/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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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
 *
 */

#ifndef __KHMERREORDERING_H
#define __KHMERREORDERING_H

#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.
//

// This list must include all types of components that can be used
// inside a syllable
struct KhmerClassTable
{
    // 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).
    enum CharClassValues
    {
        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 {
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);
};

#endif