1 /*

     2  *

     3  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved

     4  *

     5  */

     6 

     7 #include "LETypes.h"

     8 #include "LEGlyphFilter.h"

     9 #include "OpenTypeTables.h"

    10 #include "LEGlyphStorage.h"

    11 #include "ThaiShaping.h"

    12 

    13 U_NAMESPACE_BEGIN

    14 

    15 enum {

    16     CH_SPACE        = 0x0020,

    17     CH_YAMAKKAN     = 0x0E4E,

    18     CH_MAI_HANAKAT  = 0x0E31,

    19     CH_SARA_AA      = 0x0E32,

    20     CH_SARA_AM      = 0x0E33,

    21     CH_SARA_UEE     = 0x0E37,

    22     CH_MAITAIKHU    = 0x0E47,

    23     CH_NIKHAHIT     = 0x0E4D,

    24     CH_SARA_U       = 0x0E38,

    25     CH_PHINTHU      = 0x0E3A,

    26     CH_YO_YING      = 0x0E0D,

    27     CH_THO_THAN     = 0x0E10,

    28     CH_DOTTED_CIRCLE = 0x25CC

    29 };

    30 

    31     le_uint8 ThaiShaping::getCharClass(LEUnicode ch)

    32 {

    33     le_uint8 charClass = NON;

    34     

    35     if (ch >= 0x0E00 && ch <= 0x0E5B) {

    36         charClass = classTable[ch - 0x0E00];

    37     }

    38     

    39     return charClass;

    40 }

    41 

    42 

    43 LEUnicode ThaiShaping::leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet)

    44 {

    45     static const LEUnicode leftAboveVowels[][7] = {

    46         {0x0E61, 0x0E32, 0x0E33, 0x0E64, 0x0E65, 0x0E66, 0x0E67},

    47         {0xF710, 0x0E32, 0x0E33, 0xF701, 0xF702, 0xF703, 0xF704},

    48         {0xF884, 0x0E32, 0x0E33, 0xF885, 0xF886, 0xF887, 0xF788},

    49         {0x0E31, 0x0E32, 0x0E33, 0x0E34, 0x0E35, 0x0E36, 0x0E37}

    50     };

    51    

    52     if (vowel >= CH_MAI_HANAKAT && vowel <= CH_SARA_UEE) {

    53         return leftAboveVowels[glyphSet][vowel - CH_MAI_HANAKAT];

    54     }

    55     

    56     if (vowel == CH_YAMAKKAN && glyphSet == 0) {

    57         return 0x0E7E;

    58     }

    59     

    60     return vowel;

    61 }

    62 

    63 LEUnicode ThaiShaping::lowerRightTone(LEUnicode tone, le_uint8 glyphSet)

    64 {

    65     static const LEUnicode lowerRightTones[][7] = {

    66         {0x0E68, 0x0E69, 0x0E6A, 0x0E6B, 0x0E6C, 0x0E6D, 0x0E6E},

    67         {0x0E47, 0xF70A, 0xF70B, 0xF70C, 0xF70D, 0xF70E, 0x0E4D},

    68         {0x0E47, 0xF88B, 0xF88E, 0xF891, 0xF894, 0xF897, 0x0E4D},

    69         {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

    70     };

    71 

    72     if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

    73         return lowerRightTones[glyphSet][tone - CH_MAITAIKHU];

    74     }

    75     

    76     return tone;

    77 }

    78 

    79 LEUnicode ThaiShaping::lowerLeftTone(LEUnicode tone, le_uint8 glyphSet)

    80 {

    81     static const LEUnicode lowerLeftTones[][7] = {

    82         {0x0E76, 0x0E77, 0x0E78, 0x0E79, 0x0E7A, 0x0E7B, 0x0E7C},

    83         {0xF712, 0xF705, 0xF706, 0xF707, 0xF708, 0xF709, 0xF711},

    84         {0xF889, 0xF88C, 0xF88F, 0xF892, 0xF895, 0xF898, 0xF899},

    85         {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

    86     };

    87 

    88     if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

    89         return lowerLeftTones[glyphSet][tone - CH_MAITAIKHU];

    90     }

    91     

    92     return tone;

    93 }

    94 

    95 LEUnicode ThaiShaping::upperLeftTone(LEUnicode tone, le_uint8 glyphSet)

    96 {

    97     static const LEUnicode upperLeftTones[][7] = {

    98         {0x0E6F, 0x0E70, 0x0E71, 0x0E72, 0x0E73, 0x0E74, 0x0E75},

    99         {0xF712, 0xF713, 0xF714, 0xF715, 0xF716, 0xF717, 0xF711},

   100         {0xF889, 0xF88A, 0xF88D, 0xF890, 0xF893, 0xF896, 0xF899},

   101         {0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}

   102     };

   103 

   104     if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {

   105         return upperLeftTones[glyphSet][tone - CH_MAITAIKHU];

   106     }

   107     

   108     return tone;

   109 }

   110 

   111 LEUnicode ThaiShaping::lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet)

   112 {

   113     static const LEUnicode lowerBelowVowels[][3] = {

   114         {0x0E3C, 0x0E3D, 0x0E3E},

   115         {0xF718, 0xF719, 0xF71A},

   116         {0x0E38, 0x0E39, 0x0E3A},

   117         {0x0E38, 0x0E39, 0x0E3A}

   118 

   119     };

   120 

   121     if (vowel >= CH_SARA_U && vowel <= CH_PHINTHU) {

   122         return lowerBelowVowels[glyphSet][vowel - CH_SARA_U];

   123     }

   124     

   125     return vowel;

   126 }

   127 

   128 LEUnicode ThaiShaping::noDescenderCOD(LEUnicode cod, le_uint8 glyphSet)

   129 {

   130     static const LEUnicode noDescenderCODs[][4] = {

   131         {0x0E60, 0x0E0E, 0x0E0F, 0x0E63},

   132         {0xF70F, 0x0E0E, 0x0E0F, 0xF700},

   133         {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10},

   134         {0x0E0D, 0x0E0E, 0x0E0F, 0x0E10}

   135 

   136     };

   137 

   138     if (cod >= CH_YO_YING && cod <= CH_THO_THAN) {

   139         return noDescenderCODs[glyphSet][cod - CH_YO_YING];

   140     }

   141     

   142     return cod;

   143 }

   144 

   145 le_uint8 ThaiShaping::doTransition (StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,

   146         LEUnicode errorChar, LEUnicode *outputBuffer, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)

   147 {

   148     LEErrorCode success = LE_NO_ERROR;

   149 

   150     switch (transition.action) {

   151     case tA:

   152         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   153         outputBuffer[outputIndex++] = currChar;

   154         break;

   155         

   156     case tC:

   157         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   158         outputBuffer[outputIndex++] = currChar;

   159         break;

   160         

   161     case tD:

   162         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   163         outputBuffer[outputIndex++] = leftAboveVowel(currChar, glyphSet);

   164         break;

   165         

   166     case tE:

   167         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   168         outputBuffer[outputIndex++] = lowerRightTone(currChar, glyphSet);

   169         break;

   170         

   171     case tF:

   172         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   173         outputBuffer[outputIndex++] = lowerLeftTone(currChar, glyphSet);

   174         break;

   175     

   176     case tG:

   177         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   178         outputBuffer[outputIndex++] = upperLeftTone(currChar, glyphSet);

   179         break;

   180         

   181     case tH:

   182     {

   183         LEUnicode cod = outputBuffer[outputIndex - 1];

   184         LEUnicode coa = noDescenderCOD(cod, glyphSet);

   185 

   186         if (cod != coa) {

   187             outputBuffer[outputIndex - 1] = coa;

   188             

   189             glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   190             outputBuffer[outputIndex++] = currChar;

   191             break;

   192         }

   193 

   194         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   195         outputBuffer[outputIndex++] = lowerBelowVowel(currChar, glyphSet);

   196         break;

   197     }

   198         

   199     case tR:

   200         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   201         outputBuffer[outputIndex++] = errorChar;

   202 

   203         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   204         outputBuffer[outputIndex++] = currChar;

   205         break;

   206         

   207     case tS:

   208         if (currChar == CH_SARA_AM) {

   209             glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   210             outputBuffer[outputIndex++] = errorChar;

   211         }

   212 

   213         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   214         outputBuffer[outputIndex++] = currChar;

   215         break;

   216         

   217     default:

   218         // FIXME: if we get here, there's an error

   219         // in the state table!

   220         glyphStorage.setCharIndex(outputIndex, inputIndex, success);

   221         outputBuffer[outputIndex++] = currChar;

   222         break;

   223      }

   224      

   225      return transition.nextState;

   226 }

   227 

   228 le_uint8 ThaiShaping::getNextState(LEUnicode ch, le_uint8 prevState, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,

   229                               le_uint8 &charClass, LEUnicode *output, LEGlyphStorage &glyphStorage, le_int32 &outputIndex)

   230 {

   231     StateTransition transition;

   232 

   233     charClass = getCharClass(ch);

   234     transition = getTransition(prevState, charClass);

   235     

   236     return doTransition(transition, ch, inputIndex, glyphSet, errorChar, output, glyphStorage, outputIndex);

   237 }

   238 

   239 le_bool ThaiShaping::isLegalHere(LEUnicode ch, le_uint8 prevState)

   240 {

   241     le_uint8 charClass = getCharClass(ch);

   242     StateTransition transition = getTransition(prevState, charClass);

   243 

   244     switch (transition.action) {

   245     case tA:

   246     case tC:

   247     case tD:

   248     case tE:

   249     case tF:

   250     case tG:

   251     case tH:

   252         return TRUE;

   253             

   254     case tR:

   255     case tS:

   256         return FALSE;

   257             

   258     default:

   259         // FIXME: if we get here, there's an error

   260         // in the state table!

   261         return FALSE;

   262     }

   263 }

   264     

   265 le_int32 ThaiShaping::compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,

   266                           LEUnicode errorChar, LEUnicode *output, LEGlyphStorage &glyphStorage)

   267 {

   268     le_uint8 state = 0;

   269     le_int32 inputIndex;

   270     le_int32 outputIndex = 0;

   271     le_uint8 conState = 0xFF;

   272     le_int32 conInput = -1;

   273     le_int32 conOutput = -1;

   274     

   275     for (inputIndex = 0; inputIndex < charCount; inputIndex += 1) {

   276         LEUnicode ch = input[inputIndex + offset];

   277         le_uint8 charClass;

   278         

   279         // Decompose SARA AM into NIKHAHIT + SARA AA

   280         if (ch == CH_SARA_AM && isLegalHere(ch, state)) {

   281             outputIndex = conOutput;

   282             state = getNextState(CH_NIKHAHIT, conState, inputIndex, glyphSet, errorChar, charClass,

   283                 output, glyphStorage, outputIndex);

   284             

   285             for (int j = conInput + 1; j < inputIndex; j += 1) {

   286                 ch = input[j + offset];

   287                 state = getNextState(ch, state, j, glyphSet, errorChar, charClass,

   288                     output, glyphStorage, outputIndex);

   289             }

   290             

   291             ch = CH_SARA_AA;

   292         }

   293         

   294         state = getNextState(ch, state, inputIndex, glyphSet, errorChar, charClass,

   295             output, glyphStorage, outputIndex);

   296         

   297         if (charClass >= CON && charClass <= COD) {

   298             conState = state;

   299             conInput = inputIndex;

   300             conOutput = outputIndex;

   301         }

   302     }

   303     

   304     return outputIndex;

   305 }

   306 

   307 U_NAMESPACE_END