make createOpenTypeHeader and createTableEntry inner functions
This commit is contained in:
Andreas Gal
parent
75ad5aa016
commit
458625d656
135
fonts.js
135
fonts.js
@ -138,6 +138,63 @@ var Font = (function () {
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this.bind();
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};
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function createOpenTypeHeader(aFile, aOffsets, aNumTables) {
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// sfnt version (4 bytes)
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var version = [0x4F, 0x54, 0x54, 0X4F];
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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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function 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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// offset
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var offset = aOffsets.virtualOffset;
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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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// 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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/**
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* A bunch of the OpenType code is duplicate between this class and the
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@ -242,64 +299,6 @@ var Font = (function () {
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styleSheet.insertRule(rule, styleSheet.length);
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},
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_createOpenTypeHeader: function font_createOpenTypeHeader(aFile, aOffsets, aNumTables) {
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// sfnt version (4 bytes)
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var version = [0x4F, 0x54, 0x54, 0X4F];
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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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// offset
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var offset = aOffsets.virtualOffset;
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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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// 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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_createCMAPTable: function font_createCMAPTable(aGlyphs) {
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var characters = new Uint16Array(kMaxGlyphsCount);
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for (var i = 0; i < aGlyphs.length; i++)
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@ -408,12 +407,12 @@ var Font = (function () {
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// For files with only one font the offset table is the first thing of the
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// file
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this._createOpenTypeHeader(otf, offsets, tables.length);
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createOpenTypeHeader(otf, offsets, tables.length);
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// XXX It is probable that in a future we want to get rid of this glue
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// between the CFF and the OTF format in order to be able to embed TrueType
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// data.
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this._createTableEntry(otf, offsets, "CFF ", CFF);
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createTableEntry(otf, offsets, "CFF ", CFF);
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/** OS/2 */
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OS2 = [
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@ -455,14 +454,14 @@ var Font = (function () {
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0x00, 0xCD, // usBreakChar
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0x00, 0x02 // usMaxContext
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];
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this._createTableEntry(otf, offsets, "OS/2", OS2);
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createTableEntry(otf, offsets, "OS/2", OS2);
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//XXX Getting charstrings here seems wrong since this is another CFF glue
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var charstrings = aFont.getOrderedCharStrings(aProperties.glyphs);
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/** CMAP */
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cmap = this._createCMAPTable(charstrings);
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this._createTableEntry(otf, offsets, "cmap", cmap);
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createTableEntry(otf, offsets, "cmap", cmap);
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/** HEAD */
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head = [
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@ -484,7 +483,7 @@ var Font = (function () {
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0x00, 0x00, // indexToLocFormat
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0x00, 0x00 // glyphDataFormat
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];
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this._createTableEntry(otf, offsets, "head", head);
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createTableEntry(otf, offsets, "head", head);
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/** HHEA */
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hhea = [].concat(
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@ -508,7 +507,7 @@ var Font = (function () {
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],
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FontsUtils.integerToBytes(charstrings.length, 2) // numberOfHMetrics
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);
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this._createTableEntry(otf, offsets, "hhea", hhea);
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createTableEntry(otf, offsets, "hhea", hhea);
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/** HMTX */
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hmtx = [0x01, 0xF4, 0x00, 0x00];
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@ -518,7 +517,7 @@ var Font = (function () {
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var lsb = FontsUtils.integerToBytes(charstring[0], 2);
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hmtx = hmtx.concat(width, lsb);
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}
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this._createTableEntry(otf, offsets, "hmtx", hmtx);
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createTableEntry(otf, offsets, "hmtx", hmtx);
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/** MAXP */
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maxp = [].concat(
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@ -527,7 +526,7 @@ var Font = (function () {
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],
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FontsUtils.integerToBytes(charstrings.length + 1, 2) // Num of glyphs (+1 to pass the sanitizer...)
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);
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this._createTableEntry(otf, offsets, "maxp", maxp);
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createTableEntry(otf, offsets, "maxp", maxp);
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/** NAME */
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name = [
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@ -535,7 +534,7 @@ var Font = (function () {
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0x00, 0x00, // Number of names Record
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0x00, 0x00 // Storage
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];
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this._createTableEntry(otf, offsets, "name", name);
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createTableEntry(otf, offsets, "name", name);
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/** POST */
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// FIXME Get those informations from the FontInfo structure
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@ -550,7 +549,7 @@ var Font = (function () {
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0x00, 0x00, 0x00, 0x00, // minMemType1
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0x00, 0x00, 0x00, 0x00 // maxMemType1
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];
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this._createTableEntry(otf, offsets, "post", post);
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createTableEntry(otf, offsets, "post", post);
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// Once all the table entries header are written, dump the data!
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var tables = [CFF, OS2, cmap, head, hhea, hmtx, maxp, name, post];
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