pdf-lib
Version:
Create and modify PDF files with JavaScript
238 lines • 11.4 kB
JavaScript
import { __awaiter, __generator } from "tslib";
import { createCmap } from "./CMap";
import { deriveFontFlags } from "./FontFlags";
import PDFHexString from "../objects/PDFHexString";
import PDFString from "../objects/PDFString";
import { byAscendingId, Cache, sortedUniq, toHexStringOfMinLength, } from "../../utils";
/**
* A note of thanks to the developers of https://github.com/foliojs/pdfkit, as
* this class borrows from:
* https://github.com/devongovett/pdfkit/blob/e71edab0dd4657b5a767804ba86c94c58d01fbca/lib/image/jpeg.coffee
*/
var CustomFontEmbedder = /** @class */ (function () {
function CustomFontEmbedder(font, fontData, customName, fontFeatures) {
var _this = this;
this.allGlyphsInFontSortedById = function () {
var glyphs = new Array(_this.font.characterSet.length);
for (var idx = 0, len = glyphs.length; idx < len; idx++) {
var codePoint = _this.font.characterSet[idx];
glyphs[idx] = _this.font.glyphForCodePoint(codePoint);
}
return sortedUniq(glyphs.sort(byAscendingId), function (g) { return g.id; });
};
this.font = font;
this.scale = 1000 / this.font.unitsPerEm;
this.fontData = fontData;
this.fontName = this.font.postscriptName || 'Font';
this.customName = customName;
this.fontFeatures = fontFeatures;
this.baseFontName = '';
this.glyphCache = Cache.populatedBy(this.allGlyphsInFontSortedById);
}
CustomFontEmbedder.for = function (fontkit, fontData, customName, fontFeatures) {
return __awaiter(this, void 0, void 0, function () {
var font;
return __generator(this, function (_a) {
switch (_a.label) {
case 0: return [4 /*yield*/, fontkit.create(fontData)];
case 1:
font = _a.sent();
return [2 /*return*/, new CustomFontEmbedder(font, fontData, customName, fontFeatures)];
}
});
});
};
/**
* Encode the JavaScript string into this font. (JavaScript encodes strings in
* Unicode, but embedded fonts use their own custom encodings)
*/
CustomFontEmbedder.prototype.encodeText = function (text) {
var glyphs = this.font.layout(text, this.fontFeatures).glyphs;
var hexCodes = new Array(glyphs.length);
for (var idx = 0, len = glyphs.length; idx < len; idx++) {
hexCodes[idx] = toHexStringOfMinLength(glyphs[idx].id, 4);
}
return PDFHexString.of(hexCodes.join(''));
};
// The advanceWidth takes into account kerning automatically, so we don't
// have to do that manually like we do for the standard fonts.
CustomFontEmbedder.prototype.widthOfTextAtSize = function (text, size) {
var glyphs = this.font.layout(text, this.fontFeatures).glyphs;
var totalWidth = 0;
for (var idx = 0, len = glyphs.length; idx < len; idx++) {
totalWidth += glyphs[idx].advanceWidth * this.scale;
}
var scale = size / 1000;
return totalWidth * scale;
};
CustomFontEmbedder.prototype.heightOfFontAtSize = function (size, options) {
if (options === void 0) { options = {}; }
var _a = options.descender, descender = _a === void 0 ? true : _a;
var _b = this.font, ascent = _b.ascent, descent = _b.descent, bbox = _b.bbox;
var yTop = (ascent || bbox.maxY) * this.scale;
var yBottom = (descent || bbox.minY) * this.scale;
var height = yTop - yBottom;
if (!descender)
height -= Math.abs(descent) || 0;
return (height / 1000) * size;
};
CustomFontEmbedder.prototype.sizeOfFontAtHeight = function (height) {
var _a = this.font, ascent = _a.ascent, descent = _a.descent, bbox = _a.bbox;
var yTop = (ascent || bbox.maxY) * this.scale;
var yBottom = (descent || bbox.minY) * this.scale;
return (1000 * height) / (yTop - yBottom);
};
CustomFontEmbedder.prototype.embedIntoContext = function (context, ref) {
this.baseFontName =
this.customName || context.addRandomSuffix(this.fontName);
return this.embedFontDict(context, ref);
};
CustomFontEmbedder.prototype.embedFontDict = function (context, ref) {
return __awaiter(this, void 0, void 0, function () {
var cidFontDictRef, unicodeCMapRef, fontDict;
return __generator(this, function (_a) {
switch (_a.label) {
case 0: return [4 /*yield*/, this.embedCIDFontDict(context)];
case 1:
cidFontDictRef = _a.sent();
unicodeCMapRef = this.embedUnicodeCmap(context);
fontDict = context.obj({
Type: 'Font',
Subtype: 'Type0',
BaseFont: this.baseFontName,
Encoding: 'Identity-H',
DescendantFonts: [cidFontDictRef],
ToUnicode: unicodeCMapRef,
});
if (ref) {
context.assign(ref, fontDict);
return [2 /*return*/, ref];
}
else {
return [2 /*return*/, context.register(fontDict)];
}
return [2 /*return*/];
}
});
});
};
CustomFontEmbedder.prototype.isCFF = function () {
return this.font.cff;
};
CustomFontEmbedder.prototype.embedCIDFontDict = function (context) {
return __awaiter(this, void 0, void 0, function () {
var fontDescriptorRef, cidFontDict;
return __generator(this, function (_a) {
switch (_a.label) {
case 0: return [4 /*yield*/, this.embedFontDescriptor(context)];
case 1:
fontDescriptorRef = _a.sent();
cidFontDict = context.obj({
Type: 'Font',
Subtype: this.isCFF() ? 'CIDFontType0' : 'CIDFontType2',
CIDToGIDMap: 'Identity',
BaseFont: this.baseFontName,
CIDSystemInfo: {
Registry: PDFString.of('Adobe'),
Ordering: PDFString.of('Identity'),
Supplement: 0,
},
FontDescriptor: fontDescriptorRef,
W: this.computeWidths(),
});
return [2 /*return*/, context.register(cidFontDict)];
}
});
});
};
CustomFontEmbedder.prototype.embedFontDescriptor = function (context) {
return __awaiter(this, void 0, void 0, function () {
var fontStreamRef, scale, _a, italicAngle, ascent, descent, capHeight, xHeight, _b, minX, minY, maxX, maxY, fontDescriptor;
var _c;
return __generator(this, function (_d) {
switch (_d.label) {
case 0: return [4 /*yield*/, this.embedFontStream(context)];
case 1:
fontStreamRef = _d.sent();
scale = this.scale;
_a = this.font, italicAngle = _a.italicAngle, ascent = _a.ascent, descent = _a.descent, capHeight = _a.capHeight, xHeight = _a.xHeight;
_b = this.font.bbox, minX = _b.minX, minY = _b.minY, maxX = _b.maxX, maxY = _b.maxY;
fontDescriptor = context.obj((_c = {
Type: 'FontDescriptor',
FontName: this.baseFontName,
Flags: deriveFontFlags(this.font),
FontBBox: [minX * scale, minY * scale, maxX * scale, maxY * scale],
ItalicAngle: italicAngle,
Ascent: ascent * scale,
Descent: descent * scale,
CapHeight: (capHeight || ascent) * scale,
XHeight: (xHeight || 0) * scale,
// Not sure how to compute/find this, nor is anybody else really:
// https://stackoverflow.com/questions/35485179/stemv-value-of-the-truetype-font
StemV: 0
},
_c[this.isCFF() ? 'FontFile3' : 'FontFile2'] = fontStreamRef,
_c));
return [2 /*return*/, context.register(fontDescriptor)];
}
});
});
};
CustomFontEmbedder.prototype.serializeFont = function () {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
return [2 /*return*/, this.fontData];
});
});
};
CustomFontEmbedder.prototype.embedFontStream = function (context) {
return __awaiter(this, void 0, void 0, function () {
var fontStream, _a, _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0:
_b = (_a = context).flateStream;
return [4 /*yield*/, this.serializeFont()];
case 1:
fontStream = _b.apply(_a, [_c.sent(), {
Subtype: this.isCFF() ? 'CIDFontType0C' : undefined,
}]);
return [2 /*return*/, context.register(fontStream)];
}
});
});
};
CustomFontEmbedder.prototype.embedUnicodeCmap = function (context) {
var cmap = createCmap(this.glyphCache.access(), this.glyphId.bind(this));
var cmapStream = context.flateStream(cmap);
return context.register(cmapStream);
};
CustomFontEmbedder.prototype.glyphId = function (glyph) {
return glyph ? glyph.id : -1;
};
CustomFontEmbedder.prototype.computeWidths = function () {
var glyphs = this.glyphCache.access();
var widths = [];
var currSection = [];
for (var idx = 0, len = glyphs.length; idx < len; idx++) {
var currGlyph = glyphs[idx];
var prevGlyph = glyphs[idx - 1];
var currGlyphId = this.glyphId(currGlyph);
var prevGlyphId = this.glyphId(prevGlyph);
if (idx === 0) {
widths.push(currGlyphId);
}
else if (currGlyphId - prevGlyphId !== 1) {
widths.push(currSection);
widths.push(currGlyphId);
currSection = [];
}
currSection.push(currGlyph.advanceWidth * this.scale);
}
widths.push(currSection);
return widths;
};
return CustomFontEmbedder;
}());
export default CustomFontEmbedder;
//# sourceMappingURL=CustomFontEmbedder.js.map