pdfjs-dist/lib/shared/util.js

/**
 * @licstart The following is the entire license notice for the
 * JavaScript code in this page
 *
 * Copyright 2022 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @licend The above is the entire license notice for the
 * JavaScript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.VerbosityLevel = exports.Util = exports.UnknownErrorException = exports.UnexpectedResponseException = exports.UNSUPPORTED_FEATURES = exports.TextRenderingMode = exports.StreamType = exports.RenderingIntentFlag = exports.PermissionFlag = exports.PasswordResponses = exports.PasswordException = exports.PageActionEventType = exports.OPS = exports.MissingPDFException = exports.InvalidPDFException = exports.ImageKind = exports.IDENTITY_MATRIX = exports.FormatError = exports.FontType = exports.FeatureTest = exports.FONT_IDENTITY_MATRIX = exports.DocumentActionEventType = exports.CMapCompressionType = exports.BaseException = exports.AnnotationType = exports.AnnotationStateModelType = exports.AnnotationReviewState = exports.AnnotationReplyType = exports.AnnotationMode = exports.AnnotationMarkedState = exports.AnnotationFlag = exports.AnnotationFieldFlag = exports.AnnotationBorderStyleType = exports.AnnotationActionEventType = exports.AbortException = void 0;
exports.arrayByteLength = arrayByteLength;
exports.arraysToBytes = arraysToBytes;
exports.assert = assert;
exports.bytesToString = bytesToString;
exports.createPromiseCapability = createPromiseCapability;
exports.createValidAbsoluteUrl = createValidAbsoluteUrl;
exports.escapeString = escapeString;
exports.getModificationDate = getModificationDate;
exports.getVerbosityLevel = getVerbosityLevel;
exports.info = info;
exports.isArrayBuffer = isArrayBuffer;
exports.isArrayEqual = isArrayEqual;
exports.isAscii = isAscii;
exports.objectFromMap = objectFromMap;
exports.objectSize = objectSize;
exports.setVerbosityLevel = setVerbosityLevel;
exports.shadow = shadow;
exports.string32 = string32;
exports.stringToBytes = stringToBytes;
exports.stringToPDFString = stringToPDFString;
exports.stringToUTF16BEString = stringToUTF16BEString;
exports.stringToUTF8String = stringToUTF8String;
exports.unreachable = unreachable;
exports.utf8StringToString = utf8StringToString;
exports.warn = warn;

require("./compatibility.js");

const IDENTITY_MATRIX = [1, 0, 0, 1, 0, 0];
exports.IDENTITY_MATRIX = IDENTITY_MATRIX;
const FONT_IDENTITY_MATRIX = [0.001, 0, 0, 0.001, 0, 0];
exports.FONT_IDENTITY_MATRIX = FONT_IDENTITY_MATRIX;
const RenderingIntentFlag = {
  ANY: 0x01,
  DISPLAY: 0x02,
  PRINT: 0x04,
  ANNOTATIONS_FORMS: 0x10,
  ANNOTATIONS_STORAGE: 0x20,
  ANNOTATIONS_DISABLE: 0x40,
  OPLIST: 0x100
};
exports.RenderingIntentFlag = RenderingIntentFlag;
const AnnotationMode = {
  DISABLE: 0,
  ENABLE: 1,
  ENABLE_FORMS: 2,
  ENABLE_STORAGE: 3
};
exports.AnnotationMode = AnnotationMode;
const PermissionFlag = {
  PRINT: 0x04,
  MODIFY_CONTENTS: 0x08,
  COPY: 0x10,
  MODIFY_ANNOTATIONS: 0x20,
  FILL_INTERACTIVE_FORMS: 0x100,
  COPY_FOR_ACCESSIBILITY: 0x200,
  ASSEMBLE: 0x400,
  PRINT_HIGH_QUALITY: 0x800
};
exports.PermissionFlag = PermissionFlag;
const TextRenderingMode = {
  FILL: 0,
  STROKE: 1,
  FILL_STROKE: 2,
  INVISIBLE: 3,
  FILL_ADD_TO_PATH: 4,
  STROKE_ADD_TO_PATH: 5,
  FILL_STROKE_ADD_TO_PATH: 6,
  ADD_TO_PATH: 7,
  FILL_STROKE_MASK: 3,
  ADD_TO_PATH_FLAG: 4
};
exports.TextRenderingMode = TextRenderingMode;
const ImageKind = {
  GRAYSCALE_1BPP: 1,
  RGB_24BPP: 2,
  RGBA_32BPP: 3
};
exports.ImageKind = ImageKind;
const AnnotationType = {
  TEXT: 1,
  LINK: 2,
  FREETEXT: 3,
  LINE: 4,
  SQUARE: 5,
  CIRCLE: 6,
  POLYGON: 7,
  POLYLINE: 8,
  HIGHLIGHT: 9,
  UNDERLINE: 10,
  SQUIGGLY: 11,
  STRIKEOUT: 12,
  STAMP: 13,
  CARET: 14,
  INK: 15,
  POPUP: 16,
  FILEATTACHMENT: 17,
  SOUND: 18,
  MOVIE: 19,
  WIDGET: 20,
  SCREEN: 21,
  PRINTERMARK: 22,
  TRAPNET: 23,
  WATERMARK: 24,
  THREED: 25,
  REDACT: 26
};
exports.AnnotationType = AnnotationType;
const AnnotationStateModelType = {
  MARKED: "Marked",
  REVIEW: "Review"
};
exports.AnnotationStateModelType = AnnotationStateModelType;
const AnnotationMarkedState = {
  MARKED: "Marked",
  UNMARKED: "Unmarked"
};
exports.AnnotationMarkedState = AnnotationMarkedState;
const AnnotationReviewState = {
  ACCEPTED: "Accepted",
  REJECTED: "Rejected",
  CANCELLED: "Cancelled",
  COMPLETED: "Completed",
  NONE: "None"
};
exports.AnnotationReviewState = AnnotationReviewState;
const AnnotationReplyType = {
  GROUP: "Group",
  REPLY: "R"
};
exports.AnnotationReplyType = AnnotationReplyType;
const AnnotationFlag = {
  INVISIBLE: 0x01,
  HIDDEN: 0x02,
  PRINT: 0x04,
  NOZOOM: 0x08,
  NOROTATE: 0x10,
  NOVIEW: 0x20,
  READONLY: 0x40,
  LOCKED: 0x80,
  TOGGLENOVIEW: 0x100,
  LOCKEDCONTENTS: 0x200
};
exports.AnnotationFlag = AnnotationFlag;
const AnnotationFieldFlag = {
  READONLY: 0x0000001,
  REQUIRED: 0x0000002,
  NOEXPORT: 0x0000004,
  MULTILINE: 0x0001000,
  PASSWORD: 0x0002000,
  NOTOGGLETOOFF: 0x0004000,
  RADIO: 0x0008000,
  PUSHBUTTON: 0x0010000,
  COMBO: 0x0020000,
  EDIT: 0x0040000,
  SORT: 0x0080000,
  FILESELECT: 0x0100000,
  MULTISELECT: 0x0200000,
  DONOTSPELLCHECK: 0x0400000,
  DONOTSCROLL: 0x0800000,
  COMB: 0x1000000,
  RICHTEXT: 0x2000000,
  RADIOSINUNISON: 0x2000000,
  COMMITONSELCHANGE: 0x4000000
};
exports.AnnotationFieldFlag = AnnotationFieldFlag;
const AnnotationBorderStyleType = {
  SOLID: 1,
  DASHED: 2,
  BEVELED: 3,
  INSET: 4,
  UNDERLINE: 5
};
exports.AnnotationBorderStyleType = AnnotationBorderStyleType;
const AnnotationActionEventType = {
  E: "Mouse Enter",
  X: "Mouse Exit",
  D: "Mouse Down",
  U: "Mouse Up",
  Fo: "Focus",
  Bl: "Blur",
  PO: "PageOpen",
  PC: "PageClose",
  PV: "PageVisible",
  PI: "PageInvisible",
  K: "Keystroke",
  F: "Format",
  V: "Validate",
  C: "Calculate"
};
exports.AnnotationActionEventType = AnnotationActionEventType;
const DocumentActionEventType = {
  WC: "WillClose",
  WS: "WillSave",
  DS: "DidSave",
  WP: "WillPrint",
  DP: "DidPrint"
};
exports.DocumentActionEventType = DocumentActionEventType;
const PageActionEventType = {
  O: "PageOpen",
  C: "PageClose"
};
exports.PageActionEventType = PageActionEventType;
const StreamType = {
  UNKNOWN: "UNKNOWN",
  FLATE: "FLATE",
  LZW: "LZW",
  DCT: "DCT",
  JPX: "JPX",
  JBIG: "JBIG",
  A85: "A85",
  AHX: "AHX",
  CCF: "CCF",
  RLX: "RLX"
};
exports.StreamType = StreamType;
const FontType = {
  UNKNOWN: "UNKNOWN",
  TYPE1: "TYPE1",
  TYPE1STANDARD: "TYPE1STANDARD",
  TYPE1C: "TYPE1C",
  CIDFONTTYPE0: "CIDFONTTYPE0",
  CIDFONTTYPE0C: "CIDFONTTYPE0C",
  TRUETYPE: "TRUETYPE",
  CIDFONTTYPE2: "CIDFONTTYPE2",
  TYPE3: "TYPE3",
  OPENTYPE: "OPENTYPE",
  TYPE0: "TYPE0",
  MMTYPE1: "MMTYPE1"
};
exports.FontType = FontType;
const VerbosityLevel = {
  ERRORS: 0,
  WARNINGS: 1,
  INFOS: 5
};
exports.VerbosityLevel = VerbosityLevel;
const CMapCompressionType = {
  NONE: 0,
  BINARY: 1,
  STREAM: 2
};
exports.CMapCompressionType = CMapCompressionType;
const OPS = {
  dependency: 1,
  setLineWidth: 2,
  setLineCap: 3,
  setLineJoin: 4,
  setMiterLimit: 5,
  setDash: 6,
  setRenderingIntent: 7,
  setFlatness: 8,
  setGState: 9,
  save: 10,
  restore: 11,
  transform: 12,
  moveTo: 13,
  lineTo: 14,
  curveTo: 15,
  curveTo2: 16,
  curveTo3: 17,
  closePath: 18,
  rectangle: 19,
  stroke: 20,
  closeStroke: 21,
  fill: 22,
  eoFill: 23,
  fillStroke: 24,
  eoFillStroke: 25,
  closeFillStroke: 26,
  closeEOFillStroke: 27,
  endPath: 28,
  clip: 29,
  eoClip: 30,
  beginText: 31,
  endText: 32,
  setCharSpacing: 33,
  setWordSpacing: 34,
  setHScale: 35,
  setLeading: 36,
  setFont: 37,
  setTextRenderingMode: 38,
  setTextRise: 39,
  moveText: 40,
  setLeadingMoveText: 41,
  setTextMatrix: 42,
  nextLine: 43,
  showText: 44,
  showSpacedText: 45,
  nextLineShowText: 46,
  nextLineSetSpacingShowText: 47,
  setCharWidth: 48,
  setCharWidthAndBounds: 49,
  setStrokeColorSpace: 50,
  setFillColorSpace: 51,
  setStrokeColor: 52,
  setStrokeColorN: 53,
  setFillColor: 54,
  setFillColorN: 55,
  setStrokeGray: 56,
  setFillGray: 57,
  setStrokeRGBColor: 58,
  setFillRGBColor: 59,
  setStrokeCMYKColor: 60,
  setFillCMYKColor: 61,
  shadingFill: 62,
  beginInlineImage: 63,
  beginImageData: 64,
  endInlineImage: 65,
  paintXObject: 66,
  markPoint: 67,
  markPointProps: 68,
  beginMarkedContent: 69,
  beginMarkedContentProps: 70,
  endMarkedContent: 71,
  beginCompat: 72,
  endCompat: 73,
  paintFormXObjectBegin: 74,
  paintFormXObjectEnd: 75,
  beginGroup: 76,
  endGroup: 77,
  beginAnnotations: 78,
  endAnnotations: 79,
  beginAnnotation: 80,
  endAnnotation: 81,
  paintJpegXObject: 82,
  paintImageMaskXObject: 83,
  paintImageMaskXObjectGroup: 84,
  paintImageXObject: 85,
  paintInlineImageXObject: 86,
  paintInlineImageXObjectGroup: 87,
  paintImageXObjectRepeat: 88,
  paintImageMaskXObjectRepeat: 89,
  paintSolidColorImageMask: 90,
  constructPath: 91
};
exports.OPS = OPS;
const UNSUPPORTED_FEATURES = {
  unknown: "unknown",
  forms: "forms",
  javaScript: "javaScript",
  signatures: "signatures",
  smask: "smask",
  shadingPattern: "shadingPattern",
  font: "font",
  errorTilingPattern: "errorTilingPattern",
  errorExtGState: "errorExtGState",
  errorXObject: "errorXObject",
  errorFontLoadType3: "errorFontLoadType3",
  errorFontState: "errorFontState",
  errorFontMissing: "errorFontMissing",
  errorFontTranslate: "errorFontTranslate",
  errorColorSpace: "errorColorSpace",
  errorOperatorList: "errorOperatorList",
  errorFontToUnicode: "errorFontToUnicode",
  errorFontLoadNative: "errorFontLoadNative",
  errorFontBuildPath: "errorFontBuildPath",
  errorFontGetPath: "errorFontGetPath",
  errorMarkedContent: "errorMarkedContent",
  errorContentSubStream: "errorContentSubStream"
};
exports.UNSUPPORTED_FEATURES = UNSUPPORTED_FEATURES;
const PasswordResponses = {
  NEED_PASSWORD: 1,
  INCORRECT_PASSWORD: 2
};
exports.PasswordResponses = PasswordResponses;
let verbosity = VerbosityLevel.WARNINGS;

function setVerbosityLevel(level) {
  if (Number.isInteger(level)) {
    verbosity = level;
  }
}

function getVerbosityLevel() {
  return verbosity;
}

function info(msg) {
  if (verbosity >= VerbosityLevel.INFOS) {
    console.log(`Info: ${msg}`);
  }
}

function warn(msg) {
  if (verbosity >= VerbosityLevel.WARNINGS) {
    console.log(`Warning: ${msg}`);
  }
}

function unreachable(msg) {
  throw new Error(msg);
}

function assert(cond, msg) {
  if (!cond) {
    unreachable(msg);
  }
}

function _isValidProtocol(url) {
  if (!url) {
    return false;
  }

  switch (url.protocol) {
    case "http:":
    case "https:":
    case "ftp:":
    case "mailto:":
    case "tel:":
      return true;

    default:
      return false;
  }
}

function createValidAbsoluteUrl(url, baseUrl = null, options = null) {
  if (!url) {
    return null;
  }

  try {
    if (options && typeof url === "string") {
      if (options.addDefaultProtocol && url.startsWith("www.")) {
        const dots = url.match(/\./g);

        if (dots && dots.length >= 2) {
          url = `http://${url}`;
        }
      }

      if (options.tryConvertEncoding) {
        try {
          url = stringToUTF8String(url);
        } catch (ex) {}
      }
    }

    const absoluteUrl = baseUrl ? new URL(url, baseUrl) : new URL(url);

    if (_isValidProtocol(absoluteUrl)) {
      return absoluteUrl;
    }
  } catch (ex) {}

  return null;
}

function shadow(obj, prop, value) {
  Object.defineProperty(obj, prop, {
    value,
    enumerable: true,
    configurable: true,
    writable: false
  });
  return value;
}

const BaseException = function BaseExceptionClosure() {
  function BaseException(message, name) {
    if (this.constructor === BaseException) {
      unreachable("Cannot initialize BaseException.");
    }

    this.message = message;
    this.name = name;
  }

  BaseException.prototype = new Error();
  BaseException.constructor = BaseException;
  return BaseException;
}();

exports.BaseException = BaseException;

class PasswordException extends BaseException {
  constructor(msg, code) {
    super(msg, "PasswordException");
    this.code = code;
  }

}

exports.PasswordException = PasswordException;

class UnknownErrorException extends BaseException {
  constructor(msg, details) {
    super(msg, "UnknownErrorException");
    this.details = details;
  }

}

exports.UnknownErrorException = UnknownErrorException;

class InvalidPDFException extends BaseException {
  constructor(msg) {
    super(msg, "InvalidPDFException");
  }

}

exports.InvalidPDFException = InvalidPDFException;

class MissingPDFException extends BaseException {
  constructor(msg) {
    super(msg, "MissingPDFException");
  }

}

exports.MissingPDFException = MissingPDFException;

class UnexpectedResponseException extends BaseException {
  constructor(msg, status) {
    super(msg, "UnexpectedResponseException");
    this.status = status;
  }

}

exports.UnexpectedResponseException = UnexpectedResponseException;

class FormatError extends BaseException {
  constructor(msg) {
    super(msg, "FormatError");
  }

}

exports.FormatError = FormatError;

class AbortException extends BaseException {
  constructor(msg) {
    super(msg, "AbortException");
  }

}

exports.AbortException = AbortException;

function bytesToString(bytes) {
  if (typeof bytes !== "object" || bytes === null || bytes.length === undefined) {
    unreachable("Invalid argument for bytesToString");
  }

  const length = bytes.length;
  const MAX_ARGUMENT_COUNT = 8192;

  if (length < MAX_ARGUMENT_COUNT) {
    return String.fromCharCode.apply(null, bytes);
  }

  const strBuf = [];

  for (let i = 0; i < length; i += MAX_ARGUMENT_COUNT) {
    const chunkEnd = Math.min(i + MAX_ARGUMENT_COUNT, length);
    const chunk = bytes.subarray(i, chunkEnd);
    strBuf.push(String.fromCharCode.apply(null, chunk));
  }

  return strBuf.join("");
}

function stringToBytes(str) {
  if (typeof str !== "string") {
    unreachable("Invalid argument for stringToBytes");
  }

  const length = str.length;
  const bytes = new Uint8Array(length);

  for (let i = 0; i < length; ++i) {
    bytes[i] = str.charCodeAt(i) & 0xff;
  }

  return bytes;
}

function arrayByteLength(arr) {
  if (arr.length !== undefined) {
    return arr.length;
  }

  if (arr.byteLength !== undefined) {
    return arr.byteLength;
  }

  unreachable("Invalid argument for arrayByteLength");
}

function arraysToBytes(arr) {
  const length = arr.length;

  if (length === 1 && arr[0] instanceof Uint8Array) {
    return arr[0];
  }

  let resultLength = 0;

  for (let i = 0; i < length; i++) {
    resultLength += arrayByteLength(arr[i]);
  }

  let pos = 0;
  const data = new Uint8Array(resultLength);

  for (let i = 0; i < length; i++) {
    let item = arr[i];

    if (!(item instanceof Uint8Array)) {
      if (typeof item === "string") {
        item = stringToBytes(item);
      } else {
        item = new Uint8Array(item);
      }
    }

    const itemLength = item.byteLength;
    data.set(item, pos);
    pos += itemLength;
  }

  return data;
}

function string32(value) {
  return String.fromCharCode(value >> 24 & 0xff, value >> 16 & 0xff, value >> 8 & 0xff, value & 0xff);
}

function objectSize(obj) {
  return Object.keys(obj).length;
}

function objectFromMap(map) {
  const obj = Object.create(null);

  for (const [key, value] of map) {
    obj[key] = value;
  }

  return obj;
}

function isLittleEndian() {
  const buffer8 = new Uint8Array(4);
  buffer8[0] = 1;
  const view32 = new Uint32Array(buffer8.buffer, 0, 1);
  return view32[0] === 1;
}

function isEvalSupported() {
  try {
    new Function("");
    return true;
  } catch (e) {
    return false;
  }
}

class FeatureTest {
  static get isLittleEndian() {
    return shadow(this, "isLittleEndian", isLittleEndian());
  }

  static get isEvalSupported() {
    return shadow(this, "isEvalSupported", isEvalSupported());
  }

  static get isOffscreenCanvasSupported() {
    return shadow(this, "isOffscreenCanvasSupported", typeof OffscreenCanvas !== "undefined");
  }

}

exports.FeatureTest = FeatureTest;
const hexNumbers = [...Array(256).keys()].map(n => n.toString(16).padStart(2, "0"));

class Util {
  static makeHexColor(r, g, b) {
    return `#${hexNumbers[r]}${hexNumbers[g]}${hexNumbers[b]}`;
  }

  static scaleMinMax(transform, minMax) {
    let temp;

    if (transform[0]) {
      if (transform[0] < 0) {
        temp = minMax[0];
        minMax[0] = minMax[1];
        minMax[1] = temp;
      }

      minMax[0] *= transform[0];
      minMax[1] *= transform[0];

      if (transform[3] < 0) {
        temp = minMax[2];
        minMax[2] = minMax[3];
        minMax[3] = temp;
      }

      minMax[2] *= transform[3];
      minMax[3] *= transform[3];
    } else {
      temp = minMax[0];
      minMax[0] = minMax[2];
      minMax[2] = temp;
      temp = minMax[1];
      minMax[1] = minMax[3];
      minMax[3] = temp;

      if (transform[1] < 0) {
        temp = minMax[2];
        minMax[2] = minMax[3];
        minMax[3] = temp;
      }

      minMax[2] *= transform[1];
      minMax[3] *= transform[1];

      if (transform[2] < 0) {
        temp = minMax[0];
        minMax[0] = minMax[1];
        minMax[1] = temp;
      }

      minMax[0] *= transform[2];
      minMax[1] *= transform[2];
    }

    minMax[0] += transform[4];
    minMax[1] += transform[4];
    minMax[2] += transform[5];
    minMax[3] += transform[5];
  }

  static transform(m1, m2) {
    return [m1[0] * m2[0] + m1[2] * m2[1], m1[1] * m2[0] + m1[3] * m2[1], m1[0] * m2[2] + m1[2] * m2[3], m1[1] * m2[2] + m1[3] * m2[3], m1[0] * m2[4] + m1[2] * m2[5] + m1[4], m1[1] * m2[4] + m1[3] * m2[5] + m1[5]];
  }

  static applyTransform(p, m) {
    const xt = p[0] * m[0] + p[1] * m[2] + m[4];
    const yt = p[0] * m[1] + p[1] * m[3] + m[5];
    return [xt, yt];
  }

  static applyInverseTransform(p, m) {
    const d = m[0] * m[3] - m[1] * m[2];
    const xt = (p[0] * m[3] - p[1] * m[2] + m[2] * m[5] - m[4] * m[3]) / d;
    const yt = (-p[0] * m[1] + p[1] * m[0] + m[4] * m[1] - m[5] * m[0]) / d;
    return [xt, yt];
  }

  static getAxialAlignedBoundingBox(r, m) {
    const p1 = Util.applyTransform(r, m);
    const p2 = Util.applyTransform(r.slice(2, 4), m);
    const p3 = Util.applyTransform([r[0], r[3]], m);
    const p4 = Util.applyTransform([r[2], r[1]], m);
    return [Math.min(p1[0], p2[0], p3[0], p4[0]), Math.min(p1[1], p2[1], p3[1], p4[1]), Math.max(p1[0], p2[0], p3[0], p4[0]), Math.max(p1[1], p2[1], p3[1], p4[1])];
  }

  static inverseTransform(m) {
    const d = m[0] * m[3] - m[1] * m[2];
    return [m[3] / d, -m[1] / d, -m[2] / d, m[0] / d, (m[2] * m[5] - m[4] * m[3]) / d, (m[4] * m[1] - m[5] * m[0]) / d];
  }

  static apply3dTransform(m, v) {
    return [m[0] * v[0] + m[1] * v[1] + m[2] * v[2], m[3] * v[0] + m[4] * v[1] + m[5] * v[2], m[6] * v[0] + m[7] * v[1] + m[8] * v[2]];
  }

  static singularValueDecompose2dScale(m) {
    const transpose = [m[0], m[2], m[1], m[3]];
    const a = m[0] * transpose[0] + m[1] * transpose[2];
    const b = m[0] * transpose[1] + m[1] * transpose[3];
    const c = m[2] * transpose[0] + m[3] * transpose[2];
    const d = m[2] * transpose[1] + m[3] * transpose[3];
    const first = (a + d) / 2;
    const second = Math.sqrt((a + d) ** 2 - 4 * (a * d - c * b)) / 2;
    const sx = first + second || 1;
    const sy = first - second || 1;
    return [Math.sqrt(sx), Math.sqrt(sy)];
  }

  static normalizeRect(rect) {
    const r = rect.slice(0);

    if (rect[0] > rect[2]) {
      r[0] = rect[2];
      r[2] = rect[0];
    }

    if (rect[1] > rect[3]) {
      r[1] = rect[3];
      r[3] = rect[1];
    }

    return r;
  }

  static intersect(rect1, rect2) {
    const xLow = Math.max(Math.min(rect1[0], rect1[2]), Math.min(rect2[0], rect2[2]));
    const xHigh = Math.min(Math.max(rect1[0], rect1[2]), Math.max(rect2[0], rect2[2]));

    if (xLow > xHigh) {
      return null;
    }

    const yLow = Math.max(Math.min(rect1[1], rect1[3]), Math.min(rect2[1], rect2[3]));
    const yHigh = Math.min(Math.max(rect1[1], rect1[3]), Math.max(rect2[1], rect2[3]));

    if (yLow > yHigh) {
      return null;
    }

    return [xLow, yLow, xHigh, yHigh];
  }

  static bezierBoundingBox(x0, y0, x1, y1, x2, y2, x3, y3) {
    const tvalues = [],
          bounds = [[], []];
    let a, b, c, t, t1, t2, b2ac, sqrtb2ac;

    for (let i = 0; i < 2; ++i) {
      if (i === 0) {
        b = 6 * x0 - 12 * x1 + 6 * x2;
        a = -3 * x0 + 9 * x1 - 9 * x2 + 3 * x3;
        c = 3 * x1 - 3 * x0;
      } else {
        b = 6 * y0 - 12 * y1 + 6 * y2;
        a = -3 * y0 + 9 * y1 - 9 * y2 + 3 * y3;
        c = 3 * y1 - 3 * y0;
      }

      if (Math.abs(a) < 1e-12) {
        if (Math.abs(b) < 1e-12) {
          continue;
        }

        t = -c / b;

        if (0 < t && t < 1) {
          tvalues.push(t);
        }

        continue;
      }

      b2ac = b * b - 4 * c * a;
      sqrtb2ac = Math.sqrt(b2ac);

      if (b2ac < 0) {
        continue;
      }

      t1 = (-b + sqrtb2ac) / (2 * a);

      if (0 < t1 && t1 < 1) {
        tvalues.push(t1);
      }

      t2 = (-b - sqrtb2ac) / (2 * a);

      if (0 < t2 && t2 < 1) {
        tvalues.push(t2);
      }
    }

    let j = tvalues.length,
        mt;
    const jlen = j;

    while (j--) {
      t = tvalues[j];
      mt = 1 - t;
      bounds[0][j] = mt * mt * mt * x0 + 3 * mt * mt * t * x1 + 3 * mt * t * t * x2 + t * t * t * x3;
      bounds[1][j] = mt * mt * mt * y0 + 3 * mt * mt * t * y1 + 3 * mt * t * t * y2 + t * t * t * y3;
    }

    bounds[0][jlen] = x0;
    bounds[1][jlen] = y0;
    bounds[0][jlen + 1] = x3;
    bounds[1][jlen + 1] = y3;
    bounds[0].length = bounds[1].length = jlen + 2;
    return [Math.min(...bounds[0]), Math.min(...bounds[1]), Math.max(...bounds[0]), Math.max(...bounds[1])];
  }

}

exports.Util = Util;
const PDFStringTranslateTable = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x2d8, 0x2c7, 0x2c6, 0x2d9, 0x2dd, 0x2db, 0x2da, 0x2dc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x2022, 0x2020, 0x2021, 0x2026, 0x2014, 0x2013, 0x192, 0x2044, 0x2039, 0x203a, 0x2212, 0x2030, 0x201e, 0x201c, 0x201d, 0x2018, 0x2019, 0x201a, 0x2122, 0xfb01, 0xfb02, 0x141, 0x152, 0x160, 0x178, 0x17d, 0x131, 0x142, 0x153, 0x161, 0x17e, 0, 0x20ac];

function stringToPDFString(str) {
  if (str[0] >= "\xEF") {
    let encoding;

    if (str[0] === "\xFE" && str[1] === "\xFF") {
      encoding = "utf-16be";
    } else if (str[0] === "\xFF" && str[1] === "\xFE") {
      encoding = "utf-16le";
    } else if (str[0] === "\xEF" && str[1] === "\xBB" && str[2] === "\xBF") {
      encoding = "utf-8";
    }

    if (encoding) {
      try {
        const decoder = new TextDecoder(encoding, {
          fatal: true
        });
        const buffer = stringToBytes(str);
        return decoder.decode(buffer);
      } catch (ex) {
        warn(`stringToPDFString: "${ex}".`);
      }
    }
  }

  const strBuf = [];

  for (let i = 0, ii = str.length; i < ii; i++) {
    const code = PDFStringTranslateTable[str.charCodeAt(i)];
    strBuf.push(code ? String.fromCharCode(code) : str.charAt(i));
  }

  return strBuf.join("");
}

function escapeString(str) {
  return str.replace(/([()\\\n\r])/g, match => {
    if (match === "\n") {
      return "\\n";
    } else if (match === "\r") {
      return "\\r";
    }

    return `\\${match}`;
  });
}

function isAscii(str) {
  return /^[\x00-\x7F]*$/.test(str);
}

function stringToUTF16BEString(str) {
  const buf = ["\xFE\xFF"];

  for (let i = 0, ii = str.length; i < ii; i++) {
    const char = str.charCodeAt(i);
    buf.push(String.fromCharCode(char >> 8 & 0xff), String.fromCharCode(char & 0xff));
  }

  return buf.join("");
}

function stringToUTF8String(str) {
  return decodeURIComponent(escape(str));
}

function utf8StringToString(str) {
  return unescape(encodeURIComponent(str));
}

function isArrayBuffer(v) {
  return typeof v === "object" && v !== null && v.byteLength !== undefined;
}

function isArrayEqual(arr1, arr2) {
  if (arr1.length !== arr2.length) {
    return false;
  }

  for (let i = 0, ii = arr1.length; i < ii; i++) {
    if (arr1[i] !== arr2[i]) {
      return false;
    }
  }

  return true;
}

function getModificationDate(date = new Date()) {
  const buffer = [date.getUTCFullYear().toString(), (date.getUTCMonth() + 1).toString().padStart(2, "0"), date.getUTCDate().toString().padStart(2, "0"), date.getUTCHours().toString().padStart(2, "0"), date.getUTCMinutes().toString().padStart(2, "0"), date.getUTCSeconds().toString().padStart(2, "0")];
  return buffer.join("");
}

function createPromiseCapability() {
  const capability = Object.create(null);
  let isSettled = false;
  Object.defineProperty(capability, "settled", {
    get() {
      return isSettled;
    }

  });
  capability.promise = new Promise(function (resolve, reject) {
    capability.resolve = function (data) {
      isSettled = true;
      resolve(data);
    };

    capability.reject = function (reason) {
      isSettled = true;
      reject(reason);
    };
  });
  return capability;
}