[emoji] Mark emoji contination sequences as continuation

This adds a new grapheme bit.  Not used yet.

Part of https://github.com/harfbuzz/harfbuzz/issues/1159
This commit is contained in:
Behdad Esfahbod 2018-10-03 19:44:15 +02:00
parent 123326e20a
commit 3b78318510
3 changed files with 63 additions and 49 deletions

View File

@ -160,12 +160,12 @@ hb_ot_layout_position_finish_offsets (hb_font_t *font,
#define foreach_syllable(buffer, start, end) \ #define foreach_syllable(buffer, start, end) \
for (unsigned int \ for (unsigned int \
_count = buffer->len, \ _count = buffer->len, \
start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \ start = 0, end = _count ? _hb_next_syllable (buffer, 0) : 0; \
start < _count; \ start < _count; \
start = end, end = _next_syllable (buffer, start)) start = end, end = _hb_next_syllable (buffer, start))
static inline unsigned int static inline unsigned int
_next_syllable (hb_buffer_t *buffer, unsigned int start) _hb_next_syllable (hb_buffer_t *buffer, unsigned int start)
{ {
hb_glyph_info_t *info = buffer->info; hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len; unsigned int count = buffer->len;
@ -188,7 +188,7 @@ _next_syllable (hb_buffer_t *buffer, unsigned int start)
* * Whether it's one of the three Mongolian Free Variation Selectors, * * Whether it's one of the three Mongolian Free Variation Selectors,
* CGJ, or other characters that are hidden but should not be ignored * CGJ, or other characters that are hidden but should not be ignored
* like most other Default_Ignorable()s do during matching. * like most other Default_Ignorable()s do during matching.
* * One free bit right now. * * Whether it's a grapheme continuation.
* *
* The high-byte has different meanings, switched by the Gen-Cat: * The high-byte has different meanings, switched by the Gen-Cat:
* - For Mn,Mc,Me: the modified Combining_Class. * - For Mn,Mc,Me: the modified Combining_Class.
@ -202,6 +202,7 @@ enum hb_unicode_props_flags_t {
UPROPS_MASK_IGNORABLE = 0x0020u, UPROPS_MASK_IGNORABLE = 0x0020u,
UPROPS_MASK_HIDDEN = 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3, UPROPS_MASK_HIDDEN = 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3,
* or TAG characters */ * or TAG characters */
UPROPS_MASK_CONTINUATION=0x0080u,
/* If GEN_CAT=FORMAT, top byte masks: */ /* If GEN_CAT=FORMAT, top byte masks: */
UPROPS_MASK_Cf_ZWJ = 0x0100u, UPROPS_MASK_Cf_ZWJ = 0x0100u,
@ -220,6 +221,7 @@ _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer)
if (u >= 0x80) if (u >= 0x80)
{ {
buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII; buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII;
if (unlikely (unicode->is_default_ignorable (u))) if (unlikely (unicode->is_default_ignorable (u)))
{ {
buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES; buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES;
@ -245,24 +247,10 @@ _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer)
props |= UPROPS_MASK_HIDDEN; props |= UPROPS_MASK_HIDDEN;
} }
} }
else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK (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: if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (gen_cat)))
* https://unicode.org/policies/stability_policy.html#Property_Value {
* """ props |= UPROPS_MASK_CONTINUATION;
* 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 (u)<<8; props |= unicode->modified_combining_class (u)<<8;
} }
} }
@ -302,29 +290,6 @@ _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; return _hb_glyph_info_is_unicode_mark (info) ? info->unicode_props()>>8 : 0;
} }
/* Loop over grapheme. Based on foreach_cluster(). */
#define foreach_grapheme(buffer, start, end) \
for (unsigned int \
_count = buffer->len, \
start = 0, end = _count ? _next_grapheme (buffer, 0) : 0; \
start < _count; \
start = end, end = _next_grapheme (buffer, start))
static inline unsigned int
_next_grapheme (hb_buffer_t *buffer, unsigned int start)
{
hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len;
while (++start < count && _hb_glyph_info_is_unicode_mark (&info[start]))
;
return start;
}
#define info_cc(info) (_hb_glyph_info_get_modified_combining_class (&(info))) #define info_cc(info) (_hb_glyph_info_get_modified_combining_class (&(info)))
static inline bool static inline bool
@ -369,6 +334,36 @@ _hb_glyph_info_unhide (hb_glyph_info_t *info)
info->unicode_props() &= ~ UPROPS_MASK_HIDDEN; info->unicode_props() &= ~ UPROPS_MASK_HIDDEN;
} }
static inline void
_hb_glyph_info_set_continuation (hb_glyph_info_t *info)
{
info->unicode_props() |= UPROPS_MASK_CONTINUATION;
}
static inline bool
_hb_glyph_info_is_continuation (const hb_glyph_info_t *info)
{
return info->unicode_props() & UPROPS_MASK_CONTINUATION;
}
/* Loop over grapheme. Based on foreach_cluster(). */
#define foreach_grapheme(buffer, start, end) \
for (unsigned int \
_count = buffer->len, \
start = 0, end = _count ? _hb_next_grapheme (buffer, 0) : 0; \
start < _count; \
start = end, end = _hb_next_grapheme (buffer, start))
static inline unsigned int
_hb_next_grapheme (hb_buffer_t *buffer, unsigned int start)
{
hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len;
while (++start < count && _hb_glyph_info_is_continuation (&info[start]))
;
return start;
}
static inline bool static inline bool
_hb_glyph_info_is_unicode_format (const hb_glyph_info_t *info) _hb_glyph_info_is_unicode_format (const hb_glyph_info_t *info)
{ {

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@ -275,10 +275,34 @@ struct hb_ot_shape_context_t
static void static void
hb_set_unicode_props (hb_buffer_t *buffer) hb_set_unicode_props (hb_buffer_t *buffer)
{ {
/* Implement enough of Unicode Graphemes here that shaping
* in reverse-direction wouldn't break graphemes. Namely,
* we mark all marks and ZWJ and ZWJ,Extended_Pictographic
* sequences as continuations. The foreach_grapheme()
* macro uses this bit.
*
* https://www.unicode.org/reports/tr29/#Regex_Definitions
*/
unsigned int count = buffer->len; unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info; hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++) for (unsigned int i = 0; i < count; i++)
{
_hb_glyph_info_set_unicode_props (&info[i], buffer); _hb_glyph_info_set_unicode_props (&info[i], buffer);
/* Marks are already set as continuation by the above line.
* Handle ZWJ-continuation. */
if (unlikely (_hb_glyph_info_is_zwj (&info[i])))
{
_hb_glyph_info_set_continuation (&info[i]);
if (i + 1 < count &&
_hb_unicode_is_emoji_Extended_Pictographic (info[i + 1].codepoint))
{
i++;
_hb_glyph_info_set_unicode_props (&info[i], buffer);
_hb_glyph_info_set_continuation (&info[i]);
}
}
}
} }
static void static void

View File

@ -381,11 +381,6 @@ DECLARE_NULL_INSTANCE (hb_unicode_funcs_t);
FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \ FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \
FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))) FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
#define HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK(gen_cat) \
(FLAG_UNSAFE (gen_cat) & \
(FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
/* /*
* Ranges, used for bsearch tables. * Ranges, used for bsearch tables.