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harfbuzz/src/hb-ot-layout-private.hh

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/*
* 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 after all the substitute_lookup's are done */
HB_INTERNAL void
hb_ot_layout_substitute_finish (hb_font_t *font,
hb_buffer_t *buffer);
/* Should be called before all the position_lookup's are done. Resets positions to zero. */
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 */
HB_INTERNAL void
hb_ot_layout_position_finish (hb_font_t *font,
hb_buffer_t *buffer);
/*
* hb_ot_layout_t
*/
namespace OT {
struct GDEF;
struct GSUB;
struct GPOS;
}
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;
const struct OT::GDEF *gdef;
const struct OT::GSUB *gsub;
const struct OT::GPOS *gpos;
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().
* * Is it U+200D ZWJ?
* * Is it U+200C ZWNJ?
*
* The high-byte has different meanings, switched by the Gen-Cat:
* - For Mn,Mc,Me: the modified Combining_Class.
* - 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.
*
* If needed, we can use the ZWJ/ZWNJ to use the high byte as well,
* freeing two more bits.
*/
enum hb_unicode_props_flags_t {
UPROPS_MASK_ZWJ = 0x20u,
UPROPS_MASK_ZWNJ = 0x40u,
UPROPS_MASK_IGNORABLE = 0x80u,
UPROPS_MASK_GEN_CAT = 0x1Fu
};
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_ZWNJ;
if (u == 0x200Du) props |= UPROPS_MASK_ZWJ;
}
else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK (gen_cat)))
{
/* 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;
}
}
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_zwnj (const hb_glyph_info_t *info)
{
return !!(info->unicode_props() & UPROPS_MASK_ZWNJ);
}
static inline hb_bool_t
_hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
{
return !!(info->unicode_props() & UPROPS_MASK_ZWJ);
}
static inline void
_hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
{
info->unicode_props() ^= UPROPS_MASK_ZWNJ | UPROPS_MASK_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 */
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