source/layout/ArabicLayoutEngine.cpp

   1
   2 /*
   3  *
   4  * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
   5  *
   6  */
   7
   8 #include "LETypes.h"
   9 #include "LEScripts.h"
  10 #include "LEGlyphFilter.h"
  11 #include "LEGlyphStorage.h"
  12 #include "LayoutEngine.h"
  13 #include "OpenTypeLayoutEngine.h"
  14 #include "ArabicLayoutEngine.h"
  15 #include "ScriptAndLanguageTags.h"
  16 #include "CharSubstitutionFilter.h"
  17
  18 #include "GlyphSubstitutionTables.h"
  19 #include "GlyphDefinitionTables.h"
  20 #include "GlyphPositioningTables.h"
  21
  22 #include "GDEFMarkFilter.h"
  23
  24 #include "ArabicShaping.h"
  25 #include "CanonShaping.h"
  26
  27 U_NAMESPACE_BEGIN
  28
  29 le_bool CharSubstitutionFilter::accept(LEGlyphID glyph) const
  30 {
  31     return fFontInstance->canDisplay((LEUnicode) glyph);
  32 }
  33
  34 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ArabicOpenTypeLayoutEngine)
  35
  36 ArabicOpenTypeLayoutEngine::ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode,
  37                                                        le_int32 languageCode, le_int32 typoFlags,
  38                                                        const LEReferenceTo<GlyphSubstitutionTableHeader> &gsubTable,
  39                                                        LEErrorCode &success)
  40     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable, success)
  41 {
  42     fFeatureMap = ArabicShaping::getFeatureMap(fFeatureMapCount);
  43     fFeatureOrder = TRUE;
  44 }
  45
  46 ArabicOpenTypeLayoutEngine::ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode,
  47                                                        le_int32 languageCode,
  48                                                        le_int32 typoFlags, LEErrorCode &success)
  49     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, success)
  50 {
  51     fFeatureMap = ArabicShaping::getFeatureMap(fFeatureMapCount);
  52
  53     // NOTE: We don't need to set fFeatureOrder to TRUE here
  54     // because this constructor is only called by the constructor
  55     // for UnicodeArabicOpenTypeLayoutEngine, which uses a pre-built
  56     // GSUB table that has the features in the correct order.
  57
  58     //fFeatureOrder = TRUE;
  59 }
  60
  61 ArabicOpenTypeLayoutEngine::~ArabicOpenTypeLayoutEngine()
  62 {
  63     // nothing to do
  64 }
  65
  66 // Input: characters
  67 // Output: characters, char indices, tags
  68 // Returns: output character count
  69 le_int32 ArabicOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count,
  70                                                          le_int32 max, le_bool rightToLeft, LEUnicode *&outChars,
  71                                                          LEGlyphStorage &glyphStorage, LEErrorCode &success)
  72 {
  73     if (LE_FAILURE(success)) {
  74         return 0;
  75     }
  76
  77     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  78         success = LE_ILLEGAL_ARGUMENT_ERROR;
  79         return 0;
  80     }
  81
  82     outChars = LE_NEW_ARRAY(LEUnicode, count);
  83
  84     if (outChars == NULL) {
  85         success = LE_MEMORY_ALLOCATION_ERROR;
  86         return 0;
  87     }
  88
  89     glyphStorage.allocateGlyphArray(count, rightToLeft, success);
  90     glyphStorage.allocateAuxData(success);
  91
  92     if (LE_FAILURE(success)) {
  93         LE_DELETE_ARRAY(outChars);
  94         return 0;
  95     }
  96
  97     CanonShaping::reorderMarks(&chars[offset], count, rightToLeft, outChars, glyphStorage);
  98
  99     // Note: This processes the *original* character array so we can get context
 100     // for the first and last characters. This is OK because only the marks
 101     // will have been reordered, and they don't contribute to shaping.
 102     ArabicShaping::shape(chars, offset, count, max, rightToLeft, glyphStorage);
 103
 104     return count;
 105 }
 106
 107 void ArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 108                                                       LEGlyphStorage &glyphStorage, LEErrorCode &success)
 109 {
 110     if (LE_FAILURE(success)) {
 111         return;
 112     }
 113
 114     if (chars == NULL || offset < 0 || count < 0) {
 115         success = LE_ILLEGAL_ARGUMENT_ERROR;
 116         return;
 117     }
 118
 119     if (!fGPOSTable.isEmpty()) {
 120         OpenTypeLayoutEngine::adjustGlyphPositions(chars, offset, count, reverse, glyphStorage, success);
 121     } else if (!fGDEFTable.isEmpty()) {
 122         GDEFMarkFilter filter(fGDEFTable, success);
 123         adjustMarkGlyphs(glyphStorage, &filter, success);
 124     } else {
 125         LEReferenceTo<GlyphDefinitionTableHeader> gdefTable(CanonShaping::glyphDefinitionTable, CanonShaping::glyphDefinitionTableLen);
 126         GDEFMarkFilter filter(gdefTable, success);
 127
 128         adjustMarkGlyphs(&chars[offset], count, reverse, glyphStorage, &filter, success);
 129     }
 130 }
 131
 132 UnicodeArabicOpenTypeLayoutEngine::UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success)
 133   : ArabicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags | LE_CHAR_FILTER_FEATURE_FLAG, success)
 134 {
 135     fGSUBTable = (const GlyphSubstitutionTableHeader *) CanonShaping::glyphSubstitutionTable;
 136     fGDEFTable = (const GlyphDefinitionTableHeader *) CanonShaping::glyphDefinitionTable;
 137     /* OpenTypeLayoutEngine will allocate a substitution filter */
 138 }
 139
 140 UnicodeArabicOpenTypeLayoutEngine::~UnicodeArabicOpenTypeLayoutEngine()
 141 {
 142     /* OpenTypeLayoutEngine will cleanup the substitution filter */
 143 }
 144
 145 // "glyphs", "indices" -> glyphs, indices
 146 le_int32 UnicodeArabicOpenTypeLayoutEngine::glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 147 {
 148     if (LE_FAILURE(success)) {
 149         return 0;
 150     }
 151
 152     // FIXME: we could avoid the memory allocation and copy if we
 153     // made a clone of mapCharsToGlyphs which took the fake glyphs
 154     // directly.
 155     le_int32 tempGlyphCount = tempGlyphStorage.getGlyphCount();
 156     LEUnicode *tempChars = LE_NEW_ARRAY(LEUnicode, tempGlyphCount);
 157
 158     if (tempChars == NULL) {
 159         success = LE_MEMORY_ALLOCATION_ERROR;
 160         return 0;
 161     }
 162
 163     for (le_int32 i = 0; i < tempGlyphCount; i += 1) {
 164         tempChars[i] = (LEUnicode) LE_GET_GLYPH(tempGlyphStorage[i]);
 165     }
 166
 167     glyphStorage.adoptCharIndicesArray(tempGlyphStorage);
 168
 169     ArabicOpenTypeLayoutEngine::mapCharsToGlyphs(tempChars, 0, tempGlyphCount, FALSE, TRUE, glyphStorage, success);
 170
 171     LE_DELETE_ARRAY(tempChars);
 172
 173     return tempGlyphCount;
 174 }
 175
 176 void UnicodeArabicOpenTypeLayoutEngine::mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool /*mirror*/, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 177 {
 178     if (LE_FAILURE(success)) {
 179         return;
 180     }
 181
 182     if (chars == NULL || offset < 0 || count < 0) {
 183         success = LE_ILLEGAL_ARGUMENT_ERROR;
 184         return;
 185     }
 186
 187     le_int32 i, dir = 1, out = 0;
 188
 189     if (reverse) {
 190         out = count - 1;
 191         dir = -1;
 192     }
 193
 194     glyphStorage.allocateGlyphArray(count, reverse, success);
 195
 196     for (i = 0; i < count; i += 1, out += dir) {
 197         glyphStorage[out] = (LEGlyphID) chars[offset + i];
 198     }
 199 }
 200
 201 void UnicodeArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 202                                                       LEGlyphStorage &glyphStorage, LEErrorCode &success)
 203 {
 204     if (LE_FAILURE(success)) {
 205         return;
 206     }
 207
 208     if (chars == NULL || offset < 0 || count < 0) {
 209         success = LE_ILLEGAL_ARGUMENT_ERROR;
 210         return;
 211     }
 212
 213     GDEFMarkFilter filter(fGDEFTable, success);
 214
 215     adjustMarkGlyphs(&chars[offset], count, reverse, glyphStorage, &filter, success);
 216 }
 217
 218 U_NAMESPACE_END
 219