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harfbuzz/src/hb-ot-shape-complex-indic.hh

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/*
* Copyright © 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.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_SHAPE_COMPLEX_INDIC_HH
#define HB_OT_SHAPE_COMPLEX_INDIC_HH
#include "hb.hh"
#include "hb-ot-shape-complex-syllabic.hh"
/* buffer var allocations */
#define indic_category() complex_var_u8_category() /* indic_category_t */
#define indic_position() complex_var_u8_auxiliary() /* indic_position_t */
#define INDIC_TABLE_ELEMENT_TYPE uint16_t
/* Cateories used in the OpenType spec:
* https://docs.microsoft.com/en-us/typography/script-development/devanagari
*/
/* Note: This enum is duplicated in the -machine.rl source file.
* Not sure how to avoid duplication. */
enum indic_category_t {
OT_X = 0,
OT_C = 1,
OT_V = 2,
OT_N = 3,
OT_H = 4,
OT_ZWNJ = 5,
OT_ZWJ = 6,
OT_M = 7,
OT_SM = 8,
/* OT_VD = 9, UNUSED; we use OT_A instead. */
OT_A = 10,
OT_PLACEHOLDER = 11,
OT_DOTTEDCIRCLE = 12,
OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
OT_Coeng = 14, /* Khmer-style Virama. */
OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
OT_Ra = 16,
OT_CM = 17, /* Consonant-Medial. */
OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
OT_CS = 19,
/* The following are used by Khmer & Myanmar shapers. Defined
* here for them to share. */
OT_VAbv = 26,
OT_VBlw = 27,
OT_VPre = 28,
OT_VPst = 29,
};
#define MEDIAL_FLAGS (FLAG (OT_CM))
/* Note:
*
* We treat Vowels and placeholders as if they were consonants. This is safe because Vowels
* cannot happen in a consonant syllable. The plus side however is, we can call the
* consonant syllable logic from the vowel syllable function and get it all right! */
#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
#define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
/* Visual positions in a syllable from left to right. */
enum indic_position_t {
POS_START = 0,
POS_RA_TO_BECOME_REPH = 1,
POS_PRE_M = 2,
POS_PRE_C = 3,
POS_BASE_C = 4,
POS_AFTER_MAIN = 5,
POS_ABOVE_C = 6,
POS_BEFORE_SUB = 7,
POS_BELOW_C = 8,
POS_AFTER_SUB = 9,
POS_BEFORE_POST = 10,
POS_POST_C = 11,
POS_AFTER_POST = 12,
POS_FINAL_C = 13,
POS_SMVD = 14,
POS_END = 15
};
/* Categories used in IndicSyllabicCategory.txt from UCD. */
enum indic_syllabic_category_t {
INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_Symbol,
INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER = OT_PLACEHOLDER, /* Don't care. */
INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK = OT_A,
INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_CM,
INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER = OT_M, /* U+17CD only. */
INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM,
INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_PLACEHOLDER,
INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA = OT_Repha,
INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED = OT_X, /* Don't care. */
INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_CM,
INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA = OT_CM,
INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER = OT_CS,
INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK = OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */
INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER = OT_Coeng,
INDIC_SYLLABIC_CATEGORY_JOINER = OT_ZWJ,
INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
INDIC_SYLLABIC_CATEGORY_NON_JOINER = OT_ZWNJ,
INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
INDIC_SYLLABIC_CATEGORY_NUMBER = OT_PLACEHOLDER,
INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER = OT_PLACEHOLDER, /* Don't care. */
INDIC_SYLLABIC_CATEGORY_PURE_KILLER = OT_M, /* Is like a vowel matra. */
INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS,
INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER = OT_SM,
INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_N,
INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
};
/* Categories used in IndicSMatraCategory.txt from UCD */
enum indic_matra_category_t {
INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_END,
INDIC_MATRA_CATEGORY_LEFT = POS_PRE_C,
INDIC_MATRA_CATEGORY_TOP = POS_ABOVE_C,
INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW_C,
INDIC_MATRA_CATEGORY_RIGHT = POS_POST_C,
/* These should resolve to the position of the last part of the split sequence. */
INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_LEFT = INDIC_MATRA_CATEGORY_BOTTOM,
INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_TOP,
INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN,
INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M
};
#define INDIC_COMBINE_CATEGORIES(S,M) \
( \
ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
( S | \
( \
( \
S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
false \
? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
) << 8 \
) \
) \
)
HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
hb_indic_get_categories (hb_codepoint_t u);
static inline bool
is_one_of (const hb_glyph_info_t &info, unsigned int flags)
{
/* If it ligated, all bets are off. */
if (_hb_glyph_info_ligated (&info)) return false;
return !!(FLAG_UNSAFE (info.indic_category()) & flags);
}
static inline bool
is_joiner (const hb_glyph_info_t &info)
{
return is_one_of (info, JOINER_FLAGS);
}
static inline bool
is_consonant (const hb_glyph_info_t &info)
{
return is_one_of (info, CONSONANT_FLAGS);
}
static inline bool
is_halant (const hb_glyph_info_t &info)
{
return is_one_of (info, FLAG (OT_H));
}
#define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
#define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
#define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
#define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
#define MATRA_POS_LEFT(u) POS_PRE_M
#define MATRA_POS_RIGHT(u) ( \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_BENG(u) ? POS_AFTER_POST : \
IS_GURU(u) ? POS_AFTER_POST : \
IS_GUJR(u) ? POS_AFTER_POST : \
IS_ORYA(u) ? POS_AFTER_POST : \
IS_TAML(u) ? POS_AFTER_POST : \
IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
IS_MLYM(u) ? POS_AFTER_POST : \
IS_SINH(u) ? POS_AFTER_SUB : \
/*default*/ POS_AFTER_SUB \
)
#define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
IS_GUJR(u) ? POS_AFTER_SUB : \
IS_ORYA(u) ? POS_AFTER_MAIN : \
IS_TAML(u) ? POS_AFTER_SUB : \
IS_TELU(u) ? POS_BEFORE_SUB : \
IS_KNDA(u) ? POS_BEFORE_SUB : \
IS_SINH(u) ? POS_AFTER_SUB : \
/*default*/ POS_AFTER_SUB \
)
#define MATRA_POS_BOTTOM(u) ( \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_BENG(u) ? POS_AFTER_SUB : \
IS_GURU(u) ? POS_AFTER_POST : \
IS_GUJR(u) ? POS_AFTER_POST : \
IS_ORYA(u) ? POS_AFTER_SUB : \
IS_TAML(u) ? POS_AFTER_POST : \
IS_TELU(u) ? POS_BEFORE_SUB : \
IS_KNDA(u) ? POS_BEFORE_SUB : \
IS_MLYM(u) ? POS_AFTER_POST : \
IS_SINH(u) ? POS_AFTER_SUB : \
/*default*/ POS_AFTER_SUB \
)
static inline indic_position_t
matra_position_indic (hb_codepoint_t u, indic_position_t side)
{
switch ((int) side)
{
case POS_PRE_C: return MATRA_POS_LEFT (u);
case POS_POST_C: return MATRA_POS_RIGHT (u);
case POS_ABOVE_C: return MATRA_POS_TOP (u);
case POS_BELOW_C: return MATRA_POS_BOTTOM (u);
}
return side;
}
/* XXX
* This is a hack for now. We should move this data into the main Indic table.
* Or completely remove it and just check in the tables.
*/
static const hb_codepoint_t ra_chars[] = {
0x0930u, /* Devanagari */
0x09B0u, /* Bengali */
0x09F0u, /* Bengali */
0x0A30u, /* Gurmukhi */ /* No Reph */
0x0AB0u, /* Gujarati */
0x0B30u, /* Oriya */
0x0BB0u, /* Tamil */ /* No Reph */
0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
0x0CB0u, /* Kannada */
0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
0x179Au, /* Khmer */
};
static inline bool
is_ra (hb_codepoint_t u)
{
for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
if (u == ra_chars[i])
return true;
return false;
}
static inline void
set_indic_properties (hb_glyph_info_t &info)
{
hb_codepoint_t u = info.codepoint;
unsigned int type = hb_indic_get_categories (u);
indic_category_t cat = (indic_category_t) (type & 0xFFu);
indic_position_t pos = (indic_position_t) (type >> 8);
/*
* Re-assign category
*/
/* The following act more like the Bindus. */
if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u)))
cat = OT_SM;
/* The following act like consonants. */
else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u,
0x1CF5u, 0x1CF6u)))
cat = OT_C;
/* TODO: The following should only be allowed after a Visarga.
* For now, just treat them like regular tone marks. */
else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u)))
cat = OT_A;
/* TODO: The following should only be allowed after some of
* the nasalization marks, maybe only for U+1CE9..U+1CF1.
* For now, just treat them like tone marks. */
else if (unlikely (u == 0x1CEDu))
cat = OT_A;
/* The following take marks in standalone clusters, similar to Avagraha. */
else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u,
0x1CE9u, 0x1CECu,
0x1CEEu, 0x1CF1u)))
{
cat = OT_Symbol;
static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), "");
}
else if (unlikely (u == 0x0A51u))
{
/* https://github.com/harfbuzz/harfbuzz/issues/524 */
cat = OT_M;
pos = POS_BELOW_C;
}
/* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil,
* so the Indic shaper needs to know their categories. */
else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM;
else if (unlikely (u == 0x1133Bu || u == 0x1133Cu)) cat = OT_N;
else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
else if (unlikely (u == 0x09FCu)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/1613 */
else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */
else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u)))
cat = OT_PLACEHOLDER;
else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
/*
* Re-assign position.
*/
if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
{
pos = POS_BASE_C;
if (is_ra (u))
cat = OT_Ra;
}
else if (cat == OT_M)
{
pos = matra_position_indic (u, pos);
}
else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol))))
{
pos = POS_SMVD;
}
if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
info.indic_category() = cat;
info.indic_position() = pos;
}
struct hb_indic_would_substitute_feature_t
{
void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
{
zero_context = zero_context_;
map->get_stage_lookups (0/*GSUB*/,
map->get_feature_stage (0/*GSUB*/, feature_tag),
&lookups, &count);
}
bool would_substitute (const hb_codepoint_t *glyphs,
unsigned int glyphs_count,
hb_face_t *face) const
{
for (unsigned int i = 0; i < count; i++)
if (hb_ot_layout_lookup_would_substitute (face, lookups[i].index, glyphs, glyphs_count, zero_context))
return true;
return false;
}
private:
const hb_ot_map_t::lookup_map_t *lookups;
unsigned int count;
bool zero_context;
};
#endif /* HB_OT_SHAPE_COMPLEX_INDIC_HH */
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