ThaiShaping.h revision 12677:a4299d47bd00 
1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
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24 */
25
26/*
27 *
28 * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
29 *
30 */
31
32#ifndef __THAISHAPING_H
33#define __THAISHAPING_H
34
35/**
36 * \file
37 * \internal
38 */
39
40#include "LETypes.h"
41#include "LEGlyphFilter.h"
42#include "OpenTypeTables.h"
43
44U_NAMESPACE_BEGIN
45
46class LEGlyphStorage;
47
48class ThaiShaping /* not : public UObject because all methods are static */ {
49public:
50
51    enum {
52        // Character classes
53        NON =  0,
54        CON =  1,
55        COA =  2,
56        COD =  3,
57        LVO =  4,
58        FV1 =  5,
59        FV2 =  6,
60        FV3 =  7,
61        BV1 =  8,
62        BV2 =  9,
63        BDI = 10,
64        TON = 11,
65        AD1 = 12,
66        AD2 = 13,
67        AD3 = 14,
68        NIK = 15,
69        AV1 = 16,
70        AV2 = 17,
71        AV3 = 18,
72        classCount = 19,
73
74        // State Transition actions
75        tA  =  0,
76        tC  =  1,
77        tD  =  2,
78        tE  =  3,
79        tF  =  4,
80        tG  =  5,
81        tH  =  6,
82        tR  =  7,
83        tS  =  8
84    };
85
86    struct StateTransition
87    {
88        le_uint8 nextState;
89        le_uint8 action;
90
91        le_uint8 getNextState() { return nextState; };
92        le_uint8 getAction() { return action; };
93    };
94
95    static le_int32 compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,
96        LEUnicode errorChar, LEUnicode *output, LEGlyphStorage &glyphStorage);
97
98private:
99    // forbid instantiation
100    ThaiShaping();
101
102    static const le_uint8 classTable[];
103    static const StateTransition thaiStateTable[][classCount];
104
105    inline static StateTransition getTransition(le_uint8 state, le_uint8 currClass);
106
107    static le_uint8 doTransition(StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,
108        LEUnicode errorChar, LEUnicode *outputBuffer, LEGlyphStorage &glyphStorage, le_int32 &outputIndex);
109
110    static le_uint8 getNextState(LEUnicode ch, le_uint8 state, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,
111        le_uint8 &charClass, LEUnicode *output, LEGlyphStorage &glyphStorage, le_int32 &outputIndex);
112
113    static le_bool isLegalHere(LEUnicode ch, le_uint8 prevState);
114    static le_uint8 getCharClass(LEUnicode ch);
115
116    static LEUnicode noDescenderCOD(LEUnicode cod, le_uint8 glyphSet);
117    static LEUnicode leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet);
118    static LEUnicode lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet);
119    static LEUnicode lowerRightTone(LEUnicode tone, le_uint8 glyphSet);
120    static LEUnicode lowerLeftTone(LEUnicode tone, le_uint8 glyphSet);
121    static LEUnicode upperLeftTone(LEUnicode tone, le_uint8 glyphSet);
122
123};
124
125inline ThaiShaping::StateTransition ThaiShaping::getTransition(le_uint8 state, le_uint8 currClass)
126{
127    return thaiStateTable[state][currClass];
128}
129
130U_NAMESPACE_END
131#endif
132