1 /***************************************************************************

     2 *

     3 *   Copyright (C) 1998-2002, International Business Machines

     4 *   Corporation and others.  All Rights Reserved.

     5 *

     6 ************************************************************************/

     7 

     8 #include <stdio.h>

     9 

    10 #include "LETypes.h"

    11 #include "FontObject.h"

    12 #include "LESwaps.h"

    13 

    14 FontObject::FontObject(char *fileName)

    15   : directory(NULL), numTables(0), searchRange(0),entrySelector(0),

    16     cmapTable(NULL), cmSegCount(0), cmSearchRange(0), cmEntrySelector(0),

    17     cmEndCodes(NULL), cmStartCodes(NULL), cmIdDelta(0), cmIdRangeOffset(0),

    18     headTable(NULL), hmtxTable(NULL), numGlyphs(0), numOfLongHorMetrics(0), file(NULL)

    19 {

    20     file = fopen(fileName, "rb");

    21 

    22     if (file == NULL) {

    23         printf("?? Couldn't open %s", fileName);

    24         return;

    25     }

    26 

    27     SFNTDirectory tempDir;

    28 

    29     fread(&tempDir, sizeof tempDir, 1, file);

    30 

    31     numTables       = SWAPW(tempDir.numTables);

    32     searchRange     = SWAPW(tempDir.searchRange) >> 4;

    33     entrySelector   = SWAPW(tempDir.entrySelector);

    34     rangeShift      = SWAPW(tempDir.rangeShift) >> 4;

    35 

    36     int dirSize = sizeof tempDir + ((numTables - ANY_NUMBER) * sizeof(DirectoryEntry));

    37 

    38     directory = (SFNTDirectory *) new char[dirSize];

    39 

    40     fseek(file, 0L, SEEK_SET);

    41     fread(directory, sizeof(char), dirSize, file);

    42 

    43     initUnicodeCMAP();

    44 }

    45 

    46 FontObject::~FontObject()

    47 {

    48     fclose(file);

    49     delete[] directory;

    50     delete[] cmapTable;

    51     delete[] headTable;

    52     delete[] hmtxTable;

    53 }

    54 

    55 void FontObject::deleteTable(void *table)

    56 {

    57     delete[] (char *) table;

    58 }

    59 

    60 DirectoryEntry *FontObject::findTable(LETag tag)

    61 {

    62     le_uint16 table = 0;

    63     le_uint16 probe = 1 << entrySelector;

    64 

    65     if (SWAPL(directory->tableDirectory[rangeShift].tag) <= tag) {

    66         table = rangeShift;

    67     }

    68 

    69     while (probe > (1 << 0)) {

    70         probe >>= 1;

    71 

    72         if (SWAPL(directory->tableDirectory[table + probe].tag) <= tag) {

    73             table += probe;

    74         }

    75     }

    76 

    77     if (SWAPL(directory->tableDirectory[table].tag) == tag) {

    78         return &directory->tableDirectory[table];

    79     }

    80 

    81     return NULL;

    82 }

    83 

    84 void *FontObject::readTable(LETag tag, le_uint32 *length)

    85 {

    86     DirectoryEntry *entry = findTable(tag);

    87 

    88     if (entry == NULL) {

    89         *length = 0;

    90         return NULL;

    91     }

    92 

    93     *length = SWAPL(entry->length);

    94 

    95     void *table = new char[*length];

    96 

    97     fseek(file, SWAPL(entry->offset), SEEK_SET);

    98     fread(table, sizeof(char), *length, file);

    99 

   100     return table;

   101 }

   102 

   103 CMAPEncodingSubtable *FontObject::findCMAP(le_uint16 platformID, le_uint16 platformSpecificID)

   104 {

   105     LETag cmapTag = 0x636D6170; // 'cmap'

   106 

   107     if (cmapTable == NULL) {

   108         le_uint32 length;

   109 

   110         cmapTable = (CMAPTable *) readTable(cmapTag, &length);

   111     }

   112 

   113     if (cmapTable != NULL) {

   114         le_uint16 i;

   115         le_uint16 nSubtables = SWAPW(cmapTable->numberSubtables);

   116 

   117 

   118         for (i = 0; i < nSubtables; i += 1) {

   119             CMAPEncodingSubtableHeader *esh = &cmapTable->encodingSubtableHeaders[i];

   120 

   121             if (SWAPW(esh->platformID) == platformID &&

   122                 SWAPW(esh->platformSpecificID) == platformSpecificID) {

   123                 return (CMAPEncodingSubtable *) ((char *) cmapTable + SWAPL(esh->encodingOffset));

   124             }

   125         }

   126     }

   127 

   128     return NULL;

   129 }

   130 

   131 void FontObject::initUnicodeCMAP()

   132 {

   133     CMAPEncodingSubtable *encodingSubtable = findCMAP(3, 1);

   134 

   135     if (encodingSubtable == 0 ||

   136         SWAPW(encodingSubtable->format) != 4) {

   137         printf("Can't find unicode 'cmap'");

   138         return;

   139     }

   140 

   141     CMAPFormat4Encoding *header = (CMAPFormat4Encoding *) encodingSubtable;

   142 

   143     cmSegCount = SWAPW(header->segCountX2) / 2;

   144     cmSearchRange = SWAPW(header->searchRange);

   145     cmEntrySelector = SWAPW(header->entrySelector);

   146     cmRangeShift = SWAPW(header->rangeShift) / 2;

   147     cmEndCodes = &header->endCodes[0];

   148     cmStartCodes = &header->endCodes[cmSegCount + 1]; // + 1 for reservedPad...

   149     cmIdDelta = &cmStartCodes[cmSegCount];

   150     cmIdRangeOffset = &cmIdDelta[cmSegCount];

   151 }

   152 

   153 LEGlyphID FontObject::unicodeToGlyph(LEUnicode32 unicode32)

   154 {

   155     if (unicode32 >= 0x10000) {

   156         return 0;

   157     }

   158 

   159     LEUnicode16 unicode = (LEUnicode16) unicode32;

   160     le_uint16 index = 0;

   161     le_uint16 probe = 1 << cmEntrySelector;

   162     LEGlyphID result = 0;

   163 

   164     if (SWAPW(cmStartCodes[cmRangeShift]) <= unicode) {

   165         index = cmRangeShift;

   166     }

   167 

   168     while (probe > (1 << 0)) {

   169         probe >>= 1;

   170 

   171         if (SWAPW(cmStartCodes[index + probe]) <= unicode) {

   172             index += probe;

   173         }

   174     }

   175 

   176     if (unicode >= SWAPW(cmStartCodes[index]) && unicode <= SWAPW(cmEndCodes[index])) {

   177         if (cmIdRangeOffset[index] == 0) {

   178             result = (LEGlyphID) unicode;

   179         } else {

   180             le_uint16 offset = unicode - SWAPW(cmStartCodes[index]);

   181             le_uint16 rangeOffset = SWAPW(cmIdRangeOffset[index]);

   182             le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &cmIdRangeOffset[index] + rangeOffset);

   183 

   184             result = SWAPW(glyphIndexTable[offset]);

   185         }

   186 

   187         result += SWAPW(cmIdDelta[index]);

   188     } else {

   189         result = 0;

   190     }

   191 

   192     return result;

   193 }

   194 

   195 le_uint16 FontObject::getUnitsPerEM()

   196 {

   197     if (headTable == NULL) {

   198         LETag headTag = 0x68656164; // 'head'

   199         le_uint32 length;

   200 

   201         headTable = (HEADTable *) readTable(headTag, &length);

   202     }

   203 

   204     return SWAPW(headTable->unitsPerEm);

   205 }

   206 

   207 le_uint16 FontObject::getGlyphAdvance(LEGlyphID glyph)

   208 {

   209     if (hmtxTable == NULL) {

   210         LETag maxpTag = 0x6D617870; // 'maxp'

   211         LETag hheaTag = 0x68686561; // 'hhea'

   212         LETag hmtxTag = 0x686D7478; // 'hmtx'

   213         le_uint32 length;

   214         HHEATable *hheaTable;

   215         MAXPTable *maxpTable = (MAXPTable *) readTable(maxpTag, &length);

   216 

   217         numGlyphs = SWAPW(maxpTable->numGlyphs);

   218         deleteTable(maxpTable);

   219 

   220         hheaTable = (HHEATable *) readTable(hheaTag, &length);

   221         numOfLongHorMetrics = SWAPW(hheaTable->numOfLongHorMetrics);

   222         deleteTable(hheaTable);

   223 

   224         hmtxTable = (HMTXTable *) readTable(hmtxTag, &length);

   225     }

   226 

   227     le_uint16 index = glyph;

   228 

   229     if (glyph >= numGlyphs) {

   230         return 0;

   231     }

   232 

   233     if (glyph >= numOfLongHorMetrics) {

   234         index = numOfLongHorMetrics - 1;

   235     }

   236 

   237     return SWAPW(hmtxTable->hMetrics[index].advanceWidth);

   238 }

   239 

   240