_FVS = 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3 */ + + /* If GEN_CAT=FORMAT, top byte masks: */ + UPROPS_MASK_Cf_ZWJ = 0x0100u, + UPROPS_MASK_Cf_ZWNJ = 0x0200u +}; +HB_MARK_AS_FLAG_T (hb_unicode_props_flags_t); + +static inline void +_hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer) +{ + hb_unicode_funcs_t *unicode = buffer->unicode; + unsigned int u = info->codepoint; + unsigned int gen_cat = (unsigned int) unicode->general_category (u); + unsigned int props = gen_cat; + + if (u >= 0x80) + { + buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII; + if (unlikely (unicode->is_default_ignorable (u))) + { + buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES; + props |= UPROPS_MASK_IGNORABLE; + if (u == 0x200Cu) props |= UPROPS_MASK_Cf_ZWNJ; + if (u == 0x200Du) props |= UPROPS_MASK_Cf_ZWJ; + /* Mongolian Free Variation Selectors need to be remembered + * because although we need to hide them like default-ignorables, + * they need to non-ignorable during shaping. This is similar to + * what we do for joiners in Indic-like shapers, but since the + * FVSes are GC=Mn, we have use a separate bit to remember them. + * Fixes: + * https://github.com/behdad/harfbuzz/issues/234 + */ + if (unlikely (hb_in_range (u, 0x180Bu, 0x180Du))) props |= UPROPS_MASK_FVS; + } + else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK_OR_MODIFIER_SYMBOL (gen_cat))) + { + /* The above check is just an optimization to let in only things we need further + * processing on. */ + + /* Only Mn and Mc can have non-zero ccc: + * http://www.unicode.org/policies/stability_policy.html#Property_Value + * """ + * Canonical_Combining_Class, General_Category + * All characters other than those with General_Category property values + * Spacing_Mark (Mc) and Nonspacing_Mark (Mn) have the Canonical_Combining_Class + * property value 0. + * 1.1.5+ + * """ + * + * Also, all Mn's that are Default_Ignorable, have ccc=0, hence + * the "else if". + */ + props |= unicode->modified_combining_class (info->codepoint)<<8; + + /* Recategorize emoji skin-tone modifiers as Unicode mark, so they + * behave correctly in non-native directionality. They originally + * are MODIFIER_SYMBOL. Fixes: + * https://github.com/behdad/harfbuzz/issues/169 + */ + if (unlikely (hb_in_range (u, 0x1F3FBu, 0x1F3FFu))) + { + props = gen_cat = HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK; + } + } + } + + info->unicode_props() = props; +} + +static inline void +_hb_glyph_info_set_general_category (hb_glyph_info_t *info, + hb_unicode_general_category_t gen_cat) +{ + /* Clears top-byte. */ + info->unicode_props() = (unsigned int) gen_cat | (info->unicode_props() & (0xFF & ~UPROPS_MASK_GEN_CAT)); +} + +static inline hb_unicode_general_category_t +_hb_glyph_info_get_general_category (const hb_glyph_info_t *info) +{ + return (hb_unicode_general_category_t) (info->unicode_props() & UPROPS_MASK_GEN_CAT); +} + +static inline bool +_hb_glyph_info_is_unicode_mark (const hb_glyph_info_t *info) +{ + return HB_UNICODE_GENERAL_CATEGORY_IS_MARK (info->unicode_props() & UPROPS_MASK_GEN_CAT); +} +static inline void +_hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info, + unsigned int modified_class) +{ + if (unlikely (!_hb_glyph_info_is_unicode_mark (info))) + return; + info->unicode_props() = (modified_class<<8) | (info->unicode_props() & 0xFF); +} +static inline unsigned int +_hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_is_unicode_mark (info) ? info->unicode_props()>>8 : 0; +} + +static inline bool +_hb_glyph_info_is_unicode_space (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_get_general_category (info) == + HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR; +} +static inline void +_hb_glyph_info_set_unicode_space_fallback_type (hb_glyph_info_t *info, hb_unicode_funcs_t::space_t s) +{ + if (unlikely (!_hb_glyph_info_is_unicode_space (info))) + return; + info->unicode_props() = (((unsigned int) s)<<8) | (info->unicode_props() & 0xFF); +} +static inline hb_unicode_funcs_t::space_t +_hb_glyph_info_get_unicode_space_fallback_type (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_is_unicode_space (info) ? + (hb_unicode_funcs_t::space_t) (info->unicode_props()>>8) : + hb_unicode_funcs_t::NOT_SPACE; +} + +static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info); + +static inline hb_bool_t +_hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info) +{ + return (info->unicode_props() & UPROPS_MASK_IGNORABLE) && + !_hb_glyph_info_ligated (info); +} +static inline hb_bool_t +_hb_glyph_info_is_default_ignorable_and_not_fvs (const hb_glyph_info_t *info) +{ + return ((info->unicode_props() & (UPROPS_MASK_IGNORABLE|UPROPS_MASK_FVS)) + == UPROPS_MASK_IGNORABLE) && + !_hb_glyph_info_ligated (info); +} + +static inline bool +_hb_glyph_info_is_unicode_format (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_get_general_category (info) == + HB_UNICODE_GENERAL_CATEGORY_FORMAT; +} +static inline hb_bool_t +_hb_glyph_info_is_zwnj (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWNJ); +} +static inline hb_bool_t +_hb_glyph_info_is_zwj (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWJ); +} +static inline hb_bool_t +_hb_glyph_info_is_joiner (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & (UPROPS_MASK_Cf_ZWNJ|UPROPS_MASK_Cf_ZWJ)); +} +static inline void +_hb_glyph_info_flip_joiners (hb_glyph_info_t *info) +{ + if (!_hb_glyph_info_is_unicode_format (info)) + return; + info->unicode_props() ^= UPROPS_MASK_Cf_ZWNJ | UPROPS_MASK_Cf_ZWJ; +} + +/* lig_props: aka lig_id / lig_comp + * + * When a ligature is formed: + * + * - The ligature glyph and any marks in between all the same newly allocated + * lig_id, + * - The ligature glyph will get lig_num_comps set to the number of components + * - The marks get lig_comp > 0, reflecting which component of the ligature + * they were applied to. + * - This is used in GPOS to attach marks to the right component of a ligature + * in MarkLigPos, + * - Note that when marks are ligated together, much of the above is skipped + * and the current lig_id reused. + * + * When a multiple-substitution is done: + * + * - All resulting glyphs will have lig_id = 0, + * - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively. + * - This is used in GPOS to attach marks to the first component of a + * multiple substitution in MarkBasePos. + * + * The numbers are also used in GPOS to do mark-to-mark positioning only + * to marks that belong to the same component of the same ligature. + */ + +static inline void +_hb_glyph_info_clear_lig_props (hb_glyph_info_t *info) +{ + info->lig_props() = 0; +} + +#define IS_LIG_BASE 0x10 + +static inline void +_hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info, + unsigned int lig_id, + unsigned int lig_num_comps) +{ + info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F); +} + +static inline void +_hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info, + unsigned int lig_id, + unsigned int lig_comp) +{ + info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F); +} + +static inline void +_hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp) +{ + _hb_glyph_info_set_lig_props_for_mark (info, 0, comp); +} + +static inline unsigned int +_hb_glyph_info_get_lig_id (const hb_glyph_info_t *info) +{ + return info->lig_props() >> 5; +} + +static inline bool +_hb_glyph_info_ligated_internal (const hb_glyph_info_t *info) +{ + return !!(info->lig_props() & IS_LIG_BASE); +} + +static inline unsigned int +_hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info) +{ + if (_hb_glyph_info_ligated_internal (info)) + return 0; + else + return info->lig_props() & 0x0F; +} + +static inline unsigned int +_hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info) +{ + if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) && + _hb_glyph_info_ligated_internal (info)) + return info->lig_props() & 0x0F; + else + return 1; +} + +static inline uint8_t +_hb_allocate_lig_id (hb_buffer_t *buffer) { + uint8_t lig_id = buffer->next_serial () & 0x07; + if (unlikely (!lig_id)) + lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */ + return lig_id; +} + +/* glyph_props: */ + +static inline void +_hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props) +{ + info->glyph_props() = props; +} + +static inline unsigned int +_hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info) +{ + return info->glyph_props(); +} + +static inline bool +_hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH); +} + +static inline bool +_hb_glyph_info_is_ligature (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE); +} + +static inline bool +_hb_glyph_info_is_mark (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK); +} + +static inline bool +_hb_glyph_info_substituted (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED); +} + +static inline bool +_hb_glyph_info_ligated (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED); +} + +static inline bool +_hb_glyph_info_multiplied (const hb_glyph_info_t *info) +{ + return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); +} + +static inline bool +_hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info) +{ + return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info); +} + +static inline void +_hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info) +{ + info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED | + HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED); +} + +static inline void +_hb_glyph_info_clear_substituted (hb_glyph_info_t *info) +{ + info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED); +} + + +/* Allocation / deallocation. */ + +static inline void +_hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props); +} + +static inline void +_hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props); +} + +static inline void +_hb_buffer_assert_unicode_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_ASSERT_VAR (buffer, unicode_props); +} + +static inline void +_hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props); + HB_BUFFER_ALLOCATE_VAR (buffer, lig_props); + HB_BUFFER_ALLOCATE_VAR (buffer, syllable); +} + +static inline void +_hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_DEALLOCATE_VAR (buffer, syllable); + HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props); + HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props); +} + +static inline void +_hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer) +{ + HB_BUFFER_ASSERT_VAR (buffer, glyph_props); + HB_BUFFER_ASSERT_VAR (buffer, lig_props); + HB_BUFFER_ASSERT_VAR (buffer, syllable); +} + +/* Make sure no one directly touches our props... */ +#undef unicode_props0 +#undef unicode_props1 +#undef lig_props +#undef glyph_props + + +#endif /* HB_OT_LAYOUT_PRIVATE_HH */ |