/* 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.
 */

'use strict';

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define('pdfjs/core/colorspace', ['exports', 'pdfjs/shared/util',
      'pdfjs/core/primitives', 'pdfjs/core/function'],
      factory);
  } else if (typeof exports !== 'undefined') {
    factory(exports, require('../shared/util.js'), require('./primitives.js'),
      require('./function.js'));
  } else {
    factory((root.pdfjsCoreColorSpace = {}), root.pdfjsSharedUtil,
      root.pdfjsCorePrimitives, root.pdfjsCoreFunction);
  }
}(this, function (exports, sharedUtil, corePrimitives, coreFunction) {

var error = sharedUtil.error;
var info = sharedUtil.info;
var isArray = sharedUtil.isArray;
var isString = sharedUtil.isString;
var shadow = sharedUtil.shadow;
var warn = sharedUtil.warn;
var isDict = corePrimitives.isDict;
var isName = corePrimitives.isName;
var isStream = corePrimitives.isStream;
var PDFFunction = coreFunction.PDFFunction;

var ColorSpace = (function ColorSpaceClosure() {
  /**
   * Resizes an RGB image with 3 components.
   * @param {TypedArray} src - The source buffer.
   * @param {Number} bpc - Number of bits per component.
   * @param {Number} w1 - Original width.
   * @param {Number} h1 - Original height.
   * @param {Number} w2 - New width.
   * @param {Number} h2 - New height.
   * @param {Number} alpha01 - Size reserved for the alpha channel.
   * @param {TypedArray} dest - The destination buffer.
   */
  function resizeRgbImage(src, bpc, w1, h1, w2, h2, alpha01, dest) {
    var COMPONENTS = 3;
    alpha01 = alpha01 !== 1 ? 0 : alpha01;
    var xRatio = w1 / w2;
    var yRatio = h1 / h2;
    var i, j, py, newIndex = 0, oldIndex;
    var xScaled = new Uint16Array(w2);
    var w1Scanline = w1 * COMPONENTS;

    for (i = 0; i < w2; i++) {
      xScaled[i] = Math.floor(i * xRatio) * COMPONENTS;
    }
    for (i = 0; i < h2; i++) {
      py = Math.floor(i * yRatio) * w1Scanline;
      for (j = 0; j < w2; j++) {
        oldIndex = py + xScaled[j];
        dest[newIndex++] = src[oldIndex++];
        dest[newIndex++] = src[oldIndex++];
        dest[newIndex++] = src[oldIndex++];
        newIndex += alpha01;
      }
    }
  }

  // Constructor should define this.numComps, this.defaultColor, this.name
  function ColorSpace() {
    error('should not call ColorSpace constructor');
  }

  ColorSpace.prototype = {
    /**
     * Converts the color value to the RGB color. The color components are
     * located in the src array starting from the srcOffset. Returns the array
     * of the rgb components, each value ranging from [0,255].
     */
    getRgb: function ColorSpace_getRgb(src, srcOffset) {
      var rgb = new Uint8Array(3);
      this.getRgbItem(src, srcOffset, rgb, 0);
      return rgb;
    },
    /**
     * Converts the color value to the RGB color, similar to the getRgb method.
     * The result placed into the dest array starting from the destOffset.
     */
    getRgbItem: function ColorSpace_getRgbItem(src, srcOffset,
                                               dest, destOffset) {
      error('Should not call ColorSpace.getRgbItem');
    },
    /**
     * Converts the specified number of the color values to the RGB colors.
     * The colors are located in the src array starting from the srcOffset.
     * The result is placed into the dest array starting from the destOffset.
     * The src array items shall be in [0,2^bits) range, the dest array items
     * will be in [0,255] range. alpha01 indicates how many alpha components
     * there are in the dest array; it will be either 0 (RGB array) or 1 (RGBA
     * array).
     */
    getRgbBuffer: function ColorSpace_getRgbBuffer(src, srcOffset, count,
                                                   dest, destOffset, bits,
                                                   alpha01) {
      error('Should not call ColorSpace.getRgbBuffer');
    },
    /**
     * Determines the number of bytes required to store the result of the
     * conversion done by the getRgbBuffer method. As in getRgbBuffer,
     * |alpha01| is either 0 (RGB output) or 1 (RGBA output).
     */
    getOutputLength: function ColorSpace_getOutputLength(inputLength,
                                                         alpha01) {
      error('Should not call ColorSpace.getOutputLength');
    },
    /**
     * Returns true if source data will be equal the result/output data.
     */
    isPassthrough: function ColorSpace_isPassthrough(bits) {
      return false;
    },
    /**
     * Fills in the RGB colors in the destination buffer.  alpha01 indicates
     * how many alpha components there are in the dest array; it will be either
     * 0 (RGB array) or 1 (RGBA array).
     */
    fillRgb: function ColorSpace_fillRgb(dest, originalWidth,
                                         originalHeight, width, height,
                                         actualHeight, bpc, comps, alpha01) {
      var count = originalWidth * originalHeight;
      var rgbBuf = null;
      var numComponentColors = 1 << bpc;
      var needsResizing = originalHeight !== height || originalWidth !== width;
      var i, ii;

      if (this.isPassthrough(bpc)) {
        rgbBuf = comps;
      } else if (this.numComps === 1 && count > numComponentColors &&
          this.name !== 'DeviceGray' && this.name !== 'DeviceRGB') {
        // Optimization: create a color map when there is just one component and
        // we are converting more colors than the size of the color map. We
        // don't build the map if the colorspace is gray or rgb since those
        // methods are faster than building a map. This mainly offers big speed
        // ups for indexed and alternate colorspaces.
        //
        // TODO it may be worth while to cache the color map. While running
        // testing I never hit a cache so I will leave that out for now (perhaps
        // we are reparsing colorspaces too much?).
        var allColors = bpc <= 8 ? new Uint8Array(numComponentColors) :
                                   new Uint16Array(numComponentColors);
        var key;
        for (i = 0; i < numComponentColors; i++) {
          allColors[i] = i;
        }
        var colorMap = new Uint8Array(numComponentColors * 3);
        this.getRgbBuffer(allColors, 0, numComponentColors, colorMap, 0, bpc,
                          /* alpha01 = */ 0);

        var destPos, rgbPos;
        if (!needsResizing) {
          // Fill in the RGB values directly into |dest|.
          destPos = 0;
          for (i = 0; i < count; ++i) {
            key = comps[i] * 3;
            dest[destPos++] = colorMap[key];
            dest[destPos++] = colorMap[key + 1];
            dest[destPos++] = colorMap[key + 2];
            destPos += alpha01;
          }
        } else {
          rgbBuf = new Uint8Array(count * 3);
          rgbPos = 0;
          for (i = 0; i < count; ++i) {
            key = comps[i] * 3;
            rgbBuf[rgbPos++] = colorMap[key];
            rgbBuf[rgbPos++] = colorMap[key + 1];
            rgbBuf[rgbPos++] = colorMap[key + 2];
          }
        }
      } else {
        if (!needsResizing) {
          // Fill in the RGB values directly into |dest|.
          this.getRgbBuffer(comps, 0, width * actualHeight, dest, 0, bpc,
                            alpha01);
        } else {
          rgbBuf = new Uint8Array(count * 3);
          this.getRgbBuffer(comps, 0, count, rgbBuf, 0, bpc,
                            /* alpha01 = */ 0);
        }
      }

      if (rgbBuf) {
        if (needsResizing) {
          resizeRgbImage(rgbBuf, bpc, originalWidth, originalHeight,
                         width, height, alpha01, dest);
        } else {
          rgbPos = 0;
          destPos = 0;
          for (i = 0, ii = width * actualHeight; i < ii; i++) {
            dest[destPos++] = rgbBuf[rgbPos++];
            dest[destPos++] = rgbBuf[rgbPos++];
            dest[destPos++] = rgbBuf[rgbPos++];
            destPos += alpha01;
          }
        }
      }
    },
    /**
     * True if the colorspace has components in the default range of [0, 1].
     * This should be true for all colorspaces except for lab color spaces
     * which are [0,100], [-128, 127], [-128, 127].
     */
    usesZeroToOneRange: true
  };

  ColorSpace.parse = function ColorSpace_parse(cs, xref, res) {
    var IR = ColorSpace.parseToIR(cs, xref, res);
    if (IR instanceof AlternateCS) {
      return IR;
    }
    return ColorSpace.fromIR(IR);
  };

  ColorSpace.fromIR = function ColorSpace_fromIR(IR) {
    var name = isArray(IR) ? IR[0] : IR;
    var whitePoint, blackPoint, gamma;

    switch (name) {
      case 'DeviceGrayCS':
        return this.singletons.gray;
      case 'DeviceRgbCS':
        return this.singletons.rgb;
      case 'DeviceCmykCS':
        return this.singletons.cmyk;
      case 'CalGrayCS':
        whitePoint = IR[1];
        blackPoint = IR[2];
        gamma = IR[3];
        return new CalGrayCS(whitePoint, blackPoint, gamma);
      case 'CalRGBCS':
        whitePoint = IR[1];
        blackPoint = IR[2];
        gamma = IR[3];
        var matrix = IR[4];
        return new CalRGBCS(whitePoint, blackPoint, gamma, matrix);
      case 'PatternCS':
        var basePatternCS = IR[1];
        if (basePatternCS) {
          basePatternCS = ColorSpace.fromIR(basePatternCS);
        }
        return new PatternCS(basePatternCS);
      case 'IndexedCS':
        var baseIndexedCS = IR[1];
        var hiVal = IR[2];
        var lookup = IR[3];
        return new IndexedCS(ColorSpace.fromIR(baseIndexedCS), hiVal, lookup);
      case 'AlternateCS':
        var numComps = IR[1];
        var alt = IR[2];
        var tintFnIR = IR[3];

        return new AlternateCS(numComps, ColorSpace.fromIR(alt),
                               PDFFunction.fromIR(tintFnIR));
      case 'LabCS':
        whitePoint = IR[1];
        blackPoint = IR[2];
        var range = IR[3];
        return new LabCS(whitePoint, blackPoint, range);
      default:
        error('Unknown name ' + name);
    }
    return null;
  };

  ColorSpace.parseToIR = function ColorSpace_parseToIR(cs, xref, res) {
    if (isName(cs)) {
      var colorSpaces = res.get('ColorSpace');
      if (isDict(colorSpaces)) {
        var refcs = colorSpaces.get(cs.name);
        if (refcs) {
          cs = refcs;
        }
      }
    }

    cs = xref.fetchIfRef(cs);
    if (isName(cs)) {
      switch (cs.name) {
        case 'DeviceGray':
        case 'G':
          return 'DeviceGrayCS';
        case 'DeviceRGB':
        case 'RGB':
          return 'DeviceRgbCS';
        case 'DeviceCMYK':
        case 'CMYK':
          return 'DeviceCmykCS';
        case 'Pattern':
          return ['PatternCS', null];
        default:
          error('unrecognized colorspace ' + cs.name);
      }
    } else if (isArray(cs)) {
      var mode = xref.fetchIfRef(cs[0]).name;
      var numComps, params, alt, whitePoint, blackPoint, gamma;

      switch (mode) {
        case 'DeviceGray':
        case 'G':
          return 'DeviceGrayCS';
        case 'DeviceRGB':
        case 'RGB':
          return 'DeviceRgbCS';
        case 'DeviceCMYK':
        case 'CMYK':
          return 'DeviceCmykCS';
        case 'CalGray':
          params = xref.fetchIfRef(cs[1]);
          whitePoint = params.getArray('WhitePoint');
          blackPoint = params.getArray('BlackPoint');
          gamma = params.get('Gamma');
          return ['CalGrayCS', whitePoint, blackPoint, gamma];
        case 'CalRGB':
          params = xref.fetchIfRef(cs[1]);
          whitePoint = params.getArray('WhitePoint');
          blackPoint = params.getArray('BlackPoint');
          gamma = params.getArray('Gamma');
          var matrix = params.getArray('Matrix');
          return ['CalRGBCS', whitePoint, blackPoint, gamma, matrix];
        case 'ICCBased':
          var stream = xref.fetchIfRef(cs[1]);
          var dict = stream.dict;
          numComps = dict.get('N');
          alt = dict.get('Alternate');
          if (alt) {
            var altIR = ColorSpace.parseToIR(alt, xref, res);
            // Parse the /Alternate CS to ensure that the number of components
            // are correct, and also (indirectly) that it is not a PatternCS.
            var altCS = ColorSpace.fromIR(altIR);
            if (altCS.numComps === numComps) {
              return altIR;
            }
            warn('ICCBased color space: Ignoring incorrect /Alternate entry.');
          }
          if (numComps === 1) {
            return 'DeviceGrayCS';
          } else if (numComps === 3) {
            return 'DeviceRgbCS';
          } else if (numComps === 4) {
            return 'DeviceCmykCS';
          }
          break;
        case 'Pattern':
          var basePatternCS = cs[1] || null;
          if (basePatternCS) {
            basePatternCS = ColorSpace.parseToIR(basePatternCS, xref, res);
          }
          return ['PatternCS', basePatternCS];
        case 'Indexed':
        case 'I':
          var baseIndexedCS = ColorSpace.parseToIR(cs[1], xref, res);
          var hiVal = xref.fetchIfRef(cs[2]) + 1;
          var lookup = xref.fetchIfRef(cs[3]);
          if (isStream(lookup)) {
            lookup = lookup.getBytes();
          }
          return ['IndexedCS', baseIndexedCS, hiVal, lookup];
        case 'Separation':
        case 'DeviceN':
          var name = xref.fetchIfRef(cs[1]);
          numComps = isArray(name) ? name.length : 1;
          alt = ColorSpace.parseToIR(cs[2], xref, res);
          var tintFnIR = PDFFunction.getIR(xref, xref.fetchIfRef(cs[3]));
          return ['AlternateCS', numComps, alt, tintFnIR];
        case 'Lab':
          params = xref.fetchIfRef(cs[1]);
          whitePoint = params.getArray('WhitePoint');
          blackPoint = params.getArray('BlackPoint');
          var range = params.getArray('Range');
          return ['LabCS', whitePoint, blackPoint, range];
        default:
          error('unimplemented color space object "' + mode + '"');
      }
    } else {
      error('unrecognized color space object: "' + cs + '"');
    }
    return null;
  };
  /**
   * Checks if a decode map matches the default decode map for a color space.
   * This handles the general decode maps where there are two values per
   * component. e.g. [0, 1, 0, 1, 0, 1] for a RGB color.
   * This does not handle Lab, Indexed, or Pattern decode maps since they are
   * slightly different.
   * @param {Array} decode Decode map (usually from an image).
   * @param {Number} n Number of components the color space has.
   */
  ColorSpace.isDefaultDecode = function ColorSpace_isDefaultDecode(decode, n) {
    if (!isArray(decode)) {
      return true;
    }

    if (n * 2 !== decode.length) {
      warn('The decode map is not the correct length');
      return true;
    }
    for (var i = 0, ii = decode.length; i < ii; i += 2) {
      if (decode[i] !== 0 || decode[i + 1] !== 1) {
        return false;
      }
    }
    return true;
  };

  ColorSpace.singletons = {
    get gray() {
      return shadow(this, 'gray', new DeviceGrayCS());
    },
    get rgb() {
      return shadow(this, 'rgb', new DeviceRgbCS());
    },
    get cmyk() {
      return shadow(this, 'cmyk', new DeviceCmykCS());
    }
  };

  return ColorSpace;
})();

/**
 * Alternate color space handles both Separation and DeviceN color spaces.  A
 * Separation color space is actually just a DeviceN with one color component.
 * Both color spaces use a tinting function to convert colors to a base color
 * space.
 */
var AlternateCS = (function AlternateCSClosure() {
  function AlternateCS(numComps, base, tintFn) {
    this.name = 'Alternate';
    this.numComps = numComps;
    this.defaultColor = new Float32Array(numComps);
    for (var i = 0; i < numComps; ++i) {
      this.defaultColor[i] = 1;
    }
    this.base = base;
    this.tintFn = tintFn;
    this.tmpBuf = new Float32Array(base.numComps);
  }

  AlternateCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function AlternateCS_getRgbItem(src, srcOffset,
                                                dest, destOffset) {
      var tmpBuf = this.tmpBuf;
      this.tintFn(src, srcOffset, tmpBuf, 0);
      this.base.getRgbItem(tmpBuf, 0, dest, destOffset);
    },
    getRgbBuffer: function AlternateCS_getRgbBuffer(src, srcOffset, count,
                                                    dest, destOffset, bits,
                                                    alpha01) {
      var tintFn = this.tintFn;
      var base = this.base;
      var scale = 1 / ((1 << bits) - 1);
      var baseNumComps = base.numComps;
      var usesZeroToOneRange = base.usesZeroToOneRange;
      var isPassthrough = (base.isPassthrough(8) || !usesZeroToOneRange) &&
                          alpha01 === 0;
      var pos = isPassthrough ? destOffset : 0;
      var baseBuf = isPassthrough ? dest : new Uint8Array(baseNumComps * count);
      var numComps = this.numComps;

      var scaled = new Float32Array(numComps);
      var tinted = new Float32Array(baseNumComps);
      var i, j;

      for (i = 0; i < count; i++) {
        for (j = 0; j < numComps; j++) {
          scaled[j] = src[srcOffset++] * scale;
        }
        tintFn(scaled, 0, tinted, 0);
        if (usesZeroToOneRange) {
          for (j = 0; j < baseNumComps; j++) {
            baseBuf[pos++] = tinted[j] * 255;
          }
        } else {
          base.getRgbItem(tinted, 0, baseBuf, pos);
          pos += baseNumComps;
        }
      }

      if (!isPassthrough) {
        base.getRgbBuffer(baseBuf, 0, count, dest, destOffset, 8, alpha01);
      }
    },
    getOutputLength: function AlternateCS_getOutputLength(inputLength,
                                                          alpha01) {
      return this.base.getOutputLength(inputLength *
                                       this.base.numComps / this.numComps,
                                       alpha01);
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function AlternateCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };

  return AlternateCS;
})();

var PatternCS = (function PatternCSClosure() {
  function PatternCS(baseCS) {
    this.name = 'Pattern';
    this.base = baseCS;
  }
  PatternCS.prototype = {};

  return PatternCS;
})();

var IndexedCS = (function IndexedCSClosure() {
  function IndexedCS(base, highVal, lookup) {
    this.name = 'Indexed';
    this.numComps = 1;
    this.defaultColor = new Uint8Array(this.numComps);
    this.base = base;
    this.highVal = highVal;

    var baseNumComps = base.numComps;
    var length = baseNumComps * highVal;

    if (isStream(lookup)) {
      this.lookup = new Uint8Array(length);
      var bytes = lookup.getBytes(length);
      this.lookup.set(bytes);
    } else if (isString(lookup)) {
      this.lookup = new Uint8Array(length);
      for (var i = 0; i < length; ++i) {
        this.lookup[i] = lookup.charCodeAt(i);
      }
    } else if (lookup instanceof Uint8Array || lookup instanceof Array) {
      this.lookup = lookup;
    } else {
      error('Unrecognized lookup table: ' + lookup);
    }
  }

  IndexedCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function IndexedCS_getRgbItem(src, srcOffset,
                                              dest, destOffset) {
      var numComps = this.base.numComps;
      var start = src[srcOffset] * numComps;
      this.base.getRgbItem(this.lookup, start, dest, destOffset);
    },
    getRgbBuffer: function IndexedCS_getRgbBuffer(src, srcOffset, count,
                                                  dest, destOffset, bits,
                                                  alpha01) {
      var base = this.base;
      var numComps = base.numComps;
      var outputDelta = base.getOutputLength(numComps, alpha01);
      var lookup = this.lookup;

      for (var i = 0; i < count; ++i) {
        var lookupPos = src[srcOffset++] * numComps;
        base.getRgbBuffer(lookup, lookupPos, 1, dest, destOffset, 8, alpha01);
        destOffset += outputDelta;
      }
    },
    getOutputLength: function IndexedCS_getOutputLength(inputLength, alpha01) {
      return this.base.getOutputLength(inputLength * this.base.numComps,
                                       alpha01);
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function IndexedCS_isDefaultDecode(decodeMap) {
      // indexed color maps shouldn't be changed
      return true;
    },
    usesZeroToOneRange: true
  };
  return IndexedCS;
})();

var DeviceGrayCS = (function DeviceGrayCSClosure() {
  function DeviceGrayCS() {
    this.name = 'DeviceGray';
    this.numComps = 1;
    this.defaultColor = new Float32Array(this.numComps);
  }

  DeviceGrayCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function DeviceGrayCS_getRgbItem(src, srcOffset,
                                                 dest, destOffset) {
      var c = (src[srcOffset] * 255) | 0;
      c = c < 0 ? 0 : c > 255 ? 255 : c;
      dest[destOffset] = dest[destOffset + 1] = dest[destOffset + 2] = c;
    },
    getRgbBuffer: function DeviceGrayCS_getRgbBuffer(src, srcOffset, count,
                                                     dest, destOffset, bits,
                                                     alpha01) {
      var scale = 255 / ((1 << bits) - 1);
      var j = srcOffset, q = destOffset;
      for (var i = 0; i < count; ++i) {
        var c = (scale * src[j++]) | 0;
        dest[q++] = c;
        dest[q++] = c;
        dest[q++] = c;
        q += alpha01;
      }
    },
    getOutputLength: function DeviceGrayCS_getOutputLength(inputLength,
                                                           alpha01) {
      return inputLength * (3 + alpha01);
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function DeviceGrayCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };
  return DeviceGrayCS;
})();

var DeviceRgbCS = (function DeviceRgbCSClosure() {
  function DeviceRgbCS() {
    this.name = 'DeviceRGB';
    this.numComps = 3;
    this.defaultColor = new Float32Array(this.numComps);
  }
  DeviceRgbCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function DeviceRgbCS_getRgbItem(src, srcOffset,
                                                dest, destOffset) {
      var r = (src[srcOffset] * 255) | 0;
      var g = (src[srcOffset + 1] * 255) | 0;
      var b = (src[srcOffset + 2] * 255) | 0;
      dest[destOffset] = r < 0 ? 0 : r > 255 ? 255 : r;
      dest[destOffset + 1] = g < 0 ? 0 : g > 255 ? 255 : g;
      dest[destOffset + 2] = b < 0 ? 0 : b > 255 ? 255 : b;
    },
    getRgbBuffer: function DeviceRgbCS_getRgbBuffer(src, srcOffset, count,
                                                    dest, destOffset, bits,
                                                    alpha01) {
      if (bits === 8 && alpha01 === 0) {
        dest.set(src.subarray(srcOffset, srcOffset + count * 3), destOffset);
        return;
      }
      var scale = 255 / ((1 << bits) - 1);
      var j = srcOffset, q = destOffset;
      for (var i = 0; i < count; ++i) {
        dest[q++] = (scale * src[j++]) | 0;
        dest[q++] = (scale * src[j++]) | 0;
        dest[q++] = (scale * src[j++]) | 0;
        q += alpha01;
      }
    },
    getOutputLength: function DeviceRgbCS_getOutputLength(inputLength,
                                                          alpha01) {
      return (inputLength * (3 + alpha01) / 3) | 0;
    },
    isPassthrough: function DeviceRgbCS_isPassthrough(bits) {
      return bits === 8;
    },
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function DeviceRgbCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };
  return DeviceRgbCS;
})();

var DeviceCmykCS = (function DeviceCmykCSClosure() {
  // The coefficients below was found using numerical analysis: the method of
  // steepest descent for the sum((f_i - color_value_i)^2) for r/g/b colors,
  // where color_value is the tabular value from the table of sampled RGB colors
  // from CMYK US Web Coated (SWOP) colorspace, and f_i is the corresponding
  // CMYK color conversion using the estimation below:
  //   f(A, B,.. N) = Acc+Bcm+Ccy+Dck+c+Fmm+Gmy+Hmk+Im+Jyy+Kyk+Ly+Mkk+Nk+255
  function convertToRgb(src, srcOffset, srcScale, dest, destOffset) {
    var c = src[srcOffset + 0] * srcScale;
    var m = src[srcOffset + 1] * srcScale;
    var y = src[srcOffset + 2] * srcScale;
    var k = src[srcOffset + 3] * srcScale;

    var r =
      (c * (-4.387332384609988 * c + 54.48615194189176 * m +
            18.82290502165302 * y + 212.25662451639585 * k +
            -285.2331026137004) +
       m * (1.7149763477362134 * m - 5.6096736904047315 * y +
            -17.873870861415444 * k - 5.497006427196366) +
       y * (-2.5217340131683033 * y - 21.248923337353073 * k +
            17.5119270841813) +
       k * (-21.86122147463605 * k - 189.48180835922747) + 255) | 0;
    var g =
      (c * (8.841041422036149 * c + 60.118027045597366 * m +
            6.871425592049007 * y + 31.159100130055922 * k +
            -79.2970844816548) +
       m * (-15.310361306967817 * m + 17.575251261109482 * y +
            131.35250912493976 * k - 190.9453302588951) +
       y * (4.444339102852739 * y + 9.8632861493405 * k - 24.86741582555878) +
       k * (-20.737325471181034 * k - 187.80453709719578) + 255) | 0;
    var b =
      (c * (0.8842522430003296 * c + 8.078677503112928 * m +
            30.89978309703729 * y - 0.23883238689178934 * k +
            -14.183576799673286) +
       m * (10.49593273432072 * m + 63.02378494754052 * y +
            50.606957656360734 * k - 112.23884253719248) +
       y * (0.03296041114873217 * y + 115.60384449646641 * k +
            -193.58209356861505) +
       k * (-22.33816807309886 * k - 180.12613974708367) + 255) | 0;

    dest[destOffset] = r > 255 ? 255 : r < 0 ? 0 : r;
    dest[destOffset + 1] = g > 255 ? 255 : g < 0 ? 0 : g;
    dest[destOffset + 2] = b > 255 ? 255 : b < 0 ? 0 : b;
  }

  function DeviceCmykCS() {
    this.name = 'DeviceCMYK';
    this.numComps = 4;
    this.defaultColor = new Float32Array(this.numComps);
    // Set the fourth component to the maximum value for a black color.
    this.defaultColor[3] = 1;
  }
  DeviceCmykCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function DeviceCmykCS_getRgbItem(src, srcOffset,
                                                 dest, destOffset) {
      convertToRgb(src, srcOffset, 1, dest, destOffset);
    },
    getRgbBuffer: function DeviceCmykCS_getRgbBuffer(src, srcOffset, count,
                                                     dest, destOffset, bits,
                                                     alpha01) {
      var scale = 1 / ((1 << bits) - 1);
      for (var i = 0; i < count; i++) {
        convertToRgb(src, srcOffset, scale, dest, destOffset);
        srcOffset += 4;
        destOffset += 3 + alpha01;
      }
    },
    getOutputLength: function DeviceCmykCS_getOutputLength(inputLength,
                                                           alpha01) {
      return (inputLength / 4 * (3 + alpha01)) | 0;
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function DeviceCmykCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };

  return DeviceCmykCS;
})();

//
// CalGrayCS: Based on "PDF Reference, Sixth Ed", p.245
//
var CalGrayCS = (function CalGrayCSClosure() {
  function CalGrayCS(whitePoint, blackPoint, gamma) {
    this.name = 'CalGray';
    this.numComps = 1;
    this.defaultColor = new Float32Array(this.numComps);

    if (!whitePoint) {
      error('WhitePoint missing - required for color space CalGray');
    }
    blackPoint = blackPoint || [0, 0, 0];
    gamma = gamma || 1;

    // Translate arguments to spec variables.
    this.XW = whitePoint[0];
    this.YW = whitePoint[1];
    this.ZW = whitePoint[2];

    this.XB = blackPoint[0];
    this.YB = blackPoint[1];
    this.ZB = blackPoint[2];

    this.G = gamma;

    // Validate variables as per spec.
    if (this.XW < 0 || this.ZW < 0 || this.YW !== 1) {
      error('Invalid WhitePoint components for ' + this.name +
            ', no fallback available');
    }

    if (this.XB < 0 || this.YB < 0 || this.ZB < 0) {
      info('Invalid BlackPoint for ' + this.name + ', falling back to default');
      this.XB = this.YB = this.ZB = 0;
    }

    if (this.XB !== 0 || this.YB !== 0 || this.ZB !== 0) {
      warn(this.name + ', BlackPoint: XB: ' + this.XB + ', YB: ' + this.YB +
           ', ZB: ' + this.ZB + ', only default values are supported.');
    }

    if (this.G < 1) {
      info('Invalid Gamma: ' + this.G + ' for ' + this.name +
           ', falling back to default');
      this.G = 1;
    }
  }

  function convertToRgb(cs, src, srcOffset, dest, destOffset, scale) {
    // A represents a gray component of a calibrated gray space.
    // A <---> AG in the spec
    var A = src[srcOffset] * scale;
    var AG = Math.pow(A, cs.G);

    // Computes L as per spec. ( = cs.YW * AG )
    // Except if other than default BlackPoint values are used.
    var L = cs.YW * AG;
    // http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html, Ch 4.
    // Convert values to rgb range [0, 255].
    var val = Math.max(295.8 * Math.pow(L, 0.333333333333333333) - 40.8, 0) | 0;
    dest[destOffset] = val;
    dest[destOffset + 1] = val;
    dest[destOffset + 2] = val;
  }

  CalGrayCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function CalGrayCS_getRgbItem(src, srcOffset,
                                              dest, destOffset) {
      convertToRgb(this, src, srcOffset, dest, destOffset, 1);
    },
    getRgbBuffer: function CalGrayCS_getRgbBuffer(src, srcOffset, count,
                                                  dest, destOffset, bits,
                                                  alpha01) {
      var scale = 1 / ((1 << bits) - 1);

      for (var i = 0; i < count; ++i) {
        convertToRgb(this, src, srcOffset, dest, destOffset, scale);
        srcOffset += 1;
        destOffset += 3 + alpha01;
      }
    },
    getOutputLength: function CalGrayCS_getOutputLength(inputLength, alpha01) {
      return inputLength * (3 + alpha01);
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function CalGrayCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };
  return CalGrayCS;
})();

//
// CalRGBCS: Based on "PDF Reference, Sixth Ed", p.247
//
var CalRGBCS = (function CalRGBCSClosure() {

  // See http://www.brucelindbloom.com/index.html?Eqn_ChromAdapt.html for these
  // matrices.
  var BRADFORD_SCALE_MATRIX = new Float32Array([
    0.8951, 0.2664, -0.1614,
    -0.7502, 1.7135, 0.0367,
    0.0389, -0.0685, 1.0296]);

  var BRADFORD_SCALE_INVERSE_MATRIX = new Float32Array([
    0.9869929, -0.1470543, 0.1599627,
    0.4323053, 0.5183603, 0.0492912,
    -0.0085287, 0.0400428, 0.9684867]);

  // See http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html.
  var SRGB_D65_XYZ_TO_RGB_MATRIX = new Float32Array([
    3.2404542, -1.5371385, -0.4985314,
    -0.9692660, 1.8760108, 0.0415560,
    0.0556434, -0.2040259, 1.0572252]);

  var FLAT_WHITEPOINT_MATRIX = new Float32Array([1, 1, 1]);

  var tempNormalizeMatrix = new Float32Array(3);
  var tempConvertMatrix1 = new Float32Array(3);
  var tempConvertMatrix2 = new Float32Array(3);

  var DECODE_L_CONSTANT = Math.pow(((8 + 16) / 116), 3) / 8.0;

  function CalRGBCS(whitePoint, blackPoint, gamma, matrix) {
    this.name = 'CalRGB';
    this.numComps = 3;
    this.defaultColor = new Float32Array(this.numComps);

    if (!whitePoint) {
      error('WhitePoint missing - required for color space CalRGB');
    }
    blackPoint = blackPoint || new Float32Array(3);
    gamma = gamma || new Float32Array([1, 1, 1]);
    matrix = matrix || new Float32Array([1, 0, 0, 0, 1, 0, 0, 0, 1]);

    // Translate arguments to spec variables.
    var XW = whitePoint[0];
    var YW = whitePoint[1];
    var ZW = whitePoint[2];
    this.whitePoint = whitePoint;

    var XB = blackPoint[0];
    var YB = blackPoint[1];
    var ZB = blackPoint[2];
    this.blackPoint = blackPoint;

    this.GR = gamma[0];
    this.GG = gamma[1];
    this.GB = gamma[2];

    this.MXA = matrix[0];
    this.MYA = matrix[1];
    this.MZA = matrix[2];
    this.MXB = matrix[3];
    this.MYB = matrix[4];
    this.MZB = matrix[5];
    this.MXC = matrix[6];
    this.MYC = matrix[7];
    this.MZC = matrix[8];

    // Validate variables as per spec.
    if (XW < 0 || ZW < 0 || YW !== 1) {
      error('Invalid WhitePoint components for ' + this.name +
            ', no fallback available');
    }

    if (XB < 0 || YB < 0 || ZB < 0) {
      info('Invalid BlackPoint for ' + this.name + ' [' + XB + ', ' + YB +
           ', ' + ZB + '], falling back to default');
      this.blackPoint = new Float32Array(3);
    }

    if (this.GR < 0 || this.GG < 0 || this.GB < 0) {
      info('Invalid Gamma [' + this.GR + ', ' + this.GG + ', ' + this.GB +
           '] for ' + this.name + ', falling back to default');
      this.GR = this.GG = this.GB = 1;
    }

    if (this.MXA < 0 || this.MYA < 0 || this.MZA < 0 ||
        this.MXB < 0 || this.MYB < 0 || this.MZB < 0 ||
        this.MXC < 0 || this.MYC < 0 || this.MZC < 0) {
      info('Invalid Matrix for ' + this.name + ' [' +
           this.MXA + ', ' + this.MYA + ', ' + this.MZA +
           this.MXB + ', ' + this.MYB + ', ' + this.MZB +
           this.MXC + ', ' + this.MYC + ', ' + this.MZC +
           '], falling back to default');
      this.MXA = this.MYB = this.MZC = 1;
      this.MXB = this.MYA = this.MZA = this.MXC = this.MYC = this.MZB = 0;
    }
  }

  function matrixProduct(a, b, result) {
    result[0] = a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
    result[1] = a[3] * b[0] + a[4] * b[1] + a[5] * b[2];
    result[2] = a[6] * b[0] + a[7] * b[1] + a[8] * b[2];
  }

  function convertToFlat(sourceWhitePoint, LMS, result) {
    result[0] = LMS[0] * 1 / sourceWhitePoint[0];
    result[1] = LMS[1] * 1 / sourceWhitePoint[1];
    result[2] = LMS[2] * 1 / sourceWhitePoint[2];
  }

  function convertToD65(sourceWhitePoint, LMS, result) {
    var D65X = 0.95047;
    var D65Y = 1;
    var D65Z = 1.08883;

    result[0] = LMS[0] * D65X / sourceWhitePoint[0];
    result[1] = LMS[1] * D65Y / sourceWhitePoint[1];
    result[2] = LMS[2] * D65Z / sourceWhitePoint[2];
  }

  function sRGBTransferFunction(color) {
    // See http://en.wikipedia.org/wiki/SRGB.
    if (color <= 0.0031308) {
      return adjustToRange(0, 1, 12.92 * color);
    }

    return adjustToRange(0, 1, (1 + 0.055) * Math.pow(color, 1 / 2.4) - 0.055);
  }

  function adjustToRange(min, max, value) {
    return Math.max(min, Math.min(max, value));
  }

  function decodeL(L) {
    if (L < 0) {
      return -decodeL(-L);
    }

    if (L > 8.0) {
      return Math.pow(((L + 16) / 116), 3);
    }

    return L * DECODE_L_CONSTANT;
  }

  function compensateBlackPoint(sourceBlackPoint, XYZ_Flat, result) {

    // In case the blackPoint is already the default blackPoint then there is
    // no need to do compensation.
    if (sourceBlackPoint[0] === 0 &&
        sourceBlackPoint[1] === 0 &&
        sourceBlackPoint[2] === 0) {
      result[0] = XYZ_Flat[0];
      result[1] = XYZ_Flat[1];
      result[2] = XYZ_Flat[2];
      return;
    }

    // For the blackPoint calculation details, please see
    // http://www.adobe.com/content/dam/Adobe/en/devnet/photoshop/sdk/
    // AdobeBPC.pdf.
    // The destination blackPoint is the default blackPoint [0, 0, 0].
    var zeroDecodeL = decodeL(0);

    var X_DST = zeroDecodeL;
    var X_SRC = decodeL(sourceBlackPoint[0]);

    var Y_DST = zeroDecodeL;
    var Y_SRC = decodeL(sourceBlackPoint[1]);

    var Z_DST = zeroDecodeL;
    var Z_SRC = decodeL(sourceBlackPoint[2]);

    var X_Scale = (1 - X_DST) / (1 - X_SRC);
    var X_Offset = 1 - X_Scale;

    var Y_Scale = (1 - Y_DST) / (1 - Y_SRC);
    var Y_Offset = 1 - Y_Scale;

    var Z_Scale = (1 - Z_DST) / (1 - Z_SRC);
    var Z_Offset = 1 - Z_Scale;

    result[0] = XYZ_Flat[0] * X_Scale + X_Offset;
    result[1] = XYZ_Flat[1] * Y_Scale + Y_Offset;
    result[2] = XYZ_Flat[2] * Z_Scale + Z_Offset;
  }

  function normalizeWhitePointToFlat(sourceWhitePoint, XYZ_In, result) {

    // In case the whitePoint is already flat then there is no need to do
    // normalization.
    if (sourceWhitePoint[0] === 1 && sourceWhitePoint[2] === 1) {
      result[0] = XYZ_In[0];
      result[1] = XYZ_In[1];
      result[2] = XYZ_In[2];
      return;
    }

    var LMS = result;
    matrixProduct(BRADFORD_SCALE_MATRIX, XYZ_In, LMS);

    var LMS_Flat = tempNormalizeMatrix;
    convertToFlat(sourceWhitePoint, LMS, LMS_Flat);

    matrixProduct(BRADFORD_SCALE_INVERSE_MATRIX, LMS_Flat, result);
  }

  function normalizeWhitePointToD65(sourceWhitePoint, XYZ_In, result) {

    var LMS = result;
    matrixProduct(BRADFORD_SCALE_MATRIX, XYZ_In, LMS);

    var LMS_D65 = tempNormalizeMatrix;
    convertToD65(sourceWhitePoint, LMS, LMS_D65);

    matrixProduct(BRADFORD_SCALE_INVERSE_MATRIX, LMS_D65, result);
  }

  function convertToRgb(cs, src, srcOffset, dest, destOffset, scale) {
    // A, B and C represent a red, green and blue components of a calibrated
    // rgb space.
    var A = adjustToRange(0, 1, src[srcOffset] * scale);
    var B = adjustToRange(0, 1, src[srcOffset + 1] * scale);
    var C = adjustToRange(0, 1, src[srcOffset + 2] * scale);

    // A <---> AGR in the spec
    // B <---> BGG in the spec
    // C <---> CGB in the spec
    var AGR = Math.pow(A, cs.GR);
    var BGG = Math.pow(B, cs.GG);
    var CGB = Math.pow(C, cs.GB);

    // Computes intermediate variables L, M, N as per spec.
    // To decode X, Y, Z values map L, M, N directly to them.
    var X = cs.MXA * AGR + cs.MXB * BGG + cs.MXC * CGB;
    var Y = cs.MYA * AGR + cs.MYB * BGG + cs.MYC * CGB;
    var Z = cs.MZA * AGR + cs.MZB * BGG + cs.MZC * CGB;

    // The following calculations are based on this document:
    // http://www.adobe.com/content/dam/Adobe/en/devnet/photoshop/sdk/
    // AdobeBPC.pdf.
    var XYZ = tempConvertMatrix1;
    XYZ[0] = X;
    XYZ[1] = Y;
    XYZ[2] = Z;
    var XYZ_Flat = tempConvertMatrix2;

    normalizeWhitePointToFlat(cs.whitePoint, XYZ, XYZ_Flat);

    var XYZ_Black = tempConvertMatrix1;
    compensateBlackPoint(cs.blackPoint, XYZ_Flat, XYZ_Black);

    var XYZ_D65 = tempConvertMatrix2;
    normalizeWhitePointToD65(FLAT_WHITEPOINT_MATRIX, XYZ_Black, XYZ_D65);

    var SRGB = tempConvertMatrix1;
    matrixProduct(SRGB_D65_XYZ_TO_RGB_MATRIX, XYZ_D65, SRGB);

    var sR = sRGBTransferFunction(SRGB[0]);
    var sG = sRGBTransferFunction(SRGB[1]);
    var sB = sRGBTransferFunction(SRGB[2]);

    // Convert the values to rgb range [0, 255].
    dest[destOffset] = Math.round(sR * 255);
    dest[destOffset + 1] = Math.round(sG * 255);
    dest[destOffset + 2] = Math.round(sB * 255);
  }

  CalRGBCS.prototype = {
    getRgb: function CalRGBCS_getRgb(src, srcOffset) {
      var rgb = new Uint8Array(3);
      this.getRgbItem(src, srcOffset, rgb, 0);
      return rgb;
    },
    getRgbItem: function CalRGBCS_getRgbItem(src, srcOffset,
                                             dest, destOffset) {
      convertToRgb(this, src, srcOffset, dest, destOffset, 1);
    },
    getRgbBuffer: function CalRGBCS_getRgbBuffer(src, srcOffset, count,
                                                 dest, destOffset, bits,
                                                 alpha01) {
      var scale = 1 / ((1 << bits) - 1);

      for (var i = 0; i < count; ++i) {
        convertToRgb(this, src, srcOffset, dest, destOffset, scale);
        srcOffset += 3;
        destOffset += 3 + alpha01;
      }
    },
    getOutputLength: function CalRGBCS_getOutputLength(inputLength, alpha01) {
      return (inputLength * (3 + alpha01) / 3) | 0;
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function CalRGBCS_isDefaultDecode(decodeMap) {
      return ColorSpace.isDefaultDecode(decodeMap, this.numComps);
    },
    usesZeroToOneRange: true
  };
  return CalRGBCS;
})();

//
// LabCS: Based on "PDF Reference, Sixth Ed", p.250
//
var LabCS = (function LabCSClosure() {
  function LabCS(whitePoint, blackPoint, range) {
    this.name = 'Lab';
    this.numComps = 3;
    this.defaultColor = new Float32Array(this.numComps);

    if (!whitePoint) {
      error('WhitePoint missing - required for color space Lab');
    }
    blackPoint = blackPoint || [0, 0, 0];
    range = range || [-100, 100, -100, 100];

    // Translate args to spec variables
    this.XW = whitePoint[0];
    this.YW = whitePoint[1];
    this.ZW = whitePoint[2];
    this.amin = range[0];
    this.amax = range[1];
    this.bmin = range[2];
    this.bmax = range[3];

    // These are here just for completeness - the spec doesn't offer any
    // formulas that use BlackPoint in Lab
    this.XB = blackPoint[0];
    this.YB = blackPoint[1];
    this.ZB = blackPoint[2];

    // Validate vars as per spec
    if (this.XW < 0 || this.ZW < 0 || this.YW !== 1) {
      error('Invalid WhitePoint components, no fallback available');
    }

    if (this.XB < 0 || this.YB < 0 || this.ZB < 0) {
      info('Invalid BlackPoint, falling back to default');
      this.XB = this.YB = this.ZB = 0;
    }

    if (this.amin > this.amax || this.bmin > this.bmax) {
      info('Invalid Range, falling back to defaults');
      this.amin = -100;
      this.amax = 100;
      this.bmin = -100;
      this.bmax = 100;
    }
  }

  // Function g(x) from spec
  function fn_g(x) {
    var result;
    if (x >= 6 / 29) {
      result = x * x * x;
    } else {
      result = (108 / 841) * (x - 4 / 29);
    }
    return result;
  }

  function decode(value, high1, low2, high2) {
    return low2 + (value) * (high2 - low2) / (high1);
  }

  // If decoding is needed maxVal should be 2^bits per component - 1.
  function convertToRgb(cs, src, srcOffset, maxVal, dest, destOffset) {
    // XXX: Lab input is in the range of [0, 100], [amin, amax], [bmin, bmax]
    // not the usual [0, 1]. If a command like setFillColor is used the src
    // values will already be within the correct range. However, if we are
    // converting an image we have to map the values to the correct range given
    // above.
    // Ls,as,bs <---> L*,a*,b* in the spec
    var Ls = src[srcOffset];
    var as = src[srcOffset + 1];
    var bs = src[srcOffset + 2];
    if (maxVal !== false) {
      Ls = decode(Ls, maxVal, 0, 100);
      as = decode(as, maxVal, cs.amin, cs.amax);
      bs = decode(bs, maxVal, cs.bmin, cs.bmax);
    }

    // Adjust limits of 'as' and 'bs'
    as = as > cs.amax ? cs.amax : as < cs.amin ? cs.amin : as;
    bs = bs > cs.bmax ? cs.bmax : bs < cs.bmin ? cs.bmin : bs;

    // Computes intermediate variables X,Y,Z as per spec
    var M = (Ls + 16) / 116;
    var L = M + (as / 500);
    var N = M - (bs / 200);

    var X = cs.XW * fn_g(L);
    var Y = cs.YW * fn_g(M);
    var Z = cs.ZW * fn_g(N);

    var r, g, b;
    // Using different conversions for D50 and D65 white points,
    // per http://www.color.org/srgb.pdf
    if (cs.ZW < 1) {
      // Assuming D50 (X=0.9642, Y=1.00, Z=0.8249)
      r = X * 3.1339 + Y * -1.6170 + Z * -0.4906;
      g = X * -0.9785 + Y * 1.9160 + Z * 0.0333;
      b = X * 0.0720 + Y * -0.2290 + Z * 1.4057;
    } else {
      // Assuming D65 (X=0.9505, Y=1.00, Z=1.0888)
      r = X * 3.2406 + Y * -1.5372 + Z * -0.4986;
      g = X * -0.9689 + Y * 1.8758 + Z * 0.0415;
      b = X * 0.0557 + Y * -0.2040 + Z * 1.0570;
    }
    // clamp color values to [0,1] range then convert to [0,255] range.
    dest[destOffset] = r <= 0 ? 0 : r >= 1 ? 255 : Math.sqrt(r) * 255 | 0;
    dest[destOffset + 1] = g <= 0 ? 0 : g >= 1 ? 255 : Math.sqrt(g) * 255 | 0;
    dest[destOffset + 2] = b <= 0 ? 0 : b >= 1 ? 255 : Math.sqrt(b) * 255 | 0;
  }

  LabCS.prototype = {
    getRgb: ColorSpace.prototype.getRgb,
    getRgbItem: function LabCS_getRgbItem(src, srcOffset, dest, destOffset) {
      convertToRgb(this, src, srcOffset, false, dest, destOffset);
    },
    getRgbBuffer: function LabCS_getRgbBuffer(src, srcOffset, count,
                                              dest, destOffset, bits,
                                              alpha01) {
      var maxVal = (1 << bits) - 1;
      for (var i = 0; i < count; i++) {
        convertToRgb(this, src, srcOffset, maxVal, dest, destOffset);
        srcOffset += 3;
        destOffset += 3 + alpha01;
      }
    },
    getOutputLength: function LabCS_getOutputLength(inputLength, alpha01) {
      return (inputLength * (3 + alpha01) / 3) | 0;
    },
    isPassthrough: ColorSpace.prototype.isPassthrough,
    fillRgb: ColorSpace.prototype.fillRgb,
    isDefaultDecode: function LabCS_isDefaultDecode(decodeMap) {
      // XXX: Decoding is handled with the lab conversion because of the strange
      // ranges that are used.
      return true;
    },
    usesZeroToOneRange: false
  };
  return LabCS;
})();

exports.ColorSpace = ColorSpace;
}));
