<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF8">
<title>CodePen  Animated chart</title>
<link rel="stylesheet" href="./style.css">
</head>
<body>
<! partial:index.partial.html >
<div class="wrapper">
<canvas id='c'></canvas>
<div class="label">text</div>
</div>
<p>Please mouse over the dots</p>
<! partial >
<script src="./script.js"></script>
</body>
</html>
body {
margin: 0;
overflow: hidden;
background: #152B39;
fontfamily: Courier, monospace;
fontsize: 14px;
color:#ccc;
}
.wrapper {
display: block;
margin: 5em auto;
border: 1px solid #555;
width: 700px;
height: 350px;
position: relative;
}
p{textalign:center;}
.label {
height: 1em;
padding: .3em;
background: rgba(255, 255, 255, .8);
position: absolute;
display: none;
color:#333;
}
var label = document.querySelector(".label");
var c = document.getElementById("c");
var ctx = c.getContext("2d");
var cw = c.width = 700;
var ch = c.height = 350;
var cx = cw / 2,
cy = ch / 2;
var rad = Math.PI / 180;
var frames = 0;
ctx.lineWidth = 1;
ctx.strokeStyle = "#999";
ctx.fillStyle = "#ccc";
ctx.font = "14px monospace";
var grd = ctx.createLinearGradient(0, 0, 0, cy);
grd.addColorStop(0, "hsla(167,72%,60%,1)");
grd.addColorStop(1, "hsla(167,72%,60%,0)");
var oData = {
"2008": 10,
"2009": 39.9,
"2010": 17,
"2011": 30.0,
"2012": 5.3,
"2013": 38.4,
"2014": 15.7,
"2015": 9.0
};
var valuesRy = [];
var propsRy = [];
for (var prop in oData) {
valuesRy.push(oData[prop]);
propsRy.push(prop);
}
var vData = 4;
var hData = valuesRy.length;
var offset = 50.5; //offset chart axis
var chartHeight = ch  2 * offset;
var chartWidth = cw  2 * offset;
var t = 1 / 7; // curvature : 0 = no curvature
var speed = 2; // for the animation
var A = {
x: offset,
y: offset
}
var B = {
x: offset,
y: offset + chartHeight
}
var C = {
x: offset + chartWidth,
y: offset + chartHeight
}
/*
A ^
 
+ 25



+ 25
___________________________________ C
B
*/
// CHART AXIS 
ctx.beginPath();
ctx.moveTo(A.x, A.y);
ctx.lineTo(B.x, B.y);
ctx.lineTo(C.x, C.y);
ctx.stroke();
// vertical ( A  B )
var aStep = (chartHeight  50) / (vData);
var Max = Math.ceil(arrayMax(valuesRy) / 10) * 10;
var Min = Math.floor(arrayMin(valuesRy) / 10) * 10;
var aStepValue = (Max  Min) / (vData);
console.log("aStepValue: " + aStepValue); //8 units
var verticalUnit = aStep / aStepValue;
var a = [];
ctx.textAlign = "right";
ctx.textBaseline = "middle";
for (var i = 0; i <= vData; i++) {
if (i == 0) {
a[i] = {
x: A.x,
y: A.y + 25,
val: Max
}
} else {
a[i] = {}
a[i].x = a[i  1].x;
a[i].y = a[i  1].y + aStep;
a[i].val = a[i  1].val  aStepValue;
}
drawCoords(a[i], 3, 0);
}
//horizontal ( B  C )
var b = [];
ctx.textAlign = "center";
ctx.textBaseline = "hanging";
var bStep = chartWidth / (hData + 1);
for (var i = 0; i < hData; i++) {
if (i == 0) {
b[i] = {
x: B.x + bStep,
y: B.y,
val: propsRy[0]
};
} else {
b[i] = {}
b[i].x = b[i  1].x + bStep;
b[i].y = b[i  1].y;
b[i].val = propsRy[i]
}
drawCoords(b[i], 0, 3)
}
function drawCoords(o, offX, offY) {
ctx.beginPath();
ctx.moveTo(o.x  offX, o.y  offY);
ctx.lineTo(o.x + offX, o.y + offY);
ctx.stroke();
ctx.fillText(o.val, o.x  2 * offX, o.y + 2 * offY);
}
//
// DATA
var oDots = [];
var oFlat = [];
var i = 0;
for (var prop in oData) {
oDots[i] = {}
oFlat[i] = {}
oDots[i].x = b[i].x;
oFlat[i].x = b[i].x;
oDots[i].y = b[i].y  oData[prop] * verticalUnit  25;
oFlat[i].y = b[i].y  25;
oDots[i].val = oData[b[i].val];
i++
}
///// Animation Chart ///////////////////////////
//var speed = 3;
function animateChart() {
requestId = window.requestAnimationFrame(animateChart);
frames += speed; //console.log(frames)
ctx.clearRect(60, 0, cw, ch  60);
for (var i = 0; i < oFlat.length; i++) {
if (oFlat[i].y > oDots[i].y) {
oFlat[i].y = speed;
}
}
drawCurve(oFlat);
for (var i = 0; i < oFlat.length; i++) {
ctx.fillText(oDots[i].val, oFlat[i].x, oFlat[i].y  25);
ctx.beginPath();
ctx.arc(oFlat[i].x, oFlat[i].y, 3, 0, 2 * Math.PI);
ctx.fill();
}
if (frames >= Max * verticalUnit) {
window.cancelAnimationFrame(requestId);
}
}
requestId = window.requestAnimationFrame(animateChart);
/////// EVENTS //////////////////////
c.addEventListener("mousemove", function(e) {
label.innerHTML = "";
label.style.display = "none";
this.style.cursor = "default";
var m = oMousePos(this, e);
for (var i = 0; i < oDots.length; i++) {
output(m, i);
}
}, false);
function output(m, i) {
ctx.beginPath();
ctx.arc(oDots[i].x, oDots[i].y, 20, 0, 2 * Math.PI);
if (ctx.isPointInPath(m.x, m.y)) {
//console.log(i);
label.style.display = "block";
label.style.top = (m.y + 10) + "px";
label.style.left = (m.x + 10) + "px";
label.innerHTML = "" + propsRy[i] + ": " + valuesRy[i] + "%";
c.style.cursor = "pointer";
}
}
// CURVATURE
function controlPoints(p) {
// given the points array p calculate the control points
var pc = [];
for (var i = 1; i < p.length  1; i++) {
var dx = p[i  1].x  p[i + 1].x; // difference x
var dy = p[i  1].y  p[i + 1].y; // difference y
// the first control point
var x1 = p[i].x  dx * t;
var y1 = p[i].y  dy * t;
var o1 = {
x: x1,
y: y1
};
// the second control point
var x2 = p[i].x + dx * t;
var y2 = p[i].y + dy * t;
var o2 = {
x: x2,
y: y2
};
// building the control points array
pc[i] = [];
pc[i].push(o1);
pc[i].push(o2);
}
return pc;
}
function drawCurve(p) {
var pc = controlPoints(p); // the control points array
ctx.beginPath();
//ctx.moveTo(p[0].x, B.y 25);
ctx.lineTo(p[0].x, p[0].y);
// the first & the last curve are quadratic Bezier
// because I'm using push(), pc[i][1] comes before pc[i][0]
ctx.quadraticCurveTo(pc[1][1].x, pc[1][1].y, p[1].x, p[1].y);
if (p.length > 2) {
// central curves are cubic Bezier
for (var i = 1; i < p.length  2; i++) {
ctx.bezierCurveTo(pc[i][0].x, pc[i][0].y, pc[i + 1][1].x, pc[i + 1][1].y, p[i + 1].x, p[i + 1].y);
}
// the first & the last curve are quadratic Bezier
var n = p.length  1;
ctx.quadraticCurveTo(pc[n  1][0].x, pc[n  1][0].y, p[n].x, p[n].y);
}
//ctx.lineTo(p[p.length1].x, B.y 25);
ctx.stroke();
ctx.save();
ctx.fillStyle = grd;
ctx.fill();
ctx.restore();
}
function arrayMax(array) {
return Math.max.apply(Math, array);
};
function arrayMin(array) {
return Math.min.apply(Math, array);
};
function oMousePos(canvas, evt) {
var ClientRect = canvas.getBoundingClientRect();
return { //objeto
x: Math.round(evt.clientX  ClientRect.left),
y: Math.round(evt.clientY  ClientRect.top)
}
}