Add a basic support for TrueType (generate fonts with OS/2 table)
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Vivien Nicolas
parent
c8c4326ca8
commit
1dcd42b66c
233
PDFFont.js
233
PDFFont.js
@ -581,11 +581,213 @@ var FontsUtils = {
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*/
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var TrueType = function(aFile) {
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var header = this._readOpenTypeHeader(aFile);
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this.data = aFile;
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var numTables = header.numTables;
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// Check that required tables are present
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var requiredTables = [
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"OS/2",
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"cmap",
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"head",
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"hhea",
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"hmtx",
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"maxp",
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"name",
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"post"
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];
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var tables = [];
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for (var i = 0; i < numTables; i++) {
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var table = this._readTableEntry(aFile);
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var index = requiredTables.indexOf(table.tag);
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if (index != -1)
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requiredTables.splice(index, 1);
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tables.push(table);
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}
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tables.sort(function(a, b) {
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return a.tag > b.tag;
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});
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// If any tables are still in the array this means some required tables are
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// missing, which means that we need to rebuild the font in order to pass
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// the sanitizer.
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if (requiredTables.length && requiredTables[0] == "OS/2") {
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OS2 = [
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0x00, 0x03, // version
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0x02, 0x24, // xAvgCharWidth
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0x01, 0xF4, // usWeightClass
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0x00, 0x05, // usWidthClass
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0x00, 0x00, // fstype
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0x02, 0x8A, // ySubscriptXSize
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0x02, 0xBB, // ySubscriptYSize
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0x00, 0x00, // ySubscriptXOffset
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0x00, 0x8C, // ySubscriptYOffset
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0x02, 0x8A, // ySuperScriptXSize
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0x02, 0xBB, // ySuperScriptYSize
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0x00, 0x00, // ySuperScriptXOffset
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0x01, 0xDF, // ySuperScriptYOffset
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0x00, 0x31, // yStrikeOutSize
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0x01, 0x02, // yStrikeOutPosition
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0x00, 0x00, // sFamilyClass
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0x02, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Panose
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0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 0-31)
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0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 32-63)
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0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 64-95)
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0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 96-127)
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0x2A, 0x32, 0x31, 0x2A, // achVendID
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0x00, 0x20, // fsSelection
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0x00, 0x2D, // usFirstCharIndex
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0x00, 0x7A, // usLastCharIndex
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0x00, 0x03, // sTypoAscender
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0x00, 0x20, // sTypeDescender
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0x00, 0x38, // sTypoLineGap
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0x00, 0x5A, // usWinAscent
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0x02, 0xB4, // usWinDescent
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0x00, 0xCE, 0x00, 0x00, // ulCodePageRange1 (Bits 0-31)
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0x00, 0x01, 0x00, 0x00, // ulCodePageRange2 (Bits 32-63)
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0x00, 0x00, // sxHeight
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0x00, 0x00, // sCapHeight
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0x00, 0x01, // usDefaultChar
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0x00, 0xCD, // usBreakChar
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0x00, 0x02 // usMaxContext
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];
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// Create a new file to hold the new version of our truetype with a new
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// header and new offsets
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var stream = aFile.stream || aFile;
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var ttf = new Uint8Array(stream.length + 16 + OS2.length);
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// The new numbers of tables will be the last one plus the num of missing
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// tables
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var numTables = header.numTables + 1;
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// The offsets object holds at the same time a representation of where
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// to write the table entry information about a table and another offset
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// representing the offset where to draw the actual data of a particular
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// table
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var offsets = {
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currentOffset: 0,
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virtualOffset: numTables * (4 * 4)
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};
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// Write the sfnt header with one more table
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this._createOpenTypeHeader(ttf, offsets, numTables);
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// Insert the missing table
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tables.unshift({
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tag: "OS/2",
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data: OS2
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});
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// rewrite the tables but tweak offsets
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for (var i = 0; i < tables.length; i++) {
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var table = tables[i];
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var data = [];
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var tableData = table.data;
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for (var j = 0; j < tableData.length; j++)
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data.push(tableData[j]);
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this._createTableEntry(ttf, offsets, table.tag, data);
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}
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// Add the table datas
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for (var i = 0; i < tables.length; i++) {
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var table = tables[i];
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var tableData = table.data;
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ttf.set(tableData, offsets.currentOffset);
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offsets.currentOffset += tableData.length;
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if (0) {
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var data = [];
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for (var j = 0; j < tableData.length; j++)
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d.push(tableData[j]);
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log("data for table: " + table.tag + ": " + data);
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}
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// 4-byte aligned data
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while (offsets.currentOffset & 3)
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offsets.currentOffset++;
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}
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var fontData = [];
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for (var i = 0; i < ttf.length; i++)
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fontData.push(ttf[i]);
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this.data = ttf;
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//writeToFile(fontData, "/tmp/pdf.js." + fontCount + ".ttf");
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return;
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} else if (requiredTables.lenght) {
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error("Table " + requiredTables[0] + " is missing from the TruType font");
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} else {
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this.data = aFile;
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}
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};
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TrueType.prototype = {
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_readOpenTypeHeader: function(aFile) {
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_createOpenTypeHeader: function tt_createOpenTypeHeader(aFile, aOffsets, aNumTables) {
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// sfnt version (4 bytes)
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// XXX if we want to merge this function and the one from the Font class
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// XXX this need to be adapted
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var version = [0x00, 0x01, 0x00, 0X00];
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// numTables (2 bytes)
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var numTables = aNumTables;
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// searchRange (2 bytes)
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var tablesMaxPower2 = FontsUtils.getMaxPower2(numTables);
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var searchRange = tablesMaxPower2 * 16;
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// entrySelector (2 bytes)
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var entrySelector = Math.log(tablesMaxPower2) / Math.log(2);
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// rangeShift (2 bytes)
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var rangeShift = numTables * 16 - searchRange;
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var header = [].concat(version,
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FontsUtils.integerToBytes(numTables, 2),
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FontsUtils.integerToBytes(searchRange, 2),
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FontsUtils.integerToBytes(entrySelector, 2),
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FontsUtils.integerToBytes(rangeShift, 2));
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aFile.set(header, aOffsets.currentOffset);
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aOffsets.currentOffset += header.length;
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aOffsets.virtualOffset += header.length;
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},
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_createTableEntry: function font_createTableEntry(aFile, aOffsets, aTag, aData) {
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// tag
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var tag = [
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aTag.charCodeAt(0),
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aTag.charCodeAt(1),
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aTag.charCodeAt(2),
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aTag.charCodeAt(3)
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];
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// Per spec tables must be 4-bytes align so add some 0x00 if needed
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while (aData.length & 3)
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aData.push(0x00);
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while (aOffsets.virtualOffset & 3)
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aOffsets.virtualOffset++;
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// offset
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var offset = aOffsets.virtualOffset;
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// length
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var length = aData.length;
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// checksum
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var checksum = FontsUtils.bytesToInteger(tag) + offset + length;
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var tableEntry = [].concat(tag,
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FontsUtils.integerToBytes(checksum, 4),
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FontsUtils.integerToBytes(offset, 4),
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FontsUtils.integerToBytes(length, 4));
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aFile.set(tableEntry, aOffsets.currentOffset);
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aOffsets.currentOffset += tableEntry.length;
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aOffsets.virtualOffset += aData.length;
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},
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_readOpenTypeHeader: function tt_readOpenTypeHeader(aFile) {
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return {
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version: aFile.getBytes(4),
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numTables: FontsUtils.bytesToInteger(aFile.getBytes(2)),
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@ -593,6 +795,33 @@ TrueType.prototype = {
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entrySelector: FontsUtils.bytesToInteger(aFile.getBytes(2)),
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rangeShift: FontsUtils.bytesToInteger(aFile.getBytes(2))
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}
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},
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_readTableEntry: function tt_readTableEntry(aFile) {
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// tag
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var tag = aFile.getBytes(4);
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tag = String.fromCharCode(tag[0]) +
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String.fromCharCode(tag[1]) +
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String.fromCharCode(tag[2]) +
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String.fromCharCode(tag[3]);
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var checksum = FontsUtils.bytesToInteger(aFile.getBytes(4));
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var offset = FontsUtils.bytesToInteger(aFile.getBytes(4));
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var length = FontsUtils.bytesToInteger(aFile.getBytes(4));
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// Read the table associated data
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var currentPosition = aFile.pos;
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aFile.pos = aFile.start + offset;
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var data = aFile.getBytes(length);
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aFile.pos = currentPosition;
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return {
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tag: tag,
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checksum: checksum,
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length: offset,
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offset: length,
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data: data
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}
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}
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};
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18
pdf.js
18
pdf.js
@ -52,7 +52,7 @@ var Stream = (function() {
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this.bytes = new Uint8Array(arrayBuffer);
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this.start = start || 0;
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this.pos = this.start;
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this.end = (start + length) || arrayBuffer.byteLength;
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this.end = (start + length) || this.bytes.byteLength;
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this.dict = dict;
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}
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@ -1411,11 +1411,13 @@ var Page = (function() {
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var resources = xref.fetchIfRef(this.resources);
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var fontsDict = new Dict();
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// Get the fonts use on the page
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// Get the fonts use on the page if any
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var fontResources = resources.get("Font");
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fontResources.forEach(function(fontKey, fontData) {
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fontsDict.set(fontKey, xref.fetch(fontData))
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});
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if (IsDict(fontResources)) {
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fontResources.forEach(function(fontKey, fontData) {
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fontsDict.set(fontKey, xref.fetch(fontData))
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});
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}
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// Get the fonts use on xobjects of the page if any
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var xobjs = xref.fetchIfRef(resources.get("XObject"));
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@ -1864,7 +1866,11 @@ var CanvasGraphics = (function() {
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this.current.leading = leading;
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},
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setFont: function(fontRef, size) {
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var font = this.res.get("Font").get(fontRef.name);
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var font = this.res.get("Font");
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if (!IsDict(font))
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return;
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font = font.get(fontRef.name);
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font = this.xref.fetchIfRef(font);
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if (!font)
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return;
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4
test.js
4
test.js
@ -85,7 +85,9 @@ function displayPage(num) {
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// Check if the font has been loaded or is still loading
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var font = Fonts[fontName];
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if (!font) {
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var fontFile = xref.fetchIfRef(descriptor.get2("FontFile", "FontFile2"));
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var fontFile = descriptor.get2("FontFile", "FontFile2");
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fontFile = xref.fetchIfRef(fontFile);
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// Generate the custom cmap of the font if needed
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var encodingMap = {};
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if (fontDict.has("Encoding")) {
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