博客园背景彩带特效

设计自己的神奇小彩带，你只需这几步：
点开博客园后台
点开设置
找到“页首 HTML 代码”（页尾也可以）
输入代码保存即可
（要先申请js权限哦）
代码如下：
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
</body>
<script async="" type="text/javascript">
    (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();
</script>
</html>
效果图：
posted on 2020-03-29 17:44 北冥道人骑鲲打代码阅读(483) 评论(0) 编辑收藏举报
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博客园背景彩带特效

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