pdfjs-dist/lib/core/pattern.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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.getTilingPatternIR = getTilingPatternIR;
exports.Pattern = void 0;

var _util = require("../shared/util.js");

var _colorspace = require("./colorspace.js");

var _primitives = require("./primitives.js");

var _core_utils = require("./core_utils.js");

const ShadingType = {
  FUNCTION_BASED: 1,
  AXIAL: 2,
  RADIAL: 3,
  FREE_FORM_MESH: 4,
  LATTICE_FORM_MESH: 5,
  COONS_PATCH_MESH: 6,
  TENSOR_PATCH_MESH: 7
};

class Pattern {
  constructor() {
    (0, _util.unreachable)("Cannot initialize Pattern.");
  }

  static parseShading(shading, matrix, xref, res, handler, pdfFunctionFactory, localColorSpaceCache) {
    const dict = (0, _primitives.isStream)(shading) ? shading.dict : shading;
    const type = dict.get("ShadingType");

    try {
      switch (type) {
        case ShadingType.AXIAL:
        case ShadingType.RADIAL:
          return new RadialAxialShading(dict, matrix, xref, res, pdfFunctionFactory, localColorSpaceCache);

        case ShadingType.FREE_FORM_MESH:
        case ShadingType.LATTICE_FORM_MESH:
        case ShadingType.COONS_PATCH_MESH:
        case ShadingType.TENSOR_PATCH_MESH:
          return new MeshShading(shading, matrix, xref, res, pdfFunctionFactory, localColorSpaceCache);

        default:
          throw new _util.FormatError("Unsupported ShadingType: " + type);
      }
    } catch (ex) {
      if (ex instanceof _core_utils.MissingDataException) {
        throw ex;
      }

      handler.send("UnsupportedFeature", {
        featureId: _util.UNSUPPORTED_FEATURES.shadingPattern
      });
      (0, _util.warn)(ex);
      return new DummyShading();
    }
  }

}

exports.Pattern = Pattern;

class BaseShading {
  static get SMALL_NUMBER() {
    return (0, _util.shadow)(this, "SMALL_NUMBER", 1e-6);
  }

  constructor() {
    if (this.constructor === BaseShading) {
      (0, _util.unreachable)("Cannot initialize BaseShading.");
    }
  }

  getIR() {
    (0, _util.unreachable)("Abstract method `getIR` called.");
  }

}

class RadialAxialShading extends BaseShading {
  constructor(dict, matrix, xref, resources, pdfFunctionFactory, localColorSpaceCache) {
    super();
    this.matrix = matrix;
    this.coordsArr = dict.getArray("Coords");
    this.shadingType = dict.get("ShadingType");

    const cs = _colorspace.ColorSpace.parse({
      cs: dict.getRaw("ColorSpace") || dict.getRaw("CS"),
      xref,
      resources,
      pdfFunctionFactory,
      localColorSpaceCache
    });

    const bbox = dict.getArray("BBox");

    if (Array.isArray(bbox) && bbox.length === 4) {
      this.bbox = _util.Util.normalizeRect(bbox);
    } else {
      this.bbox = null;
    }

    let t0 = 0.0,
        t1 = 1.0;

    if (dict.has("Domain")) {
      const domainArr = dict.getArray("Domain");
      t0 = domainArr[0];
      t1 = domainArr[1];
    }

    let extendStart = false,
        extendEnd = false;

    if (dict.has("Extend")) {
      const extendArr = dict.getArray("Extend");
      extendStart = extendArr[0];
      extendEnd = extendArr[1];
    }

    if (this.shadingType === ShadingType.RADIAL && (!extendStart || !extendEnd)) {
      const [x1, y1, r1, x2, y2, r2] = this.coordsArr;
      const distance = Math.hypot(x1 - x2, y1 - y2);

      if (r1 <= r2 + distance && r2 <= r1 + distance) {
        (0, _util.warn)("Unsupported radial gradient.");
      }
    }

    this.extendStart = extendStart;
    this.extendEnd = extendEnd;
    const fnObj = dict.getRaw("Function");
    const fn = pdfFunctionFactory.createFromArray(fnObj);
    const NUMBER_OF_SAMPLES = 10;
    const step = (t1 - t0) / NUMBER_OF_SAMPLES;
    const colorStops = this.colorStops = [];

    if (t0 >= t1 || step <= 0) {
      (0, _util.info)("Bad shading domain.");
      return;
    }

    const color = new Float32Array(cs.numComps),
          ratio = new Float32Array(1);
    let rgbColor;

    for (let i = 0; i <= NUMBER_OF_SAMPLES; i++) {
      ratio[0] = t0 + i * step;
      fn(ratio, 0, color, 0);
      rgbColor = cs.getRgb(color, 0);

      const cssColor = _util.Util.makeHexColor(rgbColor[0], rgbColor[1], rgbColor[2]);

      colorStops.push([i / NUMBER_OF_SAMPLES, cssColor]);
    }

    let background = "transparent";

    if (dict.has("Background")) {
      rgbColor = cs.getRgb(dict.get("Background"), 0);
      background = _util.Util.makeHexColor(rgbColor[0], rgbColor[1], rgbColor[2]);
    }

    if (!extendStart) {
      colorStops.unshift([0, background]);
      colorStops[1][0] += BaseShading.SMALL_NUMBER;
    }

    if (!extendEnd) {
      colorStops[colorStops.length - 1][0] -= BaseShading.SMALL_NUMBER;
      colorStops.push([1, background]);
    }

    this.colorStops = colorStops;
  }

  getIR() {
    const coordsArr = this.coordsArr;
    const shadingType = this.shadingType;
    let type, p0, p1, r0, r1;

    if (shadingType === ShadingType.AXIAL) {
      p0 = [coordsArr[0], coordsArr[1]];
      p1 = [coordsArr[2], coordsArr[3]];
      r0 = null;
      r1 = null;
      type = "axial";
    } else if (shadingType === ShadingType.RADIAL) {
      p0 = [coordsArr[0], coordsArr[1]];
      p1 = [coordsArr[3], coordsArr[4]];
      r0 = coordsArr[2];
      r1 = coordsArr[5];
      type = "radial";
    } else {
      (0, _util.unreachable)(`getPattern type unknown: ${shadingType}`);
    }

    return ["RadialAxial", type, this.bbox, this.colorStops, p0, p1, r0, r1, this.matrix];
  }

}

class MeshStreamReader {
  constructor(stream, context) {
    this.stream = stream;
    this.context = context;
    this.buffer = 0;
    this.bufferLength = 0;
    const numComps = context.numComps;
    this.tmpCompsBuf = new Float32Array(numComps);
    const csNumComps = context.colorSpace.numComps;
    this.tmpCsCompsBuf = context.colorFn ? new Float32Array(csNumComps) : this.tmpCompsBuf;
  }

  get hasData() {
    if (this.stream.end) {
      return this.stream.pos < this.stream.end;
    }

    if (this.bufferLength > 0) {
      return true;
    }

    const nextByte = this.stream.getByte();

    if (nextByte < 0) {
      return false;
    }

    this.buffer = nextByte;
    this.bufferLength = 8;
    return true;
  }

  readBits(n) {
    let buffer = this.buffer;
    let bufferLength = this.bufferLength;

    if (n === 32) {
      if (bufferLength === 0) {
        return (this.stream.getByte() << 24 | this.stream.getByte() << 16 | this.stream.getByte() << 8 | this.stream.getByte()) >>> 0;
      }

      buffer = buffer << 24 | this.stream.getByte() << 16 | this.stream.getByte() << 8 | this.stream.getByte();
      const nextByte = this.stream.getByte();
      this.buffer = nextByte & (1 << bufferLength) - 1;
      return (buffer << 8 - bufferLength | (nextByte & 0xff) >> bufferLength) >>> 0;
    }

    if (n === 8 && bufferLength === 0) {
      return this.stream.getByte();
    }

    while (bufferLength < n) {
      buffer = buffer << 8 | this.stream.getByte();
      bufferLength += 8;
    }

    bufferLength -= n;
    this.bufferLength = bufferLength;
    this.buffer = buffer & (1 << bufferLength) - 1;
    return buffer >> bufferLength;
  }

  align() {
    this.buffer = 0;
    this.bufferLength = 0;
  }

  readFlag() {
    return this.readBits(this.context.bitsPerFlag);
  }

  readCoordinate() {
    const bitsPerCoordinate = this.context.bitsPerCoordinate;
    const xi = this.readBits(bitsPerCoordinate);
    const yi = this.readBits(bitsPerCoordinate);
    const decode = this.context.decode;
    const scale = bitsPerCoordinate < 32 ? 1 / ((1 << bitsPerCoordinate) - 1) : 2.3283064365386963e-10;
    return [xi * scale * (decode[1] - decode[0]) + decode[0], yi * scale * (decode[3] - decode[2]) + decode[2]];
  }

  readComponents() {
    const numComps = this.context.numComps;
    const bitsPerComponent = this.context.bitsPerComponent;
    const scale = bitsPerComponent < 32 ? 1 / ((1 << bitsPerComponent) - 1) : 2.3283064365386963e-10;
    const decode = this.context.decode;
    const components = this.tmpCompsBuf;

    for (let i = 0, j = 4; i < numComps; i++, j += 2) {
      const ci = this.readBits(bitsPerComponent);
      components[i] = ci * scale * (decode[j + 1] - decode[j]) + decode[j];
    }

    const color = this.tmpCsCompsBuf;

    if (this.context.colorFn) {
      this.context.colorFn(components, 0, color, 0);
    }

    return this.context.colorSpace.getRgb(color, 0);
  }

}

const getB = function getBClosure() {
  function buildB(count) {
    const lut = [];

    for (let i = 0; i <= count; i++) {
      const t = i / count,
            t_ = 1 - t;
      lut.push(new Float32Array([t_ * t_ * t_, 3 * t * t_ * t_, 3 * t * t * t_, t * t * t]));
    }

    return lut;
  }

  const cache = [];
  return function (count) {
    if (!cache[count]) {
      cache[count] = buildB(count);
    }

    return cache[count];
  };
}();

class MeshShading extends BaseShading {
  static get MIN_SPLIT_PATCH_CHUNKS_AMOUNT() {
    return (0, _util.shadow)(this, "MIN_SPLIT_PATCH_CHUNKS_AMOUNT", 3);
  }

  static get MAX_SPLIT_PATCH_CHUNKS_AMOUNT() {
    return (0, _util.shadow)(this, "MAX_SPLIT_PATCH_CHUNKS_AMOUNT", 20);
  }

  static get TRIANGLE_DENSITY() {
    return (0, _util.shadow)(this, "TRIANGLE_DENSITY", 20);
  }

  constructor(stream, matrix, xref, resources, pdfFunctionFactory, localColorSpaceCache) {
    super();

    if (!(0, _primitives.isStream)(stream)) {
      throw new _util.FormatError("Mesh data is not a stream");
    }

    const dict = stream.dict;
    this.matrix = matrix;
    this.shadingType = dict.get("ShadingType");
    const bbox = dict.getArray("BBox");

    if (Array.isArray(bbox) && bbox.length === 4) {
      this.bbox = _util.Util.normalizeRect(bbox);
    } else {
      this.bbox = null;
    }

    const cs = _colorspace.ColorSpace.parse({
      cs: dict.getRaw("ColorSpace") || dict.getRaw("CS"),
      xref,
      resources,
      pdfFunctionFactory,
      localColorSpaceCache
    });

    this.background = dict.has("Background") ? cs.getRgb(dict.get("Background"), 0) : null;
    const fnObj = dict.getRaw("Function");
    const fn = fnObj ? pdfFunctionFactory.createFromArray(fnObj) : null;
    this.coords = [];
    this.colors = [];
    this.figures = [];
    const decodeContext = {
      bitsPerCoordinate: dict.get("BitsPerCoordinate"),
      bitsPerComponent: dict.get("BitsPerComponent"),
      bitsPerFlag: dict.get("BitsPerFlag"),
      decode: dict.getArray("Decode"),
      colorFn: fn,
      colorSpace: cs,
      numComps: fn ? 1 : cs.numComps
    };
    const reader = new MeshStreamReader(stream, decodeContext);
    let patchMesh = false;

    switch (this.shadingType) {
      case ShadingType.FREE_FORM_MESH:
        this._decodeType4Shading(reader);

        break;

      case ShadingType.LATTICE_FORM_MESH:
        const verticesPerRow = dict.get("VerticesPerRow") | 0;

        if (verticesPerRow < 2) {
          throw new _util.FormatError("Invalid VerticesPerRow");
        }

        this._decodeType5Shading(reader, verticesPerRow);

        break;

      case ShadingType.COONS_PATCH_MESH:
        this._decodeType6Shading(reader);

        patchMesh = true;
        break;

      case ShadingType.TENSOR_PATCH_MESH:
        this._decodeType7Shading(reader);

        patchMesh = true;
        break;

      default:
        (0, _util.unreachable)("Unsupported mesh type.");
        break;
    }

    if (patchMesh) {
      this._updateBounds();

      for (let i = 0, ii = this.figures.length; i < ii; i++) {
        this._buildFigureFromPatch(i);
      }
    }

    this._updateBounds();

    this._packData();
  }

  _decodeType4Shading(reader) {
    const coords = this.coords;
    const colors = this.colors;
    const operators = [];
    const ps = [];
    let verticesLeft = 0;

    while (reader.hasData) {
      const f = reader.readFlag();
      const coord = reader.readCoordinate();
      const color = reader.readComponents();

      if (verticesLeft === 0) {
        if (!(0 <= f && f <= 2)) {
          throw new _util.FormatError("Unknown type4 flag");
        }

        switch (f) {
          case 0:
            verticesLeft = 3;
            break;

          case 1:
            ps.push(ps[ps.length - 2], ps[ps.length - 1]);
            verticesLeft = 1;
            break;

          case 2:
            ps.push(ps[ps.length - 3], ps[ps.length - 1]);
            verticesLeft = 1;
            break;
        }

        operators.push(f);
      }

      ps.push(coords.length);
      coords.push(coord);
      colors.push(color);
      verticesLeft--;
      reader.align();
    }

    this.figures.push({
      type: "triangles",
      coords: new Int32Array(ps),
      colors: new Int32Array(ps)
    });
  }

  _decodeType5Shading(reader, verticesPerRow) {
    const coords = this.coords;
    const colors = this.colors;
    const ps = [];

    while (reader.hasData) {
      const coord = reader.readCoordinate();
      const color = reader.readComponents();
      ps.push(coords.length);
      coords.push(coord);
      colors.push(color);
    }

    this.figures.push({
      type: "lattice",
      coords: new Int32Array(ps),
      colors: new Int32Array(ps),
      verticesPerRow
    });
  }

  _decodeType6Shading(reader) {
    const coords = this.coords;
    const colors = this.colors;
    const ps = new Int32Array(16);
    const cs = new Int32Array(4);

    while (reader.hasData) {
      const f = reader.readFlag();

      if (!(0 <= f && f <= 3)) {
        throw new _util.FormatError("Unknown type6 flag");
      }

      const pi = coords.length;

      for (let i = 0, ii = f !== 0 ? 8 : 12; i < ii; i++) {
        coords.push(reader.readCoordinate());
      }

      const ci = colors.length;

      for (let i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
        colors.push(reader.readComponents());
      }

      let tmp1, tmp2, tmp3, tmp4;

      switch (f) {
        case 0:
          ps[12] = pi + 3;
          ps[13] = pi + 4;
          ps[14] = pi + 5;
          ps[15] = pi + 6;
          ps[8] = pi + 2;
          ps[11] = pi + 7;
          ps[4] = pi + 1;
          ps[7] = pi + 8;
          ps[0] = pi;
          ps[1] = pi + 11;
          ps[2] = pi + 10;
          ps[3] = pi + 9;
          cs[2] = ci + 1;
          cs[3] = ci + 2;
          cs[0] = ci;
          cs[1] = ci + 3;
          break;

        case 1:
          tmp1 = ps[12];
          tmp2 = ps[13];
          tmp3 = ps[14];
          tmp4 = ps[15];
          ps[12] = tmp4;
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = tmp3;
          ps[11] = pi + 3;
          ps[4] = tmp2;
          ps[7] = pi + 4;
          ps[0] = tmp1;
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          tmp1 = cs[2];
          tmp2 = cs[3];
          cs[2] = tmp2;
          cs[3] = ci;
          cs[0] = tmp1;
          cs[1] = ci + 1;
          break;

        case 2:
          tmp1 = ps[15];
          tmp2 = ps[11];
          ps[12] = ps[3];
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = ps[7];
          ps[11] = pi + 3;
          ps[4] = tmp2;
          ps[7] = pi + 4;
          ps[0] = tmp1;
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          tmp1 = cs[3];
          cs[2] = cs[1];
          cs[3] = ci;
          cs[0] = tmp1;
          cs[1] = ci + 1;
          break;

        case 3:
          ps[12] = ps[0];
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = ps[1];
          ps[11] = pi + 3;
          ps[4] = ps[2];
          ps[7] = pi + 4;
          ps[0] = ps[3];
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          cs[2] = cs[0];
          cs[3] = ci;
          cs[0] = cs[1];
          cs[1] = ci + 1;
          break;
      }

      ps[5] = coords.length;
      coords.push([(-4 * coords[ps[0]][0] - coords[ps[15]][0] + 6 * (coords[ps[4]][0] + coords[ps[1]][0]) - 2 * (coords[ps[12]][0] + coords[ps[3]][0]) + 3 * (coords[ps[13]][0] + coords[ps[7]][0])) / 9, (-4 * coords[ps[0]][1] - coords[ps[15]][1] + 6 * (coords[ps[4]][1] + coords[ps[1]][1]) - 2 * (coords[ps[12]][1] + coords[ps[3]][1]) + 3 * (coords[ps[13]][1] + coords[ps[7]][1])) / 9]);
      ps[6] = coords.length;
      coords.push([(-4 * coords[ps[3]][0] - coords[ps[12]][0] + 6 * (coords[ps[2]][0] + coords[ps[7]][0]) - 2 * (coords[ps[0]][0] + coords[ps[15]][0]) + 3 * (coords[ps[4]][0] + coords[ps[14]][0])) / 9, (-4 * coords[ps[3]][1] - coords[ps[12]][1] + 6 * (coords[ps[2]][1] + coords[ps[7]][1]) - 2 * (coords[ps[0]][1] + coords[ps[15]][1]) + 3 * (coords[ps[4]][1] + coords[ps[14]][1])) / 9]);
      ps[9] = coords.length;
      coords.push([(-4 * coords[ps[12]][0] - coords[ps[3]][0] + 6 * (coords[ps[8]][0] + coords[ps[13]][0]) - 2 * (coords[ps[0]][0] + coords[ps[15]][0]) + 3 * (coords[ps[11]][0] + coords[ps[1]][0])) / 9, (-4 * coords[ps[12]][1] - coords[ps[3]][1] + 6 * (coords[ps[8]][1] + coords[ps[13]][1]) - 2 * (coords[ps[0]][1] + coords[ps[15]][1]) + 3 * (coords[ps[11]][1] + coords[ps[1]][1])) / 9]);
      ps[10] = coords.length;
      coords.push([(-4 * coords[ps[15]][0] - coords[ps[0]][0] + 6 * (coords[ps[11]][0] + coords[ps[14]][0]) - 2 * (coords[ps[12]][0] + coords[ps[3]][0]) + 3 * (coords[ps[2]][0] + coords[ps[8]][0])) / 9, (-4 * coords[ps[15]][1] - coords[ps[0]][1] + 6 * (coords[ps[11]][1] + coords[ps[14]][1]) - 2 * (coords[ps[12]][1] + coords[ps[3]][1]) + 3 * (coords[ps[2]][1] + coords[ps[8]][1])) / 9]);
      this.figures.push({
        type: "patch",
        coords: new Int32Array(ps),
        colors: new Int32Array(cs)
      });
    }
  }

  _decodeType7Shading(reader) {
    const coords = this.coords;
    const colors = this.colors;
    const ps = new Int32Array(16);
    const cs = new Int32Array(4);

    while (reader.hasData) {
      const f = reader.readFlag();

      if (!(0 <= f && f <= 3)) {
        throw new _util.FormatError("Unknown type7 flag");
      }

      const pi = coords.length;

      for (let i = 0, ii = f !== 0 ? 12 : 16; i < ii; i++) {
        coords.push(reader.readCoordinate());
      }

      const ci = colors.length;

      for (let i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
        colors.push(reader.readComponents());
      }

      let tmp1, tmp2, tmp3, tmp4;

      switch (f) {
        case 0:
          ps[12] = pi + 3;
          ps[13] = pi + 4;
          ps[14] = pi + 5;
          ps[15] = pi + 6;
          ps[8] = pi + 2;
          ps[9] = pi + 13;
          ps[10] = pi + 14;
          ps[11] = pi + 7;
          ps[4] = pi + 1;
          ps[5] = pi + 12;
          ps[6] = pi + 15;
          ps[7] = pi + 8;
          ps[0] = pi;
          ps[1] = pi + 11;
          ps[2] = pi + 10;
          ps[3] = pi + 9;
          cs[2] = ci + 1;
          cs[3] = ci + 2;
          cs[0] = ci;
          cs[1] = ci + 3;
          break;

        case 1:
          tmp1 = ps[12];
          tmp2 = ps[13];
          tmp3 = ps[14];
          tmp4 = ps[15];
          ps[12] = tmp4;
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = tmp3;
          ps[9] = pi + 9;
          ps[10] = pi + 10;
          ps[11] = pi + 3;
          ps[4] = tmp2;
          ps[5] = pi + 8;
          ps[6] = pi + 11;
          ps[7] = pi + 4;
          ps[0] = tmp1;
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          tmp1 = cs[2];
          tmp2 = cs[3];
          cs[2] = tmp2;
          cs[3] = ci;
          cs[0] = tmp1;
          cs[1] = ci + 1;
          break;

        case 2:
          tmp1 = ps[15];
          tmp2 = ps[11];
          ps[12] = ps[3];
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = ps[7];
          ps[9] = pi + 9;
          ps[10] = pi + 10;
          ps[11] = pi + 3;
          ps[4] = tmp2;
          ps[5] = pi + 8;
          ps[6] = pi + 11;
          ps[7] = pi + 4;
          ps[0] = tmp1;
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          tmp1 = cs[3];
          cs[2] = cs[1];
          cs[3] = ci;
          cs[0] = tmp1;
          cs[1] = ci + 1;
          break;

        case 3:
          ps[12] = ps[0];
          ps[13] = pi + 0;
          ps[14] = pi + 1;
          ps[15] = pi + 2;
          ps[8] = ps[1];
          ps[9] = pi + 9;
          ps[10] = pi + 10;
          ps[11] = pi + 3;
          ps[4] = ps[2];
          ps[5] = pi + 8;
          ps[6] = pi + 11;
          ps[7] = pi + 4;
          ps[0] = ps[3];
          ps[1] = pi + 7;
          ps[2] = pi + 6;
          ps[3] = pi + 5;
          cs[2] = cs[0];
          cs[3] = ci;
          cs[0] = cs[1];
          cs[1] = ci + 1;
          break;
      }

      this.figures.push({
        type: "patch",
        coords: new Int32Array(ps),
        colors: new Int32Array(cs)
      });
    }
  }

  _buildFigureFromPatch(index) {
    const figure = this.figures[index];
    (0, _util.assert)(figure.type === "patch", "Unexpected patch mesh figure");
    const coords = this.coords,
          colors = this.colors;
    const pi = figure.coords;
    const ci = figure.colors;
    const figureMinX = Math.min(coords[pi[0]][0], coords[pi[3]][0], coords[pi[12]][0], coords[pi[15]][0]);
    const figureMinY = Math.min(coords[pi[0]][1], coords[pi[3]][1], coords[pi[12]][1], coords[pi[15]][1]);
    const figureMaxX = Math.max(coords[pi[0]][0], coords[pi[3]][0], coords[pi[12]][0], coords[pi[15]][0]);
    const figureMaxY = Math.max(coords[pi[0]][1], coords[pi[3]][1], coords[pi[12]][1], coords[pi[15]][1]);
    let splitXBy = Math.ceil((figureMaxX - figureMinX) * MeshShading.TRIANGLE_DENSITY / (this.bounds[2] - this.bounds[0]));
    splitXBy = Math.max(MeshShading.MIN_SPLIT_PATCH_CHUNKS_AMOUNT, Math.min(MeshShading.MAX_SPLIT_PATCH_CHUNKS_AMOUNT, splitXBy));
    let splitYBy = Math.ceil((figureMaxY - figureMinY) * MeshShading.TRIANGLE_DENSITY / (this.bounds[3] - this.bounds[1]));
    splitYBy = Math.max(MeshShading.MIN_SPLIT_PATCH_CHUNKS_AMOUNT, Math.min(MeshShading.MAX_SPLIT_PATCH_CHUNKS_AMOUNT, splitYBy));
    const verticesPerRow = splitXBy + 1;
    const figureCoords = new Int32Array((splitYBy + 1) * verticesPerRow);
    const figureColors = new Int32Array((splitYBy + 1) * verticesPerRow);
    let k = 0;
    const cl = new Uint8Array(3),
          cr = new Uint8Array(3);
    const c0 = colors[ci[0]],
          c1 = colors[ci[1]],
          c2 = colors[ci[2]],
          c3 = colors[ci[3]];
    const bRow = getB(splitYBy),
          bCol = getB(splitXBy);

    for (let row = 0; row <= splitYBy; row++) {
      cl[0] = (c0[0] * (splitYBy - row) + c2[0] * row) / splitYBy | 0;
      cl[1] = (c0[1] * (splitYBy - row) + c2[1] * row) / splitYBy | 0;
      cl[2] = (c0[2] * (splitYBy - row) + c2[2] * row) / splitYBy | 0;
      cr[0] = (c1[0] * (splitYBy - row) + c3[0] * row) / splitYBy | 0;
      cr[1] = (c1[1] * (splitYBy - row) + c3[1] * row) / splitYBy | 0;
      cr[2] = (c1[2] * (splitYBy - row) + c3[2] * row) / splitYBy | 0;

      for (let col = 0; col <= splitXBy; col++, k++) {
        if ((row === 0 || row === splitYBy) && (col === 0 || col === splitXBy)) {
          continue;
        }

        let x = 0,
            y = 0;
        let q = 0;

        for (let i = 0; i <= 3; i++) {
          for (let j = 0; j <= 3; j++, q++) {
            const m = bRow[row][i] * bCol[col][j];
            x += coords[pi[q]][0] * m;
            y += coords[pi[q]][1] * m;
          }
        }

        figureCoords[k] = coords.length;
        coords.push([x, y]);
        figureColors[k] = colors.length;
        const newColor = new Uint8Array(3);
        newColor[0] = (cl[0] * (splitXBy - col) + cr[0] * col) / splitXBy | 0;
        newColor[1] = (cl[1] * (splitXBy - col) + cr[1] * col) / splitXBy | 0;
        newColor[2] = (cl[2] * (splitXBy - col) + cr[2] * col) / splitXBy | 0;
        colors.push(newColor);
      }
    }

    figureCoords[0] = pi[0];
    figureColors[0] = ci[0];
    figureCoords[splitXBy] = pi[3];
    figureColors[splitXBy] = ci[1];
    figureCoords[verticesPerRow * splitYBy] = pi[12];
    figureColors[verticesPerRow * splitYBy] = ci[2];
    figureCoords[verticesPerRow * splitYBy + splitXBy] = pi[15];
    figureColors[verticesPerRow * splitYBy + splitXBy] = ci[3];
    this.figures[index] = {
      type: "lattice",
      coords: figureCoords,
      colors: figureColors,
      verticesPerRow
    };
  }

  _updateBounds() {
    let minX = this.coords[0][0],
        minY = this.coords[0][1],
        maxX = minX,
        maxY = minY;

    for (let i = 1, ii = this.coords.length; i < ii; i++) {
      const x = this.coords[i][0],
            y = this.coords[i][1];
      minX = minX > x ? x : minX;
      minY = minY > y ? y : minY;
      maxX = maxX < x ? x : maxX;
      maxY = maxY < y ? y : maxY;
    }

    this.bounds = [minX, minY, maxX, maxY];
  }

  _packData() {
    let i, ii, j, jj;
    const coords = this.coords;
    const coordsPacked = new Float32Array(coords.length * 2);

    for (i = 0, j = 0, ii = coords.length; i < ii; i++) {
      const xy = coords[i];
      coordsPacked[j++] = xy[0];
      coordsPacked[j++] = xy[1];
    }

    this.coords = coordsPacked;
    const colors = this.colors;
    const colorsPacked = new Uint8Array(colors.length * 3);

    for (i = 0, j = 0, ii = colors.length; i < ii; i++) {
      const c = colors[i];
      colorsPacked[j++] = c[0];
      colorsPacked[j++] = c[1];
      colorsPacked[j++] = c[2];
    }

    this.colors = colorsPacked;
    const figures = this.figures;

    for (i = 0, ii = figures.length; i < ii; i++) {
      const figure = figures[i],
            ps = figure.coords,
            cs = figure.colors;

      for (j = 0, jj = ps.length; j < jj; j++) {
        ps[j] *= 2;
        cs[j] *= 3;
      }
    }
  }

  getIR() {
    return ["Mesh", this.shadingType, this.coords, this.colors, this.figures, this.bounds, this.matrix, this.bbox, this.background];
  }

}

class DummyShading extends BaseShading {
  getIR() {
    return ["Dummy"];
  }

}

function getTilingPatternIR(operatorList, dict, color) {
  const matrix = dict.getArray("Matrix");

  const bbox = _util.Util.normalizeRect(dict.getArray("BBox"));

  const xstep = dict.get("XStep");
  const ystep = dict.get("YStep");
  const paintType = dict.get("PaintType");
  const tilingType = dict.get("TilingType");

  if (bbox[2] - bbox[0] === 0 || bbox[3] - bbox[1] === 0) {
    throw new _util.FormatError(`Invalid getTilingPatternIR /BBox array: [${bbox}].`);
  }

  return ["TilingPattern", color, operatorList, matrix, bbox, xstep, ystep, paintType, tilingType];
}