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* (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
* This file is a modification of the ICU file IndicReordering.h
* by Jens Herden and Javier Sola for Khmer language
* \file
* \internal
#include "LETypes.h"
#include "OpenTypeTables.h"
class LEGlyphStorage;
// Vocabulary
// Base -> A consonant or an independent vowel in its full (not subscript) form. It is the
// center of the syllable, it can be souranded 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.
struct KhmerClassTable // This list must include all types of components that can be used inside a syllable
enum CharClassValues // order is important here! This order must be the same that is found in each horizontal
// line in the statetable for Khmer (file KhmerReordering.cpp).
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_ROBAT = 6, // Khmer special diacritic accent -treated differently in state table
CC_COENG = 7, // Subscript consonant combining character
CC_ZERO_WIDTH_J_MARK = 11, // Zero width joiner character
CC_COUNT = 12 // This is the number of character classes
enum CharClassFlags
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
typedef le_uint32 CharClass;
typedef le_int32 ScriptFlags;
LEUnicode firstChar; // for Khmer this will become x1780
LEUnicode lastChar; // and this x17DF
const CharClass *classTable;
CharClass getCharClass(LEUnicode ch) const;
static const KhmerClassTable *getKhmerClassTable();
class KhmerReordering /* not : public UObject because all methods are static */ {
static le_int32 reorder(const LEUnicode *theChars, le_int32 charCount, le_int32 scriptCode,
LEUnicode *outChars, LEGlyphStorage &glyphStorage);
static const FeatureMap *getFeatureMap(le_int32 &count);
// do not instantiate
static le_int32 findSyllable(const KhmerClassTable *classTable, const LEUnicode *chars, le_int32 prev, le_int32 charCount);