/*

  *

  * (C) Copyright IBM Corp. 1998-2004 - 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 LETag *getFeatureOrder();

 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