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Clean up Fonts.convert()

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This commit is contained in:
Vivien Nicolas 2011-07-03 01:17:28 +02:00
parent b390a03a1d
commit f58983f4e5
1 changed files with 63 additions and 81 deletions
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144
fonts.js
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@ -944,8 +944,6 @@ var Font = (function () {
}, },
convert: function font_convert(fontName, font, properties) { convert: function font_convert(fontName, font, properties) {
var otf = new Uint8Array(kMaxFontFileSize);
function createNameTable(name) { function createNameTable(name) {
// All the strings of the name table should be an odd number of bytes // All the strings of the name table should be an odd number of bytes
if (name.length % 2) if (name.length % 2)
@ -1008,7 +1006,7 @@ var Font = (function () {
nameTable += strings.join("") + stringsUnicode.join(""); nameTable += strings.join("") + stringsUnicode.join("");
return nameTable; return nameTable;
} }
function isFixedPitch(glyphs) { function isFixedPitch(glyphs) {
for (var i = 0; i < glyphs.length - 1; i++) { for (var i = 0; i < glyphs.length - 1; i++) {
if (glyphs[i] != glyphs[i+1]) if (glyphs[i] != glyphs[i+1])
@ -1017,46 +1015,34 @@ var Font = (function () {
return true; return true;
}; };
// Required Tables
var CFF =
font.data, // PostScript Font Program
OS2, // OS/2 and Windows Specific metrics
cmap, // Character to glyphs mapping
head, // Font header
hhea, // Horizontal header
hmtx, // Horizontal metrics
maxp, // Maximum profile
name, // Naming tables
post; // PostScript informations
var tables = [CFF, OS2, cmap, head, hhea, hmtx, maxp, name, post];
// The offsets object holds at the same time a representation of where // The offsets object holds at the same time a representation of where
// to write the table entry information about a table and another offset // to write the table entry information about a table and another offset
// representing the offset where to draw the actual data of a particular // representing the offset where to draw the actual data of a particular
// table // table
var kRequiredTablesCount = 9;
var offsets = { var offsets = {
currentOffset: 0, currentOffset: 0,
virtualOffset: tables.length * (4 * 4) virtualOffset: 9 * (4 * 4)
}; };
// It there is only one font, offset table is the first bytes of the file var otf = new Uint8Array(kMaxFontFileSize);
createOpenTypeHeader("\x4F\x54\x54\x4F", otf, offsets, tables.length); createOpenTypeHeader("\x4F\x54\x54\x4F", otf, offsets, 9);
/** CFF */
createTableEntry(otf, offsets, "CFF ", CFF);
/** OS/2 */
var charstrings = font.charstrings; var charstrings = font.charstrings;
properties.fixedPitch = isFixedPitch(charstrings); properties.fixedPitch = isFixedPitch(charstrings);
OS2 = stringToArray(createOS2Table(properties)); var fields = {
createTableEntry(otf, offsets, "OS/2", OS2); // PostScript Font Program
"CFF ": font.data,
/** CMAP */ // OS/2 and Windows Specific metrics
cmap = createCMapTable(charstrings.slice()); "OS/2": stringToArray(createOS2Table(properties)),
createTableEntry(otf, offsets, "cmap", cmap);
/** HEAD */ // Character to glyphs mapping
head = stringToArray( "cmap": createCMapTable(charstrings.slice()),
// Font header
"head": (function() {
return stringToArray(
"\x00\x01\x00\x00" + // Version number "\x00\x01\x00\x00" + // Version number
"\x00\x00\x10\x00" + // fontRevision "\x00\x00\x10\x00" + // fontRevision
"\x00\x00\x00\x00" + // checksumAdjustement "\x00\x00\x00\x00" + // checksumAdjustement
@ -1073,63 +1059,59 @@ var Font = (function () {
"\x00\x11" + // lowestRecPPEM "\x00\x11" + // lowestRecPPEM
"\x00\x00" + // fontDirectionHint "\x00\x00" + // fontDirectionHint
"\x00\x00" + // indexToLocFormat "\x00\x00" + // indexToLocFormat
"\x00\x00" // glyphDataFormat "\x00\x00"); // glyphDataFormat
); })(),
createTableEntry(otf, offsets, "head", head);
/** HHEA */ // Horizontal header
hhea = stringToArray( "hhea": (function() {
"\x00\x01\x00\x00" + // Version number return stringToArray(
string16(properties.ascent) + // Typographic Ascent "\x00\x01\x00\x00" + // Version number
string16(properties.descent) + // Typographic Descent string16(properties.ascent) + // Typographic Ascent
"\x00\x00" + // Line Gap string16(properties.descent) + // Typographic Descent
"\xFF\xFF" + // advanceWidthMax "\x00\x00" + // Line Gap
"\x00\x00" + // minLeftSidebearing "\xFF\xFF" + // advanceWidthMax
"\x00\x00" + // minRightSidebearing "\x00\x00" + // minLeftSidebearing
"\x00\x00" + // xMaxExtent "\x00\x00" + // minRightSidebearing
string16(properties.capHeight) + // caretSlopeRise "\x00\x00" + // xMaxExtent
string16(Math.tan(properties.italicAngle) * properties.xHeight) + // caretSlopeRun string16(properties.capHeight) + // caretSlopeRise
"\x00\x00" + // caretOffset string16(Math.tan(properties.italicAngle) * properties.xHeight) + // caretSlopeRun
"\x00\x00" + // -reserved- "\x00\x00" + // caretOffset
"\x00\x00" + // -reserved- "\x00\x00" + // -reserved-
"\x00\x00" + // -reserved- "\x00\x00" + // -reserved-
"\x00\x00" + // -reserved- "\x00\x00" + // -reserved-
"\x00\x00" + // metricDataFormat "\x00\x00" + // -reserved-
string16(charstrings.length + 1) // Number of HMetrics "\x00\x00" + // metricDataFormat
); string16(charstrings.length + 1)); // Number of HMetrics
createTableEntry(otf, offsets, "hhea", hhea); })(),
/** HMTX */ // Horizontal metrics
/* For some reasons, probably related to how the backend handle fonts, "hmtx": (function() {
* Linux seems to ignore this file and prefer the data from the CFF itself var hmtx = "\x00\x00\x00\x00"; // Fake .notdef
* while Windows use this data. So be careful if you hack on Linux and for (var i = 0; i < charstrings.length; i++) {
* have to touch the 'hmtx' table hmtx += string16(charstrings[i].width) + string16(0);
*/ }
hmtx = "\x00\x00\x00\x00"; // Fake .notdef return stringToArray(hmtx);
for (var i = 0; i < charstrings.length; i++) { })(),
hmtx += string16(charstrings[i].width) + string16(0);
}
hmtx = stringToArray(hmtx);
createTableEntry(otf, offsets, "hmtx", hmtx);
/** MAXP */ // Maximum profile
maxp = "\x00\x00\x50\x00" + // Version number "maxp": (function() {
string16(charstrings.length + 1); // Num of glyphs return stringToArray(
maxp = stringToArray(maxp); "\x00\x00\x50\x00" + // Version number
createTableEntry(otf, offsets, "maxp", maxp); string16(charstrings.length + 1)); // Num of glyphs
})(),
/** NAME */ // Naming tables
name = stringToArray(createNameTable(fontName)); "name": stringToArray(createNameTable(fontName)),
createTableEntry(otf, offsets, "name", name);
/** POST */ // PostScript informations
post = stringToArray(createPostTable(properties)); "post": stringToArray(createPostTable(properties))
createTableEntry(otf, offsets, "post", post); };
// Once all the table entries header are written, dump the data! for (var field in fields)
var tables = [CFF, OS2, cmap, head, hhea, hmtx, maxp, name, post]; createTableEntry(otf, offsets, field, fields[field]);
for (var i = 0; i < tables.length; i++) {
var table = tables[i]; for (var field in fields) {
var table = fields[field];
otf.set(table, offsets.currentOffset); otf.set(table, offsets.currentOffset);
offsets.currentOffset += table.length; offsets.currentOffset += table.length;
} }