icuSources/test/letest/cmaps.cpp

   1 /***************************************************************************
   2 *
   3 *   Copyright (C) 1998-2003, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 *
   6 ************************************************************************/
   7
   8 #include "LETypes.h"
   9 #include "LESwaps.h"
  10
  11 #include "sfnt.h"
  12 #include "cmaps.h"
  13
  14 #define SWAPU16(code) ((LEUnicode16) SWAPW(code))
  15 #define SWAPU32(code) ((LEUnicode32) SWAPL(code))
  16
  17 //
  18 // Finds the high bit by binary searching
  19 // through the bits in value.
  20 //
  21 le_int8 highBit(le_uint32 value)
  22 {
  23     le_uint8 bit = 0;
  24
  25     if (value >= 1 << 16) {
  26         value >>= 16;
  27         bit += 16;
  28     }
  29
  30     if (value >= 1 << 8) {
  31         value >>= 8;
  32         bit += 8;
  33     }
  34
  35     if (value >= 1 << 4) {
  36         value >>= 4;
  37         bit += 4;
  38     }
  39
  40     if (value >= 1 << 2) {
  41         value >>= 2;
  42         bit += 2;
  43     }
  44
  45     if (value >= 1 << 1) {
  46         value >>= 1;
  47         bit += 1;
  48     }
  49
  50     return bit;
  51 }
  52
  53 CMAPMapper *CMAPMapper::createUnicodeMapper(const CMAPTable *cmap)
  54 {
  55     le_uint16 i;
  56     le_uint16 nSubtables = SWAPW(cmap->numberSubtables);
  57     const CMAPEncodingSubtable *subtable = NULL;
  58     le_uint32 offset1 = 0, offset10 = 0;
  59
  60     for (i = 0; i < nSubtables; i += 1) {
  61         const CMAPEncodingSubtableHeader *esh = &cmap->encodingSubtableHeaders[i];
  62
  63         if (SWAPW(esh->platformID) == 3) {
  64             switch (SWAPW(esh->platformSpecificID)) {
  65             case 1:
  66                 offset1 = SWAPL(esh->encodingOffset);
  67                 break;
  68
  69             case 10:
  70                 offset10 = SWAPL(esh->encodingOffset);
  71                 break;
  72             }
  73         }
  74     }
  75
  76
  77     if (offset10 != 0)
  78     {
  79         subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset10);
  80     } else if (offset1 != 0) {
  81         subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset1);
  82     } else {
  83         return NULL;
  84     }
  85
  86     switch (SWAPW(subtable->format)) {
  87     case 4:
  88         return new CMAPFormat4Mapper(cmap, (const CMAPFormat4Encoding *) subtable);
  89
  90     case 12:
  91     {
  92         const CMAPFormat12Encoding *encoding = (const CMAPFormat12Encoding *) subtable;
  93
  94         return new CMAPGroupMapper(cmap, encoding->groups, SWAPL(encoding->nGroups));
  95     }
  96
  97     default:
  98         break;
  99     }
 100
 101     return NULL;
 102 }
 103
 104 CMAPFormat4Mapper::CMAPFormat4Mapper(const CMAPTable *cmap, const CMAPFormat4Encoding *header)
 105     : CMAPMapper(cmap)
 106 {
 107     le_uint16 segCount = SWAPW(header->segCountX2) / 2;
 108
 109     fEntrySelector = SWAPW(header->entrySelector);
 110     fRangeShift = SWAPW(header->rangeShift) / 2;
 111     fEndCodes = &header->endCodes[0];
 112     fStartCodes = &header->endCodes[segCount + 1]; // + 1 for reservedPad...
 113     fIdDelta = &fStartCodes[segCount];
 114     fIdRangeOffset = &fIdDelta[segCount];
 115 }
 116
 117 LEGlyphID CMAPFormat4Mapper::unicodeToGlyph(LEUnicode32 unicode32) const
 118 {
 119     if (unicode32 >= 0x10000) {
 120         return 0;
 121     }
 122
 123     LEUnicode16 unicode = (LEUnicode16) unicode32;
 124     le_uint16 index = 0;
 125     le_uint16 probe = 1 << fEntrySelector;
 126     TTGlyphID result = 0;
 127
 128     if (SWAPU16(fStartCodes[fRangeShift]) <= unicode) {
 129         index = fRangeShift;
 130     }
 131
 132     while (probe > (1 << 0)) {
 133         probe >>= 1;
 134
 135         if (SWAPU16(fStartCodes[index + probe]) <= unicode) {
 136             index += probe;
 137         }
 138     }
 139
 140     if (unicode >= SWAPU16(fStartCodes[index]) && unicode <= SWAPU16(fEndCodes[index])) {
 141         if (fIdRangeOffset[index] == 0) {
 142             result = (TTGlyphID) unicode;
 143         } else {
 144             le_uint16 offset = unicode - SWAPU16(fStartCodes[index]);
 145             le_uint16 rangeOffset = SWAPW(fIdRangeOffset[index]);
 146             le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &fIdRangeOffset[index] + rangeOffset);
 147
 148             result = SWAPW(glyphIndexTable[offset]);
 149         }
 150
 151         result += SWAPW(fIdDelta[index]);
 152     } else {
 153         result = 0;
 154     }
 155
 156     return LE_SET_GLYPH(0, result);
 157 }
 158
 159 CMAPFormat4Mapper::~CMAPFormat4Mapper()
 160 {
 161     // parent destructor does it all
 162 }
 163
 164 CMAPGroupMapper::CMAPGroupMapper(const CMAPTable *cmap, const CMAPGroup *groups, le_uint32 nGroups)
 165     : CMAPMapper(cmap), fGroups(groups)
 166 {
 167     le_uint8 bit = highBit(nGroups);
 168     fPower = 1 << bit;
 169     fRangeOffset = nGroups - fPower;
 170 }
 171
 172 LEGlyphID CMAPGroupMapper::unicodeToGlyph(LEUnicode32 unicode32) const
 173 {
 174     le_int32 probe = fPower;
 175     le_int32 range = 0;
 176
 177     if (SWAPU32(fGroups[fRangeOffset].startCharCode) <= unicode32) {
 178         range = fRangeOffset;
 179     }
 180
 181     while (probe > (1 << 0)) {
 182         probe >>= 1;
 183
 184         if (SWAPU32(fGroups[range + probe].startCharCode) <= unicode32) {
 185             range += probe;
 186         }
 187     }
 188
 189     if (SWAPU32(fGroups[range].startCharCode) <= unicode32 && SWAPU32(fGroups[range].endCharCode) >= unicode32) {
 190         return (LEGlyphID) (SWAPU32(fGroups[range].startGlyphCode) + unicode32 - SWAPU32(fGroups[range].startCharCode));
 191     }
 192
 193     return 0;
 194 }
 195
 196 CMAPGroupMapper::~CMAPGroupMapper()
 197 {
 198     // parent destructor does it all
 199 }
 200