canvas.js

/* Copyright 2012 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.
 */

import {
  FONT_IDENTITY_MATRIX,
  IDENTITY_MATRIX,
  ImageKind,
  info,
  isLittleEndian,
  isNum,
  OPS,
  shadow,
  TextRenderingMode,
  unreachable,
  Util,
  warn,
} from "../shared/util.js";
import { getShadingPatternFromIR, TilingPattern } from "./pattern_helper.js";

// <canvas> contexts store most of the state we need natively.
// However, PDF needs a bit more state, which we store here.

// Minimal font size that would be used during canvas fillText operations.
var MIN_FONT_SIZE = 16;
// Maximum font size that would be used during canvas fillText operations.
var MAX_FONT_SIZE = 100;
var MAX_GROUP_SIZE = 4096;

// Heuristic value used when enforcing minimum line widths.
var MIN_WIDTH_FACTOR = 0.65;

var COMPILE_TYPE3_GLYPHS = true;
var MAX_SIZE_TO_COMPILE = 1000;

var FULL_CHUNK_HEIGHT = 16;

var IsLittleEndianCached = {
  get value() {
    return shadow(IsLittleEndianCached, "value", isLittleEndian());
  },
};

function addContextCurrentTransform(ctx) {
  // If the context doesn't expose a `mozCurrentTransform`, add a JS based one.
  if (!ctx.mozCurrentTransform) {
    ctx._originalSave = ctx.save;
    ctx._originalRestore = ctx.restore;
    ctx._originalRotate = ctx.rotate;
    ctx._originalScale = ctx.scale;
    ctx._originalTranslate = ctx.translate;
    ctx._originalTransform = ctx.transform;
    ctx._originalSetTransform = ctx.setTransform;

    ctx._transformMatrix = ctx._transformMatrix || [1, 0, 0, 1, 0, 0];
    ctx._transformStack = [];

    Object.defineProperty(ctx, "mozCurrentTransform", {
      get: function getCurrentTransform() {
        return this._transformMatrix;
      },
    });

    Object.defineProperty(ctx, "mozCurrentTransformInverse", {
      get: function getCurrentTransformInverse() {
        // Calculation done using WolframAlpha:
        // http://www.wolframalpha.com/input/?
        //   i=Inverse+{{a%2C+c%2C+e}%2C+{b%2C+d%2C+f}%2C+{0%2C+0%2C+1}}

        var m = this._transformMatrix;
        var a = m[0],
          b = m[1],
          c = m[2],
          d = m[3],
          e = m[4],
          f = m[5];

        var ad_bc = a * d - b * c;
        var bc_ad = b * c - a * d;

        return [
          d / ad_bc,
          b / bc_ad,
          c / bc_ad,
          a / ad_bc,
          (d * e - c * f) / bc_ad,
          (b * e - a * f) / ad_bc,
        ];
      },
    });

    ctx.save = function ctxSave() {
      var old = this._transformMatrix;
      this._transformStack.push(old);
      this._transformMatrix = old.slice(0, 6);

      this._originalSave();
    };

    ctx.restore = function ctxRestore() {
      var prev = this._transformStack.pop();
      if (prev) {
        this._transformMatrix = prev;
        this._originalRestore();
      }
    };

    ctx.translate = function ctxTranslate(x, y) {
      var m = this._transformMatrix;
      m[4] = m[0] * x + m[2] * y + m[4];
      m[5] = m[1] * x + m[3] * y + m[5];

      this._originalTranslate(x, y);
    };

    ctx.scale = function ctxScale(x, y) {
      var m = this._transformMatrix;
      m[0] = m[0] * x;
      m[1] = m[1] * x;
      m[2] = m[2] * y;
      m[3] = m[3] * y;

      this._originalScale(x, y);
    };

    ctx.transform = function ctxTransform(a, b, c, d, e, f) {
      var m = this._transformMatrix;
      this._transformMatrix = [
        m[0] * a + m[2] * b,
        m[1] * a + m[3] * b,
        m[0] * c + m[2] * d,
        m[1] * c + m[3] * d,
        m[0] * e + m[2] * f + m[4],
        m[1] * e + m[3] * f + m[5],
      ];

      ctx._originalTransform(a, b, c, d, e, f);
    };

    ctx.setTransform = function ctxSetTransform(a, b, c, d, e, f) {
      this._transformMatrix = [a, b, c, d, e, f];

      ctx._originalSetTransform(a, b, c, d, e, f);
    };

    ctx.rotate = function ctxRotate(angle) {
      var cosValue = Math.cos(angle);
      var sinValue = Math.sin(angle);

      var m = this._transformMatrix;
      this._transformMatrix = [
        m[0] * cosValue + m[2] * sinValue,
        m[1] * cosValue + m[3] * sinValue,
        m[0] * -sinValue + m[2] * cosValue,
        m[1] * -sinValue + m[3] * cosValue,
        m[4],
        m[5],
      ];

      this._originalRotate(angle);
    };
  }
}

var CachedCanvases = (function CachedCanvasesClosure() {
  function CachedCanvases(canvasFactory) {
    this.canvasFactory = canvasFactory;
    this.cache = Object.create(null);
  }
  CachedCanvases.prototype = {
    getCanvas: function CachedCanvases_getCanvas(
      id,
      width,
      height,
      trackTransform
    ) {
      var canvasEntry;
      if (this.cache[id] !== undefined) {
        canvasEntry = this.cache[id];
        this.canvasFactory.reset(canvasEntry, width, height);
        // reset canvas transform for emulated mozCurrentTransform, if needed
        canvasEntry.context.setTransform(1, 0, 0, 1, 0, 0);
      } else {
        canvasEntry = this.canvasFactory.create(width, height);
        this.cache[id] = canvasEntry;
      }
      if (trackTransform) {
        addContextCurrentTransform(canvasEntry.context);
      }
      return canvasEntry;
    },
    clear() {
      for (var id in this.cache) {
        var canvasEntry = this.cache[id];
        this.canvasFactory.destroy(canvasEntry);
        delete this.cache[id];
      }
    },
  };
  return CachedCanvases;
})();

function compileType3Glyph(imgData) {
  var POINT_TO_PROCESS_LIMIT = 1000;

  var width = imgData.width,
    height = imgData.height;
  var i,
    j,
    j0,
    width1 = width + 1;
  var points = new Uint8Array(width1 * (height + 1));
  // prettier-ignore
  var POINT_TYPES =
      new Uint8Array([0, 2, 4, 0, 1, 0, 5, 4, 8, 10, 0, 8, 0, 2, 1, 0]);

  // decodes bit-packed mask data
  var lineSize = (width + 7) & ~7,
    data0 = imgData.data;
  var data = new Uint8Array(lineSize * height),
    pos = 0,
    ii;
  for (i = 0, ii = data0.length; i < ii; i++) {
    var mask = 128,
      elem = data0[i];
    while (mask > 0) {
      data[pos++] = elem & mask ? 0 : 255;
      mask >>= 1;
    }
  }

  // finding interesting points: every point is located between mask pixels,
  // so there will be points of the (width + 1)x(height + 1) grid. Every point
  // will have flags assigned based on neighboring mask pixels:
  //   4 | 8
  //   --P--
  //   2 | 1
  // We are interested only in points with the flags:
  //   - outside corners: 1, 2, 4, 8;
  //   - inside corners: 7, 11, 13, 14;
  //   - and, intersections: 5, 10.
  var count = 0;
  pos = 0;
  if (data[pos] !== 0) {
    points[0] = 1;
    ++count;
  }
  for (j = 1; j < width; j++) {
    if (data[pos] !== data[pos + 1]) {
      points[j] = data[pos] ? 2 : 1;
      ++count;
    }
    pos++;
  }
  if (data[pos] !== 0) {
    points[j] = 2;
    ++count;
  }
  for (i = 1; i < height; i++) {
    pos = i * lineSize;
    j0 = i * width1;
    if (data[pos - lineSize] !== data[pos]) {
      points[j0] = data[pos] ? 1 : 8;
      ++count;
    }
    // 'sum' is the position of the current pixel configuration in the 'TYPES'
    // array (in order 8-1-2-4, so we can use '>>2' to shift the column).
    var sum = (data[pos] ? 4 : 0) + (data[pos - lineSize] ? 8 : 0);
    for (j = 1; j < width; j++) {
      sum =
        (sum >> 2) +
        (data[pos + 1] ? 4 : 0) +
        (data[pos - lineSize + 1] ? 8 : 0);
      if (POINT_TYPES[sum]) {
        points[j0 + j] = POINT_TYPES[sum];
        ++count;
      }
      pos++;
    }
    if (data[pos - lineSize] !== data[pos]) {
      points[j0 + j] = data[pos] ? 2 : 4;
      ++count;
    }

    if (count > POINT_TO_PROCESS_LIMIT) {
      return null;
    }
  }

  pos = lineSize * (height - 1);
  j0 = i * width1;
  if (data[pos] !== 0) {
    points[j0] = 8;
    ++count;
  }
  for (j = 1; j < width; j++) {
    if (data[pos] !== data[pos + 1]) {
      points[j0 + j] = data[pos] ? 4 : 8;
      ++count;
    }
    pos++;
  }
  if (data[pos] !== 0) {
    points[j0 + j] = 4;
    ++count;
  }
  if (count > POINT_TO_PROCESS_LIMIT) {
    return null;
  }

  // building outlines
  var steps = new Int32Array([0, width1, -1, 0, -width1, 0, 0, 0, 1]);
  var outlines = [];
  for (i = 0; count && i <= height; i++) {
    var p = i * width1;
    var end = p + width;
    while (p < end && !points[p]) {
      p++;
    }
    if (p === end) {
      continue;
    }
    var coords = [p % width1, i];

    var type = points[p],
      p0 = p,
      pp;
    do {
      var step = steps[type];
      do {
        p += step;
      } while (!points[p]);

      pp = points[p];
      if (pp !== 5 && pp !== 10) {
        // set new direction
        type = pp;
        // delete mark
        points[p] = 0;
      } else {
        // type is 5 or 10, ie, a crossing
        // set new direction
        type = pp & ((0x33 * type) >> 4);
        // set new type for "future hit"
        points[p] &= (type >> 2) | (type << 2);
      }

      coords.push(p % width1);
      coords.push((p / width1) | 0);

      if (!points[p]) {
        --count;
      }
    } while (p0 !== p);
    outlines.push(coords);
    --i;
  }

  var drawOutline = function(c) {
    c.save();
    // the path shall be painted in [0..1]x[0..1] space
    c.scale(1 / width, -1 / height);
    c.translate(0, -height);
    c.beginPath();
    for (var i = 0, ii = outlines.length; i < ii; i++) {
      var o = outlines[i];
      c.moveTo(o[0], o[1]);
      for (var j = 2, jj = o.length; j < jj; j += 2) {
        c.lineTo(o[j], o[j + 1]);
      }
    }
    c.fill();
    c.beginPath();
    c.restore();
  };

  return drawOutline;
}

var CanvasExtraState = (function CanvasExtraStateClosure() {
  function CanvasExtraState() {
    // Are soft masks and alpha values shapes or opacities?
    this.alphaIsShape = false;
    this.fontSize = 0;
    this.fontSizeScale = 1;
    this.textMatrix = IDENTITY_MATRIX;
    this.textMatrixScale = 1;
    this.fontMatrix = FONT_IDENTITY_MATRIX;
    this.leading = 0;
    // Current point (in user coordinates)
    this.x = 0;
    this.y = 0;
    // Start of text line (in text coordinates)
    this.lineX = 0;
    this.lineY = 0;
    // Character and word spacing
    this.charSpacing = 0;
    this.wordSpacing = 0;
    this.textHScale = 1;
    this.textRenderingMode = TextRenderingMode.FILL;
    this.textRise = 0;
    // Default fore and background colors
    this.fillColor = "#000000";
    this.strokeColor = "#000000";
    this.patternFill = false;
    // Note: fill alpha applies to all non-stroking operations
    this.fillAlpha = 1;
    this.strokeAlpha = 1;
    this.lineWidth = 1;
    this.activeSMask = null;
    this.resumeSMaskCtx = null; // nonclonable field (see the save method below)
  }

  CanvasExtraState.prototype = {
    clone: function CanvasExtraState_clone() {
      return Object.create(this);
    },
    setCurrentPoint: function CanvasExtraState_setCurrentPoint(x, y) {
      this.x = x;
      this.y = y;
    },
  };
  return CanvasExtraState;
})();

var CanvasGraphics = (function CanvasGraphicsClosure() {
  // Defines the time the executeOperatorList is going to be executing
  // before it stops and shedules a continue of execution.
  var EXECUTION_TIME = 15;
  // Defines the number of steps before checking the execution time
  var EXECUTION_STEPS = 10;

  function CanvasGraphics(
    canvasCtx,
    commonObjs,
    objs,
    canvasFactory,
    webGLContext,
    imageLayer
  ) {
    this.ctx = canvasCtx;
    this.current = new CanvasExtraState();
    this.stateStack = [];
    this.pendingClip = null;
    this.pendingEOFill = false;
    this.res = null;
    this.xobjs = null;
    this.commonObjs = commonObjs;
    this.objs = objs;
    this.canvasFactory = canvasFactory;
    this.webGLContext = webGLContext;
    this.imageLayer = imageLayer;
    this.groupStack = [];
    this.processingType3 = null;
    // Patterns are painted relative to the initial page/form transform, see pdf
    // spec 8.7.2 NOTE 1.
    this.baseTransform = null;
    this.baseTransformStack = [];
    this.groupLevel = 0;
    this.smaskStack = [];
    this.smaskCounter = 0;
    this.tempSMask = null;
    this.cachedCanvases = new CachedCanvases(this.canvasFactory);
    if (canvasCtx) {
      // NOTE: if mozCurrentTransform is polyfilled, then the current state of
      // the transformation must already be set in canvasCtx._transformMatrix.
      addContextCurrentTransform(canvasCtx);
    }
    this._cachedGetSinglePixelWidth = null;
  }

  function putBinaryImageData(ctx, imgData) {
    if (typeof ImageData !== "undefined" && imgData instanceof ImageData) {
      ctx.putImageData(imgData, 0, 0);
      return;
    }

    // Put the image data to the canvas in chunks, rather than putting the
    // whole image at once.  This saves JS memory, because the ImageData object
    // is smaller. It also possibly saves C++ memory within the implementation
    // of putImageData(). (E.g. in Firefox we make two short-lived copies of
    // the data passed to putImageData()). |n| shouldn't be too small, however,
    // because too many putImageData() calls will slow things down.
    //
    // Note: as written, if the last chunk is partial, the putImageData() call
    // will (conceptually) put pixels past the bounds of the canvas.  But
    // that's ok; any such pixels are ignored.

    var height = imgData.height,
      width = imgData.width;
    var partialChunkHeight = height % FULL_CHUNK_HEIGHT;
    var fullChunks = (height - partialChunkHeight) / FULL_CHUNK_HEIGHT;
    var totalChunks = partialChunkHeight === 0 ? fullChunks : fullChunks + 1;

    var chunkImgData = ctx.createImageData(width, FULL_CHUNK_HEIGHT);
    var srcPos = 0,
      destPos;
    var src = imgData.data;
    var dest = chunkImgData.data;
    var i, j, thisChunkHeight, elemsInThisChunk;

    // There are multiple forms in which the pixel data can be passed, and
    // imgData.kind tells us which one this is.
    if (imgData.kind === ImageKind.GRAYSCALE_1BPP) {
      // Grayscale, 1 bit per pixel (i.e. black-and-white).
      var srcLength = src.byteLength;
      var dest32 = new Uint32Array(dest.buffer, 0, dest.byteLength >> 2);
      var dest32DataLength = dest32.length;
      var fullSrcDiff = (width + 7) >> 3;
      var white = 0xffffffff;
      var black = IsLittleEndianCached.value ? 0xff000000 : 0x000000ff;
      for (i = 0; i < totalChunks; i++) {
        thisChunkHeight =
          i < fullChunks ? FULL_CHUNK_HEIGHT : partialChunkHeight;
        destPos = 0;
        for (j = 0; j < thisChunkHeight; j++) {
          var srcDiff = srcLength - srcPos;
          var k = 0;
          var kEnd = srcDiff > fullSrcDiff ? width : srcDiff * 8 - 7;
          var kEndUnrolled = kEnd & ~7;
          var mask = 0;
          var srcByte = 0;
          for (; k < kEndUnrolled; k += 8) {
            srcByte = src[srcPos++];
            dest32[destPos++] = srcByte & 128 ? white : black;
            dest32[destPos++] = srcByte & 64 ? white : black;
            dest32[destPos++] = srcByte & 32 ? white : black;
            dest32[destPos++] = srcByte & 16 ? white : black;
            dest32[destPos++] = srcByte & 8 ? white : black;
            dest32[destPos++] = srcByte & 4 ? white : black;
            dest32[destPos++] = srcByte & 2 ? white : black;
            dest32[destPos++] = srcByte & 1 ? white : black;
          }
          for (; k < kEnd; k++) {
            if (mask === 0) {
              srcByte = src[srcPos++];
              mask = 128;
            }

            dest32[destPos++] = srcByte & mask ? white : black;
            mask >>= 1;
          }
        }
        // We ran out of input. Make all remaining pixels transparent.
        while (destPos < dest32DataLength) {
          dest32[destPos++] = 0;
        }

        ctx.putImageData(chunkImgData, 0, i * FULL_CHUNK_HEIGHT);
      }
    } else if (imgData.kind === ImageKind.RGBA_32BPP) {
      // RGBA, 32-bits per pixel.

      j = 0;
      elemsInThisChunk = width * FULL_CHUNK_HEIGHT * 4;
      for (i = 0; i < fullChunks; i++) {
        dest.set(src.subarray(srcPos, srcPos + elemsInThisChunk));
        srcPos += elemsInThisChunk;

        ctx.putImageData(chunkImgData, 0, j);
        j += FULL_CHUNK_HEIGHT;
      }
      if (i < totalChunks) {
        elemsInThisChunk = width * partialChunkHeight * 4;
        dest.set(src.subarray(srcPos, srcPos + elemsInThisChunk));
        ctx.putImageData(chunkImgData, 0, j);
      }
    } else if (imgData.kind === ImageKind.RGB_24BPP) {
      // RGB, 24-bits per pixel.
      thisChunkHeight = FULL_CHUNK_HEIGHT;
      elemsInThisChunk = width * thisChunkHeight;
      for (i = 0; i < totalChunks; i++) {
        if (i >= fullChunks) {
          thisChunkHeight = partialChunkHeight;
          elemsInThisChunk = width * thisChunkHeight;
        }

        destPos = 0;
        for (j = elemsInThisChunk; j--; ) {
          dest[destPos++] = src[srcPos++];
          dest[destPos++] = src[srcPos++];
          dest[destPos++] = src[srcPos++];
          dest[destPos++] = 255;
        }
        ctx.putImageData(chunkImgData, 0, i * FULL_CHUNK_HEIGHT);
      }
    } else {
      throw new Error(`bad image kind: ${imgData.kind}`);
    }
  }

  function putBinaryImageMask(ctx, imgData) {
    var height = imgData.height,
      width = imgData.width;
    var partialChunkHeight = height % FULL_CHUNK_HEIGHT;
    var fullChunks = (height - partialChunkHeight) / FULL_CHUNK_HEIGHT;
    var totalChunks = partialChunkHeight === 0 ? fullChunks : fullChunks + 1;

    var chunkImgData = ctx.createImageData(width, FULL_CHUNK_HEIGHT);
    var srcPos = 0;
    var src = imgData.data;
    var dest = chunkImgData.data;

    for (var i = 0; i < totalChunks; i++) {
      var thisChunkHeight =
        i < fullChunks ? FULL_CHUNK_HEIGHT : partialChunkHeight;

      // Expand the mask so it can be used by the canvas.  Any required
      // inversion has already been handled.
      var destPos = 3; // alpha component offset
      for (var j = 0; j < thisChunkHeight; j++) {
        var mask = 0;
        for (var k = 0; k < width; k++) {
          if (!mask) {
            var elem = src[srcPos++];
            mask = 128;
          }
          dest[destPos] = elem & mask ? 0 : 255;
          destPos += 4;
          mask >>= 1;
        }
      }
      ctx.putImageData(chunkImgData, 0, i * FULL_CHUNK_HEIGHT);
    }
  }

  function copyCtxState(sourceCtx, destCtx) {
    var properties = [
      "strokeStyle",
      "fillStyle",
      "fillRule",
      "globalAlpha",
      "lineWidth",
      "lineCap",
      "lineJoin",
      "miterLimit",
      "globalCompositeOperation",
      "font",
    ];
    for (var i = 0, ii = properties.length; i < ii; i++) {
      var property = properties[i];
      if (sourceCtx[property] !== undefined) {
        destCtx[property] = sourceCtx[property];
      }
    }
    if (sourceCtx.setLineDash !== undefined) {
      destCtx.setLineDash(sourceCtx.getLineDash());
      destCtx.lineDashOffset = sourceCtx.lineDashOffset;
    }
  }

  function resetCtxToDefault(ctx) {
    ctx.strokeStyle = "#000000";
    ctx.fillStyle = "#000000";
    ctx.fillRule = "nonzero";
    ctx.globalAlpha = 1;
    ctx.lineWidth = 1;
    ctx.lineCap = "butt";
    ctx.lineJoin = "miter";
    ctx.miterLimit = 10;
    ctx.globalCompositeOperation = "source-over";
    ctx.font = "10px sans-serif";
    if (ctx.setLineDash !== undefined) {
      ctx.setLineDash([]);
      ctx.lineDashOffset = 0;
    }
  }

  function composeSMaskBackdrop(bytes, r0, g0, b0) {
    var length = bytes.length;
    for (var i = 3; i < length; i += 4) {
      var alpha = bytes[i];
      if (alpha === 0) {
        bytes[i - 3] = r0;
        bytes[i - 2] = g0;
        bytes[i - 1] = b0;
      } else if (alpha < 255) {
        var alpha_ = 255 - alpha;
        bytes[i - 3] = (bytes[i - 3] * alpha + r0 * alpha_) >> 8;
        bytes[i - 2] = (bytes[i - 2] * alpha + g0 * alpha_) >> 8;
        bytes[i - 1] = (bytes[i - 1] * alpha + b0 * alpha_) >> 8;
      }
    }
  }

  function composeSMaskAlpha(maskData, layerData, transferMap) {
    var length = maskData.length;
    var scale = 1 / 255;
    for (var i = 3; i < length; i += 4) {
      var alpha = transferMap ? transferMap[maskData[i]] : maskData[i];
      layerData[i] = (layerData[i] * alpha * scale) | 0;
    }
  }

  function composeSMaskLuminosity(maskData, layerData, transferMap) {
    var length = maskData.length;
    for (var i = 3; i < length; i += 4) {
      var y =
        maskData[i - 3] * 77 + // * 0.3 / 255 * 0x10000
        maskData[i - 2] * 152 + // * 0.59 ....
        maskData[i - 1] * 28; // * 0.11 ....
      layerData[i] = transferMap
        ? (layerData[i] * transferMap[y >> 8]) >> 8
        : (layerData[i] * y) >> 16;
    }
  }

  function genericComposeSMask(
    maskCtx,
    layerCtx,
    width,
    height,
    subtype,
    backdrop,
    transferMap
  ) {
    var hasBackdrop = !!backdrop;
    var r0 = hasBackdrop ? backdrop[0] : 0;
    var g0 = hasBackdrop ? backdrop[1] : 0;
    var b0 = hasBackdrop ? backdrop[2] : 0;

    var composeFn;
    if (subtype === "Luminosity") {
      composeFn = composeSMaskLuminosity;
    } else {
      composeFn = composeSMaskAlpha;
    }

    // processing image in chunks to save memory
    var PIXELS_TO_PROCESS = 1048576;
    var chunkSize = Math.min(height, Math.ceil(PIXELS_TO_PROCESS / width));
    for (var row = 0; row < height; row += chunkSize) {
      var chunkHeight = Math.min(chunkSize, height - row);
      var maskData = maskCtx.getImageData(0, row, width, chunkHeight);
      var layerData = layerCtx.getImageData(0, row, width, chunkHeight);

      if (hasBackdrop) {
        composeSMaskBackdrop(maskData.data, r0, g0, b0);
      }
      composeFn(maskData.data, layerData.data, transferMap);

      maskCtx.putImageData(layerData, 0, row);
    }
  }

  function composeSMask(ctx, smask, layerCtx, webGLContext) {
    var mask = smask.canvas;
    var maskCtx = smask.context;

    ctx.setTransform(
      smask.scaleX,
      0,
      0,
      smask.scaleY,
      smask.offsetX,
      smask.offsetY
    );

    var backdrop = smask.backdrop || null;
    if (!smask.transferMap && webGLContext.isEnabled) {
      const composed = webGLContext.composeSMask({
        layer: layerCtx.canvas,
        mask,
        properties: {
          subtype: smask.subtype,
          backdrop,
        },
      });
      ctx.setTransform(1, 0, 0, 1, 0, 0);
      ctx.drawImage(composed, smask.offsetX, smask.offsetY);
      return;
    }
    genericComposeSMask(
      maskCtx,
      layerCtx,
      mask.width,
      mask.height,
      smask.subtype,
      backdrop,
      smask.transferMap
    );
    ctx.drawImage(mask, 0, 0);
  }

  var LINE_CAP_STYLES = ["butt", "round", "square"];
  var LINE_JOIN_STYLES = ["miter", "round", "bevel"];
  var NORMAL_CLIP = {};
  var EO_CLIP = {};

  CanvasGraphics.prototype = {
    beginDrawing({
      transform,
      viewport,
      transparency = false,
      background = null,
    }) {
      // For pdfs that use blend modes we have to clear the canvas else certain
      // blend modes can look wrong since we'd be blending with a white
      // backdrop. The problem with a transparent backdrop though is we then
      // don't get sub pixel anti aliasing on text, creating temporary
      // transparent canvas when we have blend modes.
      var width = this.ctx.canvas.width;
      var height = this.ctx.canvas.height;

      this.ctx.save();
      this.ctx.fillStyle = background || "rgb(255, 255, 255)";
      this.ctx.fillRect(0, 0, width, height);
      this.ctx.restore();

      if (transparency) {
        var transparentCanvas = this.cachedCanvases.getCanvas(
          "transparent",
          width,
          height,
          true
        );
        this.compositeCtx = this.ctx;
        this.transparentCanvas = transparentCanvas.canvas;
        this.ctx = transparentCanvas.context;
        this.ctx.save();
        // The transform can be applied before rendering, transferring it to
        // the new canvas.
        this.ctx.transform.apply(
          this.ctx,
          this.compositeCtx.mozCurrentTransform
        );
      }

      this.ctx.save();
      resetCtxToDefault(this.ctx);
      if (transform) {
        this.ctx.transform.apply(this.ctx, transform);
      }
      this.ctx.transform.apply(this.ctx, viewport.transform);

      this.baseTransform = this.ctx.mozCurrentTransform.slice();

      if (this.imageLayer) {
        this.imageLayer.beginLayout();
      }
    },

    executeOperatorList: function CanvasGraphics_executeOperatorList(
      operatorList,
      executionStartIdx,
      continueCallback,
      stepper
    ) {
      var argsArray = operatorList.argsArray;
      var fnArray = operatorList.fnArray;
      var i = executionStartIdx || 0;
      var argsArrayLen = argsArray.length;

      // Sometimes the OperatorList to execute is empty.
      if (argsArrayLen === i) {
        return i;
      }

      var chunkOperations =
        argsArrayLen - i > EXECUTION_STEPS &&
        typeof continueCallback === "function";
      var endTime = chunkOperations ? Date.now() + EXECUTION_TIME : 0;
      var steps = 0;

      var commonObjs = this.commonObjs;
      var objs = this.objs;
      var fnId;

      while (true) {
        if (stepper !== undefined && i === stepper.nextBreakPoint) {
          stepper.breakIt(i, continueCallback);
          return i;
        }

        fnId = fnArray[i];

        if (fnId !== OPS.dependency) {
          this[fnId].apply(this, argsArray[i]);
        } else {
          for (const depObjId of argsArray[i]) {
            const objsPool = depObjId.startsWith("g_") ? commonObjs : objs;

            // If the promise isn't resolved yet, add the continueCallback
            // to the promise and bail out.
            if (!objsPool.has(depObjId)) {
              objsPool.get(depObjId, continueCallback);
              return i;
            }
          }
        }

        i++;

        // If the entire operatorList was executed, stop as were done.
        if (i === argsArrayLen) {
          return i;
        }

        // If the execution took longer then a certain amount of time and
        // `continueCallback` is specified, interrupt the execution.
        if (chunkOperations && ++steps > EXECUTION_STEPS) {
          if (Date.now() > endTime) {
            continueCallback();
            return i;
          }
          steps = 0;
        }

        // If the operatorList isn't executed completely yet OR the execution
        // time was short enough, do another execution round.
      }
    },

    endDrawing: function CanvasGraphics_endDrawing() {
      // Finishing all opened operations such as SMask group painting.
      if (this.current.activeSMask !== null) {
        this.endSMaskGroup();
      }

      this.ctx.restore();

      if (this.transparentCanvas) {
        this.ctx = this.compositeCtx;
        this.ctx.save();
        this.ctx.setTransform(1, 0, 0, 1, 0, 0); // Avoid apply transform twice
        this.ctx.drawImage(this.transparentCanvas, 0, 0);
        this.ctx.restore();
        this.transparentCanvas = null;
      }

      this.cachedCanvases.clear();
      this.webGLContext.clear();

      if (this.imageLayer) {
        this.imageLayer.endLayout();
      }
    },

    // Graphics state
    setLineWidth: function CanvasGraphics_setLineWidth(width) {
      this.current.lineWidth = width;
      this.ctx.lineWidth = width;
    },
    setLineCap: function CanvasGraphics_setLineCap(style) {
      this.ctx.lineCap = LINE_CAP_STYLES[style];
    },
    setLineJoin: function CanvasGraphics_setLineJoin(style) {
      this.ctx.lineJoin = LINE_JOIN_STYLES[style];
    },
    setMiterLimit: function CanvasGraphics_setMiterLimit(limit) {
      this.ctx.miterLimit = limit;
    },
    setDash: function CanvasGraphics_setDash(dashArray, dashPhase) {
      var ctx = this.ctx;
      if (ctx.setLineDash !== undefined) {
        ctx.setLineDash(dashArray);
        ctx.lineDashOffset = dashPhase;
      }
    },
    setRenderingIntent(intent) {
      // This operation is ignored since we haven't found a use case for it yet.
    },
    setFlatness(flatness) {
      // This operation is ignored since we haven't found a use case for it yet.
    },
    setGState: function CanvasGraphics_setGState(states) {
      for (var i = 0, ii = states.length; i < ii; i++) {
        var state = states[i];
        var key = state[0];
        var value = state[1];

        switch (key) {
          case "LW":
            this.setLineWidth(value);
            break;
          case "LC":
            this.setLineCap(value);
            break;
          case "LJ":
            this.setLineJoin(value);
            break;
          case "ML":
            this.setMiterLimit(value);
            break;
          case "D":
            this.setDash(value[0], value[1]);
            break;
          case "RI":
            this.setRenderingIntent(value);
            break;
          case "FL":
            this.setFlatness(value);
            break;
          case "Font":
            this.setFont(value[0], value[1]);
            break;
          case "CA":
            this.current.strokeAlpha = state[1];
            break;
          case "ca":
            this.current.fillAlpha = state[1];
            this.ctx.globalAlpha = state[1];
            break;
          case "BM":
            this.ctx.globalCompositeOperation = value;
            break;
          case "SMask":
            if (this.current.activeSMask) {
              // If SMask is currrenly used, it needs to be suspended or
              // finished. Suspend only makes sense when at least one save()
              // was performed and state needs to be reverted on restore().
              if (
                this.stateStack.length > 0 &&
                this.stateStack[this.stateStack.length - 1].activeSMask ===
                  this.current.activeSMask
              ) {
                this.suspendSMaskGroup();
              } else {
                this.endSMaskGroup();
              }
            }
            this.current.activeSMask = value ? this.tempSMask : null;
            if (this.current.activeSMask) {
              this.beginSMaskGroup();
            }
            this.tempSMask = null;
            break;
        }
      }
    },
    beginSMaskGroup: function CanvasGraphics_beginSMaskGroup() {
      var activeSMask = this.current.activeSMask;
      var drawnWidth = activeSMask.canvas.width;
      var drawnHeight = activeSMask.canvas.height;
      var cacheId = "smaskGroupAt" + this.groupLevel;
      var scratchCanvas = this.cachedCanvases.getCanvas(
        cacheId,
        drawnWidth,
        drawnHeight,
        true
      );

      var currentCtx = this.ctx;
      var currentTransform = currentCtx.mozCurrentTransform;
      this.ctx.save();

      var groupCtx = scratchCanvas.context;
      groupCtx.scale(1 / activeSMask.scaleX, 1 / activeSMask.scaleY);
      groupCtx.translate(-activeSMask.offsetX, -activeSMask.offsetY);
      groupCtx.transform.apply(groupCtx, currentTransform);

      activeSMask.startTransformInverse = groupCtx.mozCurrentTransformInverse;

      copyCtxState(currentCtx, groupCtx);
      this.ctx = groupCtx;
      this.setGState([
        ["BM", "source-over"],
        ["ca", 1],
        ["CA", 1],
      ]);
      this.groupStack.push(currentCtx);
      this.groupLevel++;
    },
    suspendSMaskGroup: function CanvasGraphics_endSMaskGroup() {
      // Similar to endSMaskGroup, the intermediate canvas has to be composed
      // and future ctx state restored.
      var groupCtx = this.ctx;
      this.groupLevel--;
      this.ctx = this.groupStack.pop();

      composeSMask(
        this.ctx,
        this.current.activeSMask,
        groupCtx,
        this.webGLContext
      );
      this.ctx.restore();
      this.ctx.save(); // save is needed since SMask will be resumed.
      copyCtxState(groupCtx, this.ctx);

      // Saving state for resuming.
      this.current.resumeSMaskCtx = groupCtx;
      // Transform was changed in the SMask canvas, reflecting this change on
      // this.ctx.
      var deltaTransform = Util.transform(
        this.current.activeSMask.startTransformInverse,
        groupCtx.mozCurrentTransform
      );
      this.ctx.transform.apply(this.ctx, deltaTransform);

      // SMask was composed, the results at the groupCtx can be cleared.
      groupCtx.save();
      groupCtx.setTransform(1, 0, 0, 1, 0, 0);
      groupCtx.clearRect(0, 0, groupCtx.canvas.width, groupCtx.canvas.height);
      groupCtx.restore();
    },
    resumeSMaskGroup: function CanvasGraphics_endSMaskGroup() {
      // Resuming state saved by suspendSMaskGroup. We don't need to restore
      // any groupCtx state since restore() command (the only caller) will do
      // that for us. See also beginSMaskGroup.
      var groupCtx = this.current.resumeSMaskCtx;
      var currentCtx = this.ctx;
      this.ctx = groupCtx;
      this.groupStack.push(currentCtx);
      this.groupLevel++;
    },
    endSMaskGroup: function CanvasGraphics_endSMaskGroup() {
      var groupCtx = this.ctx;
      this.groupLevel--;
      this.ctx = this.groupStack.pop();

      composeSMask(
        this.ctx,
        this.current.activeSMask,
        groupCtx,
        this.webGLContext
      );
      this.ctx.restore();
      copyCtxState(groupCtx, this.ctx);
      // Transform was changed in the SMask canvas, reflecting this change on
      // this.ctx.
      var deltaTransform = Util.transform(
        this.current.activeSMask.startTransformInverse,
        groupCtx.mozCurrentTransform
      );
      this.ctx.transform.apply(this.ctx, deltaTransform);
    },
    save: function CanvasGraphics_save() {
      this.ctx.save();
      var old = this.current;
      this.stateStack.push(old);
      this.current = old.clone();
      this.current.resumeSMaskCtx = null;
    },
    restore: function CanvasGraphics_restore() {
      // SMask was suspended, we just need to resume it.
      if (this.current.resumeSMaskCtx) {
        this.resumeSMaskGroup();
      }
      // SMask has to be finished once there is no states that are using the
      // same SMask.
      if (
        this.current.activeSMask !== null &&
        (this.stateStack.length === 0 ||
          this.stateStack[this.stateStack.length - 1].activeSMask !==
            this.current.activeSMask)
      ) {
        this.endSMaskGroup();
      }

      if (this.stateStack.length !== 0) {
        this.current = this.stateStack.pop();
        this.ctx.restore();

        // Ensure that the clipping path is reset (fixes issue6413.pdf).
        this.pendingClip = null;

        this._cachedGetSinglePixelWidth = null;
      }
    },
    transform: function CanvasGraphics_transform(a, b, c, d, e, f) {
      this.ctx.transform(a, b, c, d, e, f);

      this._cachedGetSinglePixelWidth = null;
    },

    // Path
    constructPath: function CanvasGraphics_constructPath(ops, args) {
      var ctx = this.ctx;
      var current = this.current;
      var x = current.x,
        y = current.y;
      for (var i = 0, j = 0, ii = ops.length; i < ii; i++) {
        switch (ops[i] | 0) {
          case OPS.rectangle:
            x = args[j++];
            y = args[j++];
            var width = args[j++];
            var height = args[j++];
            if (width === 0) {
              width = this.getSinglePixelWidth();
            }
            if (height === 0) {
              height = this.getSinglePixelWidth();
            }
            var xw = x + width;
            var yh = y + height;
            this.ctx.moveTo(x, y);
            this.ctx.lineTo(xw, y);
            this.ctx.lineTo(xw, yh);
            this.ctx.lineTo(x, yh);
            this.ctx.lineTo(x, y);
            this.ctx.closePath();
            break;
          case OPS.moveTo:
            x = args[j++];
            y = args[j++];
            ctx.moveTo(x, y);
            break;
          case OPS.lineTo:
            x = args[j++];
            y = args[j++];
            ctx.lineTo(x, y);
            break;
          case OPS.curveTo:
            x = args[j + 4];
            y = args[j + 5];
            ctx.bezierCurveTo(
              args[j],
              args[j + 1],
              args[j + 2],
              args[j + 3],
              x,
              y
            );
            j += 6;
            break;
          case OPS.curveTo2:
            ctx.bezierCurveTo(
              x,
              y,
              args[j],
              args[j + 1],
              args[j + 2],
              args[j + 3]
            );
            x = args[j + 2];
            y = args[j + 3];
            j += 4;
            break;
          case OPS.curveTo3:
            x = args[j + 2];
            y = args[j + 3];
            ctx.bezierCurveTo(args[j], args[j + 1], x, y, x, y);
            j += 4;
            break;
          case OPS.closePath:
            ctx.closePath();
            break;
        }
      }
      current.setCurrentPoint(x, y);
    },
    closePath: function CanvasGraphics_closePath() {
      this.ctx.closePath();
    },
    stroke: function CanvasGraphics_stroke(consumePath) {
      consumePath = typeof consumePath !== "undefined" ? consumePath : true;
      var ctx = this.ctx;
      var strokeColor = this.current.strokeColor;
      // For stroke we want to temporarily change the global alpha to the
      // stroking alpha.
      ctx.globalAlpha = this.current.strokeAlpha;
      if (
        strokeColor &&
        strokeColor.hasOwnProperty("type") &&
        strokeColor.type === "Pattern"
      ) {
        // for patterns, we transform to pattern space, calculate
        // the pattern, call stroke, and restore to user space
        ctx.save();
        // The current transform will be replaced while building the pattern,
        // but the line width needs to be adjusted by the current transform, so
        // we must scale it. To properly fix this we should be using a pattern
        // transform instead (see #10955).
        const transform = ctx.mozCurrentTransform;
        const scale = Util.singularValueDecompose2dScale(transform)[0];
        ctx.strokeStyle = strokeColor.getPattern(ctx, this);
        ctx.lineWidth = Math.max(
          this.getSinglePixelWidth() * MIN_WIDTH_FACTOR,
          this.current.lineWidth * scale
        );
        ctx.stroke();
        ctx.restore();
      } else {
        // Prevent drawing too thin lines by enforcing a minimum line width.
        ctx.lineWidth = Math.max(
          this.getSinglePixelWidth() * MIN_WIDTH_FACTOR,
          this.current.lineWidth
        );
        ctx.stroke();
      }
      if (consumePath) {
        this.consumePath();
      }
      // Restore the global alpha to the fill alpha
      ctx.globalAlpha = this.current.fillAlpha;
    },
    closeStroke: function CanvasGraphics_closeStroke() {
      this.closePath();
      this.stroke();
    },
    fill: function CanvasGraphics_fill(consumePath) {
      consumePath = typeof consumePath !== "undefined" ? consumePath : true;
      var ctx = this.ctx;
      var fillColor = this.current.fillColor;
      var isPatternFill = this.current.patternFill;
      var needRestore = false;

      if (isPatternFill) {
        ctx.save();
        if (this.baseTransform) {
          ctx.setTransform.apply(ctx, this.baseTransform);
        }
        ctx.fillStyle = fillColor.getPattern(ctx, this);
        needRestore = true;
      }

      if (this.pendingEOFill) {
        ctx.fill("evenodd");
        this.pendingEOFill = false;
      } else {
        ctx.fill();
      }

      if (needRestore) {
        ctx.restore();
      }
      if (consumePath) {
        this.consumePath();
      }
    },
    eoFill: function CanvasGraphics_eoFill() {
      this.pendingEOFill = true;
      this.fill();
    },
    fillStroke: function CanvasGraphics_fillStroke() {
      this.fill(false);
      this.stroke(false);

      this.consumePath();
    },
    eoFillStroke: function CanvasGraphics_eoFillStroke() {
      this.pendingEOFill = true;
      this.fillStroke();
    },
    closeFillStroke: function CanvasGraphics_closeFillStroke() {
      this.closePath();
      this.fillStroke();
    },
    closeEOFillStroke: function CanvasGraphics_closeEOFillStroke() {
      this.pendingEOFill = true;
      this.closePath();
      this.fillStroke();
    },
    endPath: function CanvasGraphics_endPath() {
      this.consumePath();
    },

    // Clipping
    clip: function CanvasGraphics_clip() {
      this.pendingClip = NORMAL_CLIP;
    },
    eoClip: function CanvasGraphics_eoClip() {
      this.pendingClip = EO_CLIP;
    },

    // Text
    beginText: function CanvasGraphics_beginText() {
      this.current.textMatrix = IDENTITY_MATRIX;
      this.current.textMatrixScale = 1;
      this.current.x = this.current.lineX = 0;
      this.current.y = this.current.lineY = 0;
    },
    endText: function CanvasGraphics_endText() {
      var paths = this.pendingTextPaths;
      var ctx = this.ctx;
      if (paths === undefined) {
        ctx.beginPath();
        return;
      }

      ctx.save();
      ctx.beginPath();
      for (var i = 0; i < paths.length; i++) {
        var path = paths[i];
        ctx.setTransform.apply(ctx, path.transform);
        ctx.translate(path.x, path.y);
        path.addToPath(ctx, path.fontSize);
      }
      ctx.restore();
      ctx.clip();
      ctx.beginPath();
      delete this.pendingTextPaths;
    },
    setCharSpacing: function CanvasGraphics_setCharSpacing(spacing) {
      this.current.charSpacing = spacing;
    },
    setWordSpacing: function CanvasGraphics_setWordSpacing(spacing) {
      this.current.wordSpacing = spacing;
    },
    setHScale: function CanvasGraphics_setHScale(scale) {
      this.current.textHScale = scale / 100;
    },
    setLeading: function CanvasGraphics_setLeading(leading) {
      this.current.leading = -leading;
    },
    setFont: function CanvasGraphics_setFont(fontRefName, size) {
      var fontObj = this.commonObjs.get(fontRefName);
      var current = this.current;

      if (!fontObj) {
        throw new Error(`Can't find font for ${fontRefName}`);
      }

      current.fontMatrix = fontObj.fontMatrix
        ? fontObj.fontMatrix
        : FONT_IDENTITY_MATRIX;

      // A valid matrix needs all main diagonal elements to be non-zero
      // This also ensures we bypass FF bugzilla bug #719844.
      if (current.fontMatrix[0] === 0 || current.fontMatrix[3] === 0) {
        warn("Invalid font matrix for font " + fontRefName);
      }

      // The spec for Tf (setFont) says that 'size' specifies the font 'scale',
      // and in some docs this can be negative (inverted x-y axes).
      if (size < 0) {
        size = -size;
        current.fontDirection = -1;
      } else {
        current.fontDirection = 1;
      }

      this.current.font = fontObj;
      this.current.fontSize = size;

      if (fontObj.isType3Font) {
        return; // we don't need ctx.font for Type3 fonts
      }

      var name = fontObj.loadedName || "sans-serif";

      let bold = "normal";
      if (fontObj.black) {
        bold = "900";
      } else if (fontObj.bold) {
        bold = "bold";
      }
      var italic = fontObj.italic ? "italic" : "normal";
      var typeface = `"${name}", ${fontObj.fallbackName}`;

      // Some font backends cannot handle fonts below certain size.
      // Keeping the font at minimal size and using the fontSizeScale to change
      // the current transformation matrix before the fillText/strokeText.
      // See https://bugzilla.mozilla.org/show_bug.cgi?id=726227
      let browserFontSize = size;
      if (size < MIN_FONT_SIZE) {
        browserFontSize = MIN_FONT_SIZE;
      } else if (size > MAX_FONT_SIZE) {
        browserFontSize = MAX_FONT_SIZE;
      }
      this.current.fontSizeScale = size / browserFontSize;

      this.ctx.font = `${italic} ${bold} ${browserFontSize}px ${typeface}`;
    },
    setTextRenderingMode: function CanvasGraphics_setTextRenderingMode(mode) {
      this.current.textRenderingMode = mode;
    },
    setTextRise: function CanvasGraphics_setTextRise(rise) {
      this.current.textRise = rise;
    },
    moveText: function CanvasGraphics_moveText(x, y) {
      this.current.x = this.current.lineX += x;
      this.current.y = this.current.lineY += y;
    },
    setLeadingMoveText: function CanvasGraphics_setLeadingMoveText(x, y) {
      this.setLeading(-y);
      this.moveText(x, y);
    },
    setTextMatrix: function CanvasGraphics_setTextMatrix(a, b, c, d, e, f) {
      this.current.textMatrix = [a, b, c, d, e, f];
      this.current.textMatrixScale = Math.sqrt(a * a + b * b);

      this.current.x = this.current.lineX = 0;
      this.current.y = this.current.lineY = 0;
    },
    nextLine: function CanvasGraphics_nextLine() {
      this.moveText(0, this.current.leading);
    },

    paintChar(character, x, y, patternTransform) {
      var ctx = this.ctx;
      var current = this.current;
      var font = current.font;
      var textRenderingMode = current.textRenderingMode;
      var fontSize = current.fontSize / current.fontSizeScale;
      var fillStrokeMode =
        textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
      var isAddToPathSet = !!(
        textRenderingMode & TextRenderingMode.ADD_TO_PATH_FLAG
      );
      const patternFill = current.patternFill && font.data;

      var addToPath;
      if (font.disableFontFace || isAddToPathSet || patternFill) {
        addToPath = font.getPathGenerator(this.commonObjs, character);
      }

      if (font.disableFontFace || patternFill) {
        ctx.save();
        ctx.translate(x, y);
        ctx.beginPath();
        addToPath(ctx, fontSize);
        if (patternTransform) {
          ctx.setTransform.apply(ctx, patternTransform);
        }
        if (
          fillStrokeMode === TextRenderingMode.FILL ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          ctx.fill();
        }
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          ctx.stroke();
        }
        ctx.restore();
      } else {
        if (
          fillStrokeMode === TextRenderingMode.FILL ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          ctx.fillText(character, x, y);
        }
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          ctx.strokeText(character, x, y);
        }
      }

      if (isAddToPathSet) {
        var paths = this.pendingTextPaths || (this.pendingTextPaths = []);
        paths.push({
          transform: ctx.mozCurrentTransform,
          x,
          y,
          fontSize,
          addToPath,
        });
      }
    },

    get isFontSubpixelAAEnabled() {
      // Checks if anti-aliasing is enabled when scaled text is painted.
      // On Windows GDI scaled fonts looks bad.
      const { context: ctx } = this.cachedCanvases.getCanvas(
        "isFontSubpixelAAEnabled",
        10,
        10
      );
      ctx.scale(1.5, 1);
      ctx.fillText("I", 0, 10);
      var data = ctx.getImageData(0, 0, 10, 10).data;
      var enabled = false;
      for (var i = 3; i < data.length; i += 4) {
        if (data[i] > 0 && data[i] < 255) {
          enabled = true;
          break;
        }
      }
      return shadow(this, "isFontSubpixelAAEnabled", enabled);
    },

    showText: function CanvasGraphics_showText(glyphs) {
      var current = this.current;
      var font = current.font;
      if (font.isType3Font) {
        return this.showType3Text(glyphs);
      }

      var fontSize = current.fontSize;
      if (fontSize === 0) {
        return undefined;
      }

      var ctx = this.ctx;
      var fontSizeScale = current.fontSizeScale;
      var charSpacing = current.charSpacing;
      var wordSpacing = current.wordSpacing;
      var fontDirection = current.fontDirection;
      var textHScale = current.textHScale * fontDirection;
      var glyphsLength = glyphs.length;
      var vertical = font.vertical;
      var spacingDir = vertical ? 1 : -1;
      var defaultVMetrics = font.defaultVMetrics;
      var widthAdvanceScale = fontSize * current.fontMatrix[0];

      var simpleFillText =
        current.textRenderingMode === TextRenderingMode.FILL &&
        !font.disableFontFace &&
        !current.patternFill;

      ctx.save();
      let patternTransform;
      if (current.patternFill) {
        // TODO: Patterns are not applied correctly to text if a non-embedded
        // font is used. E.g. issue 8111 and ShowText-ShadingPattern.pdf.
        ctx.save();
        const pattern = current.fillColor.getPattern(ctx, this);
        patternTransform = ctx.mozCurrentTransform;
        ctx.restore();
        ctx.fillStyle = pattern;
      }
      ctx.transform.apply(ctx, current.textMatrix);
      ctx.translate(current.x, current.y + current.textRise);

      if (fontDirection > 0) {
        ctx.scale(textHScale, -1);
      } else {
        ctx.scale(textHScale, 1);
      }

      var lineWidth = current.lineWidth;
      var scale = current.textMatrixScale;
      if (scale === 0 || lineWidth === 0) {
        var fillStrokeMode =
          current.textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          this._cachedGetSinglePixelWidth = null;
          lineWidth = this.getSinglePixelWidth() * MIN_WIDTH_FACTOR;
        }
      } else {
        lineWidth /= scale;
      }

      if (fontSizeScale !== 1.0) {
        ctx.scale(fontSizeScale, fontSizeScale);
        lineWidth /= fontSizeScale;
      }

      ctx.lineWidth = lineWidth;

      var x = 0,
        i;
      for (i = 0; i < glyphsLength; ++i) {
        var glyph = glyphs[i];
        if (isNum(glyph)) {
          x += (spacingDir * glyph * fontSize) / 1000;
          continue;
        }

        var restoreNeeded = false;
        var spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;
        var character = glyph.fontChar;
        var accent = glyph.accent;
        var scaledX, scaledY, scaledAccentX, scaledAccentY;
        var width = glyph.width;
        if (vertical) {
          var vmetric, vx, vy;
          vmetric = glyph.vmetric || defaultVMetrics;
          vx = glyph.vmetric ? vmetric[1] : width * 0.5;
          vx = -vx * widthAdvanceScale;
          vy = vmetric[2] * widthAdvanceScale;

          width = vmetric ? -vmetric[0] : width;
          scaledX = vx / fontSizeScale;
          scaledY = (x + vy) / fontSizeScale;
        } else {
          scaledX = x / fontSizeScale;
          scaledY = 0;
        }

        if (font.remeasure && width > 0) {
          // Some standard fonts may not have the exact width: rescale per
          // character if measured width is greater than expected glyph width
          // and subpixel-aa is enabled, otherwise just center the glyph.
          var measuredWidth =
            ((ctx.measureText(character).width * 1000) / fontSize) *
            fontSizeScale;
          if (width < measuredWidth && this.isFontSubpixelAAEnabled) {
            var characterScaleX = width / measuredWidth;
            restoreNeeded = true;
            ctx.save();
            ctx.scale(characterScaleX, 1);
            scaledX /= characterScaleX;
          } else if (width !== measuredWidth) {
            scaledX +=
              (((width - measuredWidth) / 2000) * fontSize) / fontSizeScale;
          }
        }

        // Only attempt to draw the glyph if it is actually in the embedded font
        // file or if there isn't a font file so the fallback font is shown.
        if (glyph.isInFont || font.missingFile) {
          if (simpleFillText && !accent) {
            // common case
            ctx.fillText(character, scaledX, scaledY);
          } else {
            this.paintChar(character, scaledX, scaledY, patternTransform);
            if (accent) {
              scaledAccentX = scaledX + accent.offset.x / fontSizeScale;
              scaledAccentY = scaledY - accent.offset.y / fontSizeScale;
              this.paintChar(
                accent.fontChar,
                scaledAccentX,
                scaledAccentY,
                patternTransform
              );
            }
          }
        }

        var charWidth = width * widthAdvanceScale + spacing * fontDirection;
        x += charWidth;

        if (restoreNeeded) {
          ctx.restore();
        }
      }
      if (vertical) {
        current.y -= x * textHScale;
      } else {
        current.x += x * textHScale;
      }
      ctx.restore();
    },

    showType3Text: function CanvasGraphics_showType3Text(glyphs) {
      // Type3 fonts - each glyph is a "mini-PDF"
      var ctx = this.ctx;
      var current = this.current;
      var font = current.font;
      var fontSize = current.fontSize;
      var fontDirection = current.fontDirection;
      var spacingDir = font.vertical ? 1 : -1;
      var charSpacing = current.charSpacing;
      var wordSpacing = current.wordSpacing;
      var textHScale = current.textHScale * fontDirection;
      var fontMatrix = current.fontMatrix || FONT_IDENTITY_MATRIX;
      var glyphsLength = glyphs.length;
      var isTextInvisible =
        current.textRenderingMode === TextRenderingMode.INVISIBLE;
      var i, glyph, width, spacingLength;

      if (isTextInvisible || fontSize === 0) {
        return;
      }
      this._cachedGetSinglePixelWidth = null;

      ctx.save();
      ctx.transform.apply(ctx, current.textMatrix);
      ctx.translate(current.x, current.y);

      ctx.scale(textHScale, fontDirection);

      for (i = 0; i < glyphsLength; ++i) {
        glyph = glyphs[i];
        if (isNum(glyph)) {
          spacingLength = (spacingDir * glyph * fontSize) / 1000;
          this.ctx.translate(spacingLength, 0);
          current.x += spacingLength * textHScale;
          continue;
        }

        var spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;
        var operatorList = font.charProcOperatorList[glyph.operatorListId];
        if (!operatorList) {
          warn(`Type3 character "${glyph.operatorListId}" is not available.`);
          continue;
        }
        this.processingType3 = glyph;
        this.save();
        ctx.scale(fontSize, fontSize);
        ctx.transform.apply(ctx, fontMatrix);
        this.executeOperatorList(operatorList);
        this.restore();

        var transformed = Util.applyTransform([glyph.width, 0], fontMatrix);
        width = transformed[0] * fontSize + spacing;

        ctx.translate(width, 0);
        current.x += width * textHScale;
      }
      ctx.restore();
      this.processingType3 = null;
    },

    // Type3 fonts
    setCharWidth: function CanvasGraphics_setCharWidth(xWidth, yWidth) {
      // We can safely ignore this since the width should be the same
      // as the width in the Widths array.
    },
    setCharWidthAndBounds: function CanvasGraphics_setCharWidthAndBounds(
      xWidth,
      yWidth,
      llx,
      lly,
      urx,
      ury
    ) {
      // TODO According to the spec we're also suppose to ignore any operators
      // that set color or include images while processing this type3 font.
      this.ctx.rect(llx, lly, urx - llx, ury - lly);
      this.clip();
      this.endPath();
    },

    // Color
    getColorN_Pattern: function CanvasGraphics_getColorN_Pattern(IR) {
      var pattern;
      if (IR[0] === "TilingPattern") {
        var color = IR[1];
        var baseTransform =
          this.baseTransform || this.ctx.mozCurrentTransform.slice();
        var canvasGraphicsFactory = {
          createCanvasGraphics: ctx => {
            return new CanvasGraphics(
              ctx,
              this.commonObjs,
              this.objs,
              this.canvasFactory,
              this.webGLContext
            );
          },
        };
        pattern = new TilingPattern(
          IR,
          color,
          this.ctx,
          canvasGraphicsFactory,
          baseTransform
        );
      } else {
        pattern = getShadingPatternFromIR(IR);
      }
      return pattern;
    },
    setStrokeColorN: function CanvasGraphics_setStrokeColorN() {
      this.current.strokeColor = this.getColorN_Pattern(arguments);
    },
    setFillColorN: function CanvasGraphics_setFillColorN() {
      this.current.fillColor = this.getColorN_Pattern(arguments);
      this.current.patternFill = true;
    },
    setStrokeRGBColor: function CanvasGraphics_setStrokeRGBColor(r, g, b) {
      var color = Util.makeCssRgb(r, g, b);
      this.ctx.strokeStyle = color;
      this.current.strokeColor = color;
    },
    setFillRGBColor: function CanvasGraphics_setFillRGBColor(r, g, b) {
      var color = Util.makeCssRgb(r, g, b);
      this.ctx.fillStyle = color;
      this.current.fillColor = color;
      this.current.patternFill = false;
    },

    shadingFill: function CanvasGraphics_shadingFill(patternIR) {
      var ctx = this.ctx;

      this.save();
      var pattern = getShadingPatternFromIR(patternIR);
      ctx.fillStyle = pattern.getPattern(ctx, this, true);

      var inv = ctx.mozCurrentTransformInverse;
      if (inv) {
        var canvas = ctx.canvas;
        var width = canvas.width;
        var height = canvas.height;

        var bl = Util.applyTransform([0, 0], inv);
        var br = Util.applyTransform([0, height], inv);
        var ul = Util.applyTransform([width, 0], inv);
        var ur = Util.applyTransform([width, height], inv);

        var x0 = Math.min(bl[0], br[0], ul[0], ur[0]);
        var y0 = Math.min(bl[1], br[1], ul[1], ur[1]);
        var x1 = Math.max(bl[0], br[0], ul[0], ur[0]);
        var y1 = Math.max(bl[1], br[1], ul[1], ur[1]);

        this.ctx.fillRect(x0, y0, x1 - x0, y1 - y0);
      } else {
        // HACK to draw the gradient onto an infinite rectangle.
        // PDF gradients are drawn across the entire image while
        // Canvas only allows gradients to be drawn in a rectangle
        // The following bug should allow us to remove this.
        // https://bugzilla.mozilla.org/show_bug.cgi?id=664884

        this.ctx.fillRect(-1e10, -1e10, 2e10, 2e10);
      }

      this.restore();
    },

    // Images
    beginInlineImage: function CanvasGraphics_beginInlineImage() {
      unreachable("Should not call beginInlineImage");
    },
    beginImageData: function CanvasGraphics_beginImageData() {
      unreachable("Should not call beginImageData");
    },

    paintFormXObjectBegin: function CanvasGraphics_paintFormXObjectBegin(
      matrix,
      bbox
    ) {
      this.save();
      this.baseTransformStack.push(this.baseTransform);

      if (Array.isArray(matrix) && matrix.length === 6) {
        this.transform.apply(this, matrix);
      }

      this.baseTransform = this.ctx.mozCurrentTransform;

      if (bbox) {
        var width = bbox[2] - bbox[0];
        var height = bbox[3] - bbox[1];
        this.ctx.rect(bbox[0], bbox[1], width, height);
        this.clip();
        this.endPath();
      }
    },

    paintFormXObjectEnd: function CanvasGraphics_paintFormXObjectEnd() {
      this.restore();
      this.baseTransform = this.baseTransformStack.pop();
    },

    beginGroup: function CanvasGraphics_beginGroup(group) {
      this.save();
      var currentCtx = this.ctx;
      // TODO non-isolated groups - according to Rik at adobe non-isolated
      // group results aren't usually that different and they even have tools
      // that ignore this setting. Notes from Rik on implementing:
      // - When you encounter an transparency group, create a new canvas with
      // the dimensions of the bbox
      // - copy the content from the previous canvas to the new canvas
      // - draw as usual
      // - remove the backdrop alpha:
      // alphaNew = 1 - (1 - alpha)/(1 - alphaBackdrop) with 'alpha' the alpha
      // value of your transparency group and 'alphaBackdrop' the alpha of the
      // backdrop
      // - remove background color:
      // colorNew = color - alphaNew *colorBackdrop /(1 - alphaNew)
      if (!group.isolated) {
        info("TODO: Support non-isolated groups.");
      }

      // TODO knockout - supposedly possible with the clever use of compositing
      // modes.
      if (group.knockout) {
        warn("Knockout groups not supported.");
      }

      var currentTransform = currentCtx.mozCurrentTransform;
      if (group.matrix) {
        currentCtx.transform.apply(currentCtx, group.matrix);
      }
      if (!group.bbox) {
        throw new Error("Bounding box is required.");
      }

      // Based on the current transform figure out how big the bounding box
      // will actually be.
      var bounds = Util.getAxialAlignedBoundingBox(
        group.bbox,
        currentCtx.mozCurrentTransform
      );
      // Clip the bounding box to the current canvas.
      var canvasBounds = [
        0,
        0,
        currentCtx.canvas.width,
        currentCtx.canvas.height,
      ];
      bounds = Util.intersect(bounds, canvasBounds) || [0, 0, 0, 0];
      // Use ceil in case we're between sizes so we don't create canvas that is
      // too small and make the canvas at least 1x1 pixels.
      var offsetX = Math.floor(bounds[0]);
      var offsetY = Math.floor(bounds[1]);
      var drawnWidth = Math.max(Math.ceil(bounds[2]) - offsetX, 1);
      var drawnHeight = Math.max(Math.ceil(bounds[3]) - offsetY, 1);
      var scaleX = 1,
        scaleY = 1;
      if (drawnWidth > MAX_GROUP_SIZE) {
        scaleX = drawnWidth / MAX_GROUP_SIZE;
        drawnWidth = MAX_GROUP_SIZE;
      }
      if (drawnHeight > MAX_GROUP_SIZE) {
        scaleY = drawnHeight / MAX_GROUP_SIZE;
        drawnHeight = MAX_GROUP_SIZE;
      }

      var cacheId = "groupAt" + this.groupLevel;
      if (group.smask) {
        // Using two cache entries is case if masks are used one after another.
        cacheId += "_smask_" + (this.smaskCounter++ % 2);
      }
      var scratchCanvas = this.cachedCanvases.getCanvas(
        cacheId,
        drawnWidth,
        drawnHeight,
        true
      );
      var groupCtx = scratchCanvas.context;

      // Since we created a new canvas that is just the size of the bounding box
      // we have to translate the group ctx.
      groupCtx.scale(1 / scaleX, 1 / scaleY);
      groupCtx.translate(-offsetX, -offsetY);
      groupCtx.transform.apply(groupCtx, currentTransform);

      if (group.smask) {
        // Saving state and cached mask to be used in setGState.
        this.smaskStack.push({
          canvas: scratchCanvas.canvas,
          context: groupCtx,
          offsetX,
          offsetY,
          scaleX,
          scaleY,
          subtype: group.smask.subtype,
          backdrop: group.smask.backdrop,
          transferMap: group.smask.transferMap || null,
          startTransformInverse: null, // used during suspend operation
        });
      } else {
        // Setup the current ctx so when the group is popped we draw it at the
        // right location.
        currentCtx.setTransform(1, 0, 0, 1, 0, 0);
        currentCtx.translate(offsetX, offsetY);
        currentCtx.scale(scaleX, scaleY);
      }
      // The transparency group inherits all off the current graphics state
      // except the blend mode, soft mask, and alpha constants.
      copyCtxState(currentCtx, groupCtx);
      this.ctx = groupCtx;
      this.setGState([
        ["BM", "source-over"],
        ["ca", 1],
        ["CA", 1],
      ]);
      this.groupStack.push(currentCtx);
      this.groupLevel++;

      // Reseting mask state, masks will be applied on restore of the group.
      this.current.activeSMask = null;
    },

    endGroup: function CanvasGraphics_endGroup(group) {
      this.groupLevel--;
      var groupCtx = this.ctx;
      this.ctx = this.groupStack.pop();
      // Turn off image smoothing to avoid sub pixel interpolation which can
      // look kind of blurry for some pdfs.
      if (this.ctx.imageSmoothingEnabled !== undefined) {
        this.ctx.imageSmoothingEnabled = false;
      } else {
        this.ctx.mozImageSmoothingEnabled = false;
      }
      if (group.smask) {
        this.tempSMask = this.smaskStack.pop();
      } else {
        this.ctx.drawImage(groupCtx.canvas, 0, 0);
      }
      this.restore();
    },

    beginAnnotations: function CanvasGraphics_beginAnnotations() {
      this.save();
      if (this.baseTransform) {
        this.ctx.setTransform.apply(this.ctx, this.baseTransform);
      }
    },

    endAnnotations: function CanvasGraphics_endAnnotations() {
      this.restore();
    },

    beginAnnotation: function CanvasGraphics_beginAnnotation(
      rect,
      transform,
      matrix
    ) {
      this.save();
      resetCtxToDefault(this.ctx);
      this.current = new CanvasExtraState();

      if (Array.isArray(rect) && rect.length === 4) {
        var width = rect[2] - rect[0];
        var height = rect[3] - rect[1];
        this.ctx.rect(rect[0], rect[1], width, height);
        this.clip();
        this.endPath();
      }

      this.transform.apply(this, transform);
      this.transform.apply(this, matrix);
    },

    endAnnotation: function CanvasGraphics_endAnnotation() {
      this.restore();
    },

    paintJpegXObject: function CanvasGraphics_paintJpegXObject(objId, w, h) {
      const domImage = this.processingType3
        ? this.commonObjs.get(objId)
        : this.objs.get(objId);
      if (!domImage) {
        warn("Dependent image isn't ready yet");
        return;
      }

      this.save();

      var ctx = this.ctx;
      // scale the image to the unit square
      ctx.scale(1 / w, -1 / h);

      ctx.drawImage(
        domImage,
        0,
        0,
        domImage.width,
        domImage.height,
        0,
        -h,
        w,
        h
      );
      if (this.imageLayer) {
        var currentTransform = ctx.mozCurrentTransformInverse;
        var position = this.getCanvasPosition(0, 0);
        this.imageLayer.appendImage({
          objId,
          left: position[0],
          top: position[1],
          width: w / currentTransform[0],
          height: h / currentTransform[3],
        });
      }
      this.restore();
    },

    paintImageMaskXObject: function CanvasGraphics_paintImageMaskXObject(img) {
      var ctx = this.ctx;
      var width = img.width,
        height = img.height;
      var fillColor = this.current.fillColor;
      var isPatternFill = this.current.patternFill;

      var glyph = this.processingType3;

      if (COMPILE_TYPE3_GLYPHS && glyph && glyph.compiled === undefined) {
        if (width <= MAX_SIZE_TO_COMPILE && height <= MAX_SIZE_TO_COMPILE) {
          glyph.compiled = compileType3Glyph({ data: img.data, width, height });
        } else {
          glyph.compiled = null;
        }
      }

      if (glyph && glyph.compiled) {
        glyph.compiled(ctx);
        return;
      }

      var maskCanvas = this.cachedCanvases.getCanvas(
        "maskCanvas",
        width,
        height
      );
      var maskCtx = maskCanvas.context;
      maskCtx.save();

      putBinaryImageMask(maskCtx, img);

      maskCtx.globalCompositeOperation = "source-in";

      maskCtx.fillStyle = isPatternFill
        ? fillColor.getPattern(maskCtx, this)
        : fillColor;
      maskCtx.fillRect(0, 0, width, height);

      maskCtx.restore();

      this.paintInlineImageXObject(maskCanvas.canvas);
    },

    paintImageMaskXObjectRepeat: function CanvasGraphics_paintImageMaskXObjectRepeat(
      imgData,
      scaleX,
      scaleY,
      positions
    ) {
      var width = imgData.width;
      var height = imgData.height;
      var fillColor = this.current.fillColor;
      var isPatternFill = this.current.patternFill;

      var maskCanvas = this.cachedCanvases.getCanvas(
        "maskCanvas",
        width,
        height
      );
      var maskCtx = maskCanvas.context;
      maskCtx.save();

      putBinaryImageMask(maskCtx, imgData);

      maskCtx.globalCompositeOperation = "source-in";

      maskCtx.fillStyle = isPatternFill
        ? fillColor.getPattern(maskCtx, this)
        : fillColor;
      maskCtx.fillRect(0, 0, width, height);

      maskCtx.restore();

      var ctx = this.ctx;
      for (var i = 0, ii = positions.length; i < ii; i += 2) {
        ctx.save();
        ctx.transform(scaleX, 0, 0, scaleY, positions[i], positions[i + 1]);
        ctx.scale(1, -1);
        ctx.drawImage(maskCanvas.canvas, 0, 0, width, height, 0, -1, 1, 1);
        ctx.restore();
      }
    },

    paintImageMaskXObjectGroup: function CanvasGraphics_paintImageMaskXObjectGroup(
      images
    ) {
      var ctx = this.ctx;

      var fillColor = this.current.fillColor;
      var isPatternFill = this.current.patternFill;
      for (var i = 0, ii = images.length; i < ii; i++) {
        var image = images[i];
        var width = image.width,
          height = image.height;

        var maskCanvas = this.cachedCanvases.getCanvas(
          "maskCanvas",
          width,
          height
        );
        var maskCtx = maskCanvas.context;
        maskCtx.save();

        putBinaryImageMask(maskCtx, image);

        maskCtx.globalCompositeOperation = "source-in";

        maskCtx.fillStyle = isPatternFill
          ? fillColor.getPattern(maskCtx, this)
          : fillColor;
        maskCtx.fillRect(0, 0, width, height);

        maskCtx.restore();

        ctx.save();
        ctx.transform.apply(ctx, image.transform);
        ctx.scale(1, -1);
        ctx.drawImage(maskCanvas.canvas, 0, 0, width, height, 0, -1, 1, 1);
        ctx.restore();
      }
    },

    paintImageXObject: function CanvasGraphics_paintImageXObject(objId) {
      const imgData = this.processingType3
        ? this.commonObjs.get(objId)
        : this.objs.get(objId);
      if (!imgData) {
        warn("Dependent image isn't ready yet");
        return;
      }

      this.paintInlineImageXObject(imgData);
    },

    paintImageXObjectRepeat: function CanvasGraphics_paintImageXObjectRepeat(
      objId,
      scaleX,
      scaleY,
      positions
    ) {
      const imgData = this.processingType3
        ? this.commonObjs.get(objId)
        : this.objs.get(objId);
      if (!imgData) {
        warn("Dependent image isn't ready yet");
        return;
      }

      var width = imgData.width;
      var height = imgData.height;
      var map = [];
      for (var i = 0, ii = positions.length; i < ii; i += 2) {
        map.push({
          transform: [scaleX, 0, 0, scaleY, positions[i], positions[i + 1]],
          x: 0,
          y: 0,
          w: width,
          h: height,
        });
      }
      this.paintInlineImageXObjectGroup(imgData, map);
    },

    paintInlineImageXObject: function CanvasGraphics_paintInlineImageXObject(
      imgData
    ) {
      var width = imgData.width;
      var height = imgData.height;
      var ctx = this.ctx;

      this.save();
      // scale the image to the unit square
      ctx.scale(1 / width, -1 / height);

      var currentTransform = ctx.mozCurrentTransformInverse;
      var a = currentTransform[0],
        b = currentTransform[1];
      var widthScale = Math.max(Math.sqrt(a * a + b * b), 1);
      var c = currentTransform[2],
        d = currentTransform[3];
      var heightScale = Math.max(Math.sqrt(c * c + d * d), 1);

      var imgToPaint, tmpCanvas;
      // typeof check is needed due to node.js support, see issue #8489
      if (
        (typeof HTMLElement === "function" && imgData instanceof HTMLElement) ||
        !imgData.data
      ) {
        imgToPaint = imgData;
      } else {
        tmpCanvas = this.cachedCanvases.getCanvas("inlineImage", width, height);
        var tmpCtx = tmpCanvas.context;
        putBinaryImageData(tmpCtx, imgData);
        imgToPaint = tmpCanvas.canvas;
      }

      var paintWidth = width,
        paintHeight = height;
      var tmpCanvasId = "prescale1";
      // Vertial or horizontal scaling shall not be more than 2 to not loose the
      // pixels during drawImage operation, painting on the temporary canvas(es)
      // that are twice smaller in size
      while (
        (widthScale > 2 && paintWidth > 1) ||
        (heightScale > 2 && paintHeight > 1)
      ) {
        var newWidth = paintWidth,
          newHeight = paintHeight;
        if (widthScale > 2 && paintWidth > 1) {
          newWidth = Math.ceil(paintWidth / 2);
          widthScale /= paintWidth / newWidth;
        }
        if (heightScale > 2 && paintHeight > 1) {
          newHeight = Math.ceil(paintHeight / 2);
          heightScale /= paintHeight / newHeight;
        }
        tmpCanvas = this.cachedCanvases.getCanvas(
          tmpCanvasId,
          newWidth,
          newHeight
        );
        tmpCtx = tmpCanvas.context;
        tmpCtx.clearRect(0, 0, newWidth, newHeight);
        tmpCtx.drawImage(
          imgToPaint,
          0,
          0,
          paintWidth,
          paintHeight,
          0,
          0,
          newWidth,
          newHeight
        );
        imgToPaint = tmpCanvas.canvas;
        paintWidth = newWidth;
        paintHeight = newHeight;
        tmpCanvasId = tmpCanvasId === "prescale1" ? "prescale2" : "prescale1";
      }
      ctx.drawImage(
        imgToPaint,
        0,
        0,
        paintWidth,
        paintHeight,
        0,
        -height,
        width,
        height
      );

      if (this.imageLayer) {
        var position = this.getCanvasPosition(0, -height);
        this.imageLayer.appendImage({
          imgData,
          left: position[0],
          top: position[1],
          width: width / currentTransform[0],
          height: height / currentTransform[3],
        });
      }
      this.restore();
    },

    paintInlineImageXObjectGroup: function CanvasGraphics_paintInlineImageXObjectGroup(
      imgData,
      map
    ) {
      var ctx = this.ctx;
      var w = imgData.width;
      var h = imgData.height;

      var tmpCanvas = this.cachedCanvases.getCanvas("inlineImage", w, h);
      var tmpCtx = tmpCanvas.context;
      putBinaryImageData(tmpCtx, imgData);

      for (var i = 0, ii = map.length; i < ii; i++) {
        var entry = map[i];
        ctx.save();
        ctx.transform.apply(ctx, entry.transform);
        ctx.scale(1, -1);
        ctx.drawImage(
          tmpCanvas.canvas,
          entry.x,
          entry.y,
          entry.w,
          entry.h,
          0,
          -1,
          1,
          1
        );
        if (this.imageLayer) {
          var position = this.getCanvasPosition(entry.x, entry.y);
          this.imageLayer.appendImage({
            imgData,
            left: position[0],
            top: position[1],
            width: w,
            height: h,
          });
        }
        ctx.restore();
      }
    },

    paintSolidColorImageMask: function CanvasGraphics_paintSolidColorImageMask() {
      this.ctx.fillRect(0, 0, 1, 1);
    },

    paintXObject: function CanvasGraphics_paintXObject() {
      warn("Unsupported 'paintXObject' command.");
    },

    // Marked content

    markPoint: function CanvasGraphics_markPoint(tag) {
      // TODO Marked content.
    },
    markPointProps: function CanvasGraphics_markPointProps(tag, properties) {
      // TODO Marked content.
    },
    beginMarkedContent: function CanvasGraphics_beginMarkedContent(tag) {
      // TODO Marked content.
    },
    beginMarkedContentProps: function CanvasGraphics_beginMarkedContentProps(
      tag,
      properties
    ) {
      // TODO Marked content.
    },
    endMarkedContent: function CanvasGraphics_endMarkedContent() {
      // TODO Marked content.
    },

    // Compatibility

    beginCompat: function CanvasGraphics_beginCompat() {
      // TODO ignore undefined operators (should we do that anyway?)
    },
    endCompat: function CanvasGraphics_endCompat() {
      // TODO stop ignoring undefined operators
    },

    // Helper functions

    consumePath: function CanvasGraphics_consumePath() {
      var ctx = this.ctx;
      if (this.pendingClip) {
        if (this.pendingClip === EO_CLIP) {
          ctx.clip("evenodd");
        } else {
          ctx.clip();
        }
        this.pendingClip = null;
      }
      ctx.beginPath();
    },
    getSinglePixelWidth(scale) {
      if (this._cachedGetSinglePixelWidth === null) {
        const inverse = this.ctx.mozCurrentTransformInverse;
        // max of the current horizontal and vertical scale
        this._cachedGetSinglePixelWidth = Math.sqrt(
          Math.max(
            inverse[0] * inverse[0] + inverse[1] * inverse[1],
            inverse[2] * inverse[2] + inverse[3] * inverse[3]
          )
        );
      }
      return this._cachedGetSinglePixelWidth;
    },
    getCanvasPosition: function CanvasGraphics_getCanvasPosition(x, y) {
      var transform = this.ctx.mozCurrentTransform;
      return [
        transform[0] * x + transform[2] * y + transform[4],
        transform[1] * x + transform[3] * y + transform[5],
      ];
    },
  };

  for (var op in OPS) {
    CanvasGraphics.prototype[OPS[op]] = CanvasGraphics.prototype[op];
  }

  return CanvasGraphics;
})();

export { CanvasGraphics };