fofitruetype.cc

swf文件查看工具,能够看flash文件的格式

    }
    if (length >= 0) {
      newTables[k].tag = ((t42Tables[i].tag[0] & 0xff) << 24) |
	                 ((t42Tables[i].tag[1] & 0xff) << 16) |
	                 ((t42Tables[i].tag[2] & 0xff) <<  8) |
	                  (t42Tables[i].tag[3] & 0xff);
      newTables[k].checksum = checksum;
      newTables[k].offset = pos;
      newTables[k].len = length;
      pos += length;
      if (pos & 3) {
	pos += 4 - (length & 3);
      }
      ++k;
    }
  }

  // construct the table directory
  tableDir[0] = 0x00;		// sfnt version
  tableDir[1] = 0x01;
  tableDir[2] = 0x00;
  tableDir[3] = 0x00;
  tableDir[4] = 0;		// numTables
  tableDir[5] = nNewTables;
  tableDir[6] = 0;		// searchRange
  tableDir[7] = (Guchar)128;
  tableDir[8] = 0;		// entrySelector
  tableDir[9] = 3;
  tableDir[10] = 0;		// rangeShift
  tableDir[11] = (Guchar)(16 * nNewTables - 128);
  pos = 12;
  for (i = 0; i < nNewTables; ++i) {
    tableDir[pos   ] = (Guchar)(newTables[i].tag >> 24);
    tableDir[pos+ 1] = (Guchar)(newTables[i].tag >> 16);
    tableDir[pos+ 2] = (Guchar)(newTables[i].tag >>  8);
    tableDir[pos+ 3] = (Guchar) newTables[i].tag;
    tableDir[pos+ 4] = (Guchar)(newTables[i].checksum >> 24);
    tableDir[pos+ 5] = (Guchar)(newTables[i].checksum >> 16);
    tableDir[pos+ 6] = (Guchar)(newTables[i].checksum >>  8);
    tableDir[pos+ 7] = (Guchar) newTables[i].checksum;
    tableDir[pos+ 8] = (Guchar)(newTables[i].offset >> 24);
    tableDir[pos+ 9] = (Guchar)(newTables[i].offset >> 16);
    tableDir[pos+10] = (Guchar)(newTables[i].offset >>  8);
    tableDir[pos+11] = (Guchar) newTables[i].offset;
    tableDir[pos+12] = (Guchar)(newTables[i].len >> 24);
    tableDir[pos+13] = (Guchar)(newTables[i].len >> 16);
    tableDir[pos+14] = (Guchar)(newTables[i].len >>  8);
    tableDir[pos+15] = (Guchar) newTables[i].len;
    pos += 16;
  }

  // compute the font checksum and store it in the head table
  checksum = computeTableChecksum(tableDir, 12 + nNewTables*16);
  for (i = 0; i < nNewTables; ++i) {
    checksum += newTables[i].checksum;
  }
  checksum = 0xb1b0afba - checksum; // because the TrueType spec says so
  headData[ 8] = (Guchar)(checksum >> 24);
  headData[ 9] = (Guchar)(checksum >> 16);
  headData[10] = (Guchar)(checksum >>  8);
  headData[11] = (Guchar) checksum;

  // start the sfnts array
  if (name) {
    (*outputFunc)(outputStream, "/", 1);
    (*outputFunc)(outputStream, name->getCString(), name->getLength());
    (*outputFunc)(outputStream, " [\n", 3);
  } else {
    (*outputFunc)(outputStream, "/sfnts [\n", 9);
  }

  // write the table directory
  dumpString(tableDir, 12 + nNewTables*16, outputFunc, outputStream);

  // write the tables
  for (i = 0; i < nNewTables; ++i) {
    if (i == t42HeadTable) {
      dumpString(headData, 54, outputFunc, outputStream);
    } else if (i == t42LocaTable) {
      length = (nGlyphs + 1) * (locaFmt ? 4 : 2);
      dumpString(locaData, length, outputFunc, outputStream);
    } else if (i == t42GlyfTable) {
      glyfPos = tables[seekTable("glyf")].offset;
      for (j = 0; j < nGlyphs; ++j) {
	if (locaTable[j].len > 0 &&
	    checkRegion(glyfPos + locaTable[j].origOffset, locaTable[j].len)) {
	  dumpString(file + glyfPos + locaTable[j].origOffset,
		     locaTable[j].len, outputFunc, outputStream);
	}
      }
    } else {
      // length == 0 means the table is missing and the error was
      // already reported during the construction of the table
      // headers
      if ((length = newTables[i].len) > 0) {
	if ((j = seekTable(t42Tables[i].tag)) >= 0 &&
	    checkRegion(tables[j].offset, tables[j].len)) {
	  dumpString(file + tables[j].offset, tables[j].len,
		     outputFunc, outputStream);
	} else if (needVerticalMetrics && i == t42VheaTable) {
	  dumpString(vheaTab, length, outputFunc, outputStream);
	} else if (needVerticalMetrics && i == t42VmtxTable) {
	  dumpString(vmtxTab, length, outputFunc, outputStream);
	  gfree(vmtxTab);
	}
      }
    }
  }

  // end the sfnts array
  (*outputFunc)(outputStream, "] def\n", 6);

  gfree(locaData);
  gfree(locaTable);
}

void FoFiTrueType::dumpString(Guchar *s, int length,
			      FoFiOutputFunc outputFunc,
			      void *outputStream) {
  GString *buf;
  int pad, i, j;

  (*outputFunc)(outputStream, "<", 1);
  for (i = 0; i < length; i += 32) {
    for (j = 0; j < 32 && i+j < length; ++j) {
      buf = GString::format("{0:02x}", s[i+j] & 0xff);
      (*outputFunc)(outputStream, buf->getCString(), buf->getLength());
      delete buf;
    }
    if (i % (65536 - 32) == 65536 - 64) {
      (*outputFunc)(outputStream, ">\n<", 3);
    } else if (i+32 < length) {
      (*outputFunc)(outputStream, "\n", 1);
    }
  }
  if (length & 3) {
    pad = 4 - (length & 3);
    for (i = 0; i < pad; ++i) {
      (*outputFunc)(outputStream, "00", 2);
    }
  }
  // add an extra zero byte because the Adobe Type 42 spec says so
  (*outputFunc)(outputStream, "00>\n", 4);
}

Guint FoFiTrueType::computeTableChecksum(Guchar *data, int length) {
  Guint checksum, word;
  int i;

  checksum = 0;
  for (i = 0; i+3 < length; i += 4) {
    word = ((data[i  ] & 0xff) << 24) +
           ((data[i+1] & 0xff) << 16) +
           ((data[i+2] & 0xff) <<  8) +
            (data[i+3] & 0xff);
    checksum += word;
  }
  if (length & 3) {
    word = 0;
    i = length & ~3;
    switch (length & 3) {
    case 3:
      word |= (data[i+2] & 0xff) <<  8;
    case 2:
      word |= (data[i+1] & 0xff) << 16;
    case 1:
      word |= (data[i  ] & 0xff) << 24;
      break;
    }
    checksum += word;
  }
  return checksum;
}

void FoFiTrueType::parse() {
  Guint topTag;
  int pos, ver, i, j;

  parsedOk = gTrue;

  // look for a collection (TTC)
  topTag = getU32BE(0, &parsedOk);
  if (!parsedOk) {
    return;
  }
  if (topTag == ttcfTag) {
    pos = getU32BE(12, &parsedOk);
    if (!parsedOk) {
      return;
    }
  } else {
    pos = 0;
  }

  // check the sfnt version
  ver = getU32BE(pos, &parsedOk);
  if (!parsedOk) {
    return;
  }
  openTypeCFF = ver == 0x4f54544f; // 'OTTO'

  // read the table directory
  nTables = getU16BE(pos + 4, &parsedOk);
  if (!parsedOk) {
    return;
  }
  tables = (TrueTypeTable *)gmallocn(nTables, sizeof(TrueTypeTable));
  pos += 12;
  for (i = 0; i < nTables; ++i) {
    tables[i].tag = getU32BE(pos, &parsedOk);
    tables[i].checksum = getU32BE(pos + 4, &parsedOk);
    tables[i].offset = (int)getU32BE(pos + 8, &parsedOk);
    tables[i].len = (int)getU32BE(pos + 12, &parsedOk);
    if (tables[i].offset + tables[i].len < tables[i].offset ||
	tables[i].offset + tables[i].len > len) {
      parsedOk = gFalse;
    }
    pos += 16;
  }
  if (!parsedOk) {
    return;
  }

  // check for tables that are required by both the TrueType spec and
  // the Type 42 spec
  if (seekTable("head") < 0 ||
      seekTable("hhea") < 0 ||
      seekTable("maxp") < 0 ||
      seekTable("hmtx") < 0 ||
      (!openTypeCFF && seekTable("loca") < 0) ||
      (!openTypeCFF && seekTable("glyf") < 0) ||
      (openTypeCFF && seekTable("CFF ") < 0)) {
    parsedOk = gFalse;
    return;
  }

  // read the cmaps
  if ((i = seekTable("cmap")) >= 0) {
    pos = tables[i].offset + 2;
    nCmaps = getU16BE(pos, &parsedOk);
    pos += 2;
    if (!parsedOk) {
      return;
    }
    cmaps = (TrueTypeCmap *)gmallocn(nCmaps, sizeof(TrueTypeCmap));
    for (j = 0; j < nCmaps; ++j) {
      cmaps[j].platform = getU16BE(pos, &parsedOk);
      cmaps[j].encoding = getU16BE(pos + 2, &parsedOk);
      cmaps[j].offset = tables[i].offset + getU32BE(pos + 4, &parsedOk);
      pos += 8;
      cmaps[j].fmt = getU16BE(cmaps[j].offset, &parsedOk);
      cmaps[j].len = getU16BE(cmaps[j].offset + 2, &parsedOk);
    }
    if (!parsedOk) {
      return;
    }
  } else {
    nCmaps = 0;
  }

  // get the number of glyphs from the maxp table
  i = seekTable("maxp");
  nGlyphs = getU16BE(tables[i].offset + 4, &parsedOk);
  if (!parsedOk) {
    return;
  }

  // get the bbox and loca table format from the head table
  i = seekTable("head");
  bbox[0] = getS16BE(tables[i].offset + 36, &parsedOk);
  bbox[1] = getS16BE(tables[i].offset + 38, &parsedOk);
  bbox[2] = getS16BE(tables[i].offset + 40, &parsedOk);
  bbox[3] = getS16BE(tables[i].offset + 42, &parsedOk);
  locaFmt = getS16BE(tables[i].offset + 50, &parsedOk);
  if (!parsedOk) {
    return;
  }

  // make sure the loca table is sane (correct length and entries are
  // in bounds)
  if (!openTypeCFF) {
    i = seekTable("loca");
    if (tables[i].len < 0) {
      parsedOk = gFalse;
      return;
    }
    if (tables[i].len < (nGlyphs + 1) * (locaFmt ? 4 : 2)) {
      nGlyphs = tables[i].len / (locaFmt ? 4 : 2) - 1;
    }
    for (j = 0; j <= nGlyphs; ++j) {
      if (locaFmt) {
	pos = (int)getU32BE(tables[i].offset + j*4, &parsedOk);
      } else {
	pos = getU16BE(tables[i].offset + j*2, &parsedOk);
      }
      if (pos < 0 || pos > len) {
	parsedOk = gFalse;
      }
    }
    if (!parsedOk) {
      return;
    }
  }

  // read the post table
  readPostTable();
}

void FoFiTrueType::readPostTable() {
  GString *name;
  int tablePos, postFmt, stringIdx, stringPos;
  GBool ok;
  int i, j, n, m;

  ok = gTrue;
  if ((i = seekTable("post")) < 0) {
    return;
  }
  tablePos = tables[i].offset;
  postFmt = getU32BE(tablePos, &ok);
  if (!ok) {
    goto err;
  }
  if (postFmt == 0x00010000) {
    nameToGID = new GHash(gTrue);
    for (i = 0; i < 258; ++i) {
      nameToGID->add(new GString(macGlyphNames[i]), i);
    }
  } else if (postFmt == 0x00020000) {
    nameToGID = new GHash(gTrue);
    n = getU16BE(tablePos + 32, &ok);
    if (!ok) {
      goto err;
    }
    if (n > nGlyphs) {
      n = nGlyphs;
    }
    stringIdx = 0;
    stringPos = tablePos + 34 + 2*n;
    for (i = 0; i < n; ++i) {
      j = getU16BE(tablePos + 34 + 2*i, &ok);
      if (j < 258) {
	nameToGID->removeInt(macGlyphNames[j]);
	nameToGID->add(new GString(macGlyphNames[j]), i);
      } else {
	j -= 258;
	if (j != stringIdx) {
	  for (stringIdx = 0, stringPos = tablePos + 34 + 2*n;
	       stringIdx < j;
	       ++stringIdx, stringPos += 1 + getU8(stringPos, &ok)) ;
	  if (!ok) {
	    goto err;
	  }
	}
	m = getU8(stringPos, &ok);
	if (!ok || !checkRegion(stringPos + 1, m)) {
	  goto err;
	}
	name = new GString((char *)&file[stringPos + 1], m);
	nameToGID->removeInt(name);
	nameToGID->add(name, i);
	++stringIdx;
	stringPos += 1 + m;
      }
    }
  } else if (postFmt == 0x00028000) {
    nameToGID = new GHash(gTrue);
    for (i = 0; i < nGlyphs; ++i) {
      j = getU8(tablePos + 32 + i, &ok);
      if (!ok) {
	goto err;
      }
      if (j < 258) {
	nameToGID->removeInt(macGlyphNames[j]);
	nameToGID->add(new GString(macGlyphNames[j]), i);
      }
    }
  }

  return;

 err:
  if (nameToGID) {
    delete nameToGID;
    nameToGID = NULL;
  }
}

int FoFiTrueType::seekTable(char *tag) {
  Guint tagI;
  int i;

  tagI = ((tag[0] & 0xff) << 24) |
         ((tag[1] & 0xff) << 16) |
         ((tag[2] & 0xff) << 8) |
          (tag[3] & 0xff);
  for (i = 0; i < nTables; ++i) {
    if (tables[i].tag == tagI) {
      return i;
    }
  }
  return -1;
}