☰

Snowstorm

Let it snow, let it snow, let in snow

目前为 2024-12-09 提交的版本。查看 最新版本。

  1. // ==UserScript==
  2. // @name         Snowstorm
  3. // @namespace    sheesh
  4. // @version      1.1
  5. // @author       Ur Momma
  6. // @match        https://shikme.chat/
  7. // @icon         https://shikme.chat/default_images/icon.png?v=1528136794
  8. // @grant        none
  9. // @description  Let it snow, let it snow, let in snow
  10. // ==/UserScript==
  11.  
  12. var snowStorm = (function(window, document) {
  13.  
  14.   // --- common properties ---
  15.  
  16.   this.autoStart = true;          // Whether the snow should start automatically or not.
  17.   this.excludeMobile = true;      // Snow is likely to be bad news for mobile phones' CPUs (and batteries.) Enable at your own risk.
  18.   this.flakesMax = 128;           // Limit total amount of snow made (falling + sticking)
  19.   this.flakesMaxActive = 64;      // Limit amount of snow falling at once (less = lower CPU use)
  20.   this.animationInterval = 33;    // Theoretical "miliseconds per frame" measurement. 20 = fast + smooth, but high CPU use. 50 = more conservative, but slower
  21.   this.useGPU = true;             // Enable transform-based hardware acceleration, reduce CPU load.
  22.   this.className = null;          // CSS class name for further customization on snow elements
  23.   this.excludeMobile = true;      // Snow is likely to be bad news for mobile phones' CPUs (and batteries.) By default, be nice.
  24.   this.flakeBottom = null;        // Integer for Y axis snow limit, 0 or null for "full-screen" snow effect
  25.   this.followMouse = true;        // Snow movement can respond to the user's mouse
  26.   this.snowColor = '#fff';        // Don't eat (or use?) yellow snow.
  27.   this.snowCharacter = '•';  // • = bullet, · is square on some systems etc.
  28.   this.snowStick = true;          // Whether or not snow should "stick" at the bottom. When off, will never collect.
  29.   this.targetElement = null;      // element which snow will be appended to (null = document.body) - can be an element ID eg. 'myDiv', or a DOM node reference
  30.   this.useMeltEffect = true;      // When recycling fallen snow (or rarely, when falling), have it "melt" and fade out if browser supports it
  31.   this.useTwinkleEffect = false;  // Allow snow to randomly "flicker" in and out of view while falling
  32.   this.usePositionFixed = false;  // true = snow does not shift vertically when scrolling. May increase CPU load, disabled by default - if enabled, used only where supported
  33.   this.usePixelPosition = false;  // Whether to use pixel values for snow top/left vs. percentages. Auto-enabled if body is position:relative or targetElement is specified.
  34.  
  35.   // --- less-used bits ---
  36.  
  37.   this.freezeOnBlur = true;       // Only snow when the window is in focus (foreground.) Saves CPU.
  38.   this.flakeLeftOffset = 0;       // Left margin/gutter space on edge of container (eg. browser window.) Bump up these values if seeing horizontal scrollbars.
  39.   this.flakeRightOffset = 0;      // Right margin/gutter space on edge of container
  40.   this.flakeWidth = 8;            // Max pixel width reserved for snow element
  41.   this.flakeHeight = 8;           // Max pixel height reserved for snow element
  42.   this.vMaxX = 5;                 // Maximum X velocity range for snow
  43.   this.vMaxY = 4;                 // Maximum Y velocity range for snow
  44.   this.zIndex = 0;                // CSS stacking order applied to each snowflake
  45.  
  46.   // --- "No user-serviceable parts inside" past this point, yadda yadda ---
  47.  
  48.   var storm = this,
  49.   features,
  50.   // UA sniffing and backCompat rendering mode checks for fixed position, etc.
  51.   isIE = navigator.userAgent.match(/msie/i),
  52.   isIE6 = navigator.userAgent.match(/msie 6/i),
  53.   isMobile = navigator.userAgent.match(/mobile|opera m(ob|in)/i),
  54.   isBackCompatIE = (isIE && document.compatMode === 'BackCompat'),
  55.   noFixed = (isBackCompatIE || isIE6),
  56.   screenX = null, screenX2 = null, screenY = null, scrollY = null, docHeight = null, vRndX = null, vRndY = null,
  57.   windOffset = 1,
  58.   windMultiplier = 2,
  59.   flakeTypes = 6,
  60.   fixedForEverything = false,
  61.   targetElementIsRelative = false,
  62.   opacitySupported = (function(){
  63.     try {
  64.       document.createElement('div').style.opacity = '0.5';
  65.     } catch(e) {
  66.       return false;
  67.     }
  68.     return true;
  69.   }()),
  70.   didInit = false,
  71.   docFrag = document.createDocumentFragment();
  72.  
  73.   features = (function() {
  74.  
  75.     var getAnimationFrame;
  76.  
  77.     /**
  78.      * hat tip: paul irish
  79.      * http://paulirish.com/2011/requestanimationframe-for-smart-animating/
  80.      * https://gist.github.com/838785
  81.      */
  82.  
  83.     function timeoutShim(callback) {
  84.       window.setTimeout(callback, 1000/(storm.animationInterval || 20));
  85.     }
  86.  
  87.     var _animationFrame = (window.requestAnimationFrame ||
  88.         window.webkitRequestAnimationFrame ||
  89.         window.mozRequestAnimationFrame ||
  90.         window.oRequestAnimationFrame ||
  91.         window.msRequestAnimationFrame ||
  92.         timeoutShim);
  93.  
  94.     // apply to window, avoid "illegal invocation" errors in Chrome
  95.     getAnimationFrame = _animationFrame ? function() {
  96.       return _animationFrame.apply(window, arguments);
  97.     } : null;
  98.  
  99.     var testDiv;
  100.  
  101.     testDiv = document.createElement('div');
  102.  
  103.     function has(prop) {
  104.  
  105.       // test for feature support
  106.       var result = testDiv.style[prop];
  107.       return (result !== undefined ? prop : null);
  108.  
  109.     }
  110.  
  111.     // note local scope.
  112.     var localFeatures = {
  113.  
  114.       transform: {
  115.         ie:  has('-ms-transform'),
  116.         moz: has('MozTransform'),
  117.         opera: has('OTransform'),
  118.         webkit: has('webkitTransform'),
  119.         w3: has('transform'),
  120.         prop: null // the normalized property value
  121.       },
  122.  
  123.       getAnimationFrame: getAnimationFrame
  124.  
  125.     };
  126.  
  127.     localFeatures.transform.prop = (
  128.       localFeatures.transform.w3 ||
  129.       localFeatures.transform.moz ||
  130.       localFeatures.transform.webkit ||
  131.       localFeatures.transform.ie ||
  132.       localFeatures.transform.opera
  133.     );
  134.  
  135.     testDiv = null;
  136.  
  137.     return localFeatures;
  138.  
  139.   }());
  140.  
  141.   this.timer = null;
  142.   this.flakes = [];
  143.   this.disabled = false;
  144.   this.active = false;
  145.   this.meltFrameCount = 20;
  146.   this.meltFrames = [];
  147.  
  148.   this.setXY = function(o, x, y) {
  149.  
  150.     if (!o) {
  151.       return false;
  152.     }
  153.  
  154.     if (storm.usePixelPosition || targetElementIsRelative) {
  155.  
  156.       o.style.left = (x - storm.flakeWidth) + 'px';
  157.       o.style.top = (y - storm.flakeHeight) + 'px';
  158.  
  159.     } else if (noFixed) {
  160.  
  161.       o.style.right = (100-(x/screenX*100)) + '%';
  162.       // avoid creating vertical scrollbars
  163.       o.style.top = (Math.min(y, docHeight-storm.flakeHeight)) + 'px';
  164.  
  165.     } else {
  166.  
  167.       if (!storm.flakeBottom) {
  168.  
  169.         // if not using a fixed bottom coordinate...
  170.         o.style.right = (100-(x/screenX*100)) + '%';
  171.         o.style.bottom = (100-(y/screenY*100)) + '%';
  172.  
  173.       } else {
  174.  
  175.         // absolute top.
  176.         o.style.right = (100-(x/screenX*100)) + '%';
  177.         o.style.top = (Math.min(y, docHeight-storm.flakeHeight)) + 'px';
  178.  
  179.       }
  180.  
  181.     }
  182.  
  183.   };
  184.  
  185.   this.events = (function() {
  186.  
  187.     var old = (!window.addEventListener && window.attachEvent), slice = Array.prototype.slice,
  188.     evt = {
  189.       add: (old?'attachEvent':'addEventListener'),
  190.       remove: (old?'detachEvent':'removeEventListener')
  191.     };
  192.  
  193.     function getArgs(oArgs) {
  194.       var args = slice.call(oArgs), len = args.length;
  195.       if (old) {
  196.         args[1] = 'on' + args[1]; // prefix
  197.         if (len > 3) {
  198.           args.pop(); // no capture
  199.         }
  200.       } else if (len === 3) {
  201.         args.push(false);
  202.       }
  203.       return args;
  204.     }
  205.  
  206.     function apply(args, sType) {
  207.       var element = args.shift(),
  208.           method = [evt[sType]];
  209.       if (old) {
  210.         element[method](args[0], args[1]);
  211.       } else {
  212.         element[method].apply(element, args);
  213.       }
  214.     }
  215.  
  216.     function addEvent() {
  217.       apply(getArgs(arguments), 'add');
  218.     }
  219.  
  220.     function removeEvent() {
  221.       apply(getArgs(arguments), 'remove');
  222.     }
  223.  
  224.     return {
  225.       add: addEvent,
  226.       remove: removeEvent
  227.     };
  228.  
  229.   }());
  230.  
  231.   function rnd(n,min) {
  232.     if (isNaN(min)) {
  233.       min = 0;
  234.     }
  235.     return (Math.random()*n)+min;
  236.   }
  237.  
  238.   function plusMinus(n) {
  239.     return (parseInt(rnd(2),10)===1?n*-1:n);
  240.   }
  241.  
  242.   this.randomizeWind = function() {
  243.     var i;
  244.     vRndX = plusMinus(rnd(storm.vMaxX,0.2));
  245.     vRndY = rnd(storm.vMaxY,0.2);
  246.     if (this.flakes) {
  247.       for (i=0; i<this.flakes.length; i++) {
  248.         if (this.flakes[i].active) {
  249.           this.flakes[i].setVelocities();
  250.         }
  251.       }
  252.     }
  253.   };
  254.  
  255.   this.scrollHandler = function() {
  256.     var i;
  257.     // "attach" snowflakes to bottom of window if no absolute bottom value was given
  258.     scrollY = (storm.flakeBottom ? 0 : parseInt(window.scrollY || document.documentElement.scrollTop || (noFixed ? document.body.scrollTop : 0), 10));
  259.     if (isNaN(scrollY)) {
  260.       scrollY = 0; // Netscape 6 scroll fix
  261.     }
  262.     if (!fixedForEverything && !storm.flakeBottom && storm.flakes) {
  263.       for (i=0; i<storm.flakes.length; i++) {
  264.         if (storm.flakes[i].active === 0) {
  265.           storm.flakes[i].stick();
  266.         }
  267.       }
  268.     }
  269.   };
  270.  
  271.   this.resizeHandler = function() {
  272.     if (window.innerWidth || window.innerHeight) {
  273.       screenX = window.innerWidth - 16 - storm.flakeRightOffset;
  274.       screenY = (storm.flakeBottom || window.innerHeight);
  275.     } else {
  276.       screenX = (document.documentElement.clientWidth || document.body.clientWidth || document.body.scrollWidth) - (!isIE ? 8 : 0) - storm.flakeRightOffset;
  277.       screenY = storm.flakeBottom || document.documentElement.clientHeight || document.body.clientHeight || document.body.scrollHeight;
  278.     }
  279.     docHeight = document.body.offsetHeight;
  280.     screenX2 = parseInt(screenX/2,10);
  281.   };
  282.  
  283.   this.resizeHandlerAlt = function() {
  284.     screenX = storm.targetElement.offsetWidth - storm.flakeRightOffset;
  285.     screenY = storm.flakeBottom || storm.targetElement.offsetHeight;
  286.     screenX2 = parseInt(screenX/2,10);
  287.     docHeight = document.body.offsetHeight;
  288.   };
  289.  
  290.   this.freeze = function() {
  291.     // pause animation
  292.     if (!storm.disabled) {
  293.       storm.disabled = 1;
  294.     } else {
  295.       return false;
  296.     }
  297.     storm.timer = null;
  298.   };
  299.  
  300.   this.resume = function() {
  301.     if (storm.disabled) {
  302.        storm.disabled = 0;
  303.     } else {
  304.       return false;
  305.     }
  306.     storm.timerInit();
  307.   };
  308.  
  309.   this.toggleSnow = function() {
  310.     if (!storm.flakes.length) {
  311.       // first run
  312.       storm.start();
  313.     } else {
  314.       storm.active = !storm.active;
  315.       if (storm.active) {
  316.         storm.show();
  317.         storm.resume();
  318.       } else {
  319.         storm.stop();
  320.         storm.freeze();
  321.       }
  322.     }
  323.   };
  324.  
  325.   this.stop = function() {
  326.     var i;
  327.     this.freeze();
  328.     for (i=0; i<this.flakes.length; i++) {
  329.       this.flakes[i].o.style.display = 'none';
  330.     }
  331.     storm.events.remove(window,'scroll',storm.scrollHandler);
  332.     storm.events.remove(window,'resize',storm.resizeHandler);
  333.     if (storm.freezeOnBlur) {
  334.       if (isIE) {
  335.         storm.events.remove(document,'focusout',storm.freeze);
  336.         storm.events.remove(document,'focusin',storm.resume);
  337.       } else {
  338.         storm.events.remove(window,'blur',storm.freeze);
  339.         storm.events.remove(window,'focus',storm.resume);
  340.       }
  341.     }
  342.   };
  343.  
  344.   this.show = function() {
  345.     var i;
  346.     for (i=0; i<this.flakes.length; i++) {
  347.       this.flakes[i].o.style.display = 'block';
  348.     }
  349.   };
  350.  
  351.   this.SnowFlake = function(type,x,y) {
  352.     var s = this;
  353.     this.type = type;
  354.     this.x = x||parseInt(rnd(screenX-20),10);
  355.     this.y = (!isNaN(y)?y:-rnd(screenY)-12);
  356.     this.vX = null;
  357.     this.vY = null;
  358.     this.vAmpTypes = [1,1.2,1.4,1.6,1.8]; // "amplification" for vX/vY (based on flake size/type)
  359.     this.vAmp = this.vAmpTypes[this.type] || 1;
  360.     this.melting = false;
  361.     this.meltFrameCount = storm.meltFrameCount;
  362.     this.meltFrames = storm.meltFrames;
  363.     this.meltFrame = 0;
  364.     this.twinkleFrame = 0;
  365.     this.active = 1;
  366.     this.fontSize = (10+(this.type/5)*10);
  367.     this.o = document.createElement('div');
  368.     this.o.innerHTML = storm.snowCharacter;
  369.     if (storm.className) {
  370.       this.o.setAttribute('class', storm.className);
  371.     }
  372.     this.o.style.color = storm.snowColor;
  373.     this.o.style.position = (fixedForEverything?'fixed':'absolute');
  374.     if (storm.useGPU && features.transform.prop) {
  375.       // GPU-accelerated snow.
  376.       this.o.style[features.transform.prop] = 'translate3d(0px, 0px, 0px)';
  377.     }
  378.     this.o.style.width = storm.flakeWidth+'px';
  379.     this.o.style.height = storm.flakeHeight+'px';
  380.     this.o.style.fontFamily = 'arial,verdana';
  381.     this.o.style.cursor = 'default';
  382.     this.o.style.overflow = 'hidden';
  383.     this.o.style.fontWeight = 'normal';
  384.     this.o.style.zIndex = storm.zIndex;
  385.     docFrag.appendChild(this.o);
  386.  
  387.     this.refresh = function() {
  388.       if (isNaN(s.x) || isNaN(s.y)) {
  389.         // safety check
  390.         return false;
  391.       }
  392.       storm.setXY(s.o, s.x, s.y);
  393.     };
  394.  
  395.     this.stick = function() {
  396.       if (noFixed || (storm.targetElement !== document.documentElement && storm.targetElement !== document.body)) {
  397.         s.o.style.top = (screenY+scrollY-storm.flakeHeight)+'px';
  398.       } else if (storm.flakeBottom) {
  399.         s.o.style.top = storm.flakeBottom+'px';
  400.       } else {
  401.         s.o.style.display = 'none';
  402.         s.o.style.top = 'auto';
  403.         s.o.style.bottom = '0%';
  404.         s.o.style.position = 'fixed';
  405.         s.o.style.display = 'block';
  406.       }
  407.     };
  408.  
  409.     this.vCheck = function() {
  410.       if (s.vX>=0 && s.vX<0.2) {
  411.         s.vX = 0.2;
  412.       } else if (s.vX<0 && s.vX>-0.2) {
  413.         s.vX = -0.2;
  414.       }
  415.       if (s.vY>=0 && s.vY<0.2) {
  416.         s.vY = 0.2;
  417.       }
  418.     };
  419.  
  420.     this.move = function() {
  421.       var vX = s.vX*windOffset, yDiff;
  422.       s.x += vX;
  423.       s.y += (s.vY*s.vAmp);
  424.       if (s.x >= screenX || screenX-s.x < storm.flakeWidth) { // X-axis scroll check
  425.         s.x = 0;
  426.       } else if (vX < 0 && s.x-storm.flakeLeftOffset < -storm.flakeWidth) {
  427.         s.x = screenX-storm.flakeWidth-1; // flakeWidth;
  428.       }
  429.       s.refresh();
  430.       yDiff = screenY+scrollY-s.y+storm.flakeHeight;
  431.       if (yDiff<storm.flakeHeight) {
  432.         s.active = 0;
  433.         if (storm.snowStick) {
  434.           s.stick();
  435.         } else {
  436.           s.recycle();
  437.         }
  438.       } else {
  439.         if (storm.useMeltEffect && s.active && s.type < 3 && !s.melting && Math.random()>0.998) {
  440.           // ~1/1000 chance of melting mid-air, with each frame
  441.           s.melting = true;
  442.           s.melt();
  443.           // only incrementally melt one frame
  444.           // s.melting = false;
  445.         }
  446.         if (storm.useTwinkleEffect) {
  447.           if (s.twinkleFrame < 0) {
  448.             if (Math.random() > 0.97) {
  449.               s.twinkleFrame = parseInt(Math.random() * 8, 10);
  450.             }
  451.           } else {
  452.             s.twinkleFrame--;
  453.             if (!opacitySupported) {
  454.               s.o.style.visibility = (s.twinkleFrame && s.twinkleFrame % 2 === 0 ? 'hidden' : 'visible');
  455.             } else {
  456.               s.o.style.opacity = (s.twinkleFrame && s.twinkleFrame % 2 === 0 ? 0 : 1);
  457.             }
  458.           }
  459.         }
  460.       }
  461.     };
  462.  
  463.     this.animate = function() {
  464.       // main animation loop
  465.       // move, check status, die etc.
  466.       s.move();
  467.     };
  468.  
  469.     this.setVelocities = function() {
  470.       s.vX = vRndX+rnd(storm.vMaxX*0.12,0.1);
  471.       s.vY = vRndY+rnd(storm.vMaxY*0.12,0.1);
  472.     };
  473.  
  474.     this.setOpacity = function(o,opacity) {
  475.       if (!opacitySupported) {
  476.         return false;
  477.       }
  478.       o.style.opacity = opacity;
  479.     };
  480.  
  481.     this.melt = function() {
  482.       if (!storm.useMeltEffect || !s.melting) {
  483.         s.recycle();
  484.       } else {
  485.         if (s.meltFrame < s.meltFrameCount) {
  486.           s.setOpacity(s.o,s.meltFrames[s.meltFrame]);
  487.           s.o.style.fontSize = s.fontSize-(s.fontSize*(s.meltFrame/s.meltFrameCount))+'px';
  488.           s.o.style.lineHeight = storm.flakeHeight+2+(storm.flakeHeight*0.75*(s.meltFrame/s.meltFrameCount))+'px';
  489.           s.meltFrame++;
  490.         } else {
  491.           s.recycle();
  492.         }
  493.       }
  494.     };
  495.  
  496.     this.recycle = function() {
  497.       s.o.style.display = 'none';
  498.       s.o.style.position = (fixedForEverything?'fixed':'absolute');
  499.       s.o.style.bottom = 'auto';
  500.       s.setVelocities();
  501.       s.vCheck();
  502.       s.meltFrame = 0;
  503.       s.melting = false;
  504.       s.setOpacity(s.o,1);
  505.       s.o.style.padding = '0px';
  506.       s.o.style.margin = '0px';
  507.       s.o.style.fontSize = s.fontSize+'px';
  508.       s.o.style.lineHeight = (storm.flakeHeight+2)+'px';
  509.       s.o.style.textAlign = 'center';
  510.       s.o.style.verticalAlign = 'baseline';
  511.       s.x = parseInt(rnd(screenX-storm.flakeWidth-20),10);
  512.       s.y = parseInt(rnd(screenY)*-1,10)-storm.flakeHeight;
  513.       s.refresh();
  514.       s.o.style.display = 'block';
  515.       s.active = 1;
  516.     };
  517.  
  518.     this.recycle(); // set up x/y coords etc.
  519.     this.refresh();
  520.  
  521.   };
  522.  
  523.   this.snow = function() {
  524.     var active = 0, flake = null, i, j;
  525.     for (i=0, j=storm.flakes.length; i<j; i++) {
  526.       if (storm.flakes[i].active === 1) {
  527.         storm.flakes[i].move();
  528.         active++;
  529.       }
  530.       if (storm.flakes[i].melting) {
  531.         storm.flakes[i].melt();
  532.       }
  533.     }
  534.     if (active<storm.flakesMaxActive) {
  535.       flake = storm.flakes[parseInt(rnd(storm.flakes.length),10)];
  536.       if (flake.active === 0) {
  537.         flake.melting = true;
  538.       }
  539.     }
  540.     if (storm.timer) {
  541.       features.getAnimationFrame(storm.snow);
  542.     }
  543.   };
  544.  
  545.   this.mouseMove = function(e) {
  546.     if (!storm.followMouse) {
  547.       return true;
  548.     }
  549.     var x = parseInt(e.clientX,10);
  550.     if (x<screenX2) {
  551.       windOffset = -windMultiplier+(x/screenX2*windMultiplier);
  552.     } else {
  553.       x -= screenX2;
  554.       windOffset = (x/screenX2)*windMultiplier;
  555.     }
  556.   };
  557.  
  558.   this.createSnow = function(limit,allowInactive) {
  559.     var i;
  560.     for (i=0; i<limit; i++) {
  561.       storm.flakes[storm.flakes.length] = new storm.SnowFlake(parseInt(rnd(flakeTypes),10));
  562.       if (allowInactive || i>storm.flakesMaxActive) {
  563.         storm.flakes[storm.flakes.length-1].active = -1;
  564.       }
  565.     }
  566.     storm.targetElement.appendChild(docFrag);
  567.   };
  568.  
  569.   this.timerInit = function() {
  570.     storm.timer = true;
  571.     storm.snow();
  572.   };
  573.  
  574.   this.init = function() {
  575.     var i;
  576.     for (i=0; i<storm.meltFrameCount; i++) {
  577.       storm.meltFrames.push(1-(i/storm.meltFrameCount));
  578.     }
  579.     storm.randomizeWind();
  580.     storm.createSnow(storm.flakesMax); // create initial batch
  581.     storm.events.add(window,'resize',storm.resizeHandler);
  582.     storm.events.add(window,'scroll',storm.scrollHandler);
  583.     if (storm.freezeOnBlur) {
  584.       if (isIE) {
  585.         storm.events.add(document,'focusout',storm.freeze);
  586.         storm.events.add(document,'focusin',storm.resume);
  587.       } else {
  588.         storm.events.add(window,'blur',storm.freeze);
  589.         storm.events.add(window,'focus',storm.resume);
  590.       }
  591.     }
  592.     storm.resizeHandler();
  593.     storm.scrollHandler();
  594.     if (storm.followMouse) {
  595.       storm.events.add(isIE?document:window,'mousemove',storm.mouseMove);
  596.     }
  597.     storm.animationInterval = Math.max(20,storm.animationInterval);
  598.     storm.timerInit();
  599.   };
  600.  
  601.   this.start = function(bFromOnLoad) {
  602.     if (!didInit) {
  603.       didInit = true;
  604.     } else if (bFromOnLoad) {
  605.       // already loaded and running
  606.       return true;
  607.     }
  608.     if (typeof storm.targetElement === 'string') {
  609.       var targetID = storm.targetElement;
  610.       storm.targetElement = document.getElementById(targetID);
  611.       if (!storm.targetElement) {
  612.         throw new Error('Snowstorm: Unable to get targetElement "'+targetID+'"');
  613.       }
  614.     }
  615.     if (!storm.targetElement) {
  616.       storm.targetElement = (document.body || document.documentElement);
  617.     }
  618.     if (storm.targetElement !== document.documentElement && storm.targetElement !== document.body) {
  619.       // re-map handler to get element instead of screen dimensions
  620.       storm.resizeHandler = storm.resizeHandlerAlt;
  621.       //and force-enable pixel positioning
  622.       storm.usePixelPosition = true;
  623.     }
  624.     storm.resizeHandler(); // get bounding box elements
  625.     storm.usePositionFixed = (storm.usePositionFixed && !noFixed && !storm.flakeBottom); // whether or not position:fixed is to be used
  626.     if (window.getComputedStyle) {
  627.       // attempt to determine if body or user-specified snow parent element is relatlively-positioned.
  628.       try {
  629.         targetElementIsRelative = (window.getComputedStyle(storm.targetElement, null).getPropertyValue('position') === 'relative');
  630.       } catch(e) {
  631.         // oh well
  632.         targetElementIsRelative = false;
  633.       }
  634.     }
  635.     fixedForEverything = storm.usePositionFixed;
  636.     if (screenX && screenY && !storm.disabled) {
  637.       storm.init();
  638.       storm.active = true;
  639.     }
  640.   };
  641.  
  642.   function doDelayedStart() {
  643.     window.setTimeout(function() {
  644.       storm.start(true);
  645.     }, 20);
  646.     // event cleanup
  647.     storm.events.remove(isIE?document:window,'mousemove',doDelayedStart);
  648.   }
  649.  
  650.   function doStart() {
  651.     if (!storm.excludeMobile || !isMobile) {
  652.       doDelayedStart();
  653.     }
  654.     // event cleanup
  655.     storm.events.remove(window, 'load', doStart);
  656.   }
  657.  
  658.   // hooks for starting the snow
  659.   if (storm.autoStart) {
  660.     storm.events.add(window, 'load', doStart, false);
  661.   }
  662.  
  663.   return this;
  664.  
  665. }(window, document));