gfxfont.cc

这是一个做pdf阅读器的源代码文件,是大家学习阅读器资料的很好参考

  return charProcs.isDict() ? charProcs.getDict() : (Dict *)NULL;
}

Object *Gfx8BitFont::getCharProc(int code, Object *proc) {
  if (enc[code] && charProcs.isDict()) {
    charProcs.dictLookup(enc[code], proc);
  } else {
    proc->initNull();
  }
  return proc;
}

Dict *Gfx8BitFont::getResources() {
  return resources.isDict() ? resources.getDict() : (Dict *)NULL;
}

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

static int CDECL cmpWidthExcep(const void *w1, const void *w2) {
  return ((GfxFontCIDWidthExcep *)w1)->first -
         ((GfxFontCIDWidthExcep *)w2)->first;
}

static int CDECL cmpWidthExcepV(const void *w1, const void *w2) {
  return ((GfxFontCIDWidthExcepV *)w1)->first -
         ((GfxFontCIDWidthExcepV *)w2)->first;
}

GfxCIDFont::GfxCIDFont(XRef *xref, char *tagA, Ref idA, GString *nameA,
		       Dict *fontDict):
  GfxFont(tagA, idA, nameA)
{
  Dict *desFontDict;
  GString *collection, *cMapName;
  Object desFontDictObj;
  Object obj1, obj2, obj3, obj4, obj5, obj6;
  CharCodeToUnicode *utu;
  CharCode c;
  Unicode uBuf[8];
  int c1, c2;
  int excepsSize, i, j, k, n;

  ascent = 0.95;
  descent = -0.35;
  fontBBox[0] = fontBBox[1] = fontBBox[2] = fontBBox[3] = 0;
  cMap = NULL;
  ctu = NULL;
  widths.defWidth = 1.0;
  widths.defHeight = -1.0;
  widths.defVY = 0.880;
  widths.exceps = NULL;
  widths.nExceps = 0;
  widths.excepsV = NULL;
  widths.nExcepsV = 0;
  cidToGID = NULL;
  cidToGIDLen = 0;

  // get the descendant font
  if (!fontDict->lookup("DescendantFonts", &obj1)->isArray()) {
    error(-1, "Missing DescendantFonts entry in Type 0 font");
    obj1.free();
    goto err1;
  }
  if (!obj1.arrayGet(0, &desFontDictObj)->isDict()) {
    error(-1, "Bad descendant font in Type 0 font");
    goto err3;
  }
  obj1.free();
  desFontDict = desFontDictObj.getDict();

  // font type
  if (!desFontDict->lookup("Subtype", &obj1)) {
    error(-1, "Missing Subtype entry in Type 0 descendant font");
    goto err3;
  }
  if (obj1.isName("CIDFontType0")) {
    type = fontCIDType0;
  } else if (obj1.isName("CIDFontType2")) {
    type = fontCIDType2;
  } else {
    error(-1, "Unknown Type 0 descendant font type '%s'",
	  obj1.isName() ? obj1.getName() : "???");
    goto err3;
  }
  obj1.free();

  // get info from font descriptor
  readFontDescriptor(xref, desFontDict);

  // look for an external font file
  findExtFontFile();

  //----- encoding info -----

  // char collection
  if (!desFontDict->lookup("CIDSystemInfo", &obj1)->isDict()) {
    error(-1, "Missing CIDSystemInfo dictionary in Type 0 descendant font");
    goto err3;
  }
  obj1.dictLookup("Registry", &obj2);
  obj1.dictLookup("Ordering", &obj3);
  if (!obj2.isString() || !obj3.isString()) {
    error(-1, "Invalid CIDSystemInfo dictionary in Type 0 descendant font");
    goto err4;
  }
  collection = obj2.getString()->copy()->append('-')->append(obj3.getString());
  obj3.free();
  obj2.free();
  obj1.free();

  // look for a ToUnicode CMap
  if (!(ctu = readToUnicodeCMap(fontDict, 16, NULL))) {

    // the "Adobe-Identity" and "Adobe-UCS" collections don't have
    // cidToUnicode files
    if (collection->cmp("Adobe-Identity") &&
	collection->cmp("Adobe-UCS")) {

      // look for a user-supplied .cidToUnicode file
      if (!(ctu = globalParams->getCIDToUnicode(collection))) {
	error(-1, "Unknown character collection '%s'",
	      collection->getCString());
	// fall-through, assuming the Identity mapping -- this appears
	// to match Adobe's behavior
      }
    }
  }

  // look for a Unicode-to-Unicode mapping
  if (name && (utu = globalParams->getUnicodeToUnicode(name))) {
    if (ctu) {
      for (c = 0; c < ctu->getLength(); ++c) {
	n = ctu->mapToUnicode(c, uBuf, 8);
	if (n >= 1) {
	  n = utu->mapToUnicode((CharCode)uBuf[0], uBuf, 8);
	  if (n >= 1) {
	    ctu->setMapping(c, uBuf, n);
	  }
	}
      }
      utu->decRefCnt();
    } else {
      ctu = utu;
    }
  }

  // encoding (i.e., CMap)
  //~ need to handle a CMap stream here
  //~ also need to deal with the UseCMap entry in the stream dict
  if (!fontDict->lookup("Encoding", &obj1)->isName()) {
    error(-1, "Missing or invalid Encoding entry in Type 0 font");
    delete collection;
    goto err3;
  }
  cMapName = new GString(obj1.getName());
  obj1.free();
  if (!(cMap = globalParams->getCMap(collection, cMapName))) {
    error(-1, "Unknown CMap '%s' for character collection '%s'",
	  cMapName->getCString(), collection->getCString());
    delete collection;
    delete cMapName;
    goto err2;
  }
  delete collection;
  delete cMapName;

  // CIDToGIDMap (for embedded TrueType fonts)
  if (type == fontCIDType2) {
    desFontDict->lookup("CIDToGIDMap", &obj1);
    if (obj1.isStream()) {
      cidToGIDLen = 0;
      i = 64;
      cidToGID = (Gushort *)gmallocn(i, sizeof(Gushort));
      obj1.streamReset();
      while ((c1 = obj1.streamGetChar()) != EOF &&
	     (c2 = obj1.streamGetChar()) != EOF) {
	if (cidToGIDLen == i) {
	  i *= 2;
	  cidToGID = (Gushort *)greallocn(cidToGID, i, sizeof(Gushort));
	}
	cidToGID[cidToGIDLen++] = (Gushort)((c1 << 8) + c2);
      }
    } else if (!obj1.isName("Identity") && !obj1.isNull()) {
      error(-1, "Invalid CIDToGIDMap entry in CID font");
    }
    obj1.free();
  }

  //----- character metrics -----

  // default char width
  if (desFontDict->lookup("DW", &obj1)->isInt()) {
    widths.defWidth = obj1.getInt() * 0.001;
  }
  obj1.free();

  // char width exceptions
  if (desFontDict->lookup("W", &obj1)->isArray()) {
    excepsSize = 0;
    i = 0;
    while (i + 1 < obj1.arrayGetLength()) {
      obj1.arrayGet(i, &obj2);
      obj1.arrayGet(i + 1, &obj3);
      if (obj2.isInt() && obj3.isInt() && i + 2 < obj1.arrayGetLength()) {
	if (obj1.arrayGet(i + 2, &obj4)->isNum()) {
	  if (widths.nExceps == excepsSize) {
	    excepsSize += 16;
	    widths.exceps = (GfxFontCIDWidthExcep *)
	      greallocn(widths.exceps,
			excepsSize, sizeof(GfxFontCIDWidthExcep));
	  }
	  widths.exceps[widths.nExceps].first = obj2.getInt();
	  widths.exceps[widths.nExceps].last = obj3.getInt();
	  widths.exceps[widths.nExceps].width = obj4.getNum() * 0.001;
	  ++widths.nExceps;
	} else {
	  error(-1, "Bad widths array in Type 0 font");
	}
	obj4.free();
	i += 3;
      } else if (obj2.isInt() && obj3.isArray()) {
	if (widths.nExceps + obj3.arrayGetLength() > excepsSize) {
	  excepsSize = (widths.nExceps + obj3.arrayGetLength() + 15) & ~15;
	  widths.exceps = (GfxFontCIDWidthExcep *)
	    greallocn(widths.exceps,
		      excepsSize, sizeof(GfxFontCIDWidthExcep));
	}
	j = obj2.getInt();
	for (k = 0; k < obj3.arrayGetLength(); ++k) {
	  if (obj3.arrayGet(k, &obj4)->isNum()) {
	    widths.exceps[widths.nExceps].first = j;
	    widths.exceps[widths.nExceps].last = j;
	    widths.exceps[widths.nExceps].width = obj4.getNum() * 0.001;
	    ++j;
	    ++widths.nExceps;
	  } else {
	    error(-1, "Bad widths array in Type 0 font");
	  }
	  obj4.free();
	}
	i += 2;
      } else {
	error(-1, "Bad widths array in Type 0 font");
	++i;
      }
      obj3.free();
      obj2.free();
    }
    qsort(widths.exceps, widths.nExceps, sizeof(GfxFontCIDWidthExcep),
	  &cmpWidthExcep);
  }
  obj1.free();

  // default metrics for vertical font
  if (desFontDict->lookup("DW2", &obj1)->isArray() &&
      obj1.arrayGetLength() == 2) {
    if (obj1.arrayGet(0, &obj2)->isNum()) {
      widths.defVY = obj2.getNum() * 0.001;
    }
    obj2.free();
    if (obj1.arrayGet(1, &obj2)->isNum()) {
      widths.defHeight = obj2.getNum() * 0.001;
    }
    obj2.free();
  }
  obj1.free();

  // char metric exceptions for vertical font
  if (desFontDict->lookup("W2", &obj1)->isArray()) {
    excepsSize = 0;
    i = 0;
    while (i + 1 < obj1.arrayGetLength()) {
      obj1.arrayGet(i, &obj2);
      obj1.arrayGet(i+ 1, &obj3);
      if (obj2.isInt() && obj3.isInt() && i + 4 < obj1.arrayGetLength()) {
	if (obj1.arrayGet(i + 2, &obj4)->isNum() &&
	    obj1.arrayGet(i + 3, &obj5)->isNum() &&
	    obj1.arrayGet(i + 4, &obj6)->isNum()) {
	  if (widths.nExcepsV == excepsSize) {
	    excepsSize += 16;
	    widths.excepsV = (GfxFontCIDWidthExcepV *)
	      greallocn(widths.excepsV,
			excepsSize, sizeof(GfxFontCIDWidthExcepV));
	  }
	  widths.excepsV[widths.nExcepsV].first = obj2.getInt();
	  widths.excepsV[widths.nExcepsV].last = obj3.getInt();
	  widths.excepsV[widths.nExcepsV].height = obj4.getNum() * 0.001;
	  widths.excepsV[widths.nExcepsV].vx = obj5.getNum() * 0.001;
	  widths.excepsV[widths.nExcepsV].vy = obj6.getNum() * 0.001;
	  ++widths.nExcepsV;
	} else {
	  error(-1, "Bad widths (W2) array in Type 0 font");
	}
	obj6.free();
	obj5.free();
	obj4.free();
	i += 5;
      } else if (obj2.isInt() && obj3.isArray()) {
	if (widths.nExcepsV + obj3.arrayGetLength() / 3 > excepsSize) {
	  excepsSize =
	    (widths.nExcepsV + obj3.arrayGetLength() / 3 + 15) & ~15;
	  widths.excepsV = (GfxFontCIDWidthExcepV *)
	    greallocn(widths.excepsV,
		      excepsSize, sizeof(GfxFontCIDWidthExcepV));
	}
	j = obj2.getInt();
	for (k = 0; k < obj3.arrayGetLength(); k += 3) {
	  if (obj3.arrayGet(k, &obj4)->isNum() &&
	      obj3.arrayGet(k+1, &obj5)->isNum() &&
	      obj3.arrayGet(k+2, &obj6)->isNum()) {
	    widths.excepsV[widths.nExceps].first = j;
	    widths.excepsV[widths.nExceps].last = j;
	    widths.excepsV[widths.nExceps].height = obj4.getNum() * 0.001;
	    widths.excepsV[widths.nExceps].vx = obj5.getNum() * 0.001;
	    widths.excepsV[widths.nExceps].vy = obj6.getNum() * 0.001;
	    ++j;
	    ++widths.nExcepsV;
	  } else {
	    error(-1, "Bad widths (W2) array in Type 0 font");
	  }
	  obj6.free();
	  obj5.free();
	  obj4.free();
	}
	i += 2;
      } else {
	error(-1, "Bad widths (W2) array in Type 0 font");
	++i;
      }
      obj3.free();
      obj2.free();
    }
    qsort(widths.excepsV, widths.nExcepsV, sizeof(GfxFontCIDWidthExcepV),
	  &cmpWidthExcepV);
  }
  obj1.free();

  desFontDictObj.free();
  ok = gTrue;
  return;

 err4:
  obj3.free();
  obj2.free();
 err3:
  obj1.free();
 err2:
  desFontDictObj.free();
 err1:;
}

GfxCIDFont::~GfxCIDFont() {
  if (cMap) {
    cMap->decRefCnt();
  }
  if (ctu) {
    ctu->decRefCnt();
  }
  gfree(widths.exceps);
  gfree(widths.excepsV);
  if (cidToGID) {
    gfree(cidToGID);
  }
}

int GfxCIDFont::getNextChar(char *s, int len, CharCode *code,
			    Unicode *u, int uSize, int *uLen,
			    double *dx, double *dy, double *ox, double *oy) {
  CID cid;
  double w, h, vx, vy;
  int n, a, b, m;

  if (!cMap) {
    *code = 0;
    *uLen = 0;
    *dx = *dy = 0;
    return 1;
  }

  *code = (CharCode)(cid = cMap->getCID(s, len, &n));
  if (ctu) {
    *uLen = ctu->mapToUnicode(cid, u, uSize);
  } else {
    *uLen = 0;
  }

  // horizontal
  if (cMap->getWMode() == 0) {
    w = widths.defWidth;
    h = vx = vy = 0;
    if (widths.nExceps > 0 && cid >= widths.exceps[0].first) {
      a = 0;
      b = widths.nExceps;
      // invariant: widths.exceps[a].first <= cid < widths.exceps[b].first
      while (b - a > 1) {
	m = (a + b) / 2;
	if (widths.exceps[m].first <= cid) {
	  a = m;
	} else {
	  b = m;
	}
      }
      if (cid <= widths.exceps[a].last) {
	w = widths.exceps[a].width;
      }
    }

  // vertical
  } else {
    w = 0;
    h = widths.defHeight;
    vx = widths.defWidth / 2;
    vy = widths.defVY;
    if (widths.nExcepsV > 0 && cid >= widths.excepsV[0].first) {
      a = 0;
      b = widths.nExcepsV;
      // invariant: widths.excepsV[a].first <= cid < widths.excepsV[b].first
      while (b - a > 1) {
	m = (a + b) / 2;
	if (widths.excepsV[m].last <= cid) {
	  a = m;
	} else {
	  b = m;
	}
      }
      if (cid <= widths.excepsV[a].last) {
	h = widths.excepsV[a].height;
	vx = widths.excepsV[a].vx;
	vy = widths.excepsV[a].vy;
      }
    }
  }

  *dx = w;
  *dy = h;
  *ox = vx;
  *oy = vy;

  return n;
}

int GfxCIDFont::getWMode() {
  return cMap ? cMap->getWMode() : 0;
}

CharCodeToUnicode *GfxCIDFont::getToUnicode() {
  if (ctu) {
    ctu->incRefCnt();
  }
  return ctu;
}

GString *GfxCIDFont::getCollection() {
  return cMap ? cMap->getCollection() : (GString *)NULL;
}

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

GfxFontDict::GfxFontDict(XRef *xref, Ref *fontDictRef, Dict *fontDict) {
  int i;
  Object obj1, obj2;
  Ref r;

  numFonts = fontDict->getLength();
  fonts = (GfxFont **)gmallocn(numFonts, sizeof(GfxFont *));
  for (i = 0; i < numFonts; ++i) {
    fontDict->getValNF(i, &obj1);
    obj1.fetch(xref, &obj2);
    if (obj2.isDict()) {
      if (obj1.isRef()) {
	r = obj1.getRef();
      } else {
	// no indirect reference for this font, so invent a unique one
	// (legal generation numbers are five digits, so any 6-digit
	// number would be safe)
	r.num = i;
	if (fontDictRef) {
	  r.gen = 100000 + fontDictRef->num;
	} else {
	  r.gen = 999999;
	}
      }
      fonts[i] = GfxFont::makeFont(xref, fontDict->getKey(i),
				   r, obj2.getDict());
      if (fonts[i] && !fonts[i]->isOk()) {
	delete fonts[i];
	fonts[i] = NULL;
      }
    } else {
      error(-1, "font resource is not a dictionary");
      fonts[i] = NULL;
    }
    obj1.free();
    obj2.free();
  }
}

GfxFontDict::~GfxFontDict() {
  int i;

  for (i = 0; i < numFonts; ++i) {
    if (fonts[i]) {
      delete fonts[i];
    }
  }
  gfree(fonts);
}

GfxFont *GfxFontDict::lookup(char *tag) {
  int i;

  for (i = 0; i < numFonts; ++i) {
    if (fonts[i] && fonts[i]->matches(tag)) {
      return fonts[i];
    }
  }
  return NULL;
}