glitchmonkey.user.js

// ==UserScript==
// @name           GlitchMonkey
// @namespace      http://d.hatena.ne.jp/youpy/
// @include        *
// @require        http://www.onicos.com/staff/iz/amuse/javascript/expert/inflate.txt
// ==/UserScript==

var Corruptions = {
    'image/jpeg': function() {
      return this.replace(/0/g, Math.floor(Math.random() * 10));
    },
    'image/gif': function() {
      return this.replace(/x/ig, Math.floor(Math.random() * 10));
    },
    'image/png': function() {
      return glitchPNG(this, function(data) { return data.replace(/\d/g, Math.floor(Math.random() * 15)); });
    }
};

Array.filter(document.images, is_glitchable).forEach(glitch);

if (window.AutoPagerize) {
  window.AutoPagerize.addFilter(function (pages) {
    pages.forEach(function (page) {
      Array.filter(page.getElementsByTagName('img'), is_glitchable).forEach(glitch);
    });
  });
}
document.addEventListener("DOMNodeInserted", function(e){
	if (!e.target.tagName) return;
	Array.filter(e.target.getElementsByTagName('img'), is_glitchable).forEach(function(el){
		// Greasemonkey access violation: unsafeWindow cannot call GM_xmlhttpRequest.
		setTimeout(function(){ glitch(el); },0);
	});
}, false);

function glitch(element) {
  GM_xmlhttpRequest({
    method: "GET",
    overrideMimeType: "text/plain; charset=x-user-defined",
    url: element.src,
    onload: function (res) {
    if (debug) console.log(res);
      var type = contentType(res.responseHeaders);
      var oldsrc = element.src;
      
      if(typeof Corruptions[type] != 'undefined') {
				element.addEventListener('error', function() {
					this.src = oldsrc;
				}, false);
				
				element.src =
					[
					 'data:',
					 type,
					 ';base64,',
					 base64encode(Corruptions[type].apply(res.responseText)),
					 ].join('');
      }
    }
  });
}

function contentType(headers) {
  return headers.match(/Content-Type: (.*)/i)[1];
}

function base64encode(data) {
  return btoa(data.replace(/[\u0100-\uffff]/g, function(c) {
    return String.fromCharCode(c.charCodeAt(0) & 0xff);
  }));
}

function is_glitchable(img) {
  return img.src.match(/\.(gif|jpe?g|png)/i);
}

function glitchPNG(data, glitchBy) {
    if(data.length > 65536) return ''; // Avoid a big image (multiple IDAT), it will fail.
    var png = new PNG(data);
    png.decompressed = glitchBy(png.decompressed);
    return png.output();
}

function PNG() { this.initialize.apply(this, arguments); }
PNG.prototype = {
    initialize: function(data) {
        this.splitter = 'IDAT';
        data = data.split(this.splitter);
        this.idat = [];
        for(var size, i = 0; i < data.length; i++) {
            var d = data[i];
            if(size) {
                this.idat.push(d.slice(0, size));
                if(i == data.length - 1) 
                    this.tail = d.slice(size + 4); // without crc
            } else {
                this.head = d.slice(0, d.length - 4);
            }
            size = d.slice(d.length - 4);
            size = parseInt(this._toHex(size), 16);
        }
        this.decompressed = this.inflate(this.idat.join(''));
    },
    output: function() {
        var compressed = this.deflate(this.decompressed);
        var size = this._toByte4(compressed.length);
        var data = this.splitter + compressed;
        data = size + data + this._toByte4(this._crc32(data));
        return this.head 
             + data
             + this.tail;
    },
    deflate: function(data) {
        var cminfo = parseInt((Math.log(data.length) / Math.log(2)) - 8);
        var cmf = (cminfo << 4) | 0x8;
        var flg = 31 - ((cmf * 256 + 0) % 31);  // fdict = 0, flevel = 0
        var c = new Array(7);
        c[0] = cmf;
        c[1] = flg;
        c[2] = 1;  // final
        var blockLength = data.length;
        var blockLengthComp = (~blockLength & 0xffff);
        c[3] = blockLength & 0xff;
        c[4] = (blockLength & 0xff00) >> 8;
        c[5] = blockLengthComp & 0xff;
        c[6] = (blockLengthComp & 0xff00) >> 8;
        var checksum = this._adler32(data);
        data = this._packBytes(c) + data;
        return data + this._toByte4(checksum);
    },
    inflate: function(data) {
        var cmf = data.charCodeAt(0);
        var flg = data.charCodeAt(1);
        var b = data.slice(2, data.length - 4);
        // @require http://www.onicos.com/staff/iz/amuse/javascript/expert/inflate.txt
        return zip_inflate(b);
    },
    _toHex: function(data) {
        data = this._toByteArray(data);
        data = data.map(function(e) {
            return ((e < 16) ? '0' : '') + e.toString(16);
        });
        return data.join('');
    },
    _toByteArray: function(data) {
        data = data.replace(/[\u0100-\uffff]/g, function(c) {
            return String.fromCharCode(c.charCodeAt(0) & 0xff);
        });
        for(var bytes = new Array(data.length), i = 0; i < data.length; ++i) {
            bytes[i] = data.charCodeAt(i);
        }
        return bytes;
    },
    _packBytes: function(bytes) {
        for(var i = 0; i < bytes.length; i++) {
            bytes[i] = String.fromCharCode(bytes[i]);
        }
        return bytes.join("");
    },
    _toByte4: function(data) {
        return String.fromCharCode(
            (data >> 24) & 255, 
            (data >> 16) & 255, 
            (data >> 8) & 255, 
            data & 255
        );
    },
    _adler32: function(data) {
        var adler = 1, base = 65521;
        data = this._toByteArray(data);
        var s1 = adler & 0xffff;
        var s2 = (adler >> 16) & 0xffff;
        for(var n = 0; n < data.length; n++) {
            s1 = (s1 + data[n]) % base;
            s2 = (s2 + s1) % base;
        }
        return ((s2>>>0) << 16) + (s1>>>0) >>> 0;
    },
    _crc32: function(data) {
        var c = 0xffffffff;
        for(var n = 0; n < data.length; n++) {
            c = this._crc32table[(c ^ data.charCodeAt(n)) & 0xff] ^ (c >>> 8);
        }
        return c ^ 0xffffffff;
    },
    _crc32table: [
        0x0, 0x77073096, 0xee0e612c, 0x990951ba, 0x76dc419, 0x706af48f,
        0xe963a535, 0x9e6495a3, 0xedb8832, 0x79dcb8a4, 0xe0d5e91e,
        0x97d2d988, 0x9b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
        0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d,
        0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0,
        0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63,
        0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
        0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa,
        0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75,
        0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180,
        0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
        0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87,
        0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x1db7106,
        0x98d220bc, 0xefd5102a, 0x71b18589, 0x6b6b51f, 0x9fbfe4a5,
        0xe8b8d433, 0x7807c9a2, 0xf00f934, 0x9609a88e, 0xe10e9818,
        0x7f6a0dbb, 0x86d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4,
        0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b,
        0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea,
        0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
        0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541,
        0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc,
        0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f,
        0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
        0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e,
        0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
        0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x3b6e20c,
        0x74b1d29a, 0xead54739, 0x9dd277af, 0x4db2615, 0x73dc1683,
        0xe3630b12, 0x94643b84, 0xd6d6a3e, 0x7a6a5aa8, 0xe40ecf0b,
        0x9309ff9d, 0xa00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2,
        0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671,
        0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
        0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8,
        0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767,
        0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6,
        0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
        0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795,
        0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
        0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b,
        0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x26d930a,
        0x9c0906a9, 0xeb0e363f, 0x72076785, 0x5005713, 0x95bf4a82,
        0xe2b87a14, 0x7bb12bae, 0xcb61b38, 0x92d28e9b, 0xe5d5be0d,
        0x7cdcefb7, 0xbdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8,
        0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
        0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff,
        0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee,
        0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d,
        0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
        0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c,
        0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
        0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02,
        0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
    ]
};