js代码

var process = $('.process');

var canvas = document.getElementById('canvas');

var ctx = canvas.getContext('2d');

var SECTION_WIDTH = 200;

var sections = [];

var create = function(start) {

var section = {

start: start,

width: SECTION_WIDTH,

height: 45,

hMax: 35,

hMod: 0,

progress: 0,

dot: {

x: 0,

y: 0

}

};

section.end = section.start + section.width;

section.dot.x = section.start + section.width/2;

section.dot.y = section.height;

sections.push(section);

};

var draw = function(s) {

var wMod = s.width * 0.3;

ctx.beginPath();

ctx.moveTo(s.start, s.height);

ctx.bezierCurveTo(

s.start+wMod, s.height,

s.start+wMod, s.height - s.hMod,

s.start + s.width/2, s.height - s.hMod

);

ctx.bezierCurveTo(

s.end-wMod, s.height - s.hMod,

s.end-wMod, s.height,

s.end, s.height

);

ctx.lineWidth = 4;

ctx.strokeStyle = 'white';

ctx.stroke();

ctx.beginPath();

ctx.fillStyle = 'white';

ctx.arc(s.dot.x, s.dot.y, 8, 0, Math.PI * 2);

ctx.fill();

};

function quad(progress) {

return Math.pow(progress, 2);

}

function makeEaseOut(delta) {

return function(progress) {

return 1 - delta(1 - progress);

}

}

var quadOut = makeEaseOut(quad);

var bend = function(s) {

if(s.progress < s.hMax) {

var delta = quadOut(s.progress/s.hMax);

s.hMod = s.hMax*delta;

s.dot.y = s.height - s.hMax*delta;

s.progress++;

}

};

var reset = function(s) {

if(s.progress > 0) {

var delta = quadOut(s.progress/s.hMax);

s.hMod = s.hMax*delta;

s.dot.y = s.height - s.hMax*delta;

s.progress -= 2;

} else {

s.hMod = 0;

s.dot.y = s.height;

s.progress = 0;

}

};

var currentSection = 0;

process.on('mousemove', function(event) {

var section = Math.floor((event.clientX - process.offset().left) / SECTION_WIDTH);

currentSection = section;

process.find('.active').removeClass('active');

process.find('li').eq(section).addClass('active');

});

create(0);

create(200);

create(400);

create(600);

var loop = function() {

ctx.clearRect(0, 0, canvas.width, canvas.height);

sections.forEach(function(s, index) {

if(currentSection === index) {

bend(s);

} else {

reset(s);

}

draw(s);

});

window.requestAnimationFrame(loop);

};

loop();