cpdf.js: A JavaScript interface to cpdf
=======================================

For development server-side with node: cpdf.js / cpdflib.js

(Minified versions cpdf.min.js and cpdflib.min.js)

Load with "const cpdf = require('cpdf.js')" if installed in npm, or "const cpdf
= require('./cpdf.js')" to load from current directory.

For development client-side with the browser : cpdf.browser.js

(Minified version for deployment : cpdf.browser.min.js)

Load with <script src="cpdf.browser.js"></script> or similar.


Concurrency
===========

cpdf.js is synchronous and non-re-entrant.


Data types
==========

Arguments are integers, floating point numbers, strings, or arrays of type
UInt8Array. Page ranges are represented by arrays of numbers.


Memory Management
=================

A PDF n must be explicitly deallocated with deletePdf(n).


Errors
======

Any function may raise an exception, containing a string describing the problem. 


Enumerations and data structures
================================

These are used throughout cpdf.js, but are collected here for reference.


// Permissions

/** Cannot edit the document */
var noEdit = 0;

/** Cannot print the document */
var noPrint = 1;

/** Cannot copy the document */
var noCopy = 2;

/** Cannot annotate the document */
var noAnnot = 3;

/** Cannot edit forms in the document */
var noForms = 4;

/** Cannot extract information */
var noExtract = 5;

/** Cannot assemble into a bigger document */
var noAssemble = 6;

/** Cannot print high quality */
var noHqPrint = 7;


// Encryption types

/** 40 bit RC4 encryption */
var pdf40bit = 0;

/** 128 bit RC4 encryption */
var pdf128bit = 1;

/** 128 bit AES encryption, do not encrypt metadata */
var aes128bitfalse = 2;

/** 128 bit AES encryption, encrypt metadata */
var aes128bittrue = 3;

/** Deprecated. Do not use for new files */
var aes256bitfalse = 4;

/** Deprecated. Do not use for new files */
var aes256bittrue = 5;

/** 256 bit AES encryption, do not encrypt metadata */
var aes256bitisofalse = 6;

/** 256 bit AES encryption, encrypt metadata */
var aes256bitisotrue = 7;


// Paper sizes

/** A0 Portrait paper */
var a0portrait = 0;

/** A1 Portrait paper */
var a1portrait = 1;

/** A2 Portrait paper */
var a2portrait = 2;

/** A3 Portrait paper */
var a3portrait = 3;

/** A4 Portrait paper */
var a4portrait = 4;

/** A5 Portrait paper */
var a5portrait = 5;

/** A0 Landscape paper */
var a0landscape = 6;

/** A1 Landscape paper */
var a1landscape = 7;

/** A2 Landscape paper */
var a2landscape = 8;

/** A3 Landscape paper */
var a3landscape = 9;

/** A4 Landscape paper */
var a4landscape = 10;

/** A5 Landscape paper */
var a5landscape = 11;

/** US Letter Portrait paper */
var usletterportrait = 12;

/** US Letter Landscape paper */
var usletterlandscape = 13;

/** US Legal Portrait paper */
var uslegalportrait = 14;

/** US Legal Landscape paper */
var uslegallandscape = 15;


// Positions

/** Absolute centre */
var posCentre = 0;

/** Absolute left */
var posLeft = 1;

/** Absolute right */
var posRight = 2;

/** The top centre of the page */
var top = 3;

/** The top left of the page */
var topLeft = 4;

/** The top right of the page */
var topRight = 5;

/** The left hand side of the page, halfway down */
var left = 6;

/** The bottom left of the page */
var bottomLeft = 7;

/** The bottom middle of the page */
var bottom = 8;

/** The bottom right of the page */
var bottomRight = 9;

/** The right hand side of the page, halfway down */
var right = 10;

/** Diagonal, bottom left to top right */
var diagonal = 11;

/** Diagonal, top left to bottom right */
var reversediagonal = 12;

/** Positions on the page. Used for scaling about a point, and adding text.

A position is an anchor and zero or one or two parameters, built with the
Position function.

posCentre: Two parameters, x and y
posLeft: Two parameters, x and y
posRight: Two parameters, x and y
top: One parameter - distance from top
topLeft: One parameter - distance from top left
topRight: One parameter - distance from top right
left: One parameter - distance from left middle
bottomLeft: One parameter - distance from bottom left
bottom: One parameter - distance from bottom
bottomRight: One parameter - distance from bottom right
right: One parameter - distance from right
diagonal: Zero parameters
reverseDiagonal: Zero parameters */

function Position(anchor, p1, p2)


// Fonts

/** Times Roman */
var timesRoman = 0;

/** Times Bold */
var timesBold = 1;

/** Times Italic */
var timesItalic = 2;

/** Times Bold Italic */
var timesBoldItalic = 3;

/** Helvetica */
var helvetica = 4;

/** Helvetica Bold */
var helveticaBold = 5;

/** Helvetica Oblique */
var helveticaOblique = 6;

/** Helvetica Bold Oblique */
var helveticaBoldOblique = 7;

/** Courier */
var courier = 8;

/** Courier Bold */
var courierBold = 9;

/** Courier Oblique */
var courierOblique = 10;

/** Courier Bold Oblique */
var courierBoldOblique = 11;


// Justification types

/** Left justify */
var leftJustify = 0;

/** Centre justify */
var centreJustify = 1;

/** Right justify */
var rightJustify = 2;


/// Page layouts

/** Single page */
var singlePage = 0;

/** One column */
var oneColumn = 1;

/** Two column left */
var twoColumnLeft = 2;

/** Two column right */
var twoColumnRight = 3;

/** Two page left */
var twoPageLeft = 4;

/** Two page right */
var twoPageRight = 5;


// Page modes

/** Use none */
var useNone = 0;

/** Use outlines */
var useOutlines = 1;

/** Use thumbs */
var useThumbs = 2;

/** Use OC */
var useOC = 3;

/** Use attachments */
var useAttachments = 4;


// Page label styles

/** 1, 2, 3... */
var decimalArabic = 0;

/** I, II, III... */
var uppercaseRoman = 1;

/** i, ii, iii... */
var lowercaseRoman = 2;

/** A, B, C... */
var uppercaseLetters = 3;

/** a, b, c... */
var lowercaseLetters = 4;