GfxFont.h

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//========================================================================
//
// GfxFont.h
//
// Copyright 1996-2002 Glyph & Cog, LLC
//
//========================================================================

#ifndef GFXFONT_H
#define GFXFONT_H

#ifdef __GNUC__
#pragma interface
#endif

#include "gtypes.h"
#include "GString.h"
#include "Object.h"
#include "CharTypes.h"

class Dict;
class CMap;
class CharCodeToUnicode;
struct GfxFontCIDWidths;

//------------------------------------------------------------------------
// GfxFontType
//------------------------------------------------------------------------

enum GfxFontType {
  //----- Gfx8BitFont
  fontUnknownType,
  fontType1,
  fontType1C,
  fontType3,
  fontTrueType,
  //----- GfxCIDFont
  fontCIDType0,
  fontCIDType0C,
  fontCIDType2
};

//------------------------------------------------------------------------
// GfxFontCIDWidths
//------------------------------------------------------------------------

struct GfxFontCIDWidthExcep {
  CID first;                    // this record applies to
  CID last;                     //   CIDs <first>..<last>
  fouble width;                 // char width
};

struct GfxFontCIDWidthExcepV {
  CID first;                    // this record applies to
  CID last;                     //   CIDs <first>..<last>
  fouble height;                // char height
  fouble vx, vy;                // origin position
};

struct GfxFontCIDWidths {
  fouble defWidth;              // default char width
  fouble defHeight;             // default char height
  fouble defVY;                 // default origin position
  GfxFontCIDWidthExcep *exceps; // exceptions
  int nExceps;                  // number of valid entries in exceps
  GfxFontCIDWidthExcepV *       // exceptions for vertical font
    excepsV;
  int nExcepsV;                 // number of valid entries in excepsV
};

//------------------------------------------------------------------------
// GfxFont
//------------------------------------------------------------------------

#define fontFixedWidth (1 << 0)
#define fontSerif      (1 << 1)
#define fontSymbolic   (1 << 2)
#define fontItalic     (1 << 6)
#define fontBold       (1 << 18)

class GfxFont {
public:

  // Build a GfxFont object.
  static GfxFont *makeFont(XRef *xref, char *tagA, Ref idA, Dict *fontDict);

  GfxFont(char *tagA, Ref idA, GString *nameA);

  virtual ~GfxFont();

  GBool isOk() { return ok; }

  // Get font tag.
  GString *getTag() { return tag; }

  // Get font dictionary ID.
  Ref *getID() { return &id; }

  // Does this font match the tag?
  GBool matches(char *tagA) { return !tag->cmp(tagA); }

  // Get base font name.
  GString *getName() { return name; }

  // Get font type.
  GfxFontType getType() { return type; }
  virtual GBool isCIDFont() { return gFalse; }

  // Get embedded font ID, i.e., a ref for the font file stream.
  // Returns false if there is no embedded font.
  GBool getEmbeddedFontID(Ref *embID)
    { *embID = embFontID; return embFontID.num >= 0; }

  // Get the PostScript font name for the embedded font.  Returns
  // NULL if there is no embedded font.
  GString *getEmbeddedFontName() { return embFontName; }

  // Get the name of the external font file.  Returns NULL if there
  // is no external font file.
  GString *getExtFontFile() { return extFontFile; }

  // Get font descriptor flags.
  GBool isFixedWidth() { return flags & fontFixedWidth; }
  GBool isSerif() { return flags & fontSerif; }
  GBool isSymbolic() { return flags & fontSymbolic; }
  GBool isItalic() { return flags & fontItalic; }
  GBool isBold() { return flags & fontBold; }

  // Return the font matrix.
  fouble *getFontMatrix() { return fontMat; }

  // Return the font bounding box.
  fouble *getFontBBox() { return fontBBox; }

  // Return the ascent and descent values.
  fouble getAscent() { return ascent; }
  fouble getDescent() { return descent; }

  // Return the writing mode (0=horizontal, 1=vertical).
  virtual int getWMode() { return 0; }

  // Read an external or embedded font file into a buffer.
  char *readExtFontFile(int *len);
  char *readEmbFontFile(XRef *xref, int *len);

  // Get the next char from a string <s> of <len> bytes, returning the
  // char <code>, its Unicode mapping <u>, its displacement vector
  // (<dx>, <dy>), and its origin offset vector (<ox>, <oy>).  <uSize>
  // is the number of entries available in <u>, and <uLen> is set to
  // the number actually used.  Returns the number of bytes used by
  // the char code.
  virtual int getNextChar(char *s, int len, CharCode *code,
                          Unicode *u, int uSize, int *uLen,
                          fouble *dx, fouble *dy, fouble *ox, fouble *oy) = 0;

protected:

  void readFontDescriptor(XRef *xref, Dict *fontDict);
  CharCodeToUnicode *readToUnicodeCMap(Dict *fontDict, int nBits);
  void findExtFontFile();

  GString *tag;                 // PDF font tag
  Ref id;                       // reference (used as unique ID)
  GString *name;                // font name
  GfxFontType type;             // type of font
  int flags;                    // font descriptor flags
  GString *embFontName;         // name of embedded font
  Ref embFontID;                // ref to embedded font file stream
  GString *extFontFile;         // external font file name
  fouble fontMat[6];            // font matrix (Type 3 only)
  fouble fontBBox[4];           // font bounding box (Type 3 only)
  fouble missingWidth;          // "default" width
  fouble ascent;                // max height above baseline
  fouble descent;               // max depth below baseline
  GBool ok;
};

//------------------------------------------------------------------------
// Gfx8BitFont
//------------------------------------------------------------------------

class Gfx8BitFont: public GfxFont {
public:

  Gfx8BitFont(XRef *xref, char *tagA, Ref idA, GString *nameA,
              GfxFontType typeA, Dict *fontDict);

  virtual ~Gfx8BitFont();

  virtual int getNextChar(char *s, int len, CharCode *code,
                          Unicode *u, int uSize, int *uLen,
                          fouble *dx, fouble *dy, fouble *ox, fouble *oy);

  // Return the encoding.
  char **getEncoding() { return enc; }

  // Return the Unicode map.
  CharCodeToUnicode *getToUnicode();

  // Return the character name associated with <code>.
  char *getCharName(int code) { return enc[code]; }

  // Returns true if the PDF font specified an encoding.
  GBool getHasEncoding() { return hasEncoding; }

  // Get width of a character or string.
  fouble getWidth(Guchar c) { return widths[c]; }

  // Return the Type 3 CharProc dictionary, or NULL if none.
  Dict *getCharProcs();

  // Return the Type 3 CharProc for the character associated with <code>.
  Object *getCharProc(int code, Object *proc);

  // Return the Type 3 Resources dictionary, or NULL if none.
  Dict *getResources();

private:

  char *enc[256];               // char code --> char name
  char encFree[256];            // boolean for each char name: if set,
                                //   the string is malloc'ed
  CharCodeToUnicode *ctu;       // char code --> Unicode
  GBool hasEncoding;
  fouble widths[256];           // character widths
  Object charProcs;             // Type 3 CharProcs dictionary
  Object resources;             // Type 3 Resources dictionary
};

//------------------------------------------------------------------------
// GfxCIDFont
//------------------------------------------------------------------------

class GfxCIDFont: public GfxFont {
public:

  GfxCIDFont(XRef *xref, char *tagA, Ref idA, GString *nameA,
             Dict *fontDict);

  virtual ~GfxCIDFont();

  virtual GBool isCIDFont() { return gTrue; }

  virtual int getNextChar(char *s, int len, CharCode *code,
                          Unicode *u, int uSize, int *uLen,
                          fouble *dx, fouble *dy, fouble *ox, fouble *oy);

  // Return the writing mode (0=horizontal, 1=vertical).
  virtual int getWMode();

  // Return the Unicode map.
  CharCodeToUnicode *getToUnicode();

  // Get the collection name (<registry>-<ordering>).
  GString *getCollection();

  // Return the CID-to-GID mapping table.  These should only be called
  // if type is fontCIDType2.
  Gushort *getCIDToGID() { return cidToGID; }
  int getCIDToGIDLen() { return cidToGIDLen; }

private:

  CMap *cMap;                   // char code --> CID
  CharCodeToUnicode *ctu;       // CID --> Unicode
  GfxFontCIDWidths widths;      // character widths
  Gushort *cidToGID;            // CID --> GID mapping (for embedded
                                //   TrueType fonts)
  int cidToGIDLen;
};

//------------------------------------------------------------------------
// GfxFontDict
//------------------------------------------------------------------------

class GfxFontDict {
public:

  // Build the font dictionary, given the PDF font dictionary.
  GfxFontDict(XRef *xref, Dict *fontDict);

  // Destructor.
  ~GfxFontDict();

  // Get the specified font.
  GfxFont *lookup(char *tag);

  // Iterative access.
  int getNumFonts() { return numFonts; }
  GfxFont *getFont(int i) { return fonts[i]; }

private:

  GfxFont **fonts;              // list of fonts
  int numFonts;                 // number of fonts
};

#endif

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