CMapFormat4(Buffer buffer, int offset) {
buffer.position(offset);
buffer.getChar(); // skip, we already know format=4
int subtableLength = buffer.getChar();
/* Try to recover from some bad fonts which specify a subtable
* length that would overflow the byte buffer holding the whole
* cmap table. If this isn't a recoverable situation an exception
* may be thrown which is caught higher up the call stack.
* Whilst this may seem lenient, in practice, unless the "bad"
* subtable we are using is the last one in the cmap table we
* would have no way of knowing about this problem anyway.
*/
if (offset + subtableLength > buffer.capacity()) {
subtableLength = buffer.capacity() - offset;
}
buffer.getChar(); // skip language
segCount = buffer.getChar() / 2;
buffer.getChar(); // skip searchRange
entrySelector = buffer.getChar();
rangeShift = buffer.getChar() / 2;
startCount = new char[segCount];
endCount = new char[segCount];
idDelta = new short[segCount];
idRangeOffset = new char[segCount];
for (int i = 0; i < segCount; i++) {
endCount[i] = buffer.getChar();
}
buffer.getChar(); // 2 bytes for reserved pad
for (int i = 0; i < segCount; i++) {
startCount[i] = buffer.getChar();
}
for (int i = 0; i < segCount; i++) {
idDelta[i] = (short) buffer.getChar();
}
for (int i = 0; i < segCount; i++) {
char ctmp = buffer.getChar();
idRangeOffset[i] = (char) ((ctmp >> 1) & 0xffff);
}
/* Can calculate the number of glyph IDs by subtracting
* "pos" from the length of the cmap
*/
int pos = (segCount * 8 + 16) / 2;
buffer.position(pos * 2 + offset); // * 2 for chars
int numGlyphIds = (subtableLength / 2 - pos);
glyphIds = new char[numGlyphIds];
for (int i = 0; i < numGlyphIds; i++) {
glyphIds[i] = buffer.getChar();
}
}
CMapFormat2(Buffer buffer, int offset) {
int tableLen = buffer.getChar(offset + 2);
buffer.position(offset + 6);
char maxSubHeader = 0;
for (int i = 0; i < 256; i++) {
subHeaderKey[i] = buffer.getChar();
if (subHeaderKey[i] > maxSubHeader) {
maxSubHeader = subHeaderKey[i];
}
}
/* The value of the subHeaderKey is 8 * the subHeader index,
* so the number of subHeaders can be obtained by dividing
* this value bv 8 and adding 1.
*/
int numSubHeaders = (maxSubHeader >> 3) + 1;
firstCodeArray = new char[numSubHeaders];
entryCountArray = new char[numSubHeaders];
idDeltaArray = new short[numSubHeaders];
idRangeOffSetArray = new char[numSubHeaders];
for (int i = 0; i < numSubHeaders; i++) {
firstCodeArray[i] = buffer.getChar();
entryCountArray[i] = buffer.getChar();
idDeltaArray[i] = (short) buffer.getChar();
idRangeOffSetArray[i] = buffer.getChar();
}
int glyphIndexArrSize = (tableLen - 518 - numSubHeaders * 8) / 2;
glyphIndexArray = new char[glyphIndexArrSize];
for (int i = 0; i < glyphIndexArrSize; i++) {
glyphIndexArray[i] = buffer.getChar();
}
}
CMapFormat10(Buffer buffer, int offset) {
buffer.position(offset + 12);
startCharCode = buffer.getInt() & INTMASK;
numChars = buffer.getInt() & INTMASK;
glyphIdArray = new char[numChars];
for (int i = 0; i < numChars; i++) {
glyphIdArray[i] = buffer.getChar();
}
}
CMapFormat6(Buffer buffer, int offset) {
buffer.position(offset + 6);
firstCode = buffer.getChar();
entryCount = buffer.getChar();
glyphIdArray = new char[entryCount];
for (int i = 0; i < entryCount; i++) {
glyphIdArray[i] = buffer.getChar();
}
}
CMapFormat12(Buffer buffer, int offset) {
numGroups = buffer.getInt(offset + 12);
startCharCode = new long[numGroups];
endCharCode = new long[numGroups];
startGlyphID = new int[numGroups];
buffer.position(offset + 16);
// REMIND: why slice ?
// buffer = buffer.slice();
for (int i = 0; i < numGroups; i++) {
startCharCode[i] = buffer.getInt() & INTMASK;
endCharCode[i] = buffer.getInt() & INTMASK;
startGlyphID[i] = buffer.getInt() & INTMASK;
}
/* Finds the high bit by binary searching through the bits */
int value = numGroups;
if (value >= 1 << 16) {
value >>= 16;
highBit += 16;
}
if (value >= 1 << 8) {
value >>= 8;
highBit += 8;
}
if (value >= 1 << 4) {
value >>= 4;
highBit += 4;
}
if (value >= 1 << 2) {
value >>= 2;
highBit += 2;
}
if (value >= 1 << 1) {
value >>= 1;
highBit += 1;
}
power = 1 << highBit;
extra = numGroups - power;
}
static CMap initialize(PrismFontFile font) {
CMap cmap = null;
int offset, platformID, encodingID = -1;
int three0 = 0, three1 = 0, three10 = 0, zeroStarOffset = 0;
boolean zeroStar = false, threeStar = false;
Buffer cmapBuffer = font.readTable(FontConstants.cmapTag);
short numberSubTables = cmapBuffer.getShort(2);
/* Locate the offsets of supported 3,* Microsoft platform encodings,
* and any 0,* Unicode platform encoding. The latter is used by
* all current OS X fonts that don't have a Microsoft cmap.
* We will always prefer the Microsoft cmap, for the fonts that
* provide both. They ought to perform the same mappings. Although
* I can imagine that a vendor might provide a different looking
* glyph for some special characters for OS X vs Windows, I'm not
* actually aware of any such case.
*/
for (int i = 0; i < numberSubTables; i++) {
cmapBuffer.position(i * 8 + 4);
platformID = cmapBuffer.getShort();
if (platformID == 0) {
zeroStar = true;
encodingID = cmapBuffer.getShort();
zeroStarOffset = cmapBuffer.getInt();
} else if (platformID == 3) {
threeStar = true;
encodingID = cmapBuffer.getShort();
offset = cmapBuffer.getInt();
switch (encodingID) {
case 0:
three0 = offset;
break; // MS Symbol encoding
case 1:
three1 = offset;
break; // MS Unicode cmap
case 10:
three10 = offset;
break; // MS Unicode surrogates
}
}
}
/* This defines the preference order for cmap subtables */
if (threeStar) {
if (three10 != 0) {
cmap = createCMap(cmapBuffer, three10);
} else if (three0 != 0) {
cmap = createCMap(cmapBuffer, three0);
} else if (three1 != 0) {
cmap = createCMap(cmapBuffer, three1);
}
} else if (zeroStar && zeroStarOffset != 0) {
cmap = createCMap(cmapBuffer, zeroStarOffset);
} else {
/* No 0,* or supported 3,* subtable was found.
* Use whatever is the first table listed.
* Since these are supposed to be sorted, there's a good chance
* it will be Mac Roman (1,0). If its not that then its
* likely a really old font but not one that's found on either
* Windows or OS X
* In fact I didn't even find any OS X font that supported
* only (1,*).
* So this seems likely to be an untravelled path which is
* just as well given that its not likely to work properly.
*/
cmap = createCMap(cmapBuffer, cmapBuffer.getInt(8));
}
return cmap;
}