icuSources/layout/ArabicLayoutEngine.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 "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, le_int32 languageCode,
  37                         const GlyphSubstitutionTableHeader *gsubTable)
  38     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, gsubTable)
  39 {
  40     /**/ fFeatureOrder = ArabicShaping::getFeatureOrder();
  41 }
  42
  43 ArabicOpenTypeLayoutEngine::ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
  44     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode)
  45 {
  46     // fFeatureOrder = ArabicShaping::getFeatureOrder();
  47 }
  48
  49 ArabicOpenTypeLayoutEngine::~ArabicOpenTypeLayoutEngine()
  50 {
  51     // nothing to do
  52 }
  53
  54 // Input: characters
  55 // Output: characters, char indices, tags
  56 // Returns: output character count
  57 le_int32 ArabicOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
  58         LEUnicode *&/*outChars*/, LEGlyphStorage &glyphStorage, LEErrorCode &success)
  59 {
  60     if (LE_FAILURE(success)) {
  61         return 0;
  62     }
  63
  64     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  65         success = LE_ILLEGAL_ARGUMENT_ERROR;
  66         return 0;
  67     }
  68
  69     glyphStorage.adoptGlyphCount(count);
  70     glyphStorage.allocateAuxData(success);
  71
  72     if (LE_FAILURE(success)) {
  73         success = LE_MEMORY_ALLOCATION_ERROR;
  74         return 0;
  75     }
  76
  77     ArabicShaping::shape(chars, offset, count, max, rightToLeft, glyphStorage);
  78
  79     return count;
  80 }
  81
  82 void ArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
  83                                                       LEGlyphStorage &glyphStorage, LEErrorCode &success)
  84 {
  85     if (LE_FAILURE(success)) {
  86         return;
  87     }
  88
  89     if (chars == NULL || offset < 0 || count < 0) {
  90         success = LE_ILLEGAL_ARGUMENT_ERROR;
  91         return;
  92     }
  93
  94     if (fGPOSTable != NULL) {
  95         OpenTypeLayoutEngine::adjustGlyphPositions(chars, offset, count, reverse, glyphStorage, success);
  96     } else if (fGDEFTable != NULL) {
  97         GDEFMarkFilter filter(fGDEFTable);
  98
  99         adjustMarkGlyphs(glyphStorage, &filter, success);
 100     } else {
 101         GlyphDefinitionTableHeader *gdefTable = (GlyphDefinitionTableHeader *) CanonShaping::glyphDefinitionTable;
 102         GDEFMarkFilter filter(gdefTable);
 103
 104         adjustMarkGlyphs(&chars[offset], count, reverse, glyphStorage, &filter, success);
 105     }
 106 }
 107
 108 UnicodeArabicOpenTypeLayoutEngine::UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
 109     : ArabicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode)
 110 {
 111     fGSUBTable = (const GlyphSubstitutionTableHeader *) CanonShaping::glyphSubstitutionTable;
 112     fGDEFTable = (const GlyphDefinitionTableHeader *) CanonShaping::glyphDefinitionTable;
 113
 114     fSubstitutionFilter = new CharSubstitutionFilter(fontInstance);
 115 }
 116
 117 UnicodeArabicOpenTypeLayoutEngine::~UnicodeArabicOpenTypeLayoutEngine()
 118 {
 119     delete fSubstitutionFilter;
 120 }
 121
 122 // "glyphs", "indices" -> glyphs, indices
 123 le_int32 UnicodeArabicOpenTypeLayoutEngine::glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 124 {
 125     if (LE_FAILURE(success)) {
 126         return 0;
 127     }
 128
 129     // FIXME: we could avoid the memory allocation and copy if we
 130     // made a clone of mapCharsToGlyphs which took the fake glyphs
 131     // directly.
 132     le_int32 tempGlyphCount = tempGlyphStorage.getGlyphCount();
 133     LEUnicode *tempChars = LE_NEW_ARRAY(LEUnicode, tempGlyphCount);
 134
 135     if (tempChars == NULL) {
 136         success = LE_MEMORY_ALLOCATION_ERROR;
 137         return 0;
 138     }
 139
 140     for (le_int32 i = 0; i < tempGlyphCount; i += 1) {
 141         tempChars[i] = (LEUnicode) LE_GET_GLYPH(tempGlyphStorage[i]);
 142     }
 143
 144     glyphStorage.adoptCharIndicesArray(tempGlyphStorage);
 145
 146     ArabicOpenTypeLayoutEngine::mapCharsToGlyphs(tempChars, 0, tempGlyphCount, FALSE, TRUE, glyphStorage, success);
 147
 148     LE_DELETE_ARRAY(tempChars);
 149
 150     return tempGlyphCount;
 151 }
 152
 153 void UnicodeArabicOpenTypeLayoutEngine::mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool /*mirror*/, LEGlyphStorage &glyphStorage, LEErrorCode &success)
 154 {
 155     if (LE_FAILURE(success)) {
 156         return;
 157     }
 158
 159     if (chars == NULL || offset < 0 || count < 0) {
 160         success = LE_ILLEGAL_ARGUMENT_ERROR;
 161         return;
 162     }
 163
 164     le_int32 i, dir = 1, out = 0;
 165
 166     if (reverse) {
 167         out = count - 1;
 168         dir = -1;
 169     }
 170
 171     glyphStorage.allocateGlyphArray(count, reverse, success);
 172
 173     for (i = 0; i < count; i += 1, out += dir) {
 174         glyphStorage[out] = (LEGlyphID) chars[offset + i];
 175     }
 176 }
 177
 178 void UnicodeArabicOpenTypeLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
 179                                                       LEGlyphStorage &glyphStorage, LEErrorCode &success)
 180 {
 181     if (LE_FAILURE(success)) {
 182         return;
 183     }
 184
 185     if (chars == NULL || offset < 0 || count < 0) {
 186         success = LE_ILLEGAL_ARGUMENT_ERROR;
 187         return;
 188     }
 189
 190     GDEFMarkFilter filter(fGDEFTable);
 191
 192     adjustMarkGlyphs(&chars[offset], count, reverse, glyphStorage, &filter, success);
 193 }
 194
 195 U_NAMESPACE_END
 196