/* * * (C) Copyright IBM Corp. 1998-2007 - All Rights Reserved * * This file is a modification of the ICU file IndicReordering.cpp * by Jens Herden and Javier Sola for Khmer language * */ #include "LETypes.h" #include "OpenTypeTables.h" #include "KhmerReordering.h" #include "LEGlyphStorage.h" U_NAMESPACE_BEGIN // Characters that get refered to by name... enum { C_SIGN_ZWNJ = 0x200C, C_SIGN_ZWJ = 0x200D, C_DOTTED_CIRCLE = 0x25CC, C_RO = 0x179A, C_VOWEL_AA = 0x17B6, C_SIGN_NIKAHIT = 0x17C6, C_VOWEL_E = 0x17C1, C_COENG = 0x17D2 }; enum { // 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 independtly displayed, should be displayed with a dotted-circle to // indicate error in syllable construction _xx = KhmerClassTable::CC_RESERVED, _sa = KhmerClassTable::CC_SIGN_ABOVE | KhmerClassTable::CF_DOTTED_CIRCLE | KhmerClassTable::CF_POS_ABOVE, _sp = KhmerClassTable::CC_SIGN_AFTER | KhmerClassTable::CF_DOTTED_CIRCLE| KhmerClassTable::CF_POS_AFTER, _c1 = KhmerClassTable::CC_CONSONANT | KhmerClassTable::CF_CONSONANT, _c2 = KhmerClassTable::CC_CONSONANT2 | KhmerClassTable::CF_CONSONANT, _c3 = KhmerClassTable::CC_CONSONANT3 | KhmerClassTable::CF_CONSONANT, _rb = KhmerClassTable::CC_ROBAT | KhmerClassTable::CF_POS_ABOVE | KhmerClassTable::CF_DOTTED_CIRCLE, _cs = KhmerClassTable::CC_CONSONANT_SHIFTER | KhmerClassTable::CF_DOTTED_CIRCLE | KhmerClassTable::CF_SHIFTER, _dl = KhmerClassTable::CC_DEPENDENT_VOWEL | KhmerClassTable::CF_POS_BEFORE | KhmerClassTable::CF_DOTTED_CIRCLE, _db = KhmerClassTable::CC_DEPENDENT_VOWEL | KhmerClassTable::CF_POS_BELOW | KhmerClassTable::CF_DOTTED_CIRCLE, _da = KhmerClassTable::CC_DEPENDENT_VOWEL | KhmerClassTable::CF_POS_ABOVE | KhmerClassTable::CF_DOTTED_CIRCLE | KhmerClassTable::CF_ABOVE_VOWEL, _dr = KhmerClassTable::CC_DEPENDENT_VOWEL | KhmerClassTable::CF_POS_AFTER | KhmerClassTable::CF_DOTTED_CIRCLE, _co = KhmerClassTable::CC_COENG | KhmerClassTable::CF_COENG | KhmerClassTable::CF_DOTTED_CIRCLE, // split vowel _va = _da | KhmerClassTable::CF_SPLIT_VOWEL, _vr = _dr | KhmerClassTable::CF_SPLIT_VOWEL }; // 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 wich the first part is before the base and the second one above the base // _vr Khmer split vowel in wich the first part is before the base and the second one behind (right of) the base static const KhmerClassTable::CharClass 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 }; // // Khmer Class Tables // // // The range of characters defined in the above table is defined here. FOr Khmer 1780 to 17DF // Even if the Khmer range is bigger, all other characters are not combinable, and therefore treated // as _xx static const KhmerClassTable khmerClassTable = {0x1780, 0x17df, khmerCharClasses}; // 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 KhmerClassTable::CharClass KhmerClassTable::getCharClass(LEUnicode ch) const { if (ch == C_SIGN_ZWJ) { return CC_ZERO_WIDTH_J_MARK; } if (ch == C_SIGN_ZWNJ) { return CC_ZERO_WIDTH_NJ_MARK; } if (ch < firstChar || ch > lastChar) { return CC_RESERVED; } return classTable[ch - firstChar]; } const KhmerClassTable *KhmerClassTable::getKhmerClassTable() { return &khmerClassTable; } class KhmerReorderingOutput : public UMemory { private: le_int32 fSyllableCount; le_int32 fOutIndex; LEUnicode *fOutChars; LEGlyphStorage &fGlyphStorage; public: KhmerReorderingOutput(LEUnicode *outChars, LEGlyphStorage &glyphStorage) : fSyllableCount(0), fOutIndex(0), fOutChars(outChars), fGlyphStorage(glyphStorage) { // nothing else to do... } ~KhmerReorderingOutput() { // nothing to do here... } void reset() { fSyllableCount += 1; } void writeChar(LEUnicode ch, le_uint32 charIndex, FeatureMask charFeatures) { LEErrorCode success = LE_NO_ERROR; fOutChars[fOutIndex] = ch; fGlyphStorage.setCharIndex(fOutIndex, charIndex, success); fGlyphStorage.setAuxData(fOutIndex, charFeatures | (fSyllableCount & LE_GLYPH_GROUP_MASK), success); fOutIndex += 1; } le_int32 getOutputIndex() { return fOutIndex; } }; #define blwfFeatureTag LE_BLWF_FEATURE_TAG #define pstfFeatureTag LE_PSTF_FEATURE_TAG #define presFeatureTag LE_PRES_FEATURE_TAG #define blwsFeatureTag LE_BLWS_FEATURE_TAG #define abvsFeatureTag LE_ABVS_FEATURE_TAG #define pstsFeatureTag LE_PSTS_FEATURE_TAG #define blwmFeatureTag LE_BLWM_FEATURE_TAG #define abvmFeatureTag LE_ABVM_FEATURE_TAG #define distFeatureTag LE_DIST_FEATURE_TAG #define prefFeatureTag LE_PREF_FEATURE_TAG #define abvfFeatureTag LE_ABVF_FEATURE_TAG #define cligFeatureTag LE_CLIG_FEATURE_TAG #define mkmkFeatureTag LE_MKMK_FEATURE_TAG #define prefFeatureMask 0x80000000UL #define blwfFeatureMask 0x40000000UL #define abvfFeatureMask 0x20000000UL #define pstfFeatureMask 0x10000000UL #define presFeatureMask 0x08000000UL #define blwsFeatureMask 0x04000000UL #define abvsFeatureMask 0x02000000UL #define pstsFeatureMask 0x01000000UL #define cligFeatureMask 0x00800000UL #define distFeatureMask 0x00400000UL #define blwmFeatureMask 0x00200000UL #define abvmFeatureMask 0x00100000UL #define mkmkFeatureMask 0x00080000UL #define tagPref (prefFeatureMask | presFeatureMask | cligFeatureMask | distFeatureMask) #define tagAbvf (abvfFeatureMask | abvsFeatureMask | cligFeatureMask | distFeatureMask | abvmFeatureMask | mkmkFeatureMask) #define tagPstf (blwfFeatureMask | blwsFeatureMask | prefFeatureMask | presFeatureMask | pstfFeatureMask | pstsFeatureMask | cligFeatureMask | distFeatureMask | blwmFeatureMask) #define tagBlwf (blwfFeatureMask | blwsFeatureMask | cligFeatureMask | distFeatureMask | blwmFeatureMask | mkmkFeatureMask) #define tagDefault (prefFeatureMask | blwfFeatureMask | presFeatureMask | blwsFeatureMask | cligFeatureMask | distFeatureMask | abvmFeatureMask | blwmFeatureMask | mkmkFeatureMask) // These are in the order in which the features need to be applied // for correct processing static const FeatureMap featureMap[] = { // Shaping features {prefFeatureTag, prefFeatureMask}, {blwfFeatureTag, blwfFeatureMask}, {abvfFeatureTag, abvfFeatureMask}, {pstfFeatureTag, pstfFeatureMask}, {presFeatureTag, presFeatureMask}, {blwsFeatureTag, blwsFeatureMask}, {abvsFeatureTag, abvsFeatureMask}, {pstsFeatureTag, pstsFeatureMask}, {cligFeatureTag, cligFeatureMask}, // Positioning features {distFeatureTag, distFeatureMask}, {blwmFeatureTag, blwmFeatureMask}, {abvmFeatureTag, abvmFeatureMask}, {mkmkFeatureTag, mkmkFeatureMask}, }; static const le_int32 featureMapCount = LE_ARRAY_SIZE(featureMap); // 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 in KhmerReordering.h 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 le_int8 khmerStateTable[][KhmerClassTable::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 }; const FeatureMap *KhmerReordering::getFeatureMap(le_int32 &count) { count = featureMapCount; return featureMap; } // 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. le_int32 KhmerReordering::findSyllable(const KhmerClassTable *classTable, const LEUnicode *chars, le_int32 prev, le_int32 charCount) { le_int32 cursor = prev; le_int8 state = 0; while (cursor < charCount) { KhmerClassTable::CharClass charClass = (classTable->getCharClass(chars[cursor]) & KhmerClassTable::CF_CLASS_MASK); state = khmerStateTable[state][charClass]; if (state < 0) { break; } cursor += 1; } return cursor; } // This is the real reordering function as applied to the Khmer language le_int32 KhmerReordering::reorder(const LEUnicode *chars, le_int32 charCount, le_int32 /*scriptCode*/, LEUnicode *outChars, LEGlyphStorage &glyphStorage) { const KhmerClassTable *classTable = KhmerClassTable::getKhmerClassTable(); KhmerReorderingOutput output(outChars, glyphStorage); KhmerClassTable::CharClass charClass; le_int32 i, prev = 0, coengRo; // This loop only exits when we reach the end of a run, which may contain // several syllables. while (prev < charCount) { le_int32 syllable = findSyllable(classTable, chars, prev, charCount); output.reset(); // 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 = prev; i < syllable; i += 1) { charClass = classTable->getCharClass(chars[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 & KhmerClassTable::CF_SPLIT_VOWEL) { output.writeChar(C_VOWEL_E, i, tagPref); break; // there can be only one vowel } // if a vowel with pos before write it out if (charClass & KhmerClassTable::CF_POS_BEFORE) { output.writeChar(chars[i], i, tagPref); 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 & KhmerClassTable::CF_COENG) && (i + 1 < syllable) && ( (classTable->getCharClass(chars[i + 1]) & KhmerClassTable::CF_CLASS_MASK) == KhmerClassTable::CC_CONSONANT2) ) { coengRo = i; } } // write coeng + ro if found if (coengRo > -1) { output.writeChar(C_COENG, coengRo, tagPref); output.writeChar(C_RO, coengRo + 1, tagPref); } // 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 (classTable->getCharClass(chars[prev]) & KhmerClassTable::CF_DOTTED_CIRCLE) { output.writeChar(C_DOTTED_CIRCLE, prev, tagDefault); } // copy what is left to the output, skipping before vowels and coeng Ro if they are present for (i = prev; i < syllable; i += 1) { charClass = classTable->getCharClass(chars[i]); // skip a before vowel, it was already processed if (charClass & KhmerClassTable::CF_POS_BEFORE) { continue; } // skip coeng + ro, it was already processed if (i == coengRo) { i += 1; continue; } switch (charClass & KhmerClassTable::CF_POS_MASK) { case KhmerClassTable::CF_POS_ABOVE : output.writeChar(chars[i], i, tagAbvf); break; case KhmerClassTable::CF_POS_AFTER : output.writeChar(chars[i], i, tagPstf); break; case KhmerClassTable::CF_POS_BELOW : output.writeChar(chars[i], i, tagBlwf); 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 & KhmerClassTable::CF_COENG) && i + 1 < syllable ) { if ( (classTable->getCharClass(chars[i + 1]) & KhmerClassTable::CF_CLASS_MASK) == KhmerClassTable::CC_CONSONANT3) { output.writeChar(chars[i], i, tagPstf); i += 1; output.writeChar(chars[i], i, tagPstf); } else { output.writeChar(chars[i], i, tagBlwf); i += 1; output.writeChar(chars[i], i, tagBlwf); } 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 & KhmerClassTable::CF_SHIFTER) && (i + 1 < syllable) ) { if ((classTable->getCharClass(chars[i + 1]) & KhmerClassTable::CF_ABOVE_VOWEL) || (i + 2 < syllable && ( (classTable->getCharClass(chars[i + 1]) & KhmerClassTable::CF_CLASS_MASK) == C_VOWEL_AA) && ( (classTable->getCharClass(chars[i + 2]) & KhmerClassTable::CF_CLASS_MASK) == C_SIGN_NIKAHIT)) || (i + 3 < syllable && (classTable->getCharClass(chars[i + 3]) & KhmerClassTable::CF_ABOVE_VOWEL)) || (i + 4 < syllable && ( (classTable->getCharClass(chars[i + 3]) & KhmerClassTable::CF_CLASS_MASK) == C_VOWEL_AA) && ( (classTable->getCharClass(chars[i + 4]) & KhmerClassTable::CF_CLASS_MASK) == C_SIGN_NIKAHIT) ) ) { output.writeChar(chars[i], i, tagBlwf); break; } } // default - any other characters output.writeChar(chars[i], i, tagDefault); break; } // switch } // for prev = syllable; // move the pointer to the start of next syllable } return output.getOutputIndex(); } U_NAMESPACE_END