| /* |
| * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies) |
| * |
| * This is part of HarfBuzz, an OpenType Layout engine 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. |
| */ |
| |
| #include "harfbuzz-shaper.h" |
| #include "harfbuzz-shaper-private.h" |
| |
| #include <assert.h> |
| #include <stdio.h> |
| |
| /* |
| // Vocabulary |
| // Base -> A consonant or an independent vowel in its full (not subscript) form. It is the |
| // center of the syllable, it can be surrounded by coeng (subscript) consonants, vowels, |
| // split vowels, signs... but there is only one base in a syllable, it has to be coded as |
| // the first character of the syllable. |
| // split vowel --> vowel that has two parts placed separately (e.g. Before and after the consonant). |
| // Khmer language has five of them. Khmer split vowels either have one part before the |
| // base and one after the base or they have a part before the base and a part above the base. |
| // The first part of all Khmer split vowels is the same character, identical to |
| // the glyph of Khmer dependent vowel SRA EI |
| // coeng --> modifier used in Khmer to construct coeng (subscript) consonants |
| // Differently than indian languages, the coeng modifies the consonant that follows it, |
| // not the one preceding it Each consonant has two forms, the base form and the subscript form |
| // the base form is the normal one (using the consonants code-point), the subscript form is |
| // displayed when the combination coeng + consonant is encountered. |
| // Consonant of type 1 -> A consonant which has subscript for that only occupies space under a base consonant |
| // Consonant of type 2.-> Its subscript form occupies space under and before the base (only one, RO) |
| // Consonant of Type 3 -> Its subscript form occupies space under and after the base (KHO, CHHO, THHO, BA, YO, SA) |
| // Consonant shifter -> Khmer has to series of consonants. The same dependent vowel has different sounds |
| // if it is attached to a consonant of the first series or a consonant of the second series |
| // Most consonants have an equivalent in the other series, but some of theme exist only in |
| // one series (for example SA). If we want to use the consonant SA with a vowel sound that |
| // can only be done with a vowel sound that corresponds to a vowel accompanying a consonant |
| // of the other series, then we need to use a consonant shifter: TRIISAP or MUSIKATOAN |
| // x17C9 y x17CA. TRIISAP changes a first series consonant to second series sound and |
| // MUSIKATOAN a second series consonant to have a first series vowel sound. |
| // Consonant shifter are both normally supercript marks, but, when they are followed by a |
| // superscript, they change shape and take the form of subscript dependent vowel SRA U. |
| // If they are in the same syllable as a coeng consonant, Unicode 3.0 says that they |
| // should be typed before the coeng. Unicode 4.0 breaks the standard and says that it should |
| // be placed after the coeng consonant. |
| // Dependent vowel -> In khmer dependent vowels can be placed above, below, before or after the base |
| // Each vowel has its own position. Only one vowel per syllable is allowed. |
| // Signs -> Khmer has above signs and post signs. Only one above sign and/or one post sign are |
| // Allowed in a syllable. |
| // |
| // |
| // order is important here! This order must be the same that is found in each horizontal |
| // line in the statetable for Khmer (see khmerStateTable) . |
| */ |
| enum KhmerCharClassValues { |
| CC_RESERVED = 0, |
| CC_CONSONANT = 1, /* Consonant of type 1 or independent vowel */ |
| CC_CONSONANT2 = 2, /* Consonant of type 2 */ |
| CC_CONSONANT3 = 3, /* Consonant of type 3 */ |
| CC_ZERO_WIDTH_NJ_MARK = 4, /* Zero Width non joiner character (0x200C) */ |
| CC_CONSONANT_SHIFTER = 5, |
| CC_ROBAT = 6, /* Khmer special diacritic accent -treated differently in state table */ |
| CC_COENG = 7, /* Subscript consonant combining character */ |
| CC_DEPENDENT_VOWEL = 8, |
| CC_SIGN_ABOVE = 9, |
| CC_SIGN_AFTER = 10, |
| CC_ZERO_WIDTH_J_MARK = 11, /* Zero width joiner character */ |
| CC_COUNT = 12 /* This is the number of character classes */ |
| }; |
| |
| |
| enum KhmerCharClassFlags { |
| CF_CLASS_MASK = 0x0000FFFF, |
| |
| CF_CONSONANT = 0x01000000, /* flag to speed up comparing */ |
| CF_SPLIT_VOWEL = 0x02000000, /* flag for a split vowel -> the first part is added in front of the syllable */ |
| CF_DOTTED_CIRCLE = 0x04000000, /* add a dotted circle if a character with this flag is the first in a syllable */ |
| CF_COENG = 0x08000000, /* flag to speed up comparing */ |
| CF_SHIFTER = 0x10000000, /* flag to speed up comparing */ |
| CF_ABOVE_VOWEL = 0x20000000, /* flag to speed up comparing */ |
| |
| /* position flags */ |
| CF_POS_BEFORE = 0x00080000, |
| CF_POS_BELOW = 0x00040000, |
| CF_POS_ABOVE = 0x00020000, |
| CF_POS_AFTER = 0x00010000, |
| CF_POS_MASK = 0x000f0000 |
| }; |
| |
| |
| /* Characters that get referred to by name */ |
| enum KhmerChar { |
| C_SIGN_ZWNJ = 0x200C, |
| C_SIGN_ZWJ = 0x200D, |
| C_RO = 0x179A, |
| C_VOWEL_AA = 0x17B6, |
| C_SIGN_NIKAHIT = 0x17C6, |
| C_VOWEL_E = 0x17C1, |
| C_COENG = 0x17D2 |
| }; |
| |
| |
| /* |
| // simple classes, they are used in the statetable (in this file) to control the length of a syllable |
| // they are also used to know where a character should be placed (location in reference to the base character) |
| // and also to know if a character, when independently displayed, should be displayed with a dotted-circle to |
| // indicate error in syllable construction |
| */ |
| enum { |
| _xx = CC_RESERVED, |
| _sa = CC_SIGN_ABOVE | CF_DOTTED_CIRCLE | CF_POS_ABOVE, |
| _sp = CC_SIGN_AFTER | CF_DOTTED_CIRCLE| CF_POS_AFTER, |
| _c1 = CC_CONSONANT | CF_CONSONANT, |
| _c2 = CC_CONSONANT2 | CF_CONSONANT, |
| _c3 = CC_CONSONANT3 | CF_CONSONANT, |
| _rb = CC_ROBAT | CF_POS_ABOVE | CF_DOTTED_CIRCLE, |
| _cs = CC_CONSONANT_SHIFTER | CF_DOTTED_CIRCLE | CF_SHIFTER, |
| _dl = CC_DEPENDENT_VOWEL | CF_POS_BEFORE | CF_DOTTED_CIRCLE, |
| _db = CC_DEPENDENT_VOWEL | CF_POS_BELOW | CF_DOTTED_CIRCLE, |
| _da = CC_DEPENDENT_VOWEL | CF_POS_ABOVE | CF_DOTTED_CIRCLE | CF_ABOVE_VOWEL, |
| _dr = CC_DEPENDENT_VOWEL | CF_POS_AFTER | CF_DOTTED_CIRCLE, |
| _co = CC_COENG | CF_COENG | CF_DOTTED_CIRCLE, |
| |
| /* split vowel */ |
| _va = _da | CF_SPLIT_VOWEL, |
| _vr = _dr | CF_SPLIT_VOWEL |
| }; |
| |
| |
| /* |
| // Character class: a character class value |
| // ORed with character class flags. |
| */ |
| typedef unsigned long KhmerCharClass; |
| |
| |
| /* |
| // Character class tables |
| // _xx character does not combine into syllable, such as numbers, puntuation marks, non-Khmer signs... |
| // _sa Sign placed above the base |
| // _sp Sign placed after the base |
| // _c1 Consonant of type 1 or independent vowel (independent vowels behave as type 1 consonants) |
| // _c2 Consonant of type 2 (only RO) |
| // _c3 Consonant of type 3 |
| // _rb Khmer sign robat u17CC. combining mark for subscript consonants |
| // _cd Consonant-shifter |
| // _dl Dependent vowel placed before the base (left of the base) |
| // _db Dependent vowel placed below the base |
| // _da Dependent vowel placed above the base |
| // _dr Dependent vowel placed behind the base (right of the base) |
| // _co Khmer combining mark COENG u17D2, combines with the consonant or independent vowel following |
| // it to create a subscript consonant or independent vowel |
| // _va Khmer split vowel in which the first part is before the base and the second one above the base |
| // _vr Khmer split vowel in which the first part is before the base and the second one behind (right of) the base |
| */ |
| static const KhmerCharClass khmerCharClasses[] = { |
| _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c1, _c1, /* 1780 - 178F */ |
| _c1, _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c2, _c1, _c1, _c1, _c3, _c3, /* 1790 - 179F */ |
| _c1, _c3, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, /* 17A0 - 17AF */ |
| _c1, _c1, _c1, _c1, _dr, _dr, _dr, _da, _da, _da, _da, _db, _db, _db, _va, _vr, /* 17B0 - 17BF */ |
| _vr, _dl, _dl, _dl, _vr, _vr, _sa, _sp, _sp, _cs, _cs, _sa, _rb, _sa, _sa, _sa, /* 17C0 - 17CF */ |
| _sa, _sa, _co, _sa, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _sa, _xx, _xx /* 17D0 - 17DF */ |
| }; |
| |
| /* this enum must reflect the range of khmerCharClasses */ |
| enum KhmerCharClassesRange { |
| KhmerFirstChar = 0x1780, |
| KhmerLastChar = 0x17df |
| }; |
| |
| /* |
| // Below we define how a character in the input string is either in the khmerCharClasses table |
| // (in which case we get its type back), a ZWJ or ZWNJ (two characters that may appear |
| // within the syllable, but are not in the table) we also get their type back, or an unknown object |
| // in which case we get _xx (CC_RESERVED) back |
| */ |
| static KhmerCharClass getKhmerCharClass(HB_UChar16 uc) |
| { |
| if (uc == C_SIGN_ZWJ) { |
| return CC_ZERO_WIDTH_J_MARK; |
| } |
| |
| if (uc == C_SIGN_ZWNJ) { |
| return CC_ZERO_WIDTH_NJ_MARK; |
| } |
| |
| if (uc < KhmerFirstChar || uc > KhmerLastChar) { |
| return CC_RESERVED; |
| } |
| |
| return khmerCharClasses[uc - KhmerFirstChar]; |
| } |
| |
| |
| /* |
| // The stateTable is used to calculate the end (the length) of a well |
| // formed Khmer Syllable. |
| // |
| // Each horizontal line is ordered exactly the same way as the values in KhmerClassTable |
| // CharClassValues. This coincidence of values allows the follow up of the table. |
| // |
| // Each line corresponds to a state, which does not necessarily need to be a type |
| // of component... for example, state 2 is a base, with is always a first character |
| // in the syllable, but the state could be produced a consonant of any type when |
| // it is the first character that is analysed (in ground state). |
| // |
| // Differentiating 3 types of consonants is necessary in order to |
| // forbid the use of certain combinations, such as having a second |
| // coeng after a coeng RO, |
| // The inexistent possibility of having a type 3 after another type 3 is permitted, |
| // eliminating it would very much complicate the table, and it does not create typing |
| // problems, as the case above. |
| // |
| // The table is quite complex, in order to limit the number of coeng consonants |
| // to 2 (by means of the table). |
| // |
| // There a peculiarity, as far as Unicode is concerned: |
| // - The consonant-shifter is considered in two possible different |
| // locations, the one considered in Unicode 3.0 and the one considered in |
| // Unicode 4.0. (there is a backwards compatibility problem in this standard). |
| // |
| // |
| // xx independent character, such as a number, punctuation sign or non-khmer char |
| // |
| // c1 Khmer consonant of type 1 or an independent vowel |
| // that is, a letter in which the subscript for is only under the |
| // base, not taking any space to the right or to the left |
| // |
| // c2 Khmer consonant of type 2, the coeng form takes space under |
| // and to the left of the base (only RO is of this type) |
| // |
| // c3 Khmer consonant of type 3. Its subscript form takes space under |
| // and to the right of the base. |
| // |
| // cs Khmer consonant shifter |
| // |
| // rb Khmer robat |
| // |
| // co coeng character (u17D2) |
| // |
| // dv dependent vowel (including split vowels, they are treated in the same way). |
| // even if dv is not defined above, the component that is really tested for is |
| // KhmerClassTable::CC_DEPENDENT_VOWEL, which is common to all dependent vowels |
| // |
| // zwj Zero Width joiner |
| // |
| // zwnj Zero width non joiner |
| // |
| // sa above sign |
| // |
| // sp post sign |
| // |
| // there are lines with equal content but for an easier understanding |
| // (and maybe change in the future) we did not join them |
| */ |
| static const signed char khmerStateTable[][CC_COUNT] = |
| { |
| /* xx c1 c2 c3 zwnj cs rb co dv sa sp zwj */ |
| { 1, 2, 2, 2, 1, 1, 1, 6, 1, 1, 1, 2}, /* 0 - ground state */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}, /* 1 - exit state (or sign to the right of the syllable) */ |
| {-1, -1, -1, -1, 3, 4, 5, 6, 16, 17, 1, -1}, /* 2 - Base consonant */ |
| {-1, -1, -1, -1, -1, 4, -1, -1, 16, -1, -1, -1}, /* 3 - First ZWNJ before a register shifter It can only be followed by a shifter or a vowel */ |
| {-1, -1, -1, -1, 15, -1, -1, 6, 16, 17, 1, 14}, /* 4 - First register shifter */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, 20, -1, 1, -1}, /* 5 - Robat */ |
| {-1, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, -1}, /* 6 - First Coeng */ |
| {-1, -1, -1, -1, 12, 13, -1, 10, 16, 17, 1, 14}, /* 7 - First consonant of type 1 after coeng */ |
| {-1, -1, -1, -1, 12, 13, -1, -1, 16, 17, 1, 14}, /* 8 - First consonant of type 2 after coeng */ |
| {-1, -1, -1, -1, 12, 13, -1, 10, 16, 17, 1, 14}, /* 9 - First consonant or type 3 after ceong */ |
| {-1, 11, 11, 11, -1, -1, -1, -1, -1, -1, -1, -1}, /* 10 - Second Coeng (no register shifter before) */ |
| {-1, -1, -1, -1, 15, -1, -1, -1, 16, 17, 1, 14}, /* 11 - Second coeng consonant (or ind. vowel) no register shifter before */ |
| {-1, -1, -1, -1, -1, 13, -1, -1, 16, -1, -1, -1}, /* 12 - Second ZWNJ before a register shifter */ |
| {-1, -1, -1, -1, 15, -1, -1, -1, 16, 17, 1, 14}, /* 13 - Second register shifter */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, 16, -1, -1, -1}, /* 14 - ZWJ before vowel */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, 16, -1, -1, -1}, /* 15 - ZWNJ before vowel */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, -1, 17, 1, 18}, /* 16 - dependent vowel */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 18}, /* 17 - sign above */ |
| {-1, -1, -1, -1, -1, -1, -1, 19, -1, -1, -1, -1}, /* 18 - ZWJ after vowel */ |
| {-1, 1, -1, 1, -1, -1, -1, -1, -1, -1, -1, -1}, /* 19 - Third coeng */ |
| {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1}, /* 20 - dependent vowel after a Robat */ |
| }; |
| |
| |
| /* #define KHMER_DEBUG */ |
| #ifdef KHMER_DEBUG |
| #define KHDEBUG qDebug |
| #else |
| #define KHDEBUG if(0) printf |
| #endif |
| |
| /* |
| // Given an input string of characters and a location in which to start looking |
| // calculate, using the state table, which one is the last character of the syllable |
| // that starts in the starting position. |
| */ |
| static int khmer_nextSyllableBoundary(const HB_UChar16 *s, int start, int end, HB_Bool *invalid) |
| { |
| const HB_UChar16 *uc = s + start; |
| int state = 0; |
| int pos = start; |
| *invalid = FALSE; |
| |
| while (pos < end) { |
| KhmerCharClass charClass = getKhmerCharClass(*uc); |
| if (pos == start) { |
| *invalid = (charClass > 0) && ! (charClass & CF_CONSONANT); |
| } |
| state = khmerStateTable[state][charClass & CF_CLASS_MASK]; |
| |
| KHDEBUG("state[%d]=%d class=%8lx (uc=%4x)", pos - start, state, |
| charClass, *uc ); |
| |
| if (state < 0) { |
| break; |
| } |
| ++uc; |
| ++pos; |
| } |
| return pos; |
| } |
| |
| #ifndef NO_OPENTYPE |
| static const HB_OpenTypeFeature khmer_features[] = { |
| { HB_MAKE_TAG( 'p', 'r', 'e', 'f' ), PreFormProperty }, |
| { HB_MAKE_TAG( 'b', 'l', 'w', 'f' ), BelowFormProperty }, |
| { HB_MAKE_TAG( 'a', 'b', 'v', 'f' ), AboveFormProperty }, |
| { HB_MAKE_TAG( 'p', 's', 't', 'f' ), PostFormProperty }, |
| { HB_MAKE_TAG( 'p', 'r', 'e', 's' ), PreSubstProperty }, |
| { HB_MAKE_TAG( 'b', 'l', 'w', 's' ), BelowSubstProperty }, |
| { HB_MAKE_TAG( 'a', 'b', 'v', 's' ), AboveSubstProperty }, |
| { HB_MAKE_TAG( 'p', 's', 't', 's' ), PostSubstProperty }, |
| { HB_MAKE_TAG( 'c', 'l', 'i', 'g' ), CligProperty }, |
| { 0, 0 } |
| }; |
| #endif |
| |
| |
| static HB_Bool khmer_shape_syllable(HB_Bool openType, HB_ShaperItem *item) |
| { |
| /* KHDEBUG("syllable from %d len %d, str='%s'", item->from, item->length, |
| item->string->mid(item->from, item->length).toUtf8().data()); */ |
| |
| int len = 0; |
| int syllableEnd = item->item.pos + item->item.length; |
| unsigned short reordered[16]; |
| unsigned char properties[16]; |
| enum { |
| AboveForm = 0x01, |
| PreForm = 0x02, |
| PostForm = 0x04, |
| BelowForm = 0x08 |
| }; |
| #ifndef NO_OPENTYPE |
| const int availableGlyphs = item->num_glyphs; |
| #endif |
| int coengRo; |
| int i; |
| |
| /* according to the specs this is the max length one can get |
| ### the real value should be smaller */ |
| assert(item->item.length < 13); |
| |
| memset(properties, 0, 16*sizeof(unsigned char)); |
| |
| #ifdef KHMER_DEBUG |
| qDebug("original:"); |
| for (int i = from; i < syllableEnd; i++) { |
| qDebug(" %d: %4x", i, string[i]); |
| } |
| #endif |
| |
| /* |
| // write a pre vowel or the pre part of a split vowel first |
| // and look out for coeng + ro. RO is the only vowel of type 2, and |
| // therefore the only one that requires saving space before the base. |
| */ |
| coengRo = -1; /* There is no Coeng Ro, if found this value will change */ |
| for (i = item->item.pos; i < syllableEnd; i += 1) { |
| KhmerCharClass charClass = getKhmerCharClass(item->string[i]); |
| |
| /* if a split vowel, write the pre part. In Khmer the pre part |
| is the same for all split vowels, same glyph as pre vowel C_VOWEL_E */ |
| if (charClass & CF_SPLIT_VOWEL) { |
| reordered[len] = C_VOWEL_E; |
| properties[len] = PreForm; |
| ++len; |
| break; /* there can be only one vowel */ |
| } |
| /* if a vowel with pos before write it out */ |
| if (charClass & CF_POS_BEFORE) { |
| reordered[len] = item->string[i]; |
| properties[len] = PreForm; |
| ++len; |
| break; /* there can be only one vowel */ |
| } |
| /* look for coeng + ro and remember position |
| works because coeng + ro is always in front of a vowel (if there is a vowel) |
| and because CC_CONSONANT2 is enough to identify it, as it is the only consonant |
| with this flag */ |
| if ( (charClass & CF_COENG) && (i + 1 < syllableEnd) && |
| ( (getKhmerCharClass(item->string[i+1]) & CF_CLASS_MASK) == CC_CONSONANT2) ) { |
| coengRo = i; |
| } |
| } |
| |
| /* write coeng + ro if found */ |
| if (coengRo > -1) { |
| reordered[len] = C_COENG; |
| properties[len] = PreForm; |
| ++len; |
| reordered[len] = C_RO; |
| properties[len] = PreForm; |
| ++len; |
| } |
| |
| /* |
| shall we add a dotted circle? |
| If in the position in which the base should be (first char in the string) there is |
| a character that has the Dotted circle flag (a character that cannot be a base) |
| then write a dotted circle */ |
| if (getKhmerCharClass(item->string[item->item.pos]) & CF_DOTTED_CIRCLE) { |
| reordered[len] = C_DOTTED_CIRCLE; |
| ++len; |
| } |
| |
| /* copy what is left to the output, skipping before vowels and |
| coeng Ro if they are present */ |
| for (i = item->item.pos; i < syllableEnd; i += 1) { |
| HB_UChar16 uc = item->string[i]; |
| KhmerCharClass charClass = getKhmerCharClass(uc); |
| |
| /* skip a before vowel, it was already processed */ |
| if (charClass & CF_POS_BEFORE) { |
| continue; |
| } |
| |
| /* skip coeng + ro, it was already processed */ |
| if (i == coengRo) { |
| i += 1; |
| continue; |
| } |
| |
| switch (charClass & CF_POS_MASK) |
| { |
| case CF_POS_ABOVE : |
| reordered[len] = uc; |
| properties[len] = AboveForm; |
| ++len; |
| break; |
| |
| case CF_POS_AFTER : |
| reordered[len] = uc; |
| properties[len] = PostForm; |
| ++len; |
| break; |
| |
| case CF_POS_BELOW : |
| reordered[len] = uc; |
| properties[len] = BelowForm; |
| ++len; |
| break; |
| |
| default: |
| /* assign the correct flags to a coeng consonant |
| Consonants of type 3 are taged as Post forms and those type 1 as below forms */ |
| if ( (charClass & CF_COENG) && i + 1 < syllableEnd ) { |
| unsigned char property = (getKhmerCharClass(item->string[i+1]) & CF_CLASS_MASK) == CC_CONSONANT3 ? |
| PostForm : BelowForm; |
| reordered[len] = uc; |
| properties[len] = property; |
| ++len; |
| i += 1; |
| reordered[len] = item->string[i]; |
| properties[len] = property; |
| ++len; |
| break; |
| } |
| |
| /* if a shifter is followed by an above vowel change the shifter to below form, |
| an above vowel can have two possible positions i + 1 or i + 3 |
| (position i+1 corresponds to unicode 3, position i+3 to Unicode 4) |
| and there is an extra rule for C_VOWEL_AA + C_SIGN_NIKAHIT also for two |
| different positions, right after the shifter or after a vowel (Unicode 4) */ |
| if ( (charClass & CF_SHIFTER) && (i + 1 < syllableEnd) ) { |
| if (getKhmerCharClass(item->string[i+1]) & CF_ABOVE_VOWEL ) { |
| reordered[len] = uc; |
| properties[len] = BelowForm; |
| ++len; |
| break; |
| } |
| if (i + 2 < syllableEnd && |
| (item->string[i+1] == C_VOWEL_AA) && |
| (item->string[i+2] == C_SIGN_NIKAHIT) ) |
| { |
| reordered[len] = uc; |
| properties[len] = BelowForm; |
| ++len; |
| break; |
| } |
| if (i + 3 < syllableEnd && (getKhmerCharClass(item->string[i+3]) & CF_ABOVE_VOWEL) ) { |
| reordered[len] = uc; |
| properties[len] = BelowForm; |
| ++len; |
| break; |
| } |
| if (i + 4 < syllableEnd && |
| (item->string[i+3] == C_VOWEL_AA) && |
| (item->string[i+4] == C_SIGN_NIKAHIT) ) |
| { |
| reordered[len] = uc; |
| properties[len] = BelowForm; |
| ++len; |
| break; |
| } |
| } |
| |
| /* default - any other characters */ |
| reordered[len] = uc; |
| ++len; |
| break; |
| } /* switch */ |
| } /* for */ |
| |
| if (!item->font->klass->convertStringToGlyphIndices(item->font, |
| reordered, len, |
| item->glyphs, &item->num_glyphs, |
| item->item.bidiLevel % 2)) |
| return FALSE; |
| |
| |
| KHDEBUG("after shaping: len=%d", len); |
| for (i = 0; i < len; i++) { |
| item->attributes[i].mark = FALSE; |
| item->attributes[i].clusterStart = FALSE; |
| item->attributes[i].justification = 0; |
| item->attributes[i].zeroWidth = FALSE; |
| KHDEBUG(" %d: %4x property=%x", i, reordered[i], properties[i]); |
| } |
| |
| /* now we have the syllable in the right order, and can start running it through open type. */ |
| |
| #ifndef NO_OPENTYPE |
| if (openType) { |
| hb_uint32 where[16]; |
| for (i = 0; i < len; ++i) { |
| where[i] = ~(PreSubstProperty |
| | BelowSubstProperty |
| | AboveSubstProperty |
| | PostSubstProperty |
| | CligProperty |
| | PositioningProperties); |
| if (properties[i] == PreForm) |
| where[i] &= ~PreFormProperty; |
| else if (properties[i] == BelowForm) |
| where[i] &= ~BelowFormProperty; |
| else if (properties[i] == AboveForm) |
| where[i] &= ~AboveFormProperty; |
| else if (properties[i] == PostForm) |
| where[i] &= ~PostFormProperty; |
| } |
| |
| HB_OpenTypeShape(item, where); |
| if (!HB_OpenTypePosition(item, availableGlyphs, /*doLogClusters*/FALSE)) |
| return FALSE; |
| } else |
| #endif |
| { |
| KHDEBUG("Not using openType"); |
| HB_HeuristicPosition(item); |
| } |
| |
| item->attributes[0].clusterStart = TRUE; |
| return TRUE; |
| } |
| |
| HB_Bool HB_KhmerShape(HB_ShaperItem *item) |
| { |
| HB_Bool openType = FALSE; |
| unsigned short *logClusters = item->log_clusters; |
| int i; |
| |
| HB_ShaperItem syllable = *item; |
| int first_glyph = 0; |
| |
| int sstart = item->item.pos; |
| int end = sstart + item->item.length; |
| |
| assert(item->item.script == HB_Script_Khmer); |
| |
| #ifndef NO_OPENTYPE |
| openType = HB_SelectScript(item, khmer_features); |
| #endif |
| |
| KHDEBUG("khmer_shape: from %d length %d", item->item.pos, item->item.length); |
| while (sstart < end) { |
| HB_Bool invalid; |
| int send = khmer_nextSyllableBoundary(item->string, sstart, end, &invalid); |
| KHDEBUG("syllable from %d, length %d, invalid=%s", sstart, send-sstart, |
| invalid ? "TRUE" : "FALSE"); |
| syllable.item.pos = sstart; |
| syllable.item.length = send-sstart; |
| syllable.glyphs = item->glyphs + first_glyph; |
| syllable.attributes = item->attributes + first_glyph; |
| syllable.offsets = item->offsets + first_glyph; |
| syllable.advances = item->advances + first_glyph; |
| syllable.num_glyphs = item->num_glyphs - first_glyph; |
| if (!khmer_shape_syllable(openType, &syllable)) { |
| KHDEBUG("syllable shaping failed, syllable requests %d glyphs", syllable.num_glyphs); |
| item->num_glyphs += syllable.num_glyphs; |
| return FALSE; |
| } |
| /* fix logcluster array */ |
| KHDEBUG("syllable:"); |
| for (i = first_glyph; i < first_glyph + (int)syllable.num_glyphs; ++i) |
| KHDEBUG(" %d -> glyph %x", i, item->glyphs[i]); |
| KHDEBUG(" logclusters:"); |
| for (i = sstart; i < send; ++i) { |
| KHDEBUG(" %d -> glyph %d", i, first_glyph); |
| logClusters[i-item->item.pos] = first_glyph; |
| } |
| sstart = send; |
| first_glyph += syllable.num_glyphs; |
| } |
| item->num_glyphs = first_glyph; |
| return TRUE; |
| } |
| |
| void HB_KhmerAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes) |
| { |
| int end = from + len; |
| const HB_UChar16 *uc = text + from; |
| hb_uint32 i = 0; |
| HB_UNUSED(script); |
| attributes += from; |
| while ( i < len ) { |
| HB_Bool invalid; |
| hb_uint32 boundary = khmer_nextSyllableBoundary( text, from+i, end, &invalid ) - from; |
| |
| attributes[i].charStop = TRUE; |
| |
| if ( boundary > len-1 ) boundary = len; |
| i++; |
| while ( i < boundary ) { |
| attributes[i].charStop = FALSE; |
| ++uc; |
| ++i; |
| } |
| assert( i == boundary ); |
| } |
| } |
| |
