(function (name, factory) {
if (typeof window === "object") {
window[name] = factory();
}
})("Ribbons", function () {
var _w = window, _b = document.body, _d = document.documentElement;
var random = function () {
if (arguments.length === 1) {
if (Array.isArray(arguments[0])) {
var index = Math.round(random(0, arguments[0].length - 1));
return arguments[0][index];
}
return random(0, arguments[0]);
} else if (arguments.length === 2) {
return Math.random() * (arguments[1] - arguments[0]) + arguments[0];
}
return 0;
};
var screenInfo = function (e) {
var width = Math.max(0, _w.innerWidth || _d.clientWidth || _b.clientWidth || 0),
height = Math.max(0, _w.innerHeight || _d.clientHeight || _b.clientHeight || 0),
scrollx = Math.max(0, _w.pageXOffset || _d.scrollLeft || _b.scrollLeft || 0) - (_d.clientLeft || 0),
scrolly = Math.max(0, _w.pageYOffset || _d.scrollTop || _b.scrollTop || 0) - (_d.clientTop || 0);
return {
width: width,
height: height,
ratio: width / height,
centerx: width / 2,
centery: height / 2,
scrollx: scrollx,
scrolly: scrolly
};
};
var mouseInfo = function (e) {
var screen = screenInfo(e), mousex = e ? Math.max(0, e.pageX || e.clientX || 0) : 0,
mousey = e ? Math.max(0, e.pageY || e.clientY || 0) : 0;
return {
mousex: mousex,
mousey: mousey,
centerx: mousex - screen.width / 2,
centery: mousey - screen.height / 2
};
};
var Point = function (x, y) {
this.x = 0;
this.y = 0;
this.set(x, y);
};
Point.prototype = {
constructor: Point, set: function (x, y) {
this.x = x || 0;
this.y = y || 0;
}, copy: function (point) {
this.x = point.x || 0;
this.y = point.y || 0;
return this;
}, multiply: function (x, y) {
this.x *= x || 1;
this.y *= y || 1;
return this;
}, divide: function (x, y) {
this.x /= x || 1;
this.y /= y || 1;
return this;
}, add: function (x, y) {
this.x += x || 0;
this.y += y || 0;
return this;
}, subtract: function (x, y) {
this.x -= x || 0;
this.y -= y || 0;
return this;
}, clampX: function (min, max) {
this.x = Math.max(min, Math.min(this.x, max));
return this;
}, clampY: function (min, max) {
this.y = Math.max(min, Math.min(this.y, max));
return this;
}, flipX: function () {
this.x *= -1;
return this;
}, flipY: function () {
this.y *= -1;
return this;
}
};
var Factory = function (options) {
this._canvas = null;
this._context = null;
this._sto = null;
this._width = 0;
this._height = 0;
this._scroll = 0;
this._ribbons = [];
this._options = {
colorSaturation: "80%",
colorBrightness: "60%",
colorAlpha: 0.65,
colorCycleSpeed: 6,
verticalPosition: "center",
horizontalSpeed: 200,
ribbonCount: 4,
strokeSize: 0,
parallaxAmount: -0.5,
animateSections: true
};
this._onDraw = this._onDraw.bind(this);
this._onResize = this._onResize.bind(this);
this._onScroll = this._onScroll.bind(this);
this.setOptions(options);
this.init();
};
Factory.prototype = {
constructor: Factory, setOptions: function (options) {
if (typeof options === "object") {
for (var key in options) {
if (options.hasOwnProperty(key)) {
this._options[key] = options[key];
}
}
}
}, init: function () {
try {
this._canvas = document.createElement("canvas");
this._canvas.style["display"] = "block";
this._canvas.style["position"] = "fixed";
this._canvas.style["margin"] = "0";
this._canvas.style["padding"] = "0";
this._canvas.style["border"] = "0";
this._canvas.style["outline"] = "0";
this._canvas.style["left"] = "0";
this._canvas.style["top"] = "0";
this._canvas.style["width"] = "100%";
this._canvas.style["height"] = "100%";
this._canvas.style["z-index"] = "-1";
// this._canvas.style["background-color"] = "#1f1f1f";
this._canvas.id = "bgCanvas";
this._onResize();
this._context = this._canvas.getContext("2d");
this._context.clearRect(0, 0, this._width, this._height);
this._context.globalAlpha = this._options.colorAlpha;
// 这里可以设置是否随着窗口的滚动而滚动
window.addEventListener("resize", this._onResize);
window.addEventListener("scroll", this._onScroll);
// 这里设置添加的位置
var body_ = document.getElementsByTagName('body')[0];
body_.appendChild(this._canvas);
} catch (e) {
console.warn("Canvas Context Error: " + e.toString());
return;
}
this._onDraw();
}, addRibbon: function () {
var dir = Math.round(random(1, 9)) > 5 ? "right" : "left", stop = 1000, hide = 200, min = 0 - hide,
max = this._width + hide, movex = 0, movey = 0, startx = dir === "right" ? min : max,
starty = Math.round(random(0, this._height));
if (/^(top|min)$/i.test(this._options.verticalPosition)) {
starty = 0 + hide;
} else if (/^(middle|center)$/i.test(this._options.verticalPosition)) {
starty = this._height / 2;
} else if (/^(bottom|max)$/i.test(this._options.verticalPosition)) {
starty = this._height - hide;
}
var ribbon = [], point1 = new Point(startx, starty), point2 = new Point(startx, starty), point3 = null,
color = Math.round(random(0, 360)), delay = 0;
while (true) {
if (stop <= 0) break;
stop--;
movex = Math.round((Math.random() * 1 - 0.2) * this._options.horizontalSpeed);
movey = Math.round((Math.random() * 1 - 0.5) * (this._height * 0.25));
point3 = new Point();
point3.copy(point2);
if (dir === "right") {
point3.add(movex, movey);
if (point2.x >= max) break;
} else if (dir === "left") {
point3.subtract(movex, movey);
if (point2.x <= min) break;
}
ribbon.push({
point1: new Point(point1.x, point1.y),
point2: new Point(point2.x, point2.y),
point3: point3,
color: color,
delay: delay,
dir: dir,
alpha: 0,
phase: 0
});
point1.copy(point2);
point2.copy(point3);
delay += 4;
color += this._options.colorCycleSpeed;
}
this._ribbons.push(ribbon);
}, _drawRibbonSection: function (section) {
if (section) {
if (section.phase >= 1 && section.alpha <= 0) {
return true;
}
if (section.delay <= 0) {
section.phase += 0.02;
section.alpha = Math.sin(section.phase) * 1;
section.alpha = section.alpha <= 0 ? 0 : section.alpha;
section.alpha = section.alpha >= 1 ? 1 : section.alpha;
if (this._options.animateSections) {
var mod = Math.sin(1 + section.phase * Math.PI / 2) * 0.1;
if (section.dir === "right") {
section.point1.add(mod, 0);
section.point2.add(mod, 0);
section.point3.add(mod, 0);
} else {
section.point1.subtract(mod, 0);
section.point2.subtract(mod, 0);
section.point3.subtract(mod, 0);
}
section.point1.add(0, mod);
section.point2.add(0, mod);
section.point3.add(0, mod);
}
} else {
section.delay -= 0.5;
}
var s = this._options.colorSaturation, l = this._options.colorBrightness,
c = "hsla(" + section.color + ", " + s + ", " + l + ", " + section.alpha + " )";
this._context.save();
if (this._options.parallaxAmount !== 0) {
this._context.translate(0, this._scroll * this._options.parallaxAmount);
}
this._context.beginPath();
this._context.moveTo(section.point1.x, section.point1.y);
this._context.lineTo(section.point2.x, section.point2.y);
this._context.lineTo(section.point3.x, section.point3.y);
this._context.fillStyle = c;
this._context.fill();
if (this._options.strokeSize > 0) {
this._context.lineWidth = this._options.strokeSize;
this._context.strokeStyle = c;
this._context.lineCap = "round";
this._context.stroke();
}
this._context.restore();
}
return false;
}, _onDraw: function () {
for (var i = 0, t = this._ribbons.length; i < t; ++i) {
if (!this._ribbons[i]) {
this._ribbons.splice(i, 1);
}
}
this._context.clearRect(0, 0, this._width, this._height);
for (var a = 0; a < this._ribbons.length; ++a) {
var ribbon = this._ribbons[a], numSections = ribbon.length, numDone = 0;
for (var b = 0; b < numSections; ++b) {
if (this._drawRibbonSection(ribbon[b])) {
numDone++;
}
}
if (numDone >= numSections) {
this._ribbons[a] = null;
}
}
if (this._ribbons.length < this._options.ribbonCount) {
this.addRibbon();
}
requestAnimationFrame(this._onDraw);
}, _onResize: function (e) {
var screen = screenInfo(e);
this._width = screen.width;
this._height = screen.height;
if (this._canvas) {
this._canvas.width = this._width;
this._canvas.height = this._height;
if (this._context) {
this._context.globalAlpha = this._options.colorAlpha;
}
}
}, _onScroll: function (e) {
var screen = screenInfo(e);
this._scroll = screen.scrolly;
}
};
return Factory;
});
new Ribbons();
