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Removes bytesToString/stringToArray conversions in the font.js

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This commit is contained in:
Yury Delendik 2014-08-09 18:18:41 -05:00
parent 5e1861499c
commit 350556f085
1 changed files with 189 additions and 195 deletions
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384
src/core/fonts.js
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@ -2202,20 +2202,20 @@ var IdentityToUnicodeMap = (function IdentityToUnicodeMapClosure() {
error('should not access .length');
},
forEach: function(callback) {
forEach: function (callback) {
for (var i = this.firstChar, ii = this.lastChar; i <= ii; i++) {
callback(i, i);
}
},
get: function(i) {
get: function (i) {
if (this.firstChar <= i && i <= this.lastChar) {
return String.fromCharCode(i);
}
return undefined;
},
charCodeOf: function(v) {
charCodeOf: function (v) {
error('should not call .charCodeOf');
}
};
@ -2223,6 +2223,157 @@ var IdentityToUnicodeMap = (function IdentityToUnicodeMapClosure() {
return IdentityToUnicodeMap;
})();
var OpenTypeFileBuilder = (function OpenTypeFileBuilderClosure() {
function getMaxPower2(number) {
var maxPower = 0;
var value = number;
while (value >= 2) {
value /= 2;
maxPower++;
}
value = 2;
for (var i = 1; i < maxPower; i++) {
value *= 2;
}
return value;
}
function writeInt16(dest, offset, num) {
dest[offset] = (num >> 8) & 0xFF;
dest[offset + 1] = num & 0xFF;
}
function writeInt32(dest, offset, num) {
dest[offset] = (num >> 24) & 0xFF;
dest[offset + 1] = (num >> 16) & 0xFF;
dest[offset + 2] = (num >> 8) & 0xFF;
dest[offset + 3] = num & 0xFF;
}
function writeData(dest, offset, data) {
var i, ii;
if (data instanceof Uint8Array) {
dest.set(data, offset);
} else if (typeof data === 'string') {
for (i = 0, ii = data.length; i < ii; i++) {
dest[offset++] = data.charCodeAt(i) & 0xFF;
}
} else {
// treating everything else as array
for (i = 0, ii = data.length; i < ii; i++) {
dest[offset++] = data[i] & 0xFF;
}
}
}
function OpenTypeFileBuilder(sfnt) {
this.sfnt = sfnt;
this.tables = Object.create(null);
}
OpenTypeFileBuilder.getSearchParams =
function OpenTypeFileBuilder_getSearchParams(entriesCount, entrySize) {
var searchRange = getMaxPower2(entriesCount) * entrySize;
return {
range: searchRange,
entry: (Math.log(entriesCount) / Math.log(2)) | 0,
rangeShift: entrySize * entriesCount - searchRange
};
};
var OTF_HEADER_SIZE = 12;
var OTF_TABLE_ENTRY_SIZE = 16;
OpenTypeFileBuilder.prototype = {
toArray: function OpenTypeFileBuilder_toArray() {
var sfnt = this.sfnt;
// Tables needs to be written by ascendant alphabetic order
var tables = this.tables;
var tablesNames = Object.keys(tables);
tablesNames.sort();
var numTables = tablesNames.length;
var i, j, jj, table, tableName;
// layout the tables data
var offset = OTF_HEADER_SIZE + numTables * OTF_TABLE_ENTRY_SIZE;
var tableOffsets = [offset];
for (i = 0; i < numTables; i++) {
table = tables[tablesNames[i]];
var paddedLength = ((table.length + 3) & ~3) >>> 0;
offset += paddedLength;
tableOffsets.push(offset);
}
var file = new Uint8Array(offset);
// write the table data first (mostly for checksum)
for (i = 0; i < numTables; i++) {
table = tables[tablesNames[i]];
writeData(file, tableOffsets[i], table);
}
// sfnt version (4 bytes)
if (sfnt === 'true') {
// Windows hates the Mac TrueType sfnt version number
sfnt = string32(0x00010000);
}
file[0] = sfnt.charCodeAt(0) & 0xFF;
file[1] = sfnt.charCodeAt(1) & 0xFF;
file[2] = sfnt.charCodeAt(2) & 0xFF;
file[3] = sfnt.charCodeAt(3) & 0xFF;
// numTables (2 bytes)
writeInt16(file, 4, numTables);
var searchParams = OpenTypeFileBuilder.getSearchParams(numTables, 16);
// searchRange (2 bytes)
writeInt16(file, 6, searchParams.range);
// entrySelector (2 bytes)
writeInt16(file, 8, searchParams.entry);
// rangeShift (2 bytes)
writeInt16(file, 10, searchParams.rangeShift);
offset = OTF_HEADER_SIZE;
// writing table entries
for (i = 0; i < numTables; i++) {
tableName = tablesNames[i];
file[offset] = tableName.charCodeAt(0) & 0xFF;
file[offset + 1] = tableName.charCodeAt(1) & 0xFF;
file[offset + 2] = tableName.charCodeAt(2) & 0xFF;
file[offset + 3] = tableName.charCodeAt(3) & 0xFF;
// checksum
var checksum = 0;
for (j = tableOffsets[i], jj = tableOffsets[i + 1]; j < jj; j += 4) {
var quad = (file[j] << 24) + (file[j + 1] << 16) +
(file[j + 2] << 8) + file[j + 3];
checksum = (checksum + quad) | 0;
}
writeInt32(file, offset + 4, checksum);
// offset
writeInt32(file, offset + 8, tableOffsets[i]);
// length
writeInt32(file, offset + 12, tables[tableName].length);
offset += OTF_TABLE_ENTRY_SIZE;
}
return file;
},
addTable: function OpenTypeFileBuilder_addTable(tag, data) {
if (tag in this.tables) {
throw new Error('Table ' + tag + ' already exists');
}
this.tables[tag] = data;
}
};
return OpenTypeFileBuilder;
})();
/**
* 'Font' is the class the outside world should use, it encapsulate all the font
* decoding logics whatever type it is (assuming the font type is supported).
@ -2432,21 +2583,6 @@ var Font = (function FontClosure() {
return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
}
function getMaxPower2(number) {
var maxPower = 0;
var value = number;
while (value >= 2) {
value /= 2;
maxPower++;
}
value = 2;
for (var i = 1; i < maxPower; i++) {
value *= 2;
}
return value;
}
function string16(value) {
return String.fromCharCode((value >> 8) & 0xff, value & 0xff);
}
@ -2457,89 +2593,6 @@ var Font = (function FontClosure() {
return String.fromCharCode((value >> 8) & 0xff, value & 0xff);
}
function createOpenTypeHeader(sfnt, file, numTables) {
// Windows hates the Mac TrueType sfnt version number
if (sfnt === 'true') {
sfnt = string32(0x00010000);
}
// sfnt version (4 bytes)
var header = sfnt;
// numTables (2 bytes)
header += string16(numTables);
// searchRange (2 bytes)
var tablesMaxPower2 = getMaxPower2(numTables);
var searchRange = tablesMaxPower2 * 16;
header += string16(searchRange);
// entrySelector (2 bytes)
header += string16(Math.log(tablesMaxPower2) / Math.log(2));
// rangeShift (2 bytes)
header += string16(numTables * 16 - searchRange);
file.file += header;
file.virtualOffset += header.length;
}
function createTableEntry(file, tag, data) {
// offset
var offset = file.virtualOffset;
// length
var length = data.length;
// Per spec tables must be 4-bytes align so add padding as needed.
var paddedLength = length;
while (paddedLength & 3) {
paddedLength++;
}
var i;
var padding = paddedLength - length;
if (padding !== 0) {
// Padding is required. |data| can be an Array, Uint8Array, or
// Uint16Array. In the latter two cases we need to create slightly larger
// typed arrays and copy the old contents in. Fortunately that's not a
// common case.
var data2;
if (data instanceof Array) {
for (i = 0; i < padding; i++) {
data.push(0);
}
} else if (data instanceof Uint8Array) {
data2 = new Uint8Array(paddedLength);
data2.set(data);
data = data2;
} else if (data instanceof Uint16Array) {
data2 = new Uint16Array(paddedLength);
data2.set(data);
data = data2;
} else {
error('bad array kind in createTableEntry');
}
}
while (file.virtualOffset & 3) {
file.virtualOffset++;
}
// checksum
var checksum = 0, n = data.length;
for (i = 0; i < n; i += 4) {
checksum = (checksum + int32(data[i], data[i + 1], data[i + 2],
data[i + 3])) | 0;
}
var tableEntry = (tag + string32(checksum) +
string32(offset) + string32(length));
file.file += tableEntry;
file.virtualOffset += data.length;
return data;
}
function isTrueTypeFile(file) {
var header = file.peekBytes(4);
return readUint32(header, 0) === 0x00010000;
@ -2676,10 +2729,7 @@ var Font = (function FontClosure() {
}
var trailingRangesCount = ranges[i][1] < 0xFFFF ? 1 : 0;
var segCount = bmpLength + trailingRangesCount;
var segCount2 = segCount * 2;
var searchRange = getMaxPower2(segCount) * 2;
var searchEntry = Math.log(segCount) / Math.log(2);
var rangeShift = 2 * segCount - searchRange;
var searchParams = OpenTypeFileBuilder.getSearchParams(segCount, 2);
// Fill up the 4 parallel arrays describing the segments.
var startCount = '';
@ -2730,10 +2780,10 @@ var Font = (function FontClosure() {
}
var format314 = '\x00\x00' + // language
string16(segCount2) +
string16(searchRange) +
string16(searchEntry) +
string16(rangeShift) +
string16(2 * segCount) +
string16(searchParams.range) +
string16(searchParams.entry) +
string16(searchParams.rangeShift) +
endCount + '\x00\x00' + startCount +
idDeltas + idRangeOffsets + glyphsIds;
@ -3854,7 +3904,7 @@ var Font = (function FontClosure() {
var tables = { 'OS/2': null, cmap: null, head: null, hhea: null,
hmtx: null, maxp: null, name: null, post: null };
var table, tableData;
var table;
for (var i = 0; i < numTables; i++) {
table = readTableEntry(font);
if (VALID_TABLES.indexOf(table.tag) < 0) {
@ -3928,24 +3978,6 @@ var Font = (function FontClosure() {
delete tables['cvt '];
}
// Tables needs to be written by ascendant alphabetic order
var tablesNames = Object.keys(tables);
tablesNames.sort();
numTables = tablesNames.length;
// header and new offsets. Table entry information is appended to the
// end of file. The virtualOffset represents where to put the actual
// data of a particular table;
var ttf = {
file: '',
virtualOffset: numTables * (4 * 4)
};
// The new numbers of tables will be the last one plus the num
// of missing tables
createOpenTypeHeader(header.version, ttf, numTables);
// Ensure the hmtx table contains the advance width and
// sidebearings information for numGlyphs in the maxp table
sanitizeMetrics(font, tables.hhea, tables.hmtx, numGlyphs);
@ -4147,39 +4179,14 @@ var Font = (function FontClosure() {
tables.name.data = stringToArray(createNameTable(name, namePrototype));
}
// rewrite the tables but tweak offsets
for (i = 0; i < numTables; i++) {
table = tables[tablesNames[i]];
table.data = createTableEntry(ttf, table.tag, table.data);
var builder = new OpenTypeFileBuilder(header.version);
for (var tableTag in tables) {
builder.addTable(tableTag, tables[tableTag].data);
}
// Add the table datas
for (i = 0; i < numTables; i++) {
table = tables[tablesNames[i]];
tableData = table.data;
ttf.file += bytesToString(new Uint8Array(tableData));
// 4-byte aligned data
while (ttf.file.length & 3) {
ttf.file += String.fromCharCode(0);
}
}
return stringToArray(ttf.file);
return builder.toArray();
},
convert: function Font_convert(fontName, font, properties) {
// The offsets object holds at the same time a representation of where
// to write the table entry information about a table and another offset
// representing the offset where to draw the actual data of a particular
// table
var otf = {
file: '',
virtualOffset: 9 * (4 * 4)
};
createOpenTypeHeader('\x4F\x54\x54\x4F', otf, 9);
// TODO: Check the charstring widths to determine this.
properties.fixedPitch = false;
@ -4259,19 +4266,16 @@ var Font = (function FontClosure() {
var unitsPerEm = 1 / (properties.fontMatrix || FONT_IDENTITY_MATRIX)[0];
var fields = {
// PostScript Font Program
'CFF ': font.data,
// OS/2 and Windows Specific metrics
'OS/2': stringToArray(createOS2Table(properties,
newMapping.charCodeToGlyphId)),
// Character to glyphs mapping
'cmap': createCmapTable(newMapping.charCodeToGlyphId),
// Font header
'head': (function fontFieldsHead() {
var builder = new OpenTypeFileBuilder('\x4F\x54\x54\x4F');
// PostScript Font Program
builder.addTable('CFF ', font.data);
// OS/2 and Windows Specific metrics
builder.addTable('OS/2', stringToArray(createOS2Table(properties,
newMapping.charCodeToGlyphId)));
// Character to glyphs mapping
builder.addTable('cmap', createCmapTable(newMapping.charCodeToGlyphId));
// Font header
builder.addTable('head', (function fontFieldsHead() {
return stringToArray(
'\x00\x01\x00\x00' + // Version number
'\x00\x00\x10\x00' + // fontRevision
@ -4290,10 +4294,10 @@ var Font = (function FontClosure() {
'\x00\x00' + // fontDirectionHint
'\x00\x00' + // indexToLocFormat
'\x00\x00'); // glyphDataFormat
})(),
})());
// Horizontal header
'hhea': (function fontFieldsHhea() {
// Horizontal header
builder.addTable('hhea', (function fontFieldsHhea() {
return stringToArray(
'\x00\x01\x00\x00' + // Version number
safeString16(properties.ascent) + // Typographic Ascent
@ -4313,10 +4317,10 @@ var Font = (function FontClosure() {
'\x00\x00' + // -reserved-
'\x00\x00' + // metricDataFormat
string16(numGlyphs)); // Number of HMetrics
})(),
})());
// Horizontal metrics
'hmtx': (function fontFieldsHmtx() {
// Horizontal metrics
builder.addTable('hmtx', (function fontFieldsHmtx() {
var charstrings = font.charstrings;
var hmtx = '\x00\x00\x00\x00'; // Fake .notdef
for (var i = 1, ii = numGlyphs; i < ii; i++) {
@ -4327,32 +4331,22 @@ var Font = (function FontClosure() {
hmtx += string16(width) + string16(0);
}
return stringToArray(hmtx);
})(),
})());
// Maximum profile
'maxp': (function fontFieldsMaxp() {
// Maximum profile
builder.addTable('maxp', (function fontFieldsMaxp() {
return stringToArray(
'\x00\x00\x50\x00' + // Version number
string16(numGlyphs)); // Num of glyphs
})(),
})());
// Naming tables
'name': stringToArray(createNameTable(fontName)),
// Naming tables
builder.addTable('name', stringToArray(createNameTable(fontName)));
// PostScript informations
'post': stringToArray(createPostTable(properties))
};
// PostScript informations
builder.addTable('post', stringToArray(createPostTable(properties)));
var field;
for (field in fields) {
fields[field] = createTableEntry(otf, field, fields[field]);
}
for (field in fields) {
var table = fields[field];
otf.file += bytesToString(new Uint8Array(table));
}
return stringToArray(otf.file);
return builder.toArray();
},
/**