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Calculate the checksumAdjustement for the file

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Vivien Nicolas 2011-07-04 06:07:49 +02:00
parent 1037fdf2ad
commit 9b1d6a5e25
1 changed files with 17 additions and 3 deletions
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20
fonts.js
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@ -1024,14 +1024,14 @@ var Font = (function Font() {
// 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 tablesCount = 9;
var offsets = { var offsets = {
currentOffset: 0, currentOffset: 0,
virtualOffset: 9 * (4 * 4) virtualOffset: tablesCount * (4 * 4)
}; };
var otf = new Uint8Array(kMaxFontFileSize); var otf = new Uint8Array(kMaxFontFileSize);
createOpenTypeHeader("\x4F\x54\x54\x4F", otf, offsets, 9); createOpenTypeHeader("\x4F\x54\x54\x4F", otf, offsets, tablesCount);
var charstrings = font.charstrings; var charstrings = font.charstrings;
properties.fixedPitch = isFixedPitch(charstrings); properties.fixedPitch = isFixedPitch(charstrings);
@ -1115,12 +1115,26 @@ var Font = (function Font() {
for (var field in fields) for (var field in fields)
createTableEntry(otf, offsets, field, fields[field]); createTableEntry(otf, offsets, field, fields[field]);
var headPosition = 0;
for (var field in fields) { for (var field in fields) {
var table = fields[field]; var table = fields[field];
if (field == "head")
headPosition = offsets.currentOffset;
otf.set(table, offsets.currentOffset); otf.set(table, offsets.currentOffset);
offsets.currentOffset += table.length; offsets.currentOffset += table.length;
} }
// Now calculate the checksumAdjustement for all the file and put it into
// head. This will make the head checksum incorrect but per spec that's
// the way it works.
var checksumAdjustement = 0;
for (var i = 0; i < offsets.currentOffset; i+=4)
checksumAdjustement += int16([otf[i], otf[i+1], otf[i+2], otf[i+3]]);
checksumAdjustement = 0xB1B0AFBA - checksumAdjustement;
otf.set(stringToArray(string32(checksumAdjustement)), headPosition + (2 * 4));
var fontData = []; var fontData = [];
for (var i = 0; i < offsets.currentOffset; i++) for (var i = 0; i < offsets.currentOffset; i++)
fontData.push(otf[i]); fontData.push(otf[i]);