1 // Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 /** |
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17 @file |
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18 @internalComponent |
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19 */ |
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20 |
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21 |
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22 #include <gdi.h> |
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23 #include "FontThai.h" |
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24 |
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25 |
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26 // |
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27 // ThaiGlyph Namespace definition |
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28 // |
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29 |
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30 |
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31 /** |
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32 This namespace holds functions used to evaluate a glyph character code |
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33 against a given Thai related prediciate. The 'code' argument is a glyph |
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34 from the current output cluster and so may be a Thai glyph, Thai PUA glyph, |
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35 the dotted circle glyph or 0xffff. Therefore it was decided not to implement |
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36 these routines using a data driven table approach as it would be inefficient. |
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37 @internalComponent. |
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38 */ |
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39 namespace ThaiGlyph |
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40 { |
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41 const TText16 KYoYing = 0x0E0D; |
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42 const TText16 KYoYingPua = 0xF70F; |
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43 const TText16 KThoThan = 0x0E10; |
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44 const TText16 KThoThanPua = 0xF700; |
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45 const TText16 KNikhahit = 0x0E4D; |
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46 const TText16 KNikhahitPua = 0xF711; |
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47 const TText16 KSaraAa = 0x0E32; |
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48 const TText16 KSaraAm = 0x0E33; |
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49 |
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50 |
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51 TBool IsThaiGlyph(TUint code) |
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52 { |
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53 return ((code > 0x0E00 && code < 0x0E3B) || |
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54 (code > 0x0E3E && code < 0x0E5C) || |
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55 (code >= 0xF700 && code <= 0xF71A)); |
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56 } |
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57 |
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58 TBool IsThaiConsonant(TUint code) |
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59 { |
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60 return (code >= 0x0E01 && code <= 0x0E2E); |
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61 } |
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62 |
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63 TBool IsThaiTallConsonant(TUint code) |
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64 { |
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65 return (//code == 0x0E0A || // CHO CHANG not tall at all |
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66 //code == 0x0E0B || // SO SO not tall at all |
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67 code == 0x0E1B || // PO PLA |
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68 code == 0x0E1D || // FO FA |
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69 code == 0x0E1F || // FO FAN |
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70 code == 0x0E2C); // LO CHULA in some fonts, Unicode tables show it as tall |
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71 } |
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72 |
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73 TBool IsThaiShortConsonant(TUint code) |
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74 { |
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75 return (((code >= 0x0E01 && code <= 0x0E2E) || (code == KUnicodeDottedCircle)) && |
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76 code != 0x0E1B && // PO PLA |
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77 code != 0x0E1D && // FO FA |
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78 code != 0x0E1F && // FO FAN |
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79 code != 0x0E2C); // LO CHULA in some fonts, Unicode tables show it as tall |
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80 } |
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81 |
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82 TBool IsThaiConsonantWithDisjointDescender(TUint code) |
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83 { |
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84 return (code == ThaiGlyph::KYoYing || code == ThaiGlyph::KThoThan); |
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85 } |
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86 |
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87 TBool IsThaiConsonantWithJointDescender(TUint code) |
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88 { |
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89 return (code == 0x0E0E || // DO CHADA |
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90 code == 0x0E0F || // PO PATAK |
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91 code == 0x0E24 || // RU |
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92 code == 0x0E26); // LU |
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93 } |
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94 |
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95 TBool IsThaiVowel(TUint code) |
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96 { |
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97 return ((code >= 0x0E30 && code <= 0x0E3A) || |
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98 (code >= 0x0E40 && code <= 0x0E44) || |
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99 code == 0x0E47); // MAITAIKHU |
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100 } |
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101 |
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102 TBool IsThaiDepVowel(TUint code) |
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103 { |
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104 return (code == 0x0E31 || // MAI HAN-AKAT |
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105 (code >= 0x0E34 && code <= 0x0E3A) || |
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106 code == 0x0E47); // MAITAIKHU |
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107 } |
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108 |
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109 TBool IsThaiDepVowelAbove(TUint code) |
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110 { |
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111 return (code == 0x0E31 || // MAI HAN-AKAT |
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112 (code >= 0x0E34 && code <= 0x0E37) || |
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113 code == 0x0E47); // MAITAIKHU |
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114 } |
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115 |
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116 TBool IsThaiDepVowelAbovePUA(TUint code) |
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117 { |
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118 return (code == 0xF710 || // MAI HAN-AKAT |
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119 (code >= 0xF701 && code <= 0xF704) || |
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120 code == 0xF712); // MAITAIKHU |
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121 } |
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122 |
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123 TBool IsThaiDepVowelBelow(TUint code) |
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124 { |
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125 return (code >= 0x0E38 && code <= 0x0E3A); |
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126 } |
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127 |
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128 TBool IsThaiIndepVowel(TUint code) |
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129 { |
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130 return (code == 0x0E30 || // SARA A |
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131 code == 0x0E32 || // SARA AA |
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132 code == 0x0E33 || // SARA AM |
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133 (code >= 0x0E40 && code <= 0x0E44)); |
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134 } |
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135 |
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136 TBool IsThaiToneMark(TUint code) |
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137 { |
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138 return (code >= 0x0E48 && code <= 0x0E4B); |
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139 } |
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140 } |
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141 |
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142 |
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143 // |
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144 // |
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145 // ThaiCharRules Namespace definition |
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146 // |
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147 // |
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148 |
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149 |
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150 /** |
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151 ThaiCharRules namespace holds the data and lookup methods |
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152 implementing the WTT 2.0 input/output validation matrix. |
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153 @internalComponent |
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154 */ |
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155 namespace ThaiCharRules |
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156 { |
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157 const TUint KThaiCodePageStart = 0x0E00; |
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158 const TUint KThaiCodePageEnd = 0x0E5C; |
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159 const TUint KNumThaiCharacters = KThaiCodePageEnd-KThaiCodePageStart; |
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160 |
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161 enum Wtt2Rule |
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162 { |
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163 EUndefined, |
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164 EAccept, |
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165 EComposite, |
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166 EReject, |
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167 ERejectStrict, |
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168 }; |
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169 |
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170 /** |
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171 This enumeration holds the set of classification values a Thai |
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172 character can be categorised as in the WTT2.0 specification. |
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173 */ |
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174 enum CharClassification |
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175 { |
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176 ENull, |
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177 EControl, |
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178 ENonPrintable, |
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179 EConsonant, |
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180 ELeadingVowel, |
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181 EOrdinaryFollowingVowel, |
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182 EDependentFollowingVowel, |
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183 ESpecialFollowingVowel, |
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184 EShortBelowVowel, |
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185 ELongBelowVowel, |
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186 EBelowDiacritic, |
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187 EToneMark, |
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188 EAboveDiacritic0, |
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189 EAboveDiacritic1, |
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190 EAboveDiacritic2, |
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191 EAboveDiacritic3, |
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192 EAboveVowel1, |
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193 EAboveVowel2, |
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194 EAboveVowel3, |
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195 // marker for end |
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196 EMaxClassification |
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197 }; |
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198 |
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199 |
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200 /** |
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201 Data table holding the classification of each character. |
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202 */ |
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203 static const TUint8 iCharClassifications[KNumThaiCharacters] = |
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204 { |
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205 ENull, // No entry in code page |
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206 EConsonant, // 0x0E01 |
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207 EConsonant, // 0x0E02 |
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208 EConsonant, // 0x0E03 |
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209 EConsonant, // 0x0E04 |
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210 EConsonant, // 0x0E05 |
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211 EConsonant, // 0x0E06 |
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212 EConsonant, // 0x0E07 |
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213 EConsonant, // 0x0E08 |
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214 EConsonant, // 0x0E09 |
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215 EConsonant, // 0x0E0A |
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216 EConsonant, // 0x0E0B |
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217 EConsonant, // 0x0E0C |
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218 EConsonant, // 0x0E0D |
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219 EConsonant, // 0x0E0E |
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220 EConsonant, // 0x0E0F |
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221 |
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222 EConsonant, // 0x0E10 |
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223 EConsonant, // 0x0E11 |
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224 EConsonant, // 0x0E12 |
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225 EConsonant, // 0x0E13 |
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226 EConsonant, // 0x0E14 |
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227 EConsonant, // 0x0E15 |
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228 EConsonant, // 0x0E16 |
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229 EConsonant, // 0x0E17 |
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230 EConsonant, // 0x0E18 |
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231 EConsonant, // 0x0E19 |
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232 EConsonant, // 0x0E1A |
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233 EConsonant, // 0x0E1B |
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234 EConsonant, // 0x0E1C |
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235 EConsonant, // 0x0E1D |
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236 EConsonant, // 0x0E1E |
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237 EConsonant, // 0x0E1F |
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238 |
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239 EConsonant, // 0x0E20 |
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240 EConsonant, // 0x0E21 |
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241 EConsonant, // 0x0E22 |
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242 EConsonant, // 0x0E23 |
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243 EConsonant, // 0x0E24 |
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244 EConsonant, // 0x0E25 |
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245 EConsonant, // 0x0E26 |
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246 EConsonant, // 0x0E27 |
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247 EConsonant, // 0x0E28 |
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248 EConsonant, // 0x0E29 |
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249 EConsonant, // 0x0E2A |
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250 EConsonant, // 0x0E2B |
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251 EConsonant, // 0x0E2C |
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252 EConsonant, // 0x0E2D |
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253 EConsonant, // 0x0E2E |
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254 ENonPrintable, // 0x0E2F |
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255 |
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256 EOrdinaryFollowingVowel,// 0x0E30 |
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257 EAboveVowel2, // 0x0E31 |
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258 EOrdinaryFollowingVowel,// 0x0E32 |
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259 EOrdinaryFollowingVowel,// 0x0E33 |
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260 EAboveVowel1, // 0x0E34 |
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261 EAboveVowel3, // 0x0E35 |
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262 EAboveVowel2, // 0x0E36 |
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263 EAboveVowel3, // 0x0E37 |
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264 EShortBelowVowel, // 0x0E38 |
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265 ELongBelowVowel, // 0x0E39 |
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266 EBelowDiacritic, // 0x0E3A |
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267 ENull, // 0x0E3B |
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268 ENull, // 0x0E3C |
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269 ENull, // 0x0E3D |
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270 ENull, // 0x0E3E |
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271 ENonPrintable, // 0x0E3F |
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272 |
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273 ELeadingVowel, // 0x0E40 |
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274 ELeadingVowel, // 0x0E41 |
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275 ELeadingVowel, // 0x0E42 |
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276 ELeadingVowel, // 0x0E43 |
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277 ELeadingVowel, // 0x0E44 |
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278 EDependentFollowingVowel,//0x0E45 |
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279 ENonPrintable, // 0x0E46 |
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280 EAboveDiacritic2, // 0x0E47 |
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281 EToneMark, // 0x0E48 |
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282 EToneMark, // 0x0E49 |
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283 EToneMark, // 0x0E4A |
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284 EToneMark, // 0x0E4B |
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285 EAboveDiacritic1, // 0x0E4C |
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286 EAboveDiacritic0, // 0x0E4D |
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287 EAboveDiacritic3, // 0x0E4E |
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288 ENonPrintable, // 0x0E4F |
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289 |
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290 ENonPrintable, // 0x0E50 |
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291 ENonPrintable, // 0x0E51 |
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292 ENonPrintable, // 0x0E52 |
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293 ENonPrintable, // 0x0E53 |
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294 ENonPrintable, // 0x0E54 |
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295 ENonPrintable, // 0x0E55 |
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296 ENonPrintable, // 0x0E56 |
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297 ENonPrintable, // 0x0E57 |
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298 ENonPrintable, // 0x0E58 |
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299 ENonPrintable, // 0x0E59 |
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300 ENonPrintable, // 0x0E5A |
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301 ENonPrintable, // 0x0E5B |
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302 |
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303 // Value at last measurement was 92 bytes. 27/6/2003 |
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304 }; |
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305 |
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306 |
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307 /** |
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308 WTT 2.0 Rules data table of prev to next character |
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309 */ |
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310 static const TUint8 iInputRules[EMaxClassification][EMaxClassification] = |
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311 { |
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312 /* Previous character ENull */ |
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313 { |
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314 EUndefined, EUndefined, EUndefined, EUndefined, EUndefined, |
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315 EUndefined, EUndefined, EUndefined, EUndefined, EUndefined, |
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316 EUndefined, EUndefined, EUndefined, EUndefined, EUndefined, |
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317 EUndefined, EUndefined, EUndefined, EUndefined |
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318 }, |
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319 |
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320 /* Previous character EControl */ |
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321 { |
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322 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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323 EAccept, EAccept, EAccept, EReject, EReject, |
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324 EReject, EReject, EReject, EReject, EReject, EReject, |
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325 EReject, EReject, EReject, |
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326 }, |
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327 |
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328 /* Previous character ENonPrintable */ |
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329 { |
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330 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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331 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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332 EReject, EReject, EReject, EReject, EReject, EReject, |
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333 EReject, EReject, EReject, |
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334 }, |
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335 |
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336 /* Previous character EConsonant */ |
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337 { |
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338 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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339 EAccept, ERejectStrict, EAccept, EComposite, EComposite, |
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340 EComposite, EComposite, EComposite, EComposite, EComposite, EComposite, |
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341 EComposite, EComposite, EComposite, |
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342 }, |
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343 |
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344 /* Previous character ELeadingVowel */ |
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345 { |
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346 EUndefined, EUndefined, ERejectStrict, EAccept, ERejectStrict, |
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347 ERejectStrict, ERejectStrict, ERejectStrict, EReject, EReject, |
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348 EReject, EReject, EReject, EReject, EReject, EReject, |
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349 EReject, EReject, EReject, |
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350 }, |
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351 |
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352 /* Previous character EOrdinaryFollowingVowel */ |
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353 { |
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354 EUndefined, EUndefined, ERejectStrict, EAccept, ERejectStrict, |
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355 EAccept, ERejectStrict, EAccept, EReject, EReject, |
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356 EReject, EReject, EReject, EReject, EReject, EReject, |
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357 EReject, EReject, EReject, |
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358 }, |
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359 |
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360 /* Previous character EDependentFollowingVowel */ |
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361 { |
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362 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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363 EAccept, ERejectStrict, EAccept, EReject, EReject, |
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364 EReject, EReject, EReject, EReject, EReject, EReject, |
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365 EReject, EReject, EReject, |
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366 }, |
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367 |
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368 /* Previous character ESpecialFollowingVowel */ |
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369 { |
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370 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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371 ERejectStrict, EAccept, ERejectStrict, EReject, EReject, |
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372 EReject, EReject, EReject, EReject, EReject, EReject, |
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373 EReject, EReject, EReject, |
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374 }, |
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375 |
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376 /* Previous character EShortBelowVowel */ |
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377 { |
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378 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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379 EAccept, ERejectStrict, EAccept, EReject, EReject, |
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380 EReject, EComposite, EComposite, EComposite, EReject, EReject, |
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381 EReject, EReject, EReject, |
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382 }, |
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383 |
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384 /* Previous character ELongBelowVowel */ |
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385 { |
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386 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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387 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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388 EReject, EComposite, EReject, EReject, EReject, EReject, |
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389 EReject, EReject, EReject, |
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390 }, |
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391 |
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392 /* Previous character EBelowDiacritic */ |
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393 { |
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394 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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395 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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396 EReject, EReject, EReject, EReject, EReject, EReject, |
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397 EReject, EReject, EReject, |
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398 }, |
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399 |
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400 /* Previous character EToneMark */ |
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401 { |
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402 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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403 EAccept, EAccept, EAccept, EReject, EReject, |
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404 EReject, EReject, EReject, EReject, EReject, EReject, |
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405 EReject, EReject, EReject, |
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406 }, |
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407 |
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408 /* Previous character EAboveDiacritic0 */ |
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409 { |
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410 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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411 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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412 EReject, EReject, EReject, EReject, EReject, EReject, |
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413 EReject, EReject, EReject, |
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414 }, |
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415 |
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416 /* Previous character EAboveDiacritic1 */ |
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417 { |
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418 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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419 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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420 EReject, EReject, EReject, EReject, EReject, EReject, |
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421 EReject, EReject, EReject, |
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422 }, |
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423 |
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424 /* Previous character EAboveDiacritic2 */ |
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425 { |
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426 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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427 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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428 EReject, EReject, EReject, EReject, EReject, EReject, |
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429 EReject, EReject, EReject, |
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430 }, |
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431 |
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432 /* Previous character EAboveDiacritic3 */ |
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433 { |
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434 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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435 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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436 EReject, EReject, EReject, EReject, EReject, EReject, |
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437 EReject, EReject, EReject, |
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438 }, |
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439 |
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440 /* Previous character EAboveVowel1 */ |
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441 { |
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442 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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443 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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444 EReject, EComposite, EReject, EComposite, EReject, EReject, |
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445 // EReject, EComposite, EComposite, EComposite, EReject, EReject, |
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446 EReject, EReject, EReject, |
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447 }, |
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448 |
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449 /* Previous character EAboveVowel2 */ |
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450 { |
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451 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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452 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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453 EReject, EComposite, EReject, EReject, EReject, EReject, |
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454 EReject, EReject, EReject, |
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455 }, |
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456 |
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457 /* Previous character EAboveVowel3 */ |
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458 { |
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459 EUndefined, EUndefined, EAccept, EAccept, EAccept, |
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460 ERejectStrict, ERejectStrict, EAccept, EReject, EReject, |
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461 EReject, EComposite, EReject, EReject, EReject, EReject, |
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462 // EReject, EComposite, EReject, EComposite, EReject, |
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463 EReject, EReject, EReject, |
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464 }, |
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465 |
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466 // Value at last measurement was 324 bytes. 27/6/2003 |
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467 }; |
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468 |
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469 |
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470 /** |
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471 This routine looks up the WTT 2.0 rule for the given |
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472 Thai character codes provided in the WTT 2.0 data table. |
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473 @param aPrevChar |
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474 Unicode character code preceding the assumed position. |
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475 @param aChar |
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476 Unicode character code proceeding the assumed position. |
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477 @return Wtt2Rule |
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478 The rule value found in data table. |
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479 */ |
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480 Wtt2Rule LookupWtt2Rule(TUint aPrevChar, TUint aChar) |
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481 { |
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482 const CharClassification prevCharClassification = |
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483 static_cast<CharClassification>( |
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484 (aPrevChar > KThaiCodePageStart && aPrevChar < KThaiCodePageEnd) ? |
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485 iCharClassifications[aPrevChar - KThaiCodePageStart] : |
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486 ENonPrintable); |
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487 const CharClassification charClassification = |
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488 static_cast<CharClassification>( |
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489 (aChar > KThaiCodePageStart && aChar < KThaiCodePageEnd) ? |
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490 iCharClassifications[aChar - KThaiCodePageStart] : |
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491 ENonPrintable); |
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492 |
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493 return static_cast<Wtt2Rule> |
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494 (iInputRules[prevCharClassification][charClassification]); |
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495 } |
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496 |
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497 } |
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498 |
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499 using namespace ThaiCharRules; |
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500 |
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501 |
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502 // |
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503 // |
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504 // ThaiGlyphPUASubstitution Namespace definition |
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505 // |
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506 // |
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507 |
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508 |
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509 /** |
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510 This utility namespace holds the data and lookup mechanisms to support |
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511 the GlyphSelector_Thai glyph selection class in choosing Private User |
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512 Area (PUA) Thai character positional variant glyphs. Use of the PUA glyphs |
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513 results in a satisfactory rendition of Thai writing in Symbian OS. |
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514 @internalComponent |
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515 */ |
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516 namespace ThaiGlyphPUASubstitution |
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517 { |
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518 |
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519 typedef TBool (*UnicodeCharValidator)(const TGlyphSelectionState& aGss); |
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520 |
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521 struct PUASubstTableEntry |
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522 { |
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523 TUint iOrigGlyph; |
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524 TUint iPUAGlyph; |
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525 UnicodeCharValidator iRuleFunc; |
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526 }; |
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527 |
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528 |
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529 /** |
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530 ThaiGlyphPUASubstitution rule method which checks the context for |
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531 short consonant preceding char OR |
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532 short consonant & dependent vowel below preceding char. |
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533 @param aGss |
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534 Container object holds the glyph selection context for the method. |
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535 @return TBool |
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536 ETrue when the rule context is satisfied, EFalse if not. |
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537 */ |
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538 TBool RuleShortConsonant(const TGlyphSelectionState& aGss) |
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539 { |
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540 if (aGss.iParam.iOutputGlyphs == 1) { |
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541 //check the context for short consonant preceding char |
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542 TUint consonantGss = aGss.iParam.iOutput[0].iCode; |
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543 if (ThaiGlyph::IsThaiShortConsonant(consonantGss) || |
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544 consonantGss == ThaiGlyph::KYoYingPua || |
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545 consonantGss == ThaiGlyph::KThoThanPua) |
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546 return ETrue; |
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547 else |
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548 return EFalse; |
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549 } |
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550 if (aGss.iParam.iOutputGlyphs == 2) { |
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551 //check the context for short consonant & dependent vowel below preceding char |
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552 TUint consonantGss = aGss.iParam.iOutput[0].iCode; |
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553 TUint depVowelGss = aGss.iParam.iOutput[1].iCode; |
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554 if ((ThaiGlyph::IsThaiShortConsonant(consonantGss) || |
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555 consonantGss == ThaiGlyph::KYoYingPua || |
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556 consonantGss == ThaiGlyph::KThoThanPua) && |
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557 (ThaiGlyph::IsThaiDepVowelBelow(depVowelGss) || |
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558 (depVowelGss >= 0xF718 && |
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559 depVowelGss <= 0xF71A))) |
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560 return ETrue; |
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561 else |
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562 return EFalse; |
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563 } |
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564 return EFalse; |
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565 } |
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566 |
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567 /** |
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568 ThaiGlyphPUASubstitution rule method which checks the context for |
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569 tall consonant preceding char. |
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570 @param aGss |
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571 Container object holds the glyph selection context for the method. |
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572 @return TBool |
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573 ETrue when the rule context is satisfied, EFalse if not. |
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574 */ |
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575 TBool RuleTallConsonant(const TGlyphSelectionState& aGss) |
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576 { |
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577 if ((aGss.iParam.iOutputGlyphs == 1) && |
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578 ThaiGlyph::IsThaiTallConsonant(aGss.iParam.iOutput[0].iCode)) |
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579 return ETrue; |
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580 else |
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581 return EFalse; |
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582 } |
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583 |
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584 /** |
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585 ThaiGlyphPUASubstitution rule method which checks the context for a tall |
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586 consonant which does not have a dependent vowel above or a nikhahit or a |
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587 following sara am. |
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588 @param aGss |
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589 Container object holds the glyph selection context for the method. |
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590 @return TBool |
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591 ETrue when the rule context is satisfied, EFalse if not. |
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592 */ |
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593 TBool RuleTallConsonantNoVowelAbove(const TGlyphSelectionState& aGss) |
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594 { |
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595 if (aGss.iParam.iOutputGlyphs == 0) |
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596 return EFalse; |
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597 if (!ThaiGlyph::IsThaiTallConsonant(aGss.iParam.iOutput[0].iCode)) |
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598 return EFalse; |
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599 if (aGss.iParam.iOutputGlyphs == 1) |
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600 return ETrue; |
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601 if (aGss.iParam.iOutputGlyphs != 2) |
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602 return EFalse; |
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603 TUint wantDepVowel = aGss.iParam.iOutput[1].iCode; |
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604 if (ThaiGlyph::IsThaiDepVowelAbove(wantDepVowel) |
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605 || ThaiGlyph::IsThaiDepVowelAbovePUA(wantDepVowel) |
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606 || wantDepVowel == ThaiGlyph::KNikhahit |
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607 || wantDepVowel == ThaiGlyph::KNikhahitPua) |
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608 return EFalse; |
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609 return ETrue; |
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610 } |
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611 |
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612 /** |
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613 ThaiGlyphPUASubstitution rule method which checks the context for tall |
|
614 consonant with either a dependent vowel above or nikhahit. |
|
615 @param aGss |
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616 Container object holds the glyph selection context for the method. |
|
617 @return TBool |
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618 ETrue when the rule context is satisfied, EFalse if not. |
|
619 */ |
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620 TBool RuleTallConsonantVowelAbove(const TGlyphSelectionState& aGss) |
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621 { |
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622 if ((aGss.iParam.iOutputGlyphs == 2) && |
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623 ThaiGlyph::IsThaiTallConsonant(aGss.iParam.iOutput[0].iCode) && |
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624 (ThaiGlyph::IsThaiDepVowelAbovePUA(aGss.iParam.iOutput[1].iCode)) |
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625 || aGss.iParam.iOutput[1].iCode == ThaiGlyph::KNikhahitPua) |
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626 return ETrue; |
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627 else |
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628 return EFalse; |
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629 } |
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630 |
|
631 /** |
|
632 ThaiGlyphPUASubstitution rule method which checks the context for |
|
633 consonant with joined descender preceding char. |
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634 @param aGss |
|
635 Container object holds the glyph selection context for the method. |
|
636 @return TBool |
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637 ETrue when the rule context is satisfied, EFalse if not. |
|
638 */ |
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639 TBool RuleConsonantWithJointDescender(const TGlyphSelectionState& aGss) |
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640 { |
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641 if ((aGss.iParam.iOutputGlyphs == 1) && |
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642 ThaiGlyph::IsThaiConsonantWithJointDescender(aGss.iParam.iOutput[0].iCode)) |
|
643 return ETrue; |
|
644 else |
|
645 return EFalse; |
|
646 } |
|
647 |
|
648 |
|
649 const PUASubstTableEntry RuleTable[] = { |
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650 /** |
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651 This data member of the ThaiGlyphPUASubstitution class holds rules |
|
652 on when a given PUA glyph should be substituted for the original |
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653 0x0Exx glyph. Table lookup returns the first match found from the |
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654 start of the table, therefore duplicate match situations must be |
|
655 avoided in the rule set logic. |
|
656 */ |
|
657 /* iOrigGlyph, iPUAGlyph, iRuleFunc */ |
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658 |
|
659 // Substitutions for a tone or sign mark above a short consonant |
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660 { 0x0E48, 0xF70A, RuleShortConsonant }, |
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661 { 0x0E49, 0xF70B, RuleShortConsonant }, |
|
662 { 0x0E4A, 0xF70C, RuleShortConsonant }, |
|
663 { 0x0E4B, 0xF70D, RuleShortConsonant }, |
|
664 { 0x0E4C, 0xF70E, RuleShortConsonant }, |
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665 |
|
666 // Substitutions for a vowel or sign mark above a tall consonant |
|
667 { 0x0E34, 0xF701, RuleTallConsonant }, |
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668 { 0x0E35, 0xF702, RuleTallConsonant }, |
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669 { 0x0E36, 0xF703, RuleTallConsonant }, |
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670 { 0x0E37, 0xF704, RuleTallConsonant }, |
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671 { 0x0E31, 0xF710, RuleTallConsonant }, |
|
672 { 0x0E4D, 0xF711, RuleTallConsonant }, |
|
673 { 0x0E47, 0xF712, RuleTallConsonant }, |
|
674 |
|
675 // Substitutions for a tone or sign mark above a tall consonant |
|
676 { 0x0E48, 0xF705, RuleTallConsonantNoVowelAbove }, |
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677 { 0x0E49, 0xF706, RuleTallConsonantNoVowelAbove }, |
|
678 { 0x0E4A, 0xF707, RuleTallConsonantNoVowelAbove }, |
|
679 { 0x0E4B, 0xF708, RuleTallConsonantNoVowelAbove }, |
|
680 { 0x0E4C, 0xF709, RuleTallConsonantNoVowelAbove }, |
|
681 |
|
682 // Substitutions for a tone or sign mark above a vowel which is |
|
683 // above a tall consonant |
|
684 { 0x0E48, 0xF713, RuleTallConsonantVowelAbove }, |
|
685 { 0x0E49, 0xF714, RuleTallConsonantVowelAbove }, |
|
686 { 0x0E4A, 0xF715, RuleTallConsonantVowelAbove }, |
|
687 { 0x0E4B, 0xF716, RuleTallConsonantVowelAbove }, |
|
688 { 0x0E4C, 0xF717, RuleTallConsonantVowelAbove }, |
|
689 |
|
690 // Substitutions for a vowel or sign mark below a consonant with a |
|
691 // joined descender |
|
692 { 0x0E38, 0xF718, RuleConsonantWithJointDescender }, |
|
693 { 0x0E39, 0xF719, RuleConsonantWithJointDescender }, |
|
694 { 0x0E3A, 0xF71A, RuleConsonantWithJointDescender }, |
|
695 |
|
696 { 0, 0, 0} |
|
697 |
|
698 // Size of table at last measurement was 312 bytes. 27/6/2003 |
|
699 }; |
|
700 |
|
701 |
|
702 /** |
|
703 This is the lookup method to determine if the current character being |
|
704 processed needs to be substituted for a glyph in the PUA area given the |
|
705 supplied context. It scans the rule table and returns when it finds it's |
|
706 first match. Therefore duplicate match situations must be avoided in |
|
707 the rule set logic. |
|
708 @param aCode |
|
709 On input it is the character to lookup, on exit it is either unchanged |
|
710 or a code in the PUA 0xF700..0xF71A. |
|
711 @param aGss |
|
712 Container object holds the glyph selection context for the method. |
|
713 @return TBool |
|
714 ETrue when a match is found and aCode has changed, EFalse otherwise. |
|
715 */ |
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716 TBool Lookup(TUint& aCode, const TGlyphSelectionState& aGss) |
|
717 { |
|
718 const PUASubstTableEntry* tablePtr = RuleTable; |
|
719 while (tablePtr->iOrigGlyph) |
|
720 { |
|
721 if ((aCode == tablePtr->iOrigGlyph) && tablePtr->iRuleFunc(aGss)) |
|
722 { |
|
723 aCode = tablePtr->iPUAGlyph; |
|
724 return ETrue; // Rule match, substitute glyph code |
|
725 } |
|
726 tablePtr++; |
|
727 } |
|
728 return EFalse; // No match in table |
|
729 } |
|
730 } |
|
731 |
|
732 |
|
733 // |
|
734 // |
|
735 // GlyphSelector_Thai Class definition |
|
736 // |
|
737 // |
|
738 |
|
739 |
|
740 /** |
|
741 This is the default glyph processing method for the Thai characters in the |
|
742 range 0x0E00..0x0E7F and is invoked from the Glyph selection algorithm in |
|
743 CFont::GetCharacterPosition() method. It is capable of processing base |
|
744 Thai characters as well as Thai combining vowels, signs a tone marks. |
|
745 @param aGss |
|
746 Container object holds the input/output parameters of the method. |
|
747 @return TBool |
|
748 ETrue when glyph cluster updated successfully, EFalse on error condition. |
|
749 @see |
|
750 The method GlyphSelector_Thai::Process() also handles it for other cases. |
|
751 */ |
|
752 TBool GlyphSelector_Thai::Process(TGlyphSelectionState& aGss, RShapeInfo&) |
|
753 { |
|
754 // Get the Unicode character codes we need to process the current |
|
755 // glyph and increment the iterator onto th next character. |
|
756 TUint prevCode = (aGss.iText.LengthToStart() > 0) ? aGss.iText.Get(-1) : 0xFFFF; |
|
757 TUint code = aGss.iText.GetThenNext(); // Inc to next char |
|
758 TUint nextCode = !aGss.iText.AtEnd() ? aGss.iText.Get(0) : 0xFFFF; |
|
759 |
|
760 // Is it a Thai base char or a mark (combining) char? |
|
761 if ((aGss.iCats & 0xF0) == TChar::EMarkGroup) |
|
762 { |
|
763 |
|
764 // Thai character is combining mark but first check to see if it |
|
765 // follows a Thai base character before processing it. |
|
766 if ((aGss.iParam.iOutputGlyphs > 0) && |
|
767 !ThaiGlyph::IsThaiGlyph(prevCode)) |
|
768 { |
|
769 (void) aGss.iText.Prev(); |
|
770 aGss.iClusterState = TGlyphSelectionState::EGClusterComplete; |
|
771 return ETrue; |
|
772 } |
|
773 |
|
774 // Missing base glyph? Insert a dotted circle glyph if true. |
|
775 if (aGss.iParam.iOutputGlyphs == 0) |
|
776 { |
|
777 if (!aGss.AppendGlyphToCluster(KUnicodeDottedCircle)) |
|
778 return EFalse; |
|
779 aGss.iParam.iPen += aGss.iAdvance; |
|
780 } |
|
781 |
|
782 // Test if SARA AM follows this current Thai mark, since it is |
|
783 // a SPECIAL CASE. If present we need NIKHAHIT glyph before this |
|
784 // current Thai mark char. |
|
785 if (nextCode == ThaiGlyph::KSaraAm && |
|
786 (aGss.iParam.iOutputGlyphs == 1) && ThaiGlyph::IsThaiToneMark(code)) |
|
787 { |
|
788 TUint nikhahit = ThaiGlyph::KNikhahit; |
|
789 // Check and do PUA glyph substitution on Nikhahit |
|
790 ThaiGlyphPUASubstitution::Lookup(nikhahit, aGss); |
|
791 |
|
792 if (!aGss.AppendGlyphToCluster(nikhahit)) |
|
793 return EFalse; |
|
794 |
|
795 // Check and do PUA glyph substitution on combining mark |
|
796 ThaiGlyphPUASubstitution::Lookup(code, aGss); |
|
797 |
|
798 // Append the curernt Thai Mark to the output stack of glyphs. |
|
799 if (!aGss.AppendGlyphToCluster(code)) |
|
800 return EFalse; |
|
801 |
|
802 // We now need to add SARA AA glyph after the current Thai mark char. |
|
803 aGss.iAdvance.iWidth = aGss.iAdvance.iHeight = 0; |
|
804 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KSaraAa)) |
|
805 return EFalse; |
|
806 |
|
807 // Skip the following SARA AM character since we've added |
|
808 // its glyphs to it's previous character's glyph cluster. |
|
809 // As we've added a base char to the end of the glyph cluster |
|
810 // make sure the pen is moved on by the caller. |
|
811 (void) aGss.iText.Next(); |
|
812 aGss.iPen = TGlyphSelectionState::EPenAdvance_Yes; |
|
813 } |
|
814 else |
|
815 { |
|
816 // Check and do PUA glyph substitution on combining mark |
|
817 ThaiGlyphPUASubstitution::Lookup(code, aGss); |
|
818 |
|
819 // Append the curernt Thai Mark to the output stack of glyphs. |
|
820 if (!aGss.AppendGlyphToCluster(code)) |
|
821 return EFalse; |
|
822 |
|
823 aGss.iPen = TGlyphSelectionState::EPenAdvance_No; |
|
824 } |
|
825 } |
|
826 else |
|
827 |
|
828 { |
|
829 // Thai character is an independent consonant, digit or sign |
|
830 |
|
831 // Handle disjoint descender consonants followed by below vowel. |
|
832 // In these two cases we substitute consonant with PUA |
|
833 // consonant that the descender removed. Check code not last one. |
|
834 if (code == ThaiGlyph::KYoYing && nextCode != 0xffff && |
|
835 ThaiGlyph::IsThaiDepVowelBelow(nextCode)) |
|
836 code = ThaiGlyph::KYoYingPua; |
|
837 else if (code == ThaiGlyph::KThoThan && nextCode != 0xffff && |
|
838 ThaiGlyph::IsThaiDepVowelBelow(nextCode)) |
|
839 code = ThaiGlyph::KThoThanPua; |
|
840 |
|
841 // Append the glyph details for the Thai character onto the output |
|
842 // stack of glyphs. |
|
843 if (!aGss.AppendGlyphToCluster(code)) |
|
844 return EFalse; |
|
845 |
|
846 // Make sure the caller advances the pen for a base char! |
|
847 aGss.iPen = TGlyphSelectionState::EPenAdvance_Yes; |
|
848 } |
|
849 |
|
850 // Lookup in rule table to determine if the current glyph and cluster is |
|
851 // now complete? |
|
852 if (ThaiCharRules::LookupWtt2Rule(aGss.iCodePt, nextCode) == ThaiCharRules::EComposite) |
|
853 aGss.iClusterState = TGlyphSelectionState::EGClusterNotComplete; |
|
854 else |
|
855 aGss.iClusterState = TGlyphSelectionState::EGClusterComplete; |
|
856 |
|
857 return ETrue; |
|
858 } |
|
859 |
|
860 |
|
861 // |
|
862 // |
|
863 // GlyphSelector_ThaiSaraAm Class definition |
|
864 // |
|
865 // |
|
866 |
|
867 |
|
868 /** |
|
869 This is the glyph processing method for the Thai SARA AM (U+0E33) character |
|
870 which is handled as a special case since it is decomposed into two glyphs |
|
871 - the combining NIKHAHIT mark & SARA AA following vowel in some cases. |
|
872 It is invoked from the Glyph selection algorithm in |
|
873 CFont::GetCharacterPosition() method for all cases where SARA AM is not |
|
874 following a tone mark and thus be a glyph cluster of its own. |
|
875 @param aGss |
|
876 Container object holds the input/output parameters of the method. |
|
877 @return TBool |
|
878 ETrue when glyph cluster updated successfully, EFalse on error condition. |
|
879 @see |
|
880 The method GlyphSelector_Thai::Process() also handles it for other cases. |
|
881 */ |
|
882 TBool GlyphSelector_ThaiSaraAm::Process(TGlyphSelectionState& aGss, RShapeInfo&) |
|
883 { |
|
884 if (aGss.iCodePt != ThaiGlyph::KSaraAm) //could have got here via |
|
885 { //FindLocalisedProcessFunc in font.cpp |
|
886 RShapeInfo dummy; |
|
887 return GlyphSelector_Thai::Process(aGss, dummy); |
|
888 } |
|
889 |
|
890 // Pen advance accumulator local variable |
|
891 TSize compoundAdvance; |
|
892 |
|
893 if (aGss.iText.LengthToStart() == 0) |
|
894 { |
|
895 // If at the start of a line then render it with a preceding |
|
896 // dotted circle as this is invalid positioning for SARA AM. |
|
897 |
|
898 if (!aGss.AppendGlyphToCluster(KUnicodeDottedCircle)) |
|
899 return EFalse; |
|
900 aGss.iParam.iPen += aGss.iAdvance; |
|
901 |
|
902 aGss.iAdvance.iWidth = aGss.iAdvance.iHeight = 0; |
|
903 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KSaraAm)) |
|
904 return EFalse; |
|
905 compoundAdvance += aGss.iAdvance; |
|
906 } |
|
907 else |
|
908 { |
|
909 // Normal condition - text iterator now some way into the text line |
|
910 // being processed. |
|
911 |
|
912 TUint prevChar = aGss.iText.Get(-1); |
|
913 if (ThaiGlyph::IsThaiShortConsonant(prevChar)) |
|
914 { |
|
915 // SARA AM is following normal height consonant so we can output |
|
916 // non-decomposed SARA AM glyph. |
|
917 |
|
918 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KSaraAm)) |
|
919 return EFalse; |
|
920 compoundAdvance = aGss.iAdvance; |
|
921 } |
|
922 else if (ThaiGlyph::IsThaiTallConsonant(prevChar)) |
|
923 { |
|
924 // SARA AM is following tall consonant so we output decomposed |
|
925 // version of SARA AM but with NIKHAHIT taken from the PUA. |
|
926 |
|
927 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KNikhahitPua)) |
|
928 return EFalse; |
|
929 compoundAdvance = aGss.iAdvance; |
|
930 aGss.iAdvance.iWidth = aGss.iAdvance.iHeight = 0; |
|
931 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KSaraAa)) |
|
932 return EFalse; |
|
933 compoundAdvance += aGss.iAdvance; |
|
934 } |
|
935 else |
|
936 { |
|
937 // SARA AM is a following vowel but is not following a valid |
|
938 // consonant char and so default is to render with dotted circle. |
|
939 if (!aGss.AppendGlyphToCluster(KUnicodeDottedCircle)) |
|
940 return EFalse; |
|
941 aGss.iParam.iPen += aGss.iAdvance; |
|
942 |
|
943 aGss.iAdvance.iWidth = aGss.iAdvance.iHeight = 0; |
|
944 if (!aGss.AppendGlyphToCluster(ThaiGlyph::KSaraAm)) |
|
945 return EFalse; |
|
946 compoundAdvance += aGss.iAdvance; |
|
947 } |
|
948 |
|
949 } |
|
950 |
|
951 // Update output parameters resulting from above processing. |
|
952 // Move text iterator onto next character to process. |
|
953 aGss.iText.Next(); |
|
954 |
|
955 // Advance pen just for the SARA AA char as advance for dotted |
|
956 // circle is done above. |
|
957 aGss.iAdvance = compoundAdvance; |
|
958 aGss.iPen = TGlyphSelectionState::EPenAdvance_Yes; |
|
959 |
|
960 if (!aGss.iText.AtEnd() && |
|
961 (ThaiCharRules::LookupWtt2Rule(aGss.iCodePt, aGss.iText.Get()) == |
|
962 ThaiCharRules::EComposite)) |
|
963 aGss.iClusterState = TGlyphSelectionState::EGClusterNotComplete; |
|
964 else |
|
965 aGss.iClusterState = TGlyphSelectionState::EGClusterComplete; |
|
966 |
|
967 return ETrue; |
|
968 } |
|