1/*
2 *
3 * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
4 *
5 */
6
7#ifndef __THAISHAPING_H
8#define __THAISHAPING_H
9
10/**
11 * \file
12 * \internal
13 */
14
15#include "LETypes.h"
16#include "LEGlyphFilter.h"
17#include "OpenTypeTables.h"
18
19U_NAMESPACE_BEGIN
20
21class LEGlyphStorage;
22
23class ThaiShaping /* not : public UObject because all methods are static */ {
24public:
25
26    enum {
27        // Character classes
28        NON =  0,
29        CON =  1,
30        COA =  2,
31        COD =  3,
32        LVO =  4,
33        FV1 =  5,
34        FV2 =  6,
35        FV3 =  7,
36        BV1 =  8,
37        BV2 =  9,
38        BDI = 10,
39        TON = 11,
40        AD1 = 12,
41        AD2 = 13,
42        AD3 = 14,
43        NIK = 15,
44        AV1 = 16,
45        AV2 = 17,
46        AV3 = 18,
47        classCount = 19,
48
49        // State Transition actions
50        tA  =  0,
51        tC  =  1,
52        tD  =  2,
53        tE  =  3,
54        tF  =  4,
55        tG  =  5,
56        tH  =  6,
57        tR  =  7,
58        tS  =  8
59    };
60
61    struct StateTransition
62    {
63        le_uint8 nextState;
64        le_uint8 action;
65
66        le_uint8 getNextState() { return nextState; };
67        le_uint8 getAction() { return action; };
68    };
69
70    static le_int32 compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,
71        LEUnicode errorChar, LEUnicode *output, LEGlyphStorage &glyphStorage);
72
73private:
74    // forbid instantiation
75    ThaiShaping();
76
77    static const le_uint8 classTable[];
78    static const StateTransition thaiStateTable[][classCount];
79
80    inline static StateTransition getTransition(le_uint8 state, le_uint8 currClass);
81
82    static le_uint8 doTransition(StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,
83        LEUnicode errorChar, LEUnicode *outputBuffer, LEGlyphStorage &glyphStorage, le_int32 &outputIndex);
84
85    static le_uint8 getNextState(LEUnicode ch, le_uint8 state, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,
86        le_uint8 &charClass, LEUnicode *output, LEGlyphStorage &glyphStorage, le_int32 &outputIndex);
87
88    static le_bool isLegalHere(LEUnicode ch, le_uint8 prevState);
89    static le_uint8 getCharClass(LEUnicode ch);
90
91    static LEUnicode noDescenderCOD(LEUnicode cod, le_uint8 glyphSet);
92    static LEUnicode leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet);
93    static LEUnicode lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet);
94    static LEUnicode lowerRightTone(LEUnicode tone, le_uint8 glyphSet);
95    static LEUnicode lowerLeftTone(LEUnicode tone, le_uint8 glyphSet);
96    static LEUnicode upperLeftTone(LEUnicode tone, le_uint8 glyphSet);
97
98};
99
100inline ThaiShaping::StateTransition ThaiShaping::getTransition(le_uint8 state, le_uint8 currClass)
101{
102    return thaiStateTable[state][currClass];
103}
104
105U_NAMESPACE_END
106#endif
107
108
109