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Diffstat (limited to 'Build/source/libs/icu/icu-xetex/layout/KhmerReordering.h')
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diff --git a/Build/source/libs/icu/icu-xetex/layout/KhmerReordering.h b/Build/source/libs/icu/icu-xetex/layout/KhmerReordering.h new file mode 100644 index 00000000000..eecd12dff63 --- /dev/null +++ b/Build/source/libs/icu/icu-xetex/layout/KhmerReordering.h @@ -0,0 +1,132 @@ +/* + * (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 + * + */ + +#ifndef __KHMERREORDERING_H +#define __KHMERREORDERING_H + +/** + * \file + * \internal + */ + +#include "LETypes.h" +#include "OpenTypeTables.h" + +U_NAMESPACE_BEGIN + +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_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 CharClassFlags + { + 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 + }; + + 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 */ { +public: + static le_int32 reorder(const LEUnicode *theChars, le_int32 charCount, le_int32 scriptCode, + LEUnicode *outChars, LEGlyphStorage &glyphStorage); + + static const FeatureMap *getFeatureMap(le_int32 &count); + +private: + // do not instantiate + KhmerReordering(); + + static le_int32 findSyllable(const KhmerClassTable *classTable, const LEUnicode *chars, le_int32 prev, le_int32 charCount); + +}; + + +U_NAMESPACE_END +#endif |