icuSources/layout/OpenTypeLayoutEngine.cpp

   1
   2 /*
   3  *
   4  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
   5  *
   6  */
   7
   8 #include "LETypes.h"
   9 #include "LEScripts.h"
  10 #include "LELanguages.h"
  11
  12 #include "LayoutEngine.h"
  13 #include "OpenTypeLayoutEngine.h"
  14 #include "ScriptAndLanguageTags.h"
  15
  16 #include "GlyphSubstitutionTables.h"
  17 #include "GlyphDefinitionTables.h"
  18 #include "GlyphPositioningTables.h"
  19
  20 #include "LEGlyphStorage.h"
  21
  22 #include "GDEFMarkFilter.h"
  23
  24 U_NAMESPACE_BEGIN
  25
  26 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(OpenTypeLayoutEngine)
  27
  28 static const LETag emptyTag = 0x00000000;
  29
  30 static const LETag ccmpFeatureTag = LE_CCMP_FEATURE_TAG;
  31 static const LETag ligaFeatureTag = LE_LIGA_FEATURE_TAG;
  32 static const LETag cligFeatureTag = LE_CLIG_FEATURE_TAG;
  33 static const LETag kernFeatureTag = LE_KERN_FEATURE_TAG;
  34 static const LETag markFeatureTag = LE_MARK_FEATURE_TAG;
  35 static const LETag mkmkFeatureTag = LE_MKMK_FEATURE_TAG;
  36
  37 static const LETag defaultFeatures[] = {ccmpFeatureTag, ligaFeatureTag, cligFeatureTag, kernFeatureTag, markFeatureTag, mkmkFeatureTag, emptyTag};
  38
  39
  40 OpenTypeLayoutEngine::OpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
  41                         const GlyphSubstitutionTableHeader *gsubTable)
  42     : LayoutEngine(fontInstance, scriptCode, languageCode), fFeatureList(defaultFeatures), fFeatureOrder(NULL),
  43       fGSUBTable(gsubTable), fGDEFTable(NULL), fGPOSTable(NULL), fSubstitutionFilter(NULL)
  44 {
  45     static const le_uint32 gdefTableTag = LE_GDEF_TABLE_TAG;
  46     static const le_uint32 gposTableTag = LE_GPOS_TABLE_TAG;
  47     const GlyphPositioningTableHeader *gposTable = (const GlyphPositioningTableHeader *) getFontTable(gposTableTag);
  48
  49     setScriptAndLanguageTags();
  50
  51     fGDEFTable = (const GlyphDefinitionTableHeader *) getFontTable(gdefTableTag);
  52
  53     if (gposTable != NULL && gposTable->coversScriptAndLanguage(fScriptTag, fLangSysTag)) {
  54         fGPOSTable = gposTable;
  55     }
  56 }
  57
  58 void OpenTypeLayoutEngine::reset()
  59 {
  60     // NOTE: if we're called from
  61     // the destructor, LayoutEngine;:reset()
  62     // will have been called already by
  63     // LayoutEngine::~LayoutEngine()
  64     LayoutEngine::reset();
  65 }
  66
  67 OpenTypeLayoutEngine::OpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
  68     : LayoutEngine(fontInstance, scriptCode, languageCode), fFeatureOrder(NULL),
  69       fGSUBTable(NULL), fGDEFTable(NULL), fGPOSTable(NULL), fSubstitutionFilter(NULL)
  70 {
  71     setScriptAndLanguageTags();
  72 }
  73
  74 OpenTypeLayoutEngine::~OpenTypeLayoutEngine()
  75 {
  76     reset();
  77 }
  78
  79 LETag OpenTypeLayoutEngine::getScriptTag(le_int32 scriptCode)
  80 {
  81     if (scriptCode < 0 || scriptCode >= scriptCodeCount) {
  82         return 0xFFFFFFFF;
  83     }
  84
  85     return scriptTags[scriptCode];
  86 }
  87
  88 LETag OpenTypeLayoutEngine::getLangSysTag(le_int32 languageCode)
  89 {
  90     if (languageCode < 0 || languageCode >= languageCodeCount) {
  91         return 0xFFFFFFFF;
  92     }
  93
  94     return languageTags[languageCode];
  95 }
  96
  97 void OpenTypeLayoutEngine::setScriptAndLanguageTags()
  98 {
  99     fScriptTag  = getScriptTag(fScriptCode);
 100     fLangSysTag = getLangSysTag(fLanguageCode);
 101 }
 102
 103 le_int32 OpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
 104                 LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 105 {
 106     if (LE_FAILURE(success)) {
 107         return 0;
 108     }
 109
 110     if (offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
 111         success = LE_ILLEGAL_ARGUMENT_ERROR;
 112         return 0;
 113     }
 114
 115     le_int32 outCharCount = LayoutEngine::characterProcessing(chars, offset, count, max, rightToLeft, outChars, glyphStorage, success);
 116
 117     if (LE_FAILURE(success)) {
 118         return 0;
 119     }
 120
 121     glyphStorage.allocateGlyphArray(outCharCount, rightToLeft, success);
 122     glyphStorage.allocateAuxData(success);
 123
 124     for (le_int32 i = 0; i < outCharCount; i += 1) {
 125         glyphStorage.setAuxData(i, (void *) fFeatureList, success);
 126     }
 127
 128     return outCharCount;
 129 }
 130
 131 // Input: characters, tags
 132 // Output: glyphs, char indices
 133 le_int32 OpenTypeLayoutEngine::glyphProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
 134                                                LEGlyphStorage &glyphStorage, LEErrorCode &success)
 135 {
 136     if (LE_FAILURE(success)) {
 137         return 0;
 138     }
 139
 140     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
 141         success = LE_ILLEGAL_ARGUMENT_ERROR;
 142         return 0;
 143     }
 144
 145     mapCharsToGlyphs(chars, offset, count, rightToLeft, rightToLeft, glyphStorage, success);
 146
 147     if (LE_FAILURE(success)) {
 148         return 0;
 149     }
 150
 151     if (fGSUBTable != NULL) {
 152         count = fGSUBTable->process(glyphStorage, rightToLeft, fScriptTag, fLangSysTag, fGDEFTable, fSubstitutionFilter, fFeatureOrder);
 153     }
 154
 155     return count;
 156 }
 157
 158 le_int32 OpenTypeLayoutEngine::glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 159 {
 160     if (LE_FAILURE(success)) {
 161         return 0;
 162     }
 163
 164     glyphStorage.adoptGlyphArray(tempGlyphStorage);
 165     glyphStorage.adoptCharIndicesArray(tempGlyphStorage);
 166     glyphStorage.adoptAuxDataArray(tempGlyphStorage);
 167     glyphStorage.adoptGlyphCount(tempGlyphStorage);
 168
 169     return glyphStorage.getGlyphCount();
 170 }
 171
 172 le_int32 OpenTypeLayoutEngine::computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 173 {
 174     LEUnicode *outChars = NULL;
 175     LEGlyphStorage fakeGlyphStorage;
 176     le_int32 outCharCount, outGlyphCount, fakeGlyphCount;
 177
 178     if (LE_FAILURE(success)) {
 179         return 0;
 180     }
 181
 182     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
 183         success = LE_ILLEGAL_ARGUMENT_ERROR;
 184         return 0;
 185     }
 186
 187     outCharCount = characterProcessing(chars, offset, count, max, rightToLeft, outChars, fakeGlyphStorage, success);
 188
 189     if (outChars != NULL) {
 190         fakeGlyphCount = glyphProcessing(outChars, 0, outCharCount, outCharCount, rightToLeft, fakeGlyphStorage, success);
 191         LE_DELETE_ARRAY(outChars); // FIXME: a subclass may have allocated this, in which case this delete might not work...
 192         //adjustGlyphs(outChars, 0, outCharCount, rightToLeft, fakeGlyphs, fakeGlyphCount);
 193     } else {
 194         fakeGlyphCount = glyphProcessing(chars, offset, count, max, rightToLeft, fakeGlyphStorage, success);
 195         //adjustGlyphs(chars, offset, count, rightToLeft, fakeGlyphs, fakeGlyphCount);
 196     }
 197
 198     outGlyphCount = glyphPostProcessing(fakeGlyphStorage, glyphStorage, success);
 199
 200     return outGlyphCount;
 201 }
 202
 203 // apply GPOS table, if any
 204 void OpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 205                                                 LEGlyphStorage &glyphStorage, LEErrorCode &success)
 206 {
 207     if (LE_FAILURE(success)) {
 208         return;
 209     }
 210
 211     if (chars == NULL || offset < 0 || count < 0) {
 212         success = LE_ILLEGAL_ARGUMENT_ERROR;
 213         return;
 214     }
 215
 216     le_int32 glyphCount = glyphStorage.getGlyphCount();
 217
 218     if (glyphCount > 0 && fGPOSTable != NULL) {
 219         GlyphPositionAdjustment *adjustments = new GlyphPositionAdjustment[glyphCount];
 220         le_int32 i;
 221
 222         if (adjustments == NULL) {
 223             success = LE_MEMORY_ALLOCATION_ERROR;
 224             return;
 225         }
 226
 227 #if 0
 228         // Don't need to do this if we allocate
 229         // the adjustments array w/ new...
 230         for (i = 0; i < glyphCount; i += 1) {
 231             adjustments[i].setXPlacement(0);
 232             adjustments[i].setYPlacement(0);
 233
 234             adjustments[i].setXAdvance(0);
 235             adjustments[i].setYAdvance(0);
 236
 237             adjustments[i].setBaseOffset(-1);
 238         }
 239 #endif
 240
 241         fGPOSTable->process(glyphStorage, adjustments, reverse, fScriptTag, fLangSysTag, fGDEFTable, fFontInstance, fFeatureOrder);
 242
 243         float xAdjust = 0, yAdjust = 0;
 244
 245         for (i = 0; i < glyphCount; i += 1) {
 246             float xAdvance   = adjustments[i].getXAdvance();
 247             float yAdvance   = adjustments[i].getYAdvance();
 248             float xPlacement = 0;
 249             float yPlacement = 0;
 250
 251
 252 #if 0
 253             // This is where separate kerning adjustments
 254             // should get applied.
 255             xAdjust += xKerning;
 256             yAdjust += yKerning;
 257 #endif
 258
 259             for (le_int32 base = i; base >= 0; base = adjustments[base].getBaseOffset()) {
 260                 xPlacement += adjustments[base].getXPlacement();
 261                 yPlacement += adjustments[base].getYPlacement();
 262             }
 263
 264             xPlacement = fFontInstance->xUnitsToPoints(xPlacement);
 265             yPlacement = fFontInstance->yUnitsToPoints(yPlacement);
 266             glyphStorage.adjustPosition(i, xAdjust + xPlacement, -(yAdjust + yPlacement), success);
 267
 268             xAdjust += fFontInstance->xUnitsToPoints(xAdvance);
 269             yAdjust += fFontInstance->yUnitsToPoints(yAdvance);
 270         }
 271
 272         glyphStorage.adjustPosition(glyphCount, xAdjust, -yAdjust, success);
 273
 274         delete[] adjustments;
 275     }
 276
 277 #if 0
 278     // Don't know why this is here...
 279     LE_DELETE_ARRAY(fFeatureTags);
 280     fFeatureTags = NULL;
 281 #endif
 282 }
 283
 284 U_NAMESPACE_END