com.sun.javafx.font.CMap Maven / Gradle / Ivy
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package com.sun.javafx.font;
import com.sun.javafx.font.FontFileReader.Buffer;
/*
* A tt font has a CMAP table which is in turn made up of sub-tables which
* describe the char to glyph mapping in (possibly) multiple ways.
* CMAP subtables are described by 3 values.
* 1. Platform ID (eg 3=Microsoft, which is the id we look for in JDK)
* 2. Encoding (eg 0=symbol, 1=unicode)
* 3. TrueType subtable format (how the char->glyph mapping for the encoding
* is stored in the subtable). See the TrueType spec. Format 4 is required
* by MS in fonts for windows. Its uses segmented mapping to delta values.
* Most typically we see are (3,1,4) :
* CMAP Platform ID=3 is what we prefer. After that any 0,*.
*/
abstract class CMap {
static final char noSuchChar = (char)0xfffd;
static final int SHORTMASK = 0x0000ffff;
static final int INTMASK = 0xffffffff;
private static final int MAX_CODE_POINTS = 0x10ffff;
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 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>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= 0) {
return (char)controlGlyph;
}
/*
* Citation from the TrueType (and OpenType) spec:
* The segments are sorted in order of increasing endCode
* values, and the segment values are specified in four parallel
* arrays. You search for the first endCode that is greater than
* or equal to the character code you want to map. If the
* corresponding startCode is less than or equal to the
* character code, then you use the corresponding idDelta and
* idRangeOffset to map the character code to a glyph index
* (otherwise, the missingGlyph is returned).
*/
/*
* CMAP format4 defines several fields for optimized search of
* the segment list (entrySelector, searchRange, rangeShift).
* However, benefits are neglible and some fonts have incorrect
* data - so we use straightforward binary search (see bug 6247425)
*/
int left = 0, right = startCount.length;
index = startCount.length >> 1;
while (left < right) {
if (endCount[index] < charCode) {
left = index + 1;
} else {
right = index;
}
index = (left + right) >> 1;
}
if (charCode >= startCount[index] && charCode <= endCount[index]) {
int rangeOffset = idRangeOffset[index];
if (rangeOffset == 0) {
glyphCode = (char)(charCode + idDelta[index]);
} else {
/* Calculate an index into the glyphIds array */
int glyphIDIndex = rangeOffset - segCount + index
+ (charCode - startCount[index]);
glyphCode = glyphIds[glyphIDIndex];
if (glyphCode != 0) {
glyphCode = (char)(glyphCode + idDelta[index]);
}
}
}
return glyphCode;
}
}
// Format 0: Byte Encoding table
static class CMapFormat0 extends CMap {
byte [] cmap;
CMapFormat0(Buffer buffer, int offset) {
/* skip 6 bytes of format, length, and version */
int len = buffer.getChar(offset+2);
cmap = new byte[len-6];
buffer.get(offset+6, cmap, 0, len-6);
}
@Override
char getGlyph(int charCode) {
if (charCode < 256) {
if (charCode < 0x0010) {
switch (charCode) {
case 0x0009:
case 0x000a:
case 0x000d: return CharToGlyphMapper.INVISIBLE_GLYPH_ID;
}
}
return (char)(0xff & cmap[charCode]);
} else {
return 0;
}
}
}
// Format 2: High-byte mapping through table
static class CMapFormat2 extends CMap {
char[] subHeaderKey = new char[256];
/* Store subheaders in individual arrays
* A SubHeader entry theoretically looks like {
* char firstCode;
* char entryCount;
* short idDelta;
* char idRangeOffset;
* }
*/
char[] firstCodeArray;
char[] entryCountArray;
short[] idDeltaArray;
char[] idRangeOffSetArray;
char[] glyphIndexArray;
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= 0) {
return (char)controlGlyph;
}
char highByte = (char)(charCode >> 8);
char lowByte = (char)(charCode & 0xff);
int key = subHeaderKey[highByte]>>3; // index into subHeaders
char mapMe;
if (key != 0) {
mapMe = lowByte;
} else {
mapMe = highByte;
if (mapMe == 0) {
mapMe = lowByte;
}
}
char firstCode = firstCodeArray[key];
if (mapMe < firstCode) {
return 0;
} else {
mapMe -= firstCode;
}
if (mapMe < entryCountArray[key]) {
/* "address" arithmetic is needed to calculate the offset
* into glyphIndexArray. "idRangeOffSetArray[key]" specifies
* the number of bytes from that location in the table where
* the subarray of glyphIndexes starting at "firstCode" begins.
* Each entry in the subHeader table is 8 bytes, and the
* idRangeOffSetArray field is at offset 6 in the entry.
* The glyphIndexArray immediately follows the subHeaders.
* So if there are "N" entries then the number of bytes to the
* start of glyphIndexArray is (N-key)*8-6.
* Subtract this from the idRangeOffSetArray value to get
* the number of bytes into glyphIndexArray and divide by 2 to
* get the (char) array index.
*/
int glyphArrayOffset = ((idRangeOffSetArray.length-key)*8)-6;
int glyphSubArrayStart =
(idRangeOffSetArray[key] - glyphArrayOffset)/2;
char glyphCode = glyphIndexArray[glyphSubArrayStart+mapMe];
if (glyphCode != 0) {
glyphCode += idDeltaArray[key]; //idDelta
return glyphCode;
}
}
return 0;
}
}
// Format 6: Trimmed table mapping
static class CMapFormat6 extends CMap {
char firstCode;
char entryCount;
char[] glyphIdArray;
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();
}
}
@Override
char getGlyph(int charCode) {
int controlGlyph = getControlCodeGlyph(charCode, true);
if (controlGlyph >= 0) {
return (char)controlGlyph;
}
charCode -= firstCode;
if (charCode < 0 || charCode >= entryCount) {
return 0;
} else {
return glyphIdArray[charCode];
}
}
}
// Format 8: mixed 16-bit and 32-bit coverage
// Seems unlikely this code will ever get tested as we look for
// MS platform Cmaps and MS states (in the Opentype spec on their website)
// that MS doesn't support this format
static class CMapFormat8 extends CMap {
CMapFormat8(Buffer buffer, int offset) {
}
@Override
char getGlyph(int charCode) {
return 0;
}
}
// Format 4-byte 10: Trimmed table mapping
// MS platform Cmaps and MS states (in the Opentype spec on their website)
// that MS doesn't support this format
static class CMapFormat10 extends CMap {
long startCharCode;
int numChars;
char[] glyphIdArray;
CMapFormat10(Buffer buffer, int offset) {
buffer.position(offset+12);
startCharCode = buffer.getInt() & INTMASK;
numChars = buffer.getInt() & INTMASK;
if (numChars <= 0 || numChars > MAX_CODE_POINTS ||
offset > buffer.capacity() - numChars*2 - 12 - 8)
{
throw new RuntimeException("Invalid cmap subtable");
}
glyphIdArray = new char[numChars];
for (int i=0; i< numChars; i++) {
glyphIdArray[i] = buffer.getChar();
}
}
@Override
char getGlyph(int charCode) {
int code = (int)(charCode - startCharCode);
if (code < 0 || code >= numChars) {
return 0;
} else {
return glyphIdArray[code];
}
}
}
// Format 12: Segmented coverage for UCS-4 (fonts supporting
// surrogate pairs)
static class CMapFormat12 extends CMap {
int numGroups;
int highBit =0;
int power;
int extra;
long[] startCharCode;
long[] endCharCode;
int[] startGlyphID;
CMapFormat12(Buffer buffer, int offset) {
numGroups = buffer.getInt(offset+12);
if (numGroups <= 0 || numGroups > MAX_CODE_POINTS ||
offset > buffer.capacity() - numGroups*12 - 12 - 4)
{
throw new RuntimeException("Invalid cmap subtable");
}
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= 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;
}
@Override
char getGlyph(int charCode) {
int controlGlyph = getControlCodeGlyph(charCode, false);
if (controlGlyph >= 0) {
return (char)controlGlyph;
}
int probe = power;
int range = 0;
if (startCharCode[extra] <= charCode) {
range = extra;
}
while (probe > 1) {
probe >>= 1;
if (startCharCode[range+probe] <= charCode) {
range += probe;
}
}
if (startCharCode[range] <= charCode &&
endCharCode[range] >= charCode) {
return (char)
(startGlyphID[range] + (charCode - startCharCode[range]));
}
return 0;
}
}
/* Used to substitute for bad Cmaps. */
static class NullCMapClass extends CMap {
@Override
char getGlyph(int charCode) {
return 0;
}
}
public static final NullCMapClass theNullCmap = new NullCMapClass();
final int getControlCodeGlyph(int charCode, boolean noSurrogates) {
if (charCode < 0x0010) {
switch (charCode) {
case 0x0009:
case 0x000a:
case 0x000d: return CharToGlyphMapper.INVISIBLE_GLYPH_ID;
}
} else if (charCode >= 0x200c) {
if ((charCode <= 0x200f) ||
(charCode >= 0x2028 && charCode <= 0x202e) ||
(charCode >= 0x206a && charCode <= 0x206f)) {
return CharToGlyphMapper.INVISIBLE_GLYPH_ID;
} else if (noSurrogates && charCode >= 0xFFFF) {
return 0;
}
}
return -1;
}
}
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