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1 | /* | |
2 | * | |
3 | * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved | |
4 | * | |
5 | * Developed at DIT - Government of Bhutan | |
6 | * | |
7 | * Contact person: Pema Geyleg - <pema_geyleg@druknet.bt> | |
8 | * | |
9 | * This file is a modification of the ICU file KhmerReordering.h | |
10 | * by Jens Herden and Javier Sola who have given all their possible rights to IBM and the Governement of Bhutan | |
11 | * A first module for Dzongkha was developed by Karunakar under Panlocalisation funding. | |
12 | * Assistance for this module has been received from Namgay Thinley, Christopher Fynn and Javier Sola | |
13 | * | |
14 | */ | |
15 | ||
16 | #ifndef __TIBETANREORDERING_H | |
17 | #define __TIBETANREORDERING_H | |
18 | ||
19 | /** | |
20 | * \file | |
21 | * \internal | |
22 | */ | |
23 | ||
24 | // #include "LETypes.h" | |
25 | // #include "OpenTypeTables.h" | |
26 | ||
27 | U_NAMESPACE_BEGIN | |
28 | ||
29 | class LEGlyphStorage; | |
30 | ||
31 | // Vocabulary | |
32 | // Base -> A consonant in its full (not subscript) form. It is the | |
33 | // center of the syllable, it can be souranded by subjoined consonants, vowels, | |
34 | // signs... but there is only one base in a stack, it has to be coded as | |
35 | // the first character of the syllable.Included here are also groups of base + subjoined | |
36 | // which are represented by one single code point in unicode (e.g. 0F43) Also other characters that might take | |
37 | // subjoined consonants or other combining characters. | |
38 | // Subjoined -> Subjoined consonants and groups of subjoined consonants which have a single code-point | |
39 | // to repersent the group (even if each subjoined consonant is represented independently | |
40 | // by anothe code-point | |
41 | // Tsa Phru --> Tsa Phru character, Bhutanese people will always place it right after the base, but sometimes, due to | |
42 | // "normalization" | |
43 | // is placed after all the subjoined consonants, and it is also permitted there. | |
44 | // A Chung Vowel lengthening mark --> . 0F71 It is placed after the base and any subjoined consonants but before any vowels | |
45 | // Precomposed Sanskrit vowels --> The are combinations of subjoined consonants + vowels that have been assigned | |
46 | // a given code-point (in spite of each single part of them having also a code-point | |
47 | // They are avoided, and users are encouraged to use the combination of code-points that | |
48 | // represents the same sound instead of using this combined characters. This is included here | |
49 | // for compatibility with possible texts that use them (they are not in the Dzongkha keyboard). | |
50 | // Halanta -> The Halanta or Virama character 0F84 indicates that a consonant should not use its inheernt vowel, | |
51 | // in spite of not having other vowels present. It is usually placed immediatly after a base consonant, | |
52 | // but in some special cases it can also be placed after a subjoined consonant, so this is also | |
53 | // permitted in this algorithm. (Halanta is always displayed in Tibetan not used as a connecting char) | |
54 | // | |
55 | // Subjoined vowels -> Dependent vowels (matras) placed below the base and below all subjoined consonants. There | |
56 | // might be as much as three subjoined vowels in a given stack (only one in general text, but up | |
57 | // to three for abreviations, they have to be permitted). | |
58 | // Superscript vowels -> There are three superscript vowels, and they can be repeated or combined (up to three | |
59 | // times. They can combine with subjoined vowels, and are always coded after these. | |
60 | // Anusvara --> Nasalisation sign. Traditioinally placed in absence of vowels, but also after vowels. In some | |
61 | // special cases it can be placed before a vowel, so this is also permitted | |
62 | // Candrabindu -> Forms of the Anusvara with different glyphs (and different in identity) which can be placed | |
63 | // without vowel or after the vowel, but never before. Cannot combine with Anusvara. | |
64 | // Stress marks -> Marks placed above or below a syllable, affecting the whole syllable. They are combining | |
65 | // marks, so they have to be attached to a specific stack. The are using to emphasise a syllable. | |
66 | // | |
67 | // Digits -> Digits are not considered as non-combining characters because there are a few characters which | |
68 | // combine with them, so they have to be considered independently. | |
69 | // Digit combining marks -> dependent marks that combine with digits. | |
70 | // | |
71 | // TODO | |
72 | // There are a number of characters in the CJK block that are used in Tibetan script, two of these are symbols | |
73 | // are used as bases for combining glyphs, and have not been encoded in Tibetan. As these characters are outside | |
74 | // of the tibetan block, they have not been treated in this program. | |
75 | ||
76 | ||
77 | struct TibetanClassTable // This list must include all types of components that can be used inside a syllable | |
78 | { | |
79 | enum CharClassValues // order is important here! This order must be the same that is found in each horizontal | |
80 | // line in the statetable for Tibetan (file TibetanReordering.cpp). It assigns one number | |
81 | // to each type of character that has to be considered when analysing the order in which | |
82 | // characters can be placed | |
83 | { | |
84 | CC_RESERVED = 0, //Non Combining Characters | |
85 | CC_BASE = 1, // Base Consonants, Base Consonants with Subjoined attached in code point, Sanskrit base marks | |
86 | CC_SUBJOINED = 2, // Subjoined Consonats, combination of more than Subjoined Consonants in the code point | |
87 | CC_TSA_PHRU = 3, // Tsa-Phru character 0F39 | |
88 | CC_A_CHUNG = 4, // Vowel Lenthening a-chung mark 0F71 | |
89 | CC_COMP_SANSKRIT = 5, // Precomposed Sanskrit vowels including Subjoined characters and vowels | |
90 | CC_HALANTA = 6, // Halanta Character 0F84 | |
91 | CC_BELOW_VOWEL = 7, // Subjoined vowels | |
92 | CC_ABOVE_VOWEL = 8, // Superscript vowels | |
93 | CC_ANUSVARA = 9, // Tibetan sign Rjes Su Nga Ro 0F7E | |
94 | CC_CANDRABINDU = 10, // Tibetan sign Sna Ldan and Nyi Zla Naa Da 0F82, 0F83 | |
95 | CC_VISARGA = 11, // Tibetan sign Rnam Bcad (0F7F) | |
96 | CC_ABOVE_S_MARK = 12, // Stress Marks placed above the text | |
97 | CC_BELOW_S_MARK = 13, // Stress Marks placed below the text | |
98 | CC_DIGIT = 14, // Dzongkha Digits | |
99 | CC_PRE_DIGIT_MARK = 15, // Mark placed before the digit | |
100 | CC_POST_BELOW_DIGIT_M = 16, // Mark placed below or after the digit | |
101 | CC_COUNT = 17 // This is the number of character classes | |
102 | }; | |
103 | ||
104 | enum CharClassFlags | |
105 | { | |
106 | CF_CLASS_MASK = 0x0000FFFF, | |
107 | ||
108 | CF_DOTTED_CIRCLE = 0x04000000, // add a dotted circle if a character with this flag is the first in a syllable | |
109 | CF_DIGIT = 0x01000000, // flag to speed up comparaisson | |
110 | CF_PREDIGIT = 0x02000000, // flag to detect pre-digit marks for reordering | |
111 | ||
112 | // position flags | |
113 | CF_POS_BEFORE = 0x00080000, | |
114 | CF_POS_BELOW = 0x00040000, | |
115 | CF_POS_ABOVE = 0x00020000, | |
116 | CF_POS_AFTER = 0x00010000, | |
117 | CF_POS_MASK = 0x000f0000 | |
118 | }; | |
119 | ||
120 | typedef le_uint32 CharClass; | |
121 | ||
122 | typedef le_int32 ScriptFlags; | |
123 | ||
124 | LEUnicode firstChar; // for Tibetan this will become xOF00 | |
125 | LEUnicode lastChar; // and this x0FFF | |
126 | const CharClass *classTable; | |
127 | ||
128 | CharClass getCharClass(LEUnicode ch) const; | |
129 | ||
130 | static const TibetanClassTable *getTibetanClassTable(); | |
131 | }; | |
132 | ||
133 | ||
134 | class TibetanReordering /* not : public UObject because all methods are static */ { | |
135 | public: | |
136 | static le_int32 reorder(const LEUnicode *theChars, le_int32 charCount, le_int32 scriptCode, | |
137 | LEUnicode *outChars, LEGlyphStorage &glyphStorage); | |
138 | ||
139 | static const FeatureMap *getFeatureMap(le_int32 &count); | |
140 | ||
141 | private: | |
142 | // do not instantiate | |
143 | TibetanReordering(); | |
144 | ||
145 | static le_int32 findSyllable(const TibetanClassTable *classTable, const LEUnicode *chars, le_int32 prev, le_int32 charCount); | |
146 | ||
147 | }; | |
148 | ||
149 | ||
150 | U_NAMESPACE_END | |
151 | #endif |