/usr/share/doc/libicu-devel/samples/layout
Edit: /usr/share/doc/libicu-devel/samples/layout/cmaps.cpp (5428B)
/*
*******************************************************************************
*
* © 2016 and later: Unicode, Inc. and others.
* License & terms of use: http://www.unicode.org/copyright.html#License
*
*******************************************************************************
****************************************************************************** *
*
* Copyright (C) 1999-2003, International Business Machines
* Corporation and others. All Rights Reserved.
*
****************************************************************************** *
* file name: cmaps.cpp
*
* created on: ??/??/2001
* created by: Eric R. Mader
*/
#include "layout/LETypes.h"
#include "layout/LESwaps.h"
#include "sfnt.h"
#include "cmaps.h"
#define SWAPU16(code) ((LEUnicode16) SWAPW(code))
#define SWAPU32(code) ((LEUnicode32) SWAPL(code))
//
// Finds the high bit by binary searching
// through the bits in value.
//
le_uint8 highBit(le_uint32 value)
{
le_uint8 bit = 0;
if (value >= 1 << 16) {
value >>= 16;
bit += 16;
}
if (value >= 1 << 8) {
value >>= 8;
bit += 8;
}
if (value >= 1 << 4) {
value >>= 4;
bit += 4;
}
if (value >= 1 << 2) {
value >>= 2;
bit += 2;
}
if (value >= 1 << 1) {
value >>= 1;
bit += 1;
}
return bit;
}
CMAPMapper *CMAPMapper::createUnicodeMapper(const CMAPTable *cmap)
{
le_uint16 i;
le_uint16 nSubtables = SWAPW(cmap->numberSubtables);
const CMAPEncodingSubtable *subtable = NULL;
le_uint32 offset1 = 0, offset10 = 0;
for (i = 0; i < nSubtables; i += 1) {
const CMAPEncodingSubtableHeader *esh = &cmap->encodingSubtableHeaders[i];
if (SWAPW(esh->platformID) == 3) {
switch (SWAPW(esh->platformSpecificID)) {
case 1:
offset1 = SWAPL(esh->encodingOffset);
break;
case 10:
offset10 = SWAPL(esh->encodingOffset);
break;
}
}
}
if (offset10 != 0)
{
subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset10);
} else if (offset1 != 0) {
subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset1);
} else {
return NULL;
}
switch (SWAPW(subtable->format)) {
case 4:
return new CMAPFormat4Mapper(cmap, (const CMAPFormat4Encoding *) subtable);
case 12:
{
const CMAPFormat12Encoding *encoding = (const CMAPFormat12Encoding *) subtable;
return new CMAPGroupMapper(cmap, encoding->groups, SWAPL(encoding->nGroups));
}
default:
break;
}
return NULL;
}
CMAPFormat4Mapper::CMAPFormat4Mapper(const CMAPTable *cmap, const CMAPFormat4Encoding *header)
: CMAPMapper(cmap)
{
le_uint16 segCount = SWAPW(header->segCountX2) / 2;
fEntrySelector = SWAPW(header->entrySelector);
fRangeShift = SWAPW(header->rangeShift) / 2;
fEndCodes = &header->endCodes[0];
fStartCodes = &header->endCodes[segCount + 1]; // + 1 for reservedPad...
fIdDelta = &fStartCodes[segCount];
fIdRangeOffset = &fIdDelta[segCount];
}
LEGlyphID CMAPFormat4Mapper::unicodeToGlyph(LEUnicode32 unicode32) const
{
if (unicode32 >= 0x10000) {
return 0;
}
LEUnicode16 unicode = (LEUnicode16) unicode32;
le_uint16 index = 0;
le_uint16 probe = 1 << fEntrySelector;
TTGlyphID result = 0;
if (SWAPU16(fStartCodes[fRangeShift]) <= unicode) {
index = fRangeShift;
}
while (probe > (1 << 0)) {
probe >>= 1;
if (SWAPU16(fStartCodes[index + probe]) <= unicode) {
index += probe;
}
}
if (unicode >= SWAPU16(fStartCodes[index]) && unicode <= SWAPU16(fEndCodes[index])) {
if (fIdRangeOffset[index] == 0) {
result = (TTGlyphID) unicode;
} else {
le_uint16 offset = unicode - SWAPU16(fStartCodes[index]);
le_uint16 rangeOffset = SWAPW(fIdRangeOffset[index]);
le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &fIdRangeOffset[index] + rangeOffset);
result = SWAPW(glyphIndexTable[offset]);
}
result += SWAPW(fIdDelta[index]);
} else {
result = 0;
}
return LE_SET_GLYPH(0, result);
}
CMAPFormat4Mapper::~CMAPFormat4Mapper()
{
// parent destructor does it all
}
CMAPGroupMapper::CMAPGroupMapper(const CMAPTable *cmap, const CMAPGroup *groups, le_uint32 nGroups)
: CMAPMapper(cmap), fGroups(groups)
{
le_uint8 bit = highBit(nGroups);
fPower = 1 << bit;
fRangeOffset = nGroups - fPower;
}
LEGlyphID CMAPGroupMapper::unicodeToGlyph(LEUnicode32 unicode32) const
{
le_int32 probe = fPower;
le_int32 range = 0;
if (SWAPU32(fGroups[fRangeOffset].startCharCode) <= unicode32) {
range = fRangeOffset;
}
while (probe > (1 << 0)) {
probe >>= 1;
if (SWAPU32(fGroups[range + probe].startCharCode) <= unicode32) {
range += probe;
}
}
if (SWAPU32(fGroups[range].startCharCode) <= unicode32 && SWAPU32(fGroups[range].endCharCode) >= unicode32) {
return (LEGlyphID) (SWAPU32(fGroups[range].startGlyphCode) + unicode32 - SWAPU32(fGroups[range].startCharCode));
}
return 0;
}
CMAPGroupMapper::~CMAPGroupMapper()
{
// parent destructor does it all
}