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

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C++

/*
* 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_PRIVATE_HH
#define HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
#include "hb-private.hh"
#include "hb-ot-shape-complex-private.hh"
#include "hb-ot-shape-private.hh" /* XXX Remove */
/* buffer var allocations */
#define indic_category() complex_var_u8_0() /* indic_category_t */
#define indic_position() complex_var_u8_1() /* indic_matra_category_t */
#define INDIC_TABLE_ELEMENT_TYPE uint16_t
/* Cateories used in the OpenType spec:
* https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
*/
/* 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,
OT_V,
OT_N,
OT_H,
OT_ZWNJ,
OT_ZWJ,
OT_M,
OT_SM,
OT_VD,
OT_A,
OT_NBSP,
OT_DOTTEDCIRCLE, /* Not in the spec, but special in Uniscribe. /Very very/ special! */
OT_RS, /* Register Shifter, used in Khmer OT spec */
OT_Coeng,
OT_Repha,
OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */
OT_CM
};
/* Visual positions in a syllable from left to right. */
enum indic_position_t {
POS_START,
POS_RA_TO_BECOME_REPH,
POS_PRE_M,
POS_PRE_C,
POS_BASE_C,
POS_AFTER_MAIN,
POS_ABOVE_C,
POS_BEFORE_SUB,
POS_BELOW_C,
POS_AFTER_SUB,
POS_BEFORE_POST,
POS_POST_C,
POS_AFTER_POST,
POS_FINAL_C,
POS_SMVD,
POS_END
};
/* Categories used in IndicSyllabicCategory.txt from UCD. */
enum indic_syllabic_category_t {
INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_X,
INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM,
INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP,
INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_C,
INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA = OT_Repha,
INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS,
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_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_INVISIBLE = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN,
INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M
};
/* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation
* because gcc fails to optimize the latter and fills the table in at runtime. */
#define INDIC_COMBINE_CATEGORIES(S,M) \
(ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)) + \
ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
((M << 8) | S))
#include "hb-ot-shape-complex-indic-table.hh"
#define IN_HALF_BLOCK(u, Base) (((u) & ~0x7F) == (Base))
#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900))
#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980))
#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00))
#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80))
#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00))
#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80))
#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00))
#define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80))
#define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00))
#define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80))
#define IS_KHMR(u) (IN_HALF_BLOCK (u, 0x1780))
#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 <= 0x0C42 ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
IS_KNDA(u) ? (u < 0x0CC3 || u > 0xCD6 ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
IS_MLYM(u) ? POS_AFTER_POST : \
IS_SINH(u) ? POS_AFTER_SUB : \
IS_KHMR(u) ? POS_AFTER_POST : \
/*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 : \
IS_KHMR(u) ? POS_AFTER_POST : \
/*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 : \
IS_KHMR(u) ? POS_AFTER_POST : \
/*default*/ POS_AFTER_SUB \
)
static inline indic_position_t
matra_position (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[] = {
0x0930, /* Devanagari */
0x09B0, /* Bengali */
0x09F0, /* Bengali */
0x0A30, /* Gurmukhi */ /* No Reph */
0x0AB0, /* Gujarati */
0x0B30, /* Oriya */
0x0BB0, /* Tamil */ /* No Reph */
0x0C30, /* Telugu */ /* Reph formed only with ZWJ */
0x0CB0, /* Kannada */
0x0D30, /* Malayalam */ /* No Reph, Logical Repha */
0x0DBB, /* Sinhala */ /* Reph formed only with ZWJ */
0x179A, /* Khmer */ /* No Reph, Visual Repha */
};
static inline indic_position_t
consonant_position (hb_codepoint_t u)
{
if ((u & ~0x007F) == 0x1780)
return POS_BELOW_C; /* In Khmer coeng model, post and below forms should not be reordered. */
return POS_BASE_C; /* Will recategorize later based on font lookups. */
}
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 bool
is_one_of (const hb_glyph_info_t &info, unsigned int flags)
{
/* If it ligated, all bets are off. */
if (is_a_ligature (info)) return false;
return !!(FLAG (info.indic_category()) & flags);
}
#define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
static inline bool
is_joiner (const hb_glyph_info_t &info)
{
return is_one_of (info, JOINER_FLAGS);
}
/* 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_CM) | FLAG (OT_Ra) | FLAG (OT_V) | FLAG (OT_NBSP) | FLAG (OT_DOTTEDCIRCLE))
static inline bool
is_consonant (const hb_glyph_info_t &info)
{
return is_one_of (info, CONSONANT_FLAGS);
}
#define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng))
static inline bool
is_halant_or_coeng (const hb_glyph_info_t &info)
{
return is_one_of (info, HALANT_OR_COENG_FLAGS);
}
static inline void
set_indic_properties (hb_glyph_info_t &info)
{
hb_codepoint_t u = info.codepoint;
unsigned int type = get_indic_categories (u);
indic_category_t cat = (indic_category_t) (type & 0x7F);
indic_position_t pos = (indic_position_t) (type >> 8);
/*
* Re-assign category
*/
/* The spec says U+0952 is OT_A. However, testing shows that Uniscribe
* treats U+0951..U+0952 all as OT_VD.
* TESTS:
* U+092E,U+0947,U+0952
* U+092E,U+0952,U+0947
* U+092E,U+0947,U+0951
* U+092E,U+0951,U+0947
* */
if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0951, 0x0954)))
cat = OT_VD;
if (unlikely (u == 0x17D1))
cat = OT_X;
if (cat == OT_X &&
unlikely (hb_in_range<hb_codepoint_t> (u, 0x17CB, 0x17D3))) /* Khmer Various signs */
{
/* These are like Top Matras. */
cat = OT_M;
pos = POS_ABOVE_C;
}
if (u == 0x17C6) /* Khmer Bindu doesn't like to be repositioned. */
cat = OT_N;
if (unlikely (u == 0x17D2)) cat = OT_Coeng; /* Khmer coeng */
else if (unlikely (u == 0x200C)) cat = OT_ZWNJ;
else if (unlikely (u == 0x200D)) cat = OT_ZWJ;
else if (unlikely (u == 0x25CC)) cat = OT_DOTTEDCIRCLE;
else if (unlikely (u == 0x0A71)) cat = OT_SM; /* GURMUKHI ADDAK. More like consonant medial. like 0A75. */
if (cat == OT_Repha) {
/* There are two kinds of characters marked as Repha:
* - The ones that are GenCat=Mn are already positioned visually, ie. after base. (eg. Khmer)
* - The ones that are GenCat=Lo is encoded logically, ie. beginning of syllable. (eg. Malayalam)
*
* We recategorize the first kind to look like a Nukta and attached to the base directly.
*/
if (_hb_glyph_info_get_general_category (&info) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
cat = OT_N;
}
/*
* Re-assign position.
*/
if ((FLAG (cat) & CONSONANT_FLAGS))
{
pos = consonant_position (u);
if (is_ra (u))
cat = OT_Ra;
}
else if (cat == OT_M)
{
pos = matra_position (u, pos);
}
else if (cat == OT_SM || cat == OT_VD)
{
pos = POS_SMVD;
}
if (unlikely (u == 0x0B01)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
info.indic_category() = cat;
info.indic_position() = pos;
}
#endif /* HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH */