// Generated by CoffeeScript 1.4.0

/*
# PNG.js
# Copyright (c) 2011 Devon Govett
# MIT LICENSE
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy of this 
# software and associated documentation files (the "Software"), to deal in the Software 
# without restriction, including without limitation the rights to use, copy, modify, merge, 
# publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons 
# to whom the Software is furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all copies or 
# substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
# BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/


(function(global) {
  var PNG;

  PNG = (function() {
    var APNG_BLEND_OP_OVER, APNG_BLEND_OP_SOURCE, APNG_DISPOSE_OP_BACKGROUND, APNG_DISPOSE_OP_NONE, APNG_DISPOSE_OP_PREVIOUS, makeImage, scratchCanvas, scratchCtx;

    PNG.load = function(url, canvas, callback) {
      var xhr,
        _this = this;
      if (typeof canvas === 'function') {
        callback = canvas;
      }
      xhr = new XMLHttpRequest;
      xhr.open("GET", url, true);
      xhr.responseType = "arraybuffer";
      xhr.onload = function() {
        var data, png;
        data = new Uint8Array(xhr.response || xhr.mozResponseArrayBuffer);
        png = new PNG(data);
        if (typeof (canvas != null ? canvas.getContext : void 0) === 'function') {
          png.render(canvas);
        }
        return typeof callback === "function" ? callback(png) : void 0;
      };
      return xhr.send(null);
    };

    APNG_DISPOSE_OP_NONE = 0;

    APNG_DISPOSE_OP_BACKGROUND = 1;

    APNG_DISPOSE_OP_PREVIOUS = 2;

    APNG_BLEND_OP_SOURCE = 0;

    APNG_BLEND_OP_OVER = 1;

    function PNG(data) {
      var chunkSize, colors, palLen, delayDen, delayNum, frame, i, index, key, section, palShort, text, _i, _j, _ref;
      this.data = data;
      this.pos = 8;
      this.palette = [];
      this.imgData = [];
      this.transparency = {};
      this.animation = null;
      this.text = {};
      frame = null;
      while (true) {
        chunkSize = this.readUInt32();
        section = ((function() {
          var _i, _results;
          _results = [];
          for (i = _i = 0; _i < 4; i = ++_i) {
            _results.push(String.fromCharCode(this.data[this.pos++]));
          }
          return _results;
        }).call(this)).join('');
        switch (section) {
          case 'IHDR':
            this.width = this.readUInt32();
            this.height = this.readUInt32();
            this.bits = this.data[this.pos++];
            this.colorType = this.data[this.pos++];
            this.compressionMethod = this.data[this.pos++];
            this.filterMethod = this.data[this.pos++];
            this.interlaceMethod = this.data[this.pos++];
            break;
          case 'acTL':
            this.animation = {
              numFrames: this.readUInt32(),
              numPlays: this.readUInt32() || Infinity,
              frames: []
            };
            break;
          case 'PLTE':
            this.palette = this.read(chunkSize);
            break;
          case 'fcTL':
            if (frame) {
              this.animation.frames.push(frame);
            }
            this.pos += 4;
            frame = {
              width: this.readUInt32(),
              height: this.readUInt32(),
              xOffset: this.readUInt32(),
              yOffset: this.readUInt32()
            };
            delayNum = this.readUInt16();
            delayDen = this.readUInt16() || 100;
            frame.delay = 1000 * delayNum / delayDen;
            frame.disposeOp = this.data[this.pos++];
            frame.blendOp = this.data[this.pos++];
            frame.data = [];
            break;
          case 'IDAT':
          case 'fdAT':
            if (section === 'fdAT') {
              this.pos += 4;
              chunkSize -= 4;
            }
            data = (frame != null ? frame.data : void 0) || this.imgData;
            for (i = _i = 0; 0 <= chunkSize ? _i < chunkSize : _i > chunkSize; i = 0 <= chunkSize ? ++_i : --_i) {
              data.push(this.data[this.pos++]);
            }
            break;
          case 'tRNS':
            this.transparency = {};
            switch (this.colorType) {
              case 3:
            	palLen = this.palette.length/3;
                this.transparency.indexed = this.read(chunkSize);
                if(this.transparency.indexed.length > palLen)
                	throw new Error('More transparent colors than palette size');
                /*
                 * According to the PNG spec trns should be increased to the same size as palette if shorter
                 */
                //palShort = 255 - this.transparency.indexed.length;
                palShort = palLen - this.transparency.indexed.length;
                if (palShort > 0) {
                  for (i = _j = 0; 0 <= palShort ? _j < palShort : _j > palShort; i = 0 <= palShort ? ++_j : --_j) {
                    this.transparency.indexed.push(255);
                  }
                }
                break;
              case 0:
                this.transparency.grayscale = this.read(chunkSize)[0];
                break;
              case 2:
                this.transparency.rgb = this.read(chunkSize);
            }
            break;
          case 'tEXt':
            text = this.read(chunkSize);
            index = text.indexOf(0);
            key = String.fromCharCode.apply(String, text.slice(0, index));
            this.text[key] = String.fromCharCode.apply(String, text.slice(index + 1));
            break;
          case 'IEND':
            if (frame) {
              this.animation.frames.push(frame);
            }
            this.colors = (function() {
              switch (this.colorType) {
                case 0:
                case 3:
                case 4:
                  return 1;
                case 2:
                case 6:
                  return 3;
              }
            }).call(this);
            this.hasAlphaChannel = (_ref = this.colorType) === 4 || _ref === 6;
            colors = this.colors + (this.hasAlphaChannel ? 1 : 0);
            this.pixelBitlength = this.bits * colors;
            this.colorSpace = (function() {
              switch (this.colors) {
                case 1:
                  return 'DeviceGray';
                case 3:
                  return 'DeviceRGB';
              }
            }).call(this);
            this.imgData = new Uint8Array(this.imgData);
            return;
          default:
            this.pos += chunkSize;
        }
        this.pos += 4;
        if (this.pos > this.data.length) {
          throw new Error("Incomplete or corrupt PNG file");
        }
      }
      return;
    }

    PNG.prototype.read = function(bytes) {
      var i, _i, _results;
      _results = [];
      for (i = _i = 0; 0 <= bytes ? _i < bytes : _i > bytes; i = 0 <= bytes ? ++_i : --_i) {
        _results.push(this.data[this.pos++]);
      }
      return _results;
    };

    PNG.prototype.readUInt32 = function() {
      var b1, b2, b3, b4;
      b1 = this.data[this.pos++] << 24;
      b2 = this.data[this.pos++] << 16;
      b3 = this.data[this.pos++] << 8;
      b4 = this.data[this.pos++];
      return b1 | b2 | b3 | b4;
    };

    PNG.prototype.readUInt16 = function() {
      var b1, b2;
      b1 = this.data[this.pos++] << 8;
      b2 = this.data[this.pos++];
      return b1 | b2;
    };

    PNG.prototype.decodePixels = function(data) {
      var abyte, c, col, i, left, length, p, pa, paeth, pb, pc, pixelBytes, pixels, pos, row, scanlineLength, upper, upperLeft, _i, _j, _k, _l, _m;
      if (data == null) {
        data = this.imgData;
      }
      if (data.length === 0) {
        return new Uint8Array(0);
      }
      data = new FlateStream(data);
      data = data.getBytes();
      pixelBytes = this.pixelBitlength / 8;
      scanlineLength = pixelBytes * this.width;
      pixels = new Uint8Array(scanlineLength * this.height);
      length = data.length;
      row = 0;
      pos = 0;
      c = 0;
      while (pos < length) {
        switch (data[pos++]) {
          case 0:
            for (i = _i = 0; _i < scanlineLength; i = _i += 1) {
              pixels[c++] = data[pos++];
            }
            break;
          case 1:
            for (i = _j = 0; _j < scanlineLength; i = _j += 1) {
              abyte = data[pos++];
              left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
              pixels[c++] = (abyte + left) % 256;
            }
            break;
          case 2:
            for (i = _k = 0; _k < scanlineLength; i = _k += 1) {
              abyte = data[pos++];
              col = (i - (i % pixelBytes)) / pixelBytes;
              upper = row && pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
              pixels[c++] = (upper + abyte) % 256;
            }
            break;
          case 3:
            for (i = _l = 0; _l < scanlineLength; i = _l += 1) {
              abyte = data[pos++];
              col = (i - (i % pixelBytes)) / pixelBytes;
              left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
              upper = row && pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
              pixels[c++] = (abyte + Math.floor((left + upper) / 2)) % 256;
            }
            break;
          case 4:
            for (i = _m = 0; _m < scanlineLength; i = _m += 1) {
              abyte = data[pos++];
              col = (i - (i % pixelBytes)) / pixelBytes;
              left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
              if (row === 0) {
                upper = upperLeft = 0;
              } else {
                upper = pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
                upperLeft = col && pixels[(row - 1) * scanlineLength + (col - 1) * pixelBytes + (i % pixelBytes)];
              }
              p = left + upper - upperLeft;
              pa = Math.abs(p - left);
              pb = Math.abs(p - upper);
              pc = Math.abs(p - upperLeft);
              if (pa <= pb && pa <= pc) {
                paeth = left;
              } else if (pb <= pc) {
                paeth = upper;
              } else {
                paeth = upperLeft;
              }
              pixels[c++] = (abyte + paeth) % 256;
            }
            break;
          default:
            throw new Error("Invalid filter algorithm: " + data[pos - 1]);
        }
        row++;
      }
      return pixels;
    };

    PNG.prototype.decodePalette = function() {
      var c, i, length, palette, pos, ret, transparency, _i, _ref, _ref1;
      palette = this.palette;
      transparency = this.transparency.indexed || [];
      ret = new Uint8Array((transparency.length || 0) + palette.length);
      pos = 0;
      length = palette.length;
      c = 0;
      for (i = _i = 0, _ref = palette.length; _i < _ref; i = _i += 3) {
        ret[pos++] = palette[i];
        ret[pos++] = palette[i + 1];
        ret[pos++] = palette[i + 2];
        ret[pos++] = (_ref1 = transparency[c++]) != null ? _ref1 : 255;
      }
      return ret;
    };

    PNG.prototype.copyToImageData = function(imageData, pixels) {
      var alpha, colors, data, i, input, j, k, length, palette, v, _ref;
      colors = this.colors;
      palette = null;
      alpha = this.hasAlphaChannel;
      if (this.palette.length) {
        palette = (_ref = this._decodedPalette) != null ? _ref : this._decodedPalette = this.decodePalette();
        colors = 4;
        alpha = true;
      }
      data = imageData.data || imageData;
      length = data.length;
      input = palette || pixels;
      i = j = 0;
      if (colors === 1) {
        while (i < length) {
          k = palette ? pixels[i / 4] * 4 : j;
          v = input[k++];
          data[i++] = v;
          data[i++] = v;
          data[i++] = v;
          data[i++] = alpha ? input[k++] : 255;
          j = k;
        }
      } else {
        while (i < length) {
          k = palette ? pixels[i / 4] * 4 : j;
          data[i++] = input[k++];
          data[i++] = input[k++];
          data[i++] = input[k++];
          data[i++] = alpha ? input[k++] : 255;
          j = k;
        }
      }
    };

    PNG.prototype.decode = function() {
      var ret;
      ret = new Uint8Array(this.width * this.height * 4);
      this.copyToImageData(ret, this.decodePixels());
      return ret;
    };

    try {
        scratchCanvas = global.document.createElement('canvas');
        scratchCtx = scratchCanvas.getContext('2d');
    } catch(e) {
        return -1;
    }

    makeImage = function(imageData) {
      var img;
      scratchCtx.width = imageData.width;
      scratchCtx.height = imageData.height;
      scratchCtx.clearRect(0, 0, imageData.width, imageData.height);
      scratchCtx.putImageData(imageData, 0, 0);
      img = new Image;
      img.src = scratchCanvas.toDataURL();
      return img;
    };

    PNG.prototype.decodeFrames = function(ctx) {
      var frame, i, imageData, pixels, _i, _len, _ref, _results;
      if (!this.animation) {
        return;
      }
      _ref = this.animation.frames;
      _results = [];
      for (i = _i = 0, _len = _ref.length; _i < _len; i = ++_i) {
        frame = _ref[i];
        imageData = ctx.createImageData(frame.width, frame.height);
        pixels = this.decodePixels(new Uint8Array(frame.data));
        this.copyToImageData(imageData, pixels);
        frame.imageData = imageData;
        _results.push(frame.image = makeImage(imageData));
      }
      return _results;
    };

    PNG.prototype.renderFrame = function(ctx, number) {
      var frame, frames, prev;
      frames = this.animation.frames;
      frame = frames[number];
      prev = frames[number - 1];
      if (number === 0) {
        ctx.clearRect(0, 0, this.width, this.height);
      }
      if ((prev != null ? prev.disposeOp : void 0) === APNG_DISPOSE_OP_BACKGROUND) {
        ctx.clearRect(prev.xOffset, prev.yOffset, prev.width, prev.height);
      } else if ((prev != null ? prev.disposeOp : void 0) === APNG_DISPOSE_OP_PREVIOUS) {
        ctx.putImageData(prev.imageData, prev.xOffset, prev.yOffset);
      }
      if (frame.blendOp === APNG_BLEND_OP_SOURCE) {
        ctx.clearRect(frame.xOffset, frame.yOffset, frame.width, frame.height);
      }
      return ctx.drawImage(frame.image, frame.xOffset, frame.yOffset);
    };

    PNG.prototype.animate = function(ctx) {
      var doFrame, frameNumber, frames, numFrames, numPlays, _ref,
        _this = this;
      frameNumber = 0;
      _ref = this.animation, numFrames = _ref.numFrames, frames = _ref.frames, numPlays = _ref.numPlays;
      return (doFrame = function() {
        var f, frame;
        f = frameNumber++ % numFrames;
        frame = frames[f];
        _this.renderFrame(ctx, f);
        if (numFrames > 1 && frameNumber / numFrames < numPlays) {
          return _this.animation._timeout = setTimeout(doFrame, frame.delay);
        }
      })();
    };

    PNG.prototype.stopAnimation = function() {
      var _ref;
      return clearTimeout((_ref = this.animation) != null ? _ref._timeout : void 0);
    };

    PNG.prototype.render = function(canvas) {
      var ctx, data;
      if (canvas._png) {
        canvas._png.stopAnimation();
      }
      canvas._png = this;
      canvas.width = this.width;
      canvas.height = this.height;
      ctx = canvas.getContext("2d");
      if (this.animation) {
        this.decodeFrames(ctx);
        return this.animate(ctx);
      } else {
        data = ctx.createImageData(this.width, this.height);
        this.copyToImageData(data, this.decodePixels());
        return ctx.putImageData(data, 0, 0);
      }
    };

    return PNG;

  })();

  global.PNG = PNG;

})(typeof window !== "undefined" && window || this);
