icuSources/layout/ArabicLayoutEngine.cpp

   1
   2 /*
   3  * %W% %E%
   4  *
   5  * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
   6  *
   7  */
   8
   9 #include "LETypes.h"
  10 #include "LEScripts.h"
  11 #include "LEGlyphFilter.h"
  12 #include "LayoutEngine.h"
  13 #include "OpenTypeLayoutEngine.h"
  14 #include "ArabicLayoutEngine.h"
  15 #include "ScriptAndLanguageTags.h"
  16
  17 #include "GlyphSubstitutionTables.h"
  18 #include "GlyphDefinitionTables.h"
  19 #include "GlyphPositioningTables.h"
  20
  21 #include "GDEFMarkFilter.h"
  22
  23 #include "ArabicShaping.h"
  24 #include "HebrewShaping.h"
  25
  26 U_NAMESPACE_BEGIN
  27
  28 class CharSubstitutionFilter : public UMemory, public LEGlyphFilter
  29 {
  30 private:
  31     const LEFontInstance *fFontInstance;
  32
  33     CharSubstitutionFilter(const CharSubstitutionFilter &other); // forbid copying of this class
  34     CharSubstitutionFilter &operator=(const CharSubstitutionFilter &other); // forbid copying of this class
  35
  36 public:
  37     CharSubstitutionFilter(const LEFontInstance *fontInstance);
  38     le_bool accept(LEGlyphID glyph) const;
  39 };
  40
  41 CharSubstitutionFilter::CharSubstitutionFilter(const LEFontInstance *fontInstance)
  42   : fFontInstance(fontInstance)
  43 {
  44     // nothing to do
  45 }
  46
  47 le_bool CharSubstitutionFilter::accept(LEGlyphID glyph) const
  48 {
  49     return fFontInstance->canDisplay((LEUnicode) glyph);
  50 }
  51
  52 const char ArabicOpenTypeLayoutEngine::fgClassID=0;
  53
  54 ArabicOpenTypeLayoutEngine::ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
  55                         const GlyphSubstitutionTableHeader *gsubTable)
  56     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, gsubTable)
  57 {
  58     // fFeatureOrder = ArabicShaping::getFeatureOrder();
  59 }
  60
  61 ArabicOpenTypeLayoutEngine::ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
  62     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode)
  63 {
  64     // fFeatureOrder = ArabicShaping::getFeatureOrder();
  65 }
  66
  67 ArabicOpenTypeLayoutEngine::~ArabicOpenTypeLayoutEngine()
  68 {
  69     // nothing to do
  70 }
  71
  72 // Input: characters
  73 // Output: characters, char indices, tags
  74 // Returns: output character count
  75 le_int32 ArabicOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
  76         LEUnicode *&/*outChars*/, le_int32 *&/*charIndices*/, const LETag **&featureTags, LEErrorCode &success)
  77 {
  78     if (LE_FAILURE(success)) {
  79         return 0;
  80     }
  81
  82     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  83         success = LE_ILLEGAL_ARGUMENT_ERROR;
  84         return 0;
  85     }
  86
  87     featureTags = LE_NEW_ARRAY(const LETag *, count);
  88
  89     if (featureTags == NULL) {
  90         success = LE_MEMORY_ALLOCATION_ERROR;
  91         return 0;
  92     }
  93
  94     switch (fScriptCode) {
  95     case arabScriptCode:
  96     {
  97         GlyphShaper shaper(featureTags);
  98
  99         // NOTE: may not need seperate shaper if always use tags...
 100         // NOTE: shaper could allocate the feature tags...
 101         ArabicShaping::shape(chars, offset, count, max, rightToLeft, shaper);
 102         break;
 103     }
 104
 105     case hebrScriptCode:
 106         HebrewShaping::shape(chars, offset, count, max, rightToLeft, featureTags);
 107         break;
 108     }
 109
 110     return count;
 111 }
 112
 113 void ArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 114                                                       LEGlyphID glyphs[], le_int32 glyphCount, float positions[], LEErrorCode &success)
 115 {
 116     if (LE_FAILURE(success)) {
 117         return;
 118     }
 119
 120     if (chars == NULL || glyphs == NULL || positions == NULL || offset < 0 || count < 0) {
 121         success = LE_ILLEGAL_ARGUMENT_ERROR;
 122         return;
 123     }
 124
 125     if (fGPOSTable != NULL) {
 126         OpenTypeLayoutEngine::adjustGlyphPositions(chars, offset, count, reverse, glyphs, glyphCount, positions, success);
 127     } else if (fGDEFTable != NULL) {
 128         GDEFMarkFilter filter(fGDEFTable);
 129
 130         adjustMarkGlyphs(glyphs, glyphCount, false, &filter, positions, success);
 131     } else {
 132         GlyphDefinitionTableHeader *gdefTable = (GlyphDefinitionTableHeader *) ArabicShaping::glyphDefinitionTable;
 133         GDEFMarkFilter filter(gdefTable);
 134         LEGlyphID *tempGlyphs;
 135
 136         // FIXME: we could avoid the memory allocation and copying here by
 137         // making a clone of the adjustMarkGlyphs method which took characters
 138         // directly...
 139         tempGlyphs = LE_NEW_ARRAY(LEGlyphID, count);
 140
 141         if (tempGlyphs == NULL) {
 142             success = LE_MEMORY_ALLOCATION_ERROR;
 143             return;
 144         }
 145
 146         for (le_int32 i = 0; i < count; i += 1) {
 147             tempGlyphs[i] = (LEGlyphID) chars[offset + i];
 148         }
 149
 150         adjustMarkGlyphs(tempGlyphs, count, reverse, &filter, positions, success);
 151
 152         LE_DELETE_ARRAY(tempGlyphs);
 153     }
 154 }
 155
 156 UnicodeArabicOpenTypeLayoutEngine::UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
 157     : ArabicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode)
 158 {
 159     switch (scriptCode) {
 160     case arabScriptCode:
 161         fGSUBTable = (const GlyphSubstitutionTableHeader *) ArabicShaping::glyphSubstitutionTable;
 162         fGDEFTable = (const GlyphDefinitionTableHeader *) ArabicShaping::glyphDefinitionTable;
 163         break;
 164
 165     case hebrScriptCode:
 166         fGSUBTable = (const GlyphSubstitutionTableHeader *) HebrewShaping::glyphSubstitutionTable;
 167         fGDEFTable = (const GlyphDefinitionTableHeader *) HebrewShaping::glyphDefinitionTable;
 168         break;
 169     }
 170
 171
 172     fSubstitutionFilter = new CharSubstitutionFilter(fontInstance);
 173 }
 174
 175 UnicodeArabicOpenTypeLayoutEngine::~UnicodeArabicOpenTypeLayoutEngine()
 176 {
 177     delete fSubstitutionFilter;
 178 }
 179
 180 // "glyphs", "indices" -> glyphs, indices
 181 le_int32 UnicodeArabicOpenTypeLayoutEngine::glyphPostProcessing(LEGlyphID tempGlyphs[], le_int32 tempCharIndices[], le_int32 tempGlyphCount,
 182                 LEGlyphID *&glyphs, le_int32 *&charIndices, LEErrorCode &success)
 183 {
 184     if (LE_FAILURE(success)) {
 185         return 0;
 186     }
 187
 188     if (tempGlyphs == NULL || tempCharIndices == NULL ||tempGlyphCount < 0) {
 189         success = LE_ILLEGAL_ARGUMENT_ERROR;
 190         return 0;
 191     }
 192
 193     // FIXME: we could avoid the memory allocation and copy if we
 194     // made a clone of mapCharsToGlyphs which took the fake glyphs
 195     // directly.
 196     LEUnicode *tempChars = LE_NEW_ARRAY(LEUnicode, tempGlyphCount);
 197
 198     if (tempChars == NULL) {
 199         success = LE_MEMORY_ALLOCATION_ERROR;
 200         return 0;
 201     }
 202
 203     for (le_int32 i = 0; i < tempGlyphCount; i += 1) {
 204         tempChars[i] = (LEUnicode) LE_GET_GLYPH(tempGlyphs[i]);
 205     }
 206
 207     charIndices = tempCharIndices;
 208
 209     ArabicOpenTypeLayoutEngine::mapCharsToGlyphs(tempChars, 0, tempGlyphCount, false, true, glyphs, charIndices, success);
 210
 211     LE_DELETE_ARRAY(tempChars);
 212
 213     return tempGlyphCount;
 214 }
 215
 216 void UnicodeArabicOpenTypeLayoutEngine::mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool /*mirror*/, LEGlyphID *&glyphs, le_int32 *&charIndices, LEErrorCode &success)
 217 {
 218     if (LE_FAILURE(success)) {
 219         return;
 220     }
 221
 222     if (chars == NULL || offset < 0 || count < 0) {
 223         success = LE_ILLEGAL_ARGUMENT_ERROR;
 224         return;
 225     }
 226
 227     le_int32 i, dir, out;
 228
 229     out = 0;
 230     dir = 1;
 231
 232     if (reverse) {
 233         out = count - 1;
 234         dir = -1;
 235     }
 236
 237     glyphs = LE_NEW_ARRAY(LEGlyphID, count);
 238
 239     if (glyphs == NULL) {
 240         success = LE_MEMORY_ALLOCATION_ERROR;
 241         return;
 242     }
 243
 244     charIndices = LE_NEW_ARRAY(le_int32, count);
 245
 246     if (charIndices == NULL) {
 247         LE_DELETE_ARRAY(glyphs);
 248         success = LE_MEMORY_ALLOCATION_ERROR;
 249         return;
 250     }
 251
 252     for (i = 0; i < count; i += 1, out += dir) {
 253         glyphs[out] = (LEGlyphID) chars[offset + i];
 254         charIndices[out] = i;
 255     }
 256 }
 257
 258 void UnicodeArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 259                                                       LEGlyphID glyphs[], le_int32 glyphCount, float positions[], LEErrorCode &success)
 260 {
 261     if (LE_FAILURE(success)) {
 262         return;
 263     }
 264
 265     if (chars == NULL || glyphs == NULL || positions == NULL || offset < 0 || count < 0 || glyphCount < 0) {
 266         success = LE_ILLEGAL_ARGUMENT_ERROR;
 267         return;
 268     }
 269
 270     GDEFMarkFilter filter(fGDEFTable);
 271
 272     // FIXME: we could avoid the memory allocation and copying here by
 273     // making a clone of the adjustMarkGlyphs method which took characters
 274     // directly...
 275     LEGlyphID *tempGlyphs = LE_NEW_ARRAY(LEGlyphID, count);
 276
 277     if (tempGlyphs == NULL) {
 278         success = LE_MEMORY_ALLOCATION_ERROR;
 279         return;
 280     }
 281
 282     for (le_int32 i = 0; i < count; i += 1) {
 283         tempGlyphs[i] = (LEGlyphID) chars[offset + i];
 284     }
 285
 286     adjustMarkGlyphs(tempGlyphs, count, reverse, &filter, positions, success);
 287
 288     LE_DELETE_ARRAY(tempGlyphs);
 289 }
 290
 291 U_NAMESPACE_END
 292