opentype.js
Version:
OpenType font parser
1,321 lines (1,178 loc) • 47.8 kB
JavaScript
// The `CFF` table contains the glyph outlines in PostScript format.
// https://www.microsoft.com/typography/OTSPEC/cff.htm
// http://download.microsoft.com/download/8/0/1/801a191c-029d-4af3-9642-555f6fe514ee/cff.pdf
// http://download.microsoft.com/download/8/0/1/801a191c-029d-4af3-9642-555f6fe514ee/type2.pdf
import { CffEncoding, cffStandardEncoding, cffExpertEncoding, cffStandardStrings } from '../encoding';
import glyphset from '../glyphset';
import parse from '../parse';
import Path from '../path';
import table from '../table';
// Custom equals function that can also check lists.
function equals(a, b) {
if (a === b) {
return true;
} else if (Array.isArray(a) && Array.isArray(b)) {
if (a.length !== b.length) {
return false;
}
for (let i = 0; i < a.length; i += 1) {
if (!equals(a[i], b[i])) {
return false;
}
}
return true;
} else {
return false;
}
}
// Subroutines are encoded using the negative half of the number space.
// See type 2 chapter 4.7 "Subroutine operators".
function calcCFFSubroutineBias(subrs) {
let bias;
if (subrs.length < 1240) {
bias = 107;
} else if (subrs.length < 33900) {
bias = 1131;
} else {
bias = 32768;
}
return bias;
}
// Parse a `CFF` INDEX array.
// An index array consists of a list of offsets, then a list of objects at those offsets.
function parseCFFIndex(data, start, conversionFn) {
const offsets = [];
const objects = [];
const count = parse.getCard16(data, start);
let objectOffset;
let endOffset;
if (count !== 0) {
const offsetSize = parse.getByte(data, start + 2);
objectOffset = start + ((count + 1) * offsetSize) + 2;
let pos = start + 3;
for (let i = 0; i < count + 1; i += 1) {
offsets.push(parse.getOffset(data, pos, offsetSize));
pos += offsetSize;
}
// The total size of the index array is 4 header bytes + the value of the last offset.
endOffset = objectOffset + offsets[count];
} else {
endOffset = start + 2;
}
for (let i = 0; i < offsets.length - 1; i += 1) {
let value = parse.getBytes(data, objectOffset + offsets[i], objectOffset + offsets[i + 1]);
if (conversionFn) {
value = conversionFn(value);
}
objects.push(value);
}
return {objects: objects, startOffset: start, endOffset: endOffset};
}
function parseCFFIndexLowMemory(data, start) {
const offsets = [];
const count = parse.getCard16(data, start);
let objectOffset;
let endOffset;
if (count !== 0) {
const offsetSize = parse.getByte(data, start + 2);
objectOffset = start + ((count + 1) * offsetSize) + 2;
let pos = start + 3;
for (let i = 0; i < count + 1; i += 1) {
offsets.push(parse.getOffset(data, pos, offsetSize));
pos += offsetSize;
}
// The total size of the index array is 4 header bytes + the value of the last offset.
endOffset = objectOffset + offsets[count];
} else {
endOffset = start + 2;
}
return {offsets: offsets, startOffset: start, endOffset: endOffset};
}
function getCffIndexObject(i, offsets, data, start, conversionFn) {
const count = parse.getCard16(data, start);
let objectOffset = 0;
if (count !== 0) {
const offsetSize = parse.getByte(data, start + 2);
objectOffset = start + ((count + 1) * offsetSize) + 2;
}
let value = parse.getBytes(data, objectOffset + offsets[i], objectOffset + offsets[i + 1]);
if (conversionFn) {
value = conversionFn(value);
}
return value;
}
// Parse a `CFF` DICT real value.
function parseFloatOperand(parser) {
let s = '';
const eof = 15;
const lookup = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', 'E', 'E-', null, '-'];
while (true) {
const b = parser.parseByte();
const n1 = b >> 4;
const n2 = b & 15;
if (n1 === eof) {
break;
}
s += lookup[n1];
if (n2 === eof) {
break;
}
s += lookup[n2];
}
return parseFloat(s);
}
// Parse a `CFF` DICT operand.
function parseOperand(parser, b0) {
let b1;
let b2;
let b3;
let b4;
if (b0 === 28) {
b1 = parser.parseByte();
b2 = parser.parseByte();
return b1 << 8 | b2;
}
if (b0 === 29) {
b1 = parser.parseByte();
b2 = parser.parseByte();
b3 = parser.parseByte();
b4 = parser.parseByte();
return b1 << 24 | b2 << 16 | b3 << 8 | b4;
}
if (b0 === 30) {
return parseFloatOperand(parser);
}
if (b0 >= 32 && b0 <= 246) {
return b0 - 139;
}
if (b0 >= 247 && b0 <= 250) {
b1 = parser.parseByte();
return (b0 - 247) * 256 + b1 + 108;
}
if (b0 >= 251 && b0 <= 254) {
b1 = parser.parseByte();
return -(b0 - 251) * 256 - b1 - 108;
}
throw new Error('Invalid b0 ' + b0);
}
// Convert the entries returned by `parseDict` to a proper dictionary.
// If a value is a list of one, it is unpacked.
function entriesToObject(entries) {
const o = {};
for (let i = 0; i < entries.length; i += 1) {
const key = entries[i][0];
const values = entries[i][1];
let value;
if (values.length === 1) {
value = values[0];
} else {
value = values;
}
if (o.hasOwnProperty(key) && !isNaN(o[key])) {
throw new Error('Object ' + o + ' already has key ' + key);
}
o[key] = value;
}
return o;
}
// Parse a `CFF` DICT object.
// A dictionary contains key-value pairs in a compact tokenized format.
function parseCFFDict(data, start, size) {
start = start !== undefined ? start : 0;
const parser = new parse.Parser(data, start);
const entries = [];
let operands = [];
size = size !== undefined ? size : data.length;
while (parser.relativeOffset < size) {
let op = parser.parseByte();
// The first byte for each dict item distinguishes between operator (key) and operand (value).
// Values <= 21 are operators.
if (op <= 21) {
// Two-byte operators have an initial escape byte of 12.
if (op === 12) {
op = 1200 + parser.parseByte();
}
entries.push([op, operands]);
operands = [];
} else {
// Since the operands (values) come before the operators (keys), we store all operands in a list
// until we encounter an operator.
operands.push(parseOperand(parser, op));
}
}
return entriesToObject(entries);
}
// Given a String Index (SID), return the value of the string.
// Strings below index 392 are standard CFF strings and are not encoded in the font.
function getCFFString(strings, index) {
if (index <= 390) {
index = cffStandardStrings[index];
} else {
index = strings[index - 391];
}
return index;
}
// Interpret a dictionary and return a new dictionary with readable keys and values for missing entries.
// This function takes `meta` which is a list of objects containing `operand`, `name` and `default`.
function interpretDict(dict, meta, strings) {
const newDict = {};
let value;
// Because we also want to include missing values, we start out from the meta list
// and lookup values in the dict.
for (let i = 0; i < meta.length; i += 1) {
const m = meta[i];
if (Array.isArray(m.type)) {
const values = [];
values.length = m.type.length;
for (let j = 0; j < m.type.length; j++) {
value = dict[m.op] !== undefined ? dict[m.op][j] : undefined;
if (value === undefined) {
value = m.value !== undefined && m.value[j] !== undefined ? m.value[j] : null;
}
if (m.type[j] === 'SID') {
value = getCFFString(strings, value);
}
values[j] = value;
}
newDict[m.name] = values;
} else {
value = dict[m.op];
if (value === undefined) {
value = m.value !== undefined ? m.value : null;
}
if (m.type === 'SID') {
value = getCFFString(strings, value);
}
newDict[m.name] = value;
}
}
return newDict;
}
// Parse the CFF header.
function parseCFFHeader(data, start) {
const header = {};
header.formatMajor = parse.getCard8(data, start);
header.formatMinor = parse.getCard8(data, start + 1);
header.size = parse.getCard8(data, start + 2);
header.offsetSize = parse.getCard8(data, start + 3);
header.startOffset = start;
header.endOffset = start + 4;
return header;
}
const TOP_DICT_META = [
{name: 'version', op: 0, type: 'SID'},
{name: 'notice', op: 1, type: 'SID'},
{name: 'copyright', op: 1200, type: 'SID'},
{name: 'fullName', op: 2, type: 'SID'},
{name: 'familyName', op: 3, type: 'SID'},
{name: 'weight', op: 4, type: 'SID'},
{name: 'isFixedPitch', op: 1201, type: 'number', value: 0},
{name: 'italicAngle', op: 1202, type: 'number', value: 0},
{name: 'underlinePosition', op: 1203, type: 'number', value: -100},
{name: 'underlineThickness', op: 1204, type: 'number', value: 50},
{name: 'paintType', op: 1205, type: 'number', value: 0},
{name: 'charstringType', op: 1206, type: 'number', value: 2},
{
name: 'fontMatrix',
op: 1207,
type: ['real', 'real', 'real', 'real', 'real', 'real'],
value: [0.001, 0, 0, 0.001, 0, 0]
},
{name: 'uniqueId', op: 13, type: 'number'},
{name: 'fontBBox', op: 5, type: ['number', 'number', 'number', 'number'], value: [0, 0, 0, 0]},
{name: 'strokeWidth', op: 1208, type: 'number', value: 0},
{name: 'xuid', op: 14, type: [], value: null},
{name: 'charset', op: 15, type: 'offset', value: 0},
{name: 'encoding', op: 16, type: 'offset', value: 0},
{name: 'charStrings', op: 17, type: 'offset', value: 0},
{name: 'private', op: 18, type: ['number', 'offset'], value: [0, 0]},
{name: 'ros', op: 1230, type: ['SID', 'SID', 'number']},
{name: 'cidFontVersion', op: 1231, type: 'number', value: 0},
{name: 'cidFontRevision', op: 1232, type: 'number', value: 0},
{name: 'cidFontType', op: 1233, type: 'number', value: 0},
{name: 'cidCount', op: 1234, type: 'number', value: 8720},
{name: 'uidBase', op: 1235, type: 'number'},
{name: 'fdArray', op: 1236, type: 'offset'},
{name: 'fdSelect', op: 1237, type: 'offset'},
{name: 'fontName', op: 1238, type: 'SID'}
];
const PRIVATE_DICT_META = [
{name: 'subrs', op: 19, type: 'offset', value: 0},
{name: 'defaultWidthX', op: 20, type: 'number', value: 0},
{name: 'nominalWidthX', op: 21, type: 'number', value: 0}
];
// Parse the CFF top dictionary. A CFF table can contain multiple fonts, each with their own top dictionary.
// The top dictionary contains the essential metadata for the font, together with the private dictionary.
function parseCFFTopDict(data, strings) {
const dict = parseCFFDict(data, 0, data.byteLength);
return interpretDict(dict, TOP_DICT_META, strings);
}
// Parse the CFF private dictionary. We don't fully parse out all the values, only the ones we need.
function parseCFFPrivateDict(data, start, size, strings) {
const dict = parseCFFDict(data, start, size);
return interpretDict(dict, PRIVATE_DICT_META, strings);
}
// Returns a list of "Top DICT"s found using an INDEX list.
// Used to read both the usual high-level Top DICTs and also the FDArray
// discovered inside CID-keyed fonts. When a Top DICT has a reference to
// a Private DICT that is read and saved into the Top DICT.
//
// In addition to the expected/optional values as outlined in TOP_DICT_META
// the following values might be saved into the Top DICT.
//
// _subrs [] array of local CFF subroutines from Private DICT
// _subrsBias bias value computed from number of subroutines
// (see calcCFFSubroutineBias() and parseCFFCharstring())
// _defaultWidthX default widths for CFF characters
// _nominalWidthX bias added to width embedded within glyph description
//
// _privateDict saved copy of parsed Private DICT from Top DICT
function gatherCFFTopDicts(data, start, cffIndex, strings) {
const topDictArray = [];
for (let iTopDict = 0; iTopDict < cffIndex.length; iTopDict += 1) {
const topDictData = new DataView(new Uint8Array(cffIndex[iTopDict]).buffer);
const topDict = parseCFFTopDict(topDictData, strings);
topDict._subrs = [];
topDict._subrsBias = 0;
topDict._defaultWidthX = 0;
topDict._nominalWidthX = 0;
const privateSize = topDict.private[0];
const privateOffset = topDict.private[1];
if (privateSize !== 0 && privateOffset !== 0) {
const privateDict = parseCFFPrivateDict(data, privateOffset + start, privateSize, strings);
topDict._defaultWidthX = privateDict.defaultWidthX;
topDict._nominalWidthX = privateDict.nominalWidthX;
if (privateDict.subrs !== 0) {
const subrOffset = privateOffset + privateDict.subrs;
const subrIndex = parseCFFIndex(data, subrOffset + start);
topDict._subrs = subrIndex.objects;
topDict._subrsBias = calcCFFSubroutineBias(topDict._subrs);
}
topDict._privateDict = privateDict;
}
topDictArray.push(topDict);
}
return topDictArray;
}
// Parse the CFF charset table, which contains internal names for all the glyphs.
// This function will return a list of glyph names.
// See Adobe TN #5176 chapter 13, "Charsets".
function parseCFFCharset(data, start, nGlyphs, strings) {
let sid;
let count;
const parser = new parse.Parser(data, start);
// The .notdef glyph is not included, so subtract 1.
nGlyphs -= 1;
const charset = ['.notdef'];
const format = parser.parseCard8();
if (format === 0) {
for (let i = 0; i < nGlyphs; i += 1) {
sid = parser.parseSID();
charset.push(getCFFString(strings, sid));
}
} else if (format === 1) {
while (charset.length <= nGlyphs) {
sid = parser.parseSID();
count = parser.parseCard8();
for (let i = 0; i <= count; i += 1) {
charset.push(getCFFString(strings, sid));
sid += 1;
}
}
} else if (format === 2) {
while (charset.length <= nGlyphs) {
sid = parser.parseSID();
count = parser.parseCard16();
for (let i = 0; i <= count; i += 1) {
charset.push(getCFFString(strings, sid));
sid += 1;
}
}
} else {
throw new Error('Unknown charset format ' + format);
}
return charset;
}
// Parse the CFF encoding data. Only one encoding can be specified per font.
// See Adobe TN #5176 chapter 12, "Encodings".
function parseCFFEncoding(data, start, charset) {
let code;
const enc = {};
const parser = new parse.Parser(data, start);
const format = parser.parseCard8();
if (format === 0) {
const nCodes = parser.parseCard8();
for (let i = 0; i < nCodes; i += 1) {
code = parser.parseCard8();
enc[code] = i;
}
} else if (format === 1) {
const nRanges = parser.parseCard8();
code = 1;
for (let i = 0; i < nRanges; i += 1) {
const first = parser.parseCard8();
const nLeft = parser.parseCard8();
for (let j = first; j <= first + nLeft; j += 1) {
enc[j] = code;
code += 1;
}
}
} else {
throw new Error('Unknown encoding format ' + format);
}
return new CffEncoding(enc, charset);
}
// Take in charstring code and return a Glyph object.
// The encoding is described in the Type 2 Charstring Format
// https://www.microsoft.com/typography/OTSPEC/charstr2.htm
function parseCFFCharstring(font, glyph, code) {
let c1x;
let c1y;
let c2x;
let c2y;
const p = new Path();
const stack = [];
let nStems = 0;
let haveWidth = false;
let open = false;
let x = 0;
let y = 0;
let subrs;
let subrsBias;
let defaultWidthX;
let nominalWidthX;
if (font.isCIDFont) {
const fdIndex = font.tables.cff.topDict._fdSelect[glyph.index];
const fdDict = font.tables.cff.topDict._fdArray[fdIndex];
subrs = fdDict._subrs;
subrsBias = fdDict._subrsBias;
defaultWidthX = fdDict._defaultWidthX;
nominalWidthX = fdDict._nominalWidthX;
} else {
subrs = font.tables.cff.topDict._subrs;
subrsBias = font.tables.cff.topDict._subrsBias;
defaultWidthX = font.tables.cff.topDict._defaultWidthX;
nominalWidthX = font.tables.cff.topDict._nominalWidthX;
}
let width = defaultWidthX;
function newContour(x, y) {
if (open) {
p.closePath();
}
p.moveTo(x, y);
open = true;
}
function parseStems() {
let hasWidthArg;
// The number of stem operators on the stack is always even.
// If the value is uneven, that means a width is specified.
hasWidthArg = stack.length % 2 !== 0;
if (hasWidthArg && !haveWidth) {
width = stack.shift() + nominalWidthX;
}
nStems += stack.length >> 1;
stack.length = 0;
haveWidth = true;
}
function parse(code) {
let b1;
let b2;
let b3;
let b4;
let codeIndex;
let subrCode;
let jpx;
let jpy;
let c3x;
let c3y;
let c4x;
let c4y;
let i = 0;
while (i < code.length) {
let v = code[i];
i += 1;
switch (v) {
case 1: // hstem
parseStems();
break;
case 3: // vstem
parseStems();
break;
case 4: // vmoveto
if (stack.length > 1 && !haveWidth) {
width = stack.shift() + nominalWidthX;
haveWidth = true;
}
y += stack.pop();
newContour(x, y);
break;
case 5: // rlineto
while (stack.length > 0) {
x += stack.shift();
y += stack.shift();
p.lineTo(x, y);
}
break;
case 6: // hlineto
while (stack.length > 0) {
x += stack.shift();
p.lineTo(x, y);
if (stack.length === 0) {
break;
}
y += stack.shift();
p.lineTo(x, y);
}
break;
case 7: // vlineto
while (stack.length > 0) {
y += stack.shift();
p.lineTo(x, y);
if (stack.length === 0) {
break;
}
x += stack.shift();
p.lineTo(x, y);
}
break;
case 8: // rrcurveto
while (stack.length > 0) {
c1x = x + stack.shift();
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y + stack.shift();
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
break;
case 10: // callsubr
codeIndex = stack.pop() + subrsBias;
subrCode = subrs[codeIndex];
if (subrCode) {
parse(subrCode);
}
break;
case 11: // return
return;
case 12: // flex operators
v = code[i];
i += 1;
switch (v) {
case 35: // flex
// |- dx1 dy1 dx2 dy2 dx3 dy3 dx4 dy4 dx5 dy5 dx6 dy6 fd flex (12 35) |-
c1x = x + stack.shift(); // dx1
c1y = y + stack.shift(); // dy1
c2x = c1x + stack.shift(); // dx2
c2y = c1y + stack.shift(); // dy2
jpx = c2x + stack.shift(); // dx3
jpy = c2y + stack.shift(); // dy3
c3x = jpx + stack.shift(); // dx4
c3y = jpy + stack.shift(); // dy4
c4x = c3x + stack.shift(); // dx5
c4y = c3y + stack.shift(); // dy5
x = c4x + stack.shift(); // dx6
y = c4y + stack.shift(); // dy6
stack.shift(); // flex depth
p.curveTo(c1x, c1y, c2x, c2y, jpx, jpy);
p.curveTo(c3x, c3y, c4x, c4y, x, y);
break;
case 34: // hflex
// |- dx1 dx2 dy2 dx3 dx4 dx5 dx6 hflex (12 34) |-
c1x = x + stack.shift(); // dx1
c1y = y; // dy1
c2x = c1x + stack.shift(); // dx2
c2y = c1y + stack.shift(); // dy2
jpx = c2x + stack.shift(); // dx3
jpy = c2y; // dy3
c3x = jpx + stack.shift(); // dx4
c3y = c2y; // dy4
c4x = c3x + stack.shift(); // dx5
c4y = y; // dy5
x = c4x + stack.shift(); // dx6
p.curveTo(c1x, c1y, c2x, c2y, jpx, jpy);
p.curveTo(c3x, c3y, c4x, c4y, x, y);
break;
case 36: // hflex1
// |- dx1 dy1 dx2 dy2 dx3 dx4 dx5 dy5 dx6 hflex1 (12 36) |-
c1x = x + stack.shift(); // dx1
c1y = y + stack.shift(); // dy1
c2x = c1x + stack.shift(); // dx2
c2y = c1y + stack.shift(); // dy2
jpx = c2x + stack.shift(); // dx3
jpy = c2y; // dy3
c3x = jpx + stack.shift(); // dx4
c3y = c2y; // dy4
c4x = c3x + stack.shift(); // dx5
c4y = c3y + stack.shift(); // dy5
x = c4x + stack.shift(); // dx6
p.curveTo(c1x, c1y, c2x, c2y, jpx, jpy);
p.curveTo(c3x, c3y, c4x, c4y, x, y);
break;
case 37: // flex1
// |- dx1 dy1 dx2 dy2 dx3 dy3 dx4 dy4 dx5 dy5 d6 flex1 (12 37) |-
c1x = x + stack.shift(); // dx1
c1y = y + stack.shift(); // dy1
c2x = c1x + stack.shift(); // dx2
c2y = c1y + stack.shift(); // dy2
jpx = c2x + stack.shift(); // dx3
jpy = c2y + stack.shift(); // dy3
c3x = jpx + stack.shift(); // dx4
c3y = jpy + stack.shift(); // dy4
c4x = c3x + stack.shift(); // dx5
c4y = c3y + stack.shift(); // dy5
if (Math.abs(c4x - x) > Math.abs(c4y - y)) {
x = c4x + stack.shift();
} else {
y = c4y + stack.shift();
}
p.curveTo(c1x, c1y, c2x, c2y, jpx, jpy);
p.curveTo(c3x, c3y, c4x, c4y, x, y);
break;
default:
console.log('Glyph ' + glyph.index + ': unknown operator ' + 1200 + v);
stack.length = 0;
}
break;
case 14: // endchar
if (stack.length > 0 && !haveWidth) {
width = stack.shift() + nominalWidthX;
haveWidth = true;
}
if (open) {
p.closePath();
open = false;
}
break;
case 18: // hstemhm
parseStems();
break;
case 19: // hintmask
case 20: // cntrmask
parseStems();
i += (nStems + 7) >> 3;
break;
case 21: // rmoveto
if (stack.length > 2 && !haveWidth) {
width = stack.shift() + nominalWidthX;
haveWidth = true;
}
y += stack.pop();
x += stack.pop();
newContour(x, y);
break;
case 22: // hmoveto
if (stack.length > 1 && !haveWidth) {
width = stack.shift() + nominalWidthX;
haveWidth = true;
}
x += stack.pop();
newContour(x, y);
break;
case 23: // vstemhm
parseStems();
break;
case 24: // rcurveline
while (stack.length > 2) {
c1x = x + stack.shift();
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y + stack.shift();
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
x += stack.shift();
y += stack.shift();
p.lineTo(x, y);
break;
case 25: // rlinecurve
while (stack.length > 6) {
x += stack.shift();
y += stack.shift();
p.lineTo(x, y);
}
c1x = x + stack.shift();
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y + stack.shift();
p.curveTo(c1x, c1y, c2x, c2y, x, y);
break;
case 26: // vvcurveto
if (stack.length % 2) {
x += stack.shift();
}
while (stack.length > 0) {
c1x = x;
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x;
y = c2y + stack.shift();
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
break;
case 27: // hhcurveto
if (stack.length % 2) {
y += stack.shift();
}
while (stack.length > 0) {
c1x = x + stack.shift();
c1y = y;
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y;
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
break;
case 28: // shortint
b1 = code[i];
b2 = code[i + 1];
stack.push(((b1 << 24) | (b2 << 16)) >> 16);
i += 2;
break;
case 29: // callgsubr
codeIndex = stack.pop() + font.gsubrsBias;
subrCode = font.gsubrs[codeIndex];
if (subrCode) {
parse(subrCode);
}
break;
case 30: // vhcurveto
while (stack.length > 0) {
c1x = x;
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y + (stack.length === 1 ? stack.shift() : 0);
p.curveTo(c1x, c1y, c2x, c2y, x, y);
if (stack.length === 0) {
break;
}
c1x = x + stack.shift();
c1y = y;
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
y = c2y + stack.shift();
x = c2x + (stack.length === 1 ? stack.shift() : 0);
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
break;
case 31: // hvcurveto
while (stack.length > 0) {
c1x = x + stack.shift();
c1y = y;
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
y = c2y + stack.shift();
x = c2x + (stack.length === 1 ? stack.shift() : 0);
p.curveTo(c1x, c1y, c2x, c2y, x, y);
if (stack.length === 0) {
break;
}
c1x = x;
c1y = y + stack.shift();
c2x = c1x + stack.shift();
c2y = c1y + stack.shift();
x = c2x + stack.shift();
y = c2y + (stack.length === 1 ? stack.shift() : 0);
p.curveTo(c1x, c1y, c2x, c2y, x, y);
}
break;
default:
if (v < 32) {
console.log('Glyph ' + glyph.index + ': unknown operator ' + v);
} else if (v < 247) {
stack.push(v - 139);
} else if (v < 251) {
b1 = code[i];
i += 1;
stack.push((v - 247) * 256 + b1 + 108);
} else if (v < 255) {
b1 = code[i];
i += 1;
stack.push(-(v - 251) * 256 - b1 - 108);
} else {
b1 = code[i];
b2 = code[i + 1];
b3 = code[i + 2];
b4 = code[i + 3];
i += 4;
stack.push(((b1 << 24) | (b2 << 16) | (b3 << 8) | b4) / 65536);
}
}
}
}
parse(code);
glyph.advanceWidth = width;
return p;
}
function parseCFFFDSelect(data, start, nGlyphs, fdArrayCount) {
const fdSelect = [];
let fdIndex;
const parser = new parse.Parser(data, start);
const format = parser.parseCard8();
if (format === 0) {
// Simple list of nGlyphs elements
for (let iGid = 0; iGid < nGlyphs; iGid++) {
fdIndex = parser.parseCard8();
if (fdIndex >= fdArrayCount) {
throw new Error('CFF table CID Font FDSelect has bad FD index value ' + fdIndex + ' (FD count ' + fdArrayCount + ')');
}
fdSelect.push(fdIndex);
}
} else if (format === 3) {
// Ranges
const nRanges = parser.parseCard16();
let first = parser.parseCard16();
if (first !== 0) {
throw new Error('CFF Table CID Font FDSelect format 3 range has bad initial GID ' + first);
}
let next;
for (let iRange = 0; iRange < nRanges; iRange++) {
fdIndex = parser.parseCard8();
next = parser.parseCard16();
if (fdIndex >= fdArrayCount) {
throw new Error('CFF table CID Font FDSelect has bad FD index value ' + fdIndex + ' (FD count ' + fdArrayCount + ')');
}
if (next > nGlyphs) {
throw new Error('CFF Table CID Font FDSelect format 3 range has bad GID ' + next);
}
for (; first < next; first++) {
fdSelect.push(fdIndex);
}
first = next;
}
if (next !== nGlyphs) {
throw new Error('CFF Table CID Font FDSelect format 3 range has bad final GID ' + next);
}
} else {
throw new Error('CFF Table CID Font FDSelect table has unsupported format ' + format);
}
return fdSelect;
}
// Parse the `CFF` table, which contains the glyph outlines in PostScript format.
function parseCFFTable(data, start, font, opt) {
font.tables.cff = {};
const header = parseCFFHeader(data, start);
const nameIndex = parseCFFIndex(data, header.endOffset, parse.bytesToString);
const topDictIndex = parseCFFIndex(data, nameIndex.endOffset);
const stringIndex = parseCFFIndex(data, topDictIndex.endOffset, parse.bytesToString);
const globalSubrIndex = parseCFFIndex(data, stringIndex.endOffset);
font.gsubrs = globalSubrIndex.objects;
font.gsubrsBias = calcCFFSubroutineBias(font.gsubrs);
const topDictArray = gatherCFFTopDicts(data, start, topDictIndex.objects, stringIndex.objects);
if (topDictArray.length !== 1) {
throw new Error('CFF table has too many fonts in \'FontSet\' - count of fonts NameIndex.length = ' + topDictArray.length);
}
const topDict = topDictArray[0];
font.tables.cff.topDict = topDict;
if (topDict._privateDict) {
font.defaultWidthX = topDict._privateDict.defaultWidthX;
font.nominalWidthX = topDict._privateDict.nominalWidthX;
}
if (topDict.ros[0] !== undefined && topDict.ros[1] !== undefined) {
font.isCIDFont = true;
}
if (font.isCIDFont) {
let fdArrayOffset = topDict.fdArray;
let fdSelectOffset = topDict.fdSelect;
if (fdArrayOffset === 0 || fdSelectOffset === 0) {
throw new Error('Font is marked as a CID font, but FDArray and/or FDSelect information is missing');
}
fdArrayOffset += start;
const fdArrayIndex = parseCFFIndex(data, fdArrayOffset);
const fdArray = gatherCFFTopDicts(data, start, fdArrayIndex.objects, stringIndex.objects);
topDict._fdArray = fdArray;
fdSelectOffset += start;
topDict._fdSelect = parseCFFFDSelect(data, fdSelectOffset, font.numGlyphs, fdArray.length);
}
const privateDictOffset = start + topDict.private[1];
const privateDict = parseCFFPrivateDict(data, privateDictOffset, topDict.private[0], stringIndex.objects);
font.defaultWidthX = privateDict.defaultWidthX;
font.nominalWidthX = privateDict.nominalWidthX;
if (privateDict.subrs !== 0) {
const subrOffset = privateDictOffset + privateDict.subrs;
const subrIndex = parseCFFIndex(data, subrOffset);
font.subrs = subrIndex.objects;
font.subrsBias = calcCFFSubroutineBias(font.subrs);
} else {
font.subrs = [];
font.subrsBias = 0;
}
// Offsets in the top dict are relative to the beginning of the CFF data, so add the CFF start offset.
let charStringsIndex;
if (opt.lowMemory) {
charStringsIndex = parseCFFIndexLowMemory(data, start + topDict.charStrings);
font.nGlyphs = charStringsIndex.offsets.length;
} else {
charStringsIndex = parseCFFIndex(data, start + topDict.charStrings);
font.nGlyphs = charStringsIndex.objects.length;
}
const charset = parseCFFCharset(data, start + topDict.charset, font.nGlyphs, stringIndex.objects);
if (topDict.encoding === 0) {
// Standard encoding
font.cffEncoding = new CffEncoding(cffStandardEncoding, charset);
} else if (topDict.encoding === 1) {
// Expert encoding
font.cffEncoding = new CffEncoding(cffExpertEncoding, charset);
} else {
font.cffEncoding = parseCFFEncoding(data, start + topDict.encoding, charset);
}
// Prefer the CMAP encoding to the CFF encoding.
font.encoding = font.encoding || font.cffEncoding;
font.glyphs = new glyphset.GlyphSet(font);
if (opt.lowMemory) {
font._push = function(i) {
const charString = getCffIndexObject(i, charStringsIndex.offsets, data, start + topDict.charStrings);
font.glyphs.push(i, glyphset.cffGlyphLoader(font, i, parseCFFCharstring, charString));
};
} else {
for (let i = 0; i < font.nGlyphs; i += 1) {
const charString = charStringsIndex.objects[i];
font.glyphs.push(i, glyphset.cffGlyphLoader(font, i, parseCFFCharstring, charString));
}
}
}
// Convert a string to a String ID (SID).
// The list of strings is modified in place.
function encodeString(s, strings) {
let sid;
// Is the string in the CFF standard strings?
let i = cffStandardStrings.indexOf(s);
if (i >= 0) {
sid = i;
}
// Is the string already in the string index?
i = strings.indexOf(s);
if (i >= 0) {
sid = i + cffStandardStrings.length;
} else {
sid = cffStandardStrings.length + strings.length;
strings.push(s);
}
return sid;
}
function makeHeader() {
return new table.Record('Header', [
{name: 'major', type: 'Card8', value: 1},
{name: 'minor', type: 'Card8', value: 0},
{name: 'hdrSize', type: 'Card8', value: 4},
{name: 'major', type: 'Card8', value: 1}
]);
}
function makeNameIndex(fontNames) {
const t = new table.Record('Name INDEX', [
{name: 'names', type: 'INDEX', value: []}
]);
t.names = [];
for (let i = 0; i < fontNames.length; i += 1) {
t.names.push({name: 'name_' + i, type: 'NAME', value: fontNames[i]});
}
return t;
}
// Given a dictionary's metadata, create a DICT structure.
function makeDict(meta, attrs, strings) {
const m = {};
for (let i = 0; i < meta.length; i += 1) {
const entry = meta[i];
let value = attrs[entry.name];
if (value !== undefined && !equals(value, entry.value)) {
if (entry.type === 'SID') {
value = encodeString(value, strings);
}
m[entry.op] = {name: entry.name, type: entry.type, value: value};
}
}
return m;
}
// The Top DICT houses the global font attributes.
function makeTopDict(attrs, strings) {
const t = new table.Record('Top DICT', [
{name: 'dict', type: 'DICT', value: {}}
]);
t.dict = makeDict(TOP_DICT_META, attrs, strings);
return t;
}
function makeTopDictIndex(topDict) {
const t = new table.Record('Top DICT INDEX', [
{name: 'topDicts', type: 'INDEX', value: []}
]);
t.topDicts = [{name: 'topDict_0', type: 'TABLE', value: topDict}];
return t;
}
function makeStringIndex(strings) {
const t = new table.Record('String INDEX', [
{name: 'strings', type: 'INDEX', value: []}
]);
t.strings = [];
for (let i = 0; i < strings.length; i += 1) {
t.strings.push({name: 'string_' + i, type: 'STRING', value: strings[i]});
}
return t;
}
function makeGlobalSubrIndex() {
// Currently we don't use subroutines.
return new table.Record('Global Subr INDEX', [
{name: 'subrs', type: 'INDEX', value: []}
]);
}
function makeCharsets(glyphNames, strings) {
const t = new table.Record('Charsets', [
{name: 'format', type: 'Card8', value: 0}
]);
for (let i = 0; i < glyphNames.length; i += 1) {
const glyphName = glyphNames[i];
const glyphSID = encodeString(glyphName, strings);
t.fields.push({name: 'glyph_' + i, type: 'SID', value: glyphSID});
}
return t;
}
function glyphToOps(glyph) {
const ops = [];
const path = glyph.path;
ops.push({name: 'width', type: 'NUMBER', value: glyph.advanceWidth});
let x = 0;
let y = 0;
for (let i = 0; i < path.commands.length; i += 1) {
let dx;
let dy;
let cmd = path.commands[i];
if (cmd.type === 'Q') {
// CFF only supports bézier curves, so convert the quad to a bézier.
const _13 = 1 / 3;
const _23 = 2 / 3;
// We're going to create a new command so we don't change the original path.
// Since all coordinates are relative, we round() them ASAP to avoid propagating errors.
cmd = {
type: 'C',
x: cmd.x,
y: cmd.y,
x1: Math.round(_13 * x + _23 * cmd.x1),
y1: Math.round(_13 * y + _23 * cmd.y1),
x2: Math.round(_13 * cmd.x + _23 * cmd.x1),
y2: Math.round(_13 * cmd.y + _23 * cmd.y1)
};
}
if (cmd.type === 'M') {
dx = Math.round(cmd.x - x);
dy = Math.round(cmd.y - y);
ops.push({name: 'dx', type: 'NUMBER', value: dx});
ops.push({name: 'dy', type: 'NUMBER', value: dy});
ops.push({name: 'rmoveto', type: 'OP', value: 21});
x = Math.round(cmd.x);
y = Math.round(cmd.y);
} else if (cmd.type === 'L') {
dx = Math.round(cmd.x - x);
dy = Math.round(cmd.y - y);
ops.push({name: 'dx', type: 'NUMBER', value: dx});
ops.push({name: 'dy', type: 'NUMBER', value: dy});
ops.push({name: 'rlineto', type: 'OP', value: 5});
x = Math.round(cmd.x);
y = Math.round(cmd.y);
} else if (cmd.type === 'C') {
const dx1 = Math.round(cmd.x1 - x);
const dy1 = Math.round(cmd.y1 - y);
const dx2 = Math.round(cmd.x2 - cmd.x1);
const dy2 = Math.round(cmd.y2 - cmd.y1);
dx = Math.round(cmd.x - cmd.x2);
dy = Math.round(cmd.y - cmd.y2);
ops.push({name: 'dx1', type: 'NUMBER', value: dx1});
ops.push({name: 'dy1', type: 'NUMBER', value: dy1});
ops.push({name: 'dx2', type: 'NUMBER', value: dx2});
ops.push({name: 'dy2', type: 'NUMBER', value: dy2});
ops.push({name: 'dx', type: 'NUMBER', value: dx});
ops.push({name: 'dy', type: 'NUMBER', value: dy});
ops.push({name: 'rrcurveto', type: 'OP', value: 8});
x = Math.round(cmd.x);
y = Math.round(cmd.y);
}
// Contours are closed automatically.
}
ops.push({name: 'endchar', type: 'OP', value: 14});
return ops;
}
function makeCharStringsIndex(glyphs) {
const t = new table.Record('CharStrings INDEX', [
{name: 'charStrings', type: 'INDEX', value: []}
]);
for (let i = 0; i < glyphs.length; i += 1) {
const glyph = glyphs.get(i);
const ops = glyphToOps(glyph);
t.charStrings.push({name: glyph.name, type: 'CHARSTRING', value: ops});
}
return t;
}
function makePrivateDict(attrs, strings) {
const t = new table.Record('Private DICT', [
{name: 'dict', type: 'DICT', value: {}}
]);
t.dict = makeDict(PRIVATE_DICT_META, attrs, strings);
return t;
}
function makeCFFTable(glyphs, options) {
const t = new table.Table('CFF ', [
{name: 'header', type: 'RECORD'},
{name: 'nameIndex', type: 'RECORD'},
{name: 'topDictIndex', type: 'RECORD'},
{name: 'stringIndex', type: 'RECORD'},
{name: 'globalSubrIndex', type: 'RECORD'},
{name: 'charsets', type: 'RECORD'},
{name: 'charStringsIndex', type: 'RECORD'},
{name: 'privateDict', type: 'RECORD'}
]);
const fontScale = 1 / options.unitsPerEm;
// We use non-zero values for the offsets so that the DICT encodes them.
// This is important because the size of the Top DICT plays a role in offset calculation,
// and the size shouldn't change after we've written correct offsets.
const attrs = {
version: options.version,
fullName: options.fullName,
familyName: options.familyName,
weight: options.weightName,
fontBBox: options.fontBBox || [0, 0, 0, 0],
fontMatrix: [fontScale, 0, 0, fontScale, 0, 0],
charset: 999,
encoding: 0,
charStrings: 999,
private: [0, 999]
};
const privateAttrs = {};
const glyphNames = [];
let glyph;
// Skip first glyph (.notdef)
for (let i = 1; i < glyphs.length; i += 1) {
glyph = glyphs.get(i);
glyphNames.push(glyph.name);
}
const strings = [];
t.header = makeHeader();
t.nameIndex = makeNameIndex([options.postScriptName]);
let topDict = makeTopDict(attrs, strings);
t.topDictIndex = makeTopDictIndex(topDict);
t.globalSubrIndex = makeGlobalSubrIndex();
t.charsets = makeCharsets(glyphNames, strings);
t.charStringsIndex = makeCharStringsIndex(glyphs);
t.privateDict = makePrivateDict(privateAttrs, strings);
// Needs to come at the end, to encode all custom strings used in the font.
t.stringIndex = makeStringIndex(strings);
const startOffset = t.header.sizeOf() +
t.nameIndex.sizeOf() +
t.topDictIndex.sizeOf() +
t.stringIndex.sizeOf() +
t.globalSubrIndex.sizeOf();
attrs.charset = startOffset;
// We use the CFF standard encoding; proper encoding will be handled in cmap.
attrs.encoding = 0;
attrs.charStrings = attrs.charset + t.charsets.sizeOf();
attrs.private[1] = attrs.charStrings + t.charStringsIndex.sizeOf();
// Recreate the Top DICT INDEX with the correct offsets.
topDict = makeTopDict(attrs, strings);
t.topDictIndex = makeTopDictIndex(topDict);
return t;
}
export default { parse: parseCFFTable, make: makeCFFTable };