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/***************************************************************************
*
* Copyright (C) 1998-2002, International Business Machines
* Corporation and others. All Rights Reserved.
*
************************************************************************/
#include <stdio.h>
#include "LETypes.h"
#include "FontObject.h"
#include "LESwaps.h"
FontObject::FontObject(char *fileName)
: directory(NULL), numTables(0), searchRange(0),entrySelector(0),
cmapTable(NULL), cmSegCount(0), cmSearchRange(0), cmEntrySelector(0),
cmEndCodes(NULL), cmStartCodes(NULL), cmIdDelta(0), cmIdRangeOffset(0),
headTable(NULL), hmtxTable(NULL), numGlyphs(0), numOfLongHorMetrics(0), file(NULL)
{
file = fopen(fileName, "rb");
if (file == NULL) {
printf("?? Couldn't open %s", fileName);
return;
}
SFNTDirectory tempDir;
fread(&tempDir, sizeof tempDir, 1, file);
numTables = SWAPW(tempDir.numTables);
searchRange = SWAPW(tempDir.searchRange) >> 4;
entrySelector = SWAPW(tempDir.entrySelector);
rangeShift = SWAPW(tempDir.rangeShift) >> 4;
int dirSize = sizeof tempDir + ((numTables - ANY_NUMBER) * sizeof(DirectoryEntry));
directory = (SFNTDirectory *) new char[dirSize];
fseek(file, 0L, SEEK_SET);
fread(directory, sizeof(char), dirSize, file);
initUnicodeCMAP();
}
FontObject::~FontObject()
{
fclose(file);
delete[] directory;
delete[] cmapTable;
delete[] headTable;
delete[] hmtxTable;
}
void FontObject::deleteTable(void *table)
{
delete[] (char *) table;
}
DirectoryEntry *FontObject::findTable(LETag tag)
{
le_uint16 table = 0;
le_uint16 probe = 1 << entrySelector;
if (SWAPL(directory->tableDirectory[rangeShift].tag) <= tag) {
table = rangeShift;
}
while (probe > (1 << 0)) {
probe >>= 1;
if (SWAPL(directory->tableDirectory[table + probe].tag) <= tag) {
table += probe;
}
}
if (SWAPL(directory->tableDirectory[table].tag) == tag) {
return &directory->tableDirectory[table];
}
return NULL;
}
void *FontObject::readTable(LETag tag, le_uint32 *length)
{
DirectoryEntry *entry = findTable(tag);
if (entry == NULL) {
*length = 0;
return NULL;
}
*length = SWAPL(entry->length);
void *table = new char[*length];
fseek(file, SWAPL(entry->offset), SEEK_SET);
fread(table, sizeof(char), *length, file);
return table;
}
CMAPEncodingSubtable *FontObject::findCMAP(le_uint16 platformID, le_uint16 platformSpecificID)
{
LETag cmapTag = 0x636D6170; // 'cmap'
if (cmapTable == NULL) {
le_uint32 length;
cmapTable = (CMAPTable *) readTable(cmapTag, &length);
}
if (cmapTable != NULL) {
le_uint16 i;
le_uint16 nSubtables = SWAPW(cmapTable->numberSubtables);
for (i = 0; i < nSubtables; i += 1) {
CMAPEncodingSubtableHeader *esh = &cmapTable->encodingSubtableHeaders[i];
if (SWAPW(esh->platformID) == platformID &&
SWAPW(esh->platformSpecificID) == platformSpecificID) {
return (CMAPEncodingSubtable *) ((char *) cmapTable + SWAPL(esh->encodingOffset));
}
}
}
return NULL;
}
void FontObject::initUnicodeCMAP()
{
CMAPEncodingSubtable *encodingSubtable = findCMAP(3, 1);
if (encodingSubtable == 0 ||
SWAPW(encodingSubtable->format) != 4) {
printf("Can't find unicode 'cmap'");
return;
}
CMAPFormat4Encoding *header = (CMAPFormat4Encoding *) encodingSubtable;
cmSegCount = SWAPW(header->segCountX2) / 2;
cmSearchRange = SWAPW(header->searchRange);
cmEntrySelector = SWAPW(header->entrySelector);
cmRangeShift = SWAPW(header->rangeShift) / 2;
cmEndCodes = &header->endCodes[0];
cmStartCodes = &header->endCodes[cmSegCount + 1]; // + 1 for reservedPad...
cmIdDelta = &cmStartCodes[cmSegCount];
cmIdRangeOffset = &cmIdDelta[cmSegCount];
}
LEGlyphID FontObject::unicodeToGlyph(LEUnicode32 unicode32)
{
if (unicode32 >= 0x10000) {
return 0;
}
LEUnicode16 unicode = (LEUnicode16) unicode32;
le_uint16 index = 0;
le_uint16 probe = 1 << cmEntrySelector;
LEGlyphID result = 0;
if (SWAPW(cmStartCodes[cmRangeShift]) <= unicode) {
index = cmRangeShift;
}
while (probe > (1 << 0)) {
probe >>= 1;
if (SWAPW(cmStartCodes[index + probe]) <= unicode) {
index += probe;
}
}
if (unicode >= SWAPW(cmStartCodes[index]) && unicode <= SWAPW(cmEndCodes[index])) {
if (cmIdRangeOffset[index] == 0) {
result = (LEGlyphID) unicode;
} else {
le_uint16 offset = unicode - SWAPW(cmStartCodes[index]);
le_uint16 rangeOffset = SWAPW(cmIdRangeOffset[index]);
le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &cmIdRangeOffset[index] + rangeOffset);
result = SWAPW(glyphIndexTable[offset]);
}
result += SWAPW(cmIdDelta[index]);
} else {
result = 0;
}
return result;
}
le_uint16 FontObject::getUnitsPerEM()
{
if (headTable == NULL) {
LETag headTag = 0x68656164; // 'head'
le_uint32 length;
headTable = (HEADTable *) readTable(headTag, &length);
}
return SWAPW(headTable->unitsPerEm);
}
le_uint16 FontObject::getGlyphAdvance(LEGlyphID glyph)
{
if (hmtxTable == NULL) {
LETag maxpTag = 0x6D617870; // 'maxp'
LETag hheaTag = 0x68686561; // 'hhea'
LETag hmtxTag = 0x686D7478; // 'hmtx'
le_uint32 length;
HHEATable *hheaTable;
MAXPTable *maxpTable = (MAXPTable *) readTable(maxpTag, &length);
numGlyphs = SWAPW(maxpTable->numGlyphs);
deleteTable(maxpTable);
hheaTable = (HHEATable *) readTable(hheaTag, &length);
numOfLongHorMetrics = SWAPW(hheaTable->numOfLongHorMetrics);
deleteTable(hheaTable);
hmtxTable = (HMTXTable *) readTable(hmtxTag, &length);
}
le_uint16 index = glyph;
if (glyph >= numGlyphs) {
return 0;
}
if (glyph >= numOfLongHorMetrics) {
index = numOfLongHorMetrics - 1;
}
return SWAPW(hmtxTable->hMetrics[index].advanceWidth);
}
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