com.adobe.fontengine.font.opentype

Class Cmap

java.lang.Object

com.adobe.fontengine.font.opentype.Table

com.adobe.fontengine.font.opentype.Cmap

public final class Cmap
extends Table

Gives access to a 'cmap' table.

Encoding forms support

A number of subtable formats are designed to combine the decoding of a character stream and the computation of the glyph ID. For example, format 8 is geared to support encoding forms with one or two 16 bits code units (such as UTF-16) and has a 64K bit array to indicate those code units which represent a code point on their own and those code units which are the first of a pair. The idea is that the details of the encoding form can be captured in the font.

Our point of view is that encoding forms are not the business of fonts, so we ignore those parts of those formats.

Version handling

'cmap' tables have only a minor version number. This implementation:

• fully supports version 0 tables
• interprets version x > 0 tables as version 0 tables

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Cmap.CmapSelector Class used to receive the list of recognized subtables in this cmap table.
static class	Cmap.MacEncodingID
static class	Cmap.MS_EncodingID
static class	Cmap.PlatformID Enum classes for the various platformIDs and encodingIDs.
static class	Cmap.UnicodeEncodingID

Method Summary

Modifier and Type	Method and Description
int	char2glyph(int ch, int index)
int	coolTypeUnicodeChar2glyph(int usv) Approximates CoolType's interpretation of cmaps.
void	enumerateCmaps(Cmap.CmapSelector selector) Enumerate the cmaps contained in the cmap table.
int	getCmapSubtableIndex(int platformId, int encodingId)
int	getHighestMappedCode(int stOffset, boolean max2bytes) Get the character code that is the highest that is mapped by the cmap found at stOffset.
int	getLowestMappedCode(int stOffset) Get the character code that is the lowest that is mapped by the cmap found at stOffset.
int	getMapping(int stOffset, int charCode) Get the glyphID for charCode using the subtable at stOffset.
int	getOffset(int subtableIndex)
int[]	glyph2char(int numGlyphs, int index) Get the inverted mapping from glyphs to characters for one subtable.
boolean	isSymbolic() Tell whether the font is symbolic.
int	probe(int platformID, int encodingID) Return the offset of a give cmap subtable if present, -1 otherwise.
void	stream(Map tables)
void	streamForSWF(Map tables, int numGlyphs)
void	subsetAndStream(Subset subset, SubsetSimpleTrueType ttSubset, Map tables) In the SubsetSimpleTrueType case, the client will have provided a cmap and a set of codepoints to map against it.
void	subsetAndStreamForSWF(TreeSet codePoints, Subset subset, Map tables, boolean includeVariationCmap)
int	unicodeChar2glyph(int usv) Get the glyph mapped from a given character.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

probe

public int probe(int platformID,
                 int encodingID)
          throws InvalidFontException,
                 UnsupportedFontException

Return the offset of a give cmap subtable if present, -1 otherwise.

Throws:

InvalidFontException

UnsupportedFontException

isSymbolic

public boolean isSymbolic()
                   throws UnsupportedFontException,
                          InvalidFontException

Tell whether the font is symbolic.

Throws:

UnsupportedFontException

InvalidFontException

enumerateCmaps

public void enumerateCmaps(Cmap.CmapSelector selector)
                    throws UnsupportedFontException,
                           InvalidFontException

Enumerate the cmaps contained in the cmap table. Call the selector's cmapFound method for each recognized platform id/encoding id combination.

Parameters:

selector -

Throws:

UnsupportedFontException

InvalidFontException

getCmapSubtableIndex

public int getCmapSubtableIndex(int platformId,
                                int encodingId)
                         throws InvalidFontException

Throws:

InvalidFontException

unicodeChar2glyph

public int unicodeChar2glyph(int usv)
                      throws UnsupportedFontException,
                             InvalidFontException

Get the glyph mapped from a given character.

Parameters:

usv - the Unicode scalar value to look up

Returns:

the gid of the glyph mapped from usv, 0 if not mapped. Note that this is the true OpenType gid, even in the case of cid cff otf. It is NOT the cid.

Throws:

UnsupportedFontException

InvalidFontException

coolTypeUnicodeChar2glyph

public int coolTypeUnicodeChar2glyph(int usv)
                              throws UnsupportedFontException,
                                     InvalidFontException

Approximates CoolType's interpretation of cmaps. This approximation is fairly incomplete: for example, CoolType has some heuristics to interpret the cmaps of Win 3.1 ME fonts (which have an MS/Symbol cmap that follows some conventions and are marked with high order bits in OS/2.fsSelection).

Throws:

UnsupportedFontException

InvalidFontException

char2glyph

public int char2glyph(int ch,
                      int index)
               throws UnsupportedFontException,
                      InvalidFontException

Throws:

UnsupportedFontException

InvalidFontException

getLowestMappedCode

public int getLowestMappedCode(int stOffset)
                        throws UnsupportedFontException,
                               InvalidFontException

Get the character code that is the lowest that is mapped by the cmap found at stOffset.

Throws:

UnsupportedFontException

InvalidFontException

getHighestMappedCode

public int getHighestMappedCode(int stOffset,
                                boolean max2bytes)
                         throws UnsupportedFontException,
                                InvalidFontException

Get the character code that is the highest that is mapped by the cmap found at stOffset. If max2bytes is true, the highest code that is at most 2 bytes is returned.

Throws:

UnsupportedFontException

InvalidFontException

getMapping

public int getMapping(int stOffset,
                      int charCode)
               throws UnsupportedFontException,
                      InvalidFontException

Get the glyphID for charCode using the subtable at stOffset.

Parameters:

stOffset - the offset (in the cmap table) of the subtable to use

charCode - the character code to map

Returns:

the glyphID for charCode

Throws:

UnsupportedFontException

InvalidFontException

getOffset

public int getOffset(int subtableIndex)
              throws InvalidFontException,
                     UnsupportedFontException

Throws:

InvalidFontException

UnsupportedFontException

glyph2char

public int[] glyph2char(int numGlyphs,
                        int index)
                 throws UnsupportedFontException,
                        InvalidFontException

Get the inverted mapping from glyphs to characters for one subtable. The subtable, identified by index must be present.

Parameters:

numGlyphs - the number of glyphs in the font

index - the index of the cmap to invert

Returns:

array of numGlyphs integers, mapping glyphIDs to characters; if a glyphs is not mapped by the subtable, the value in this array is -1.

Throws:

UnsupportedFontException

InvalidFontException

subsetAndStream

public void subsetAndStream(Subset subset,
                            SubsetSimpleTrueType ttSubset,
                            Map tables)
                     throws UnsupportedFontException,
                            InvalidFontException

In the SubsetSimpleTrueType case, the client will have provided a cmap and a set of codepoints to map against it. We will convert these to relate to the new subset GlyphIDs stored in the OTSubset. We don't bother to emit cmaps in any other case than the SubsetSimpleTrueType case.

Throws:

UnsupportedFontException

InvalidFontException

subsetAndStreamForSWF

public void subsetAndStreamForSWF(TreeSet codePoints,
                                  Subset subset,
                                  Map tables,
                                  boolean includeVariationCmap)
                           throws UnsupportedFontException,
                                  InvalidFontException

Throws:

UnsupportedFontException

InvalidFontException

stream

public void stream(Map tables)

streamForSWF

public void streamForSWF(Map tables,
                         int numGlyphs)
                  throws UnsupportedFontException,
                         InvalidFontException

Throws:

UnsupportedFontException

InvalidFontException