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/*
*
* (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