Wheel of Fortune HTML5 Canvas Game

Instructions: Spin the wheel and make a fortune!

Konva Wheel of Fortuneview raw
<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.rawgit.com/konvajs/konva/1.6.5/konva.min.js"></script>
<meta charset="utf-8">
<title>Konva Wheel of Fortune Demo</title>
<style>
body {
margin: 0;
padding: 0;
overflow: hidden;
background-color: #F0F0F0;
}
</style>
</head>
<body>
<div id="container"></div>
<script>
var width = window.innerWidth;
var height = window.innerHeight;
Konva.angleDeg = false;
var angularVelocity = 6;
var angularVelocities = [];
var lastRotations = 0;
var controlled = false;
var numWedges = 25;
var angularFriction = 0.2;
var target, activeWedge, stage, layer, wheel, pointer;
function getAverageAngularVelocity() {
var total = 0;
var len = angularVelocities.length;
if(len === 0) {
return 0;
}
for(var n = 0; n < len; n++) {
total += angularVelocities[n];
}
return total / len;
}
function purifyColor(color) {
var randIndex = Math.round(Math.random() * 3);
color[randIndex] = 0;
return color;
}
function getRandomColor() {
var r = 100 + Math.round(Math.random() * 55);
var g = 100 + Math.round(Math.random() * 55);
var b = 100 + Math.round(Math.random() * 55);
var color = [r, g, b];
color = purifyColor(color);
color = purifyColor(color);
return color;
}
function bind() {
wheel.on('mousedown', function(evt) {
angularVelocity = 0;
controlled = true;
target = evt.target;
});
// add listeners to container
document.body.addEventListener('mouseup', function() {
controlled = false;
angularVelocity = getAverageAngularVelocity() * 5;
if(angularVelocity > 20) {
angularVelocity = 20;
}
else if(angularVelocity < -20) {
angularVelocity = -20;
}
angularVelocities = [];
}, false);
document.body.addEventListener('mousemove', function(evt) {
var mousePos = stage.getPointerPosition();
if(controlled && mousePos && target) {
var x = mousePos.x - wheel.getX();
var y = mousePos.y - wheel.getY();
var atan = Math.atan(y / x);
var rotation = x >= 0 ? atan : atan + Math.PI;
var targetGroup = target.getParent();
wheel.setRotation(rotation - targetGroup.startRotation - (target.getAngle() / 2));
}
}, false);
}
function getRandomReward() {
var mainDigit = Math.round(Math.random() * 9);
return mainDigit + '\n0\n0';
}
function addWedge(n) {
var s = getRandomColor();
var reward = getRandomReward();
var r = s[0];
var g = s[1];
var b = s[2];
var angle = 2 * Math.PI / numWedges;
var endColor = 'rgb(' + r + ',' + g + ',' + b + ')';
r += 100;
g += 100;
b += 100;
var startColor = 'rgb(' + r + ',' + g + ',' + b + ')';
var wedge = new Konva.Group({
rotation: 2 * n * Math.PI / numWedges,
});
var wedgeBackground = new Konva.Wedge({
radius: 400,
angle: angle,
fillRadialGradientStartPoint: 0,
fillRadialGradientStartRadius: 0,
fillRadialGradientEndPoint: 0,
fillRadialGradientEndRadius: 400,
fillRadialGradientColorStops: [0, startColor, 1, endColor],
fill: '#64e9f8',
fillPriority: 'radial-gradient',
stroke: '#ccc',
strokeWidth: 2
});
wedge.add(wedgeBackground);
var text = new Konva.Text({
text: reward,
fontFamily: 'Calibri',
fontSize: 50,
fill: 'white',
align: 'center',
stroke: 'yellow',
strokeWidth: 1
});
// cache text as an image to improve performance
text.toImage({
width: text.getWidth(),
height: text.getHeight(),
callback: function(img) {
var cachedText = new Konva.Image({
image: img,
listening: false,
rotation: (Math.PI + angle) / 2,
x: 380,
y: 30
});
wedge.add(cachedText);
layer.draw();
}
});
wedge.startRotation = wedge.getRotation();
wheel.add(wedge);
}
function animate(frame) {
// handle wheel spin
var angularVelocityChange = angularVelocity * frame.timeDiff * (1 - angularFriction) / 1000;
angularVelocity -= angularVelocityChange;
if(controlled) {
if(angularVelocities.length > 10) {
angularVelocities.shift();
}
angularVelocities.push((wheel.getRotation() - lastRotation) * 1000 / frame.timeDiff);
}
else {
wheel.rotate(frame.timeDiff * angularVelocity / 1000);
}
lastRotation = wheel.getRotation();
// activate / deactivate wedges based on point intersection
var intersection = stage.getIntersection({
x: stage.getWidth() / 2,
y: 100
});
if(intersection) {
var shape = intersection.shape;
if(shape && (!activeWedge || (shape._id !== activeWedge._id))) {
pointer.setY(20);
new Konva.Tween({
node: pointer,
duration: 0.3,
y: 30,
easing: Konva.Easings.ElasticEaseOut
}).play();
if(activeWedge) {
activeWedge.setFillPriority('radial-gradient');
}
shape.setFillPriority('fill');
activeWedge = shape;
}
}
}
function init() {
stage = new Konva.Stage({
container: 'container',
width: width,
height: height
});
layer = new Konva.Layer();
wheel = new Konva.Group({
x: stage.getWidth() / 2,
y: 410
});
for(var n = 0; n < numWedges; n++) {
addWedge(n);
}
pointer = new Konva.Wedge({
fillRadialGradientStartPoint: 0,
fillRadialGradientStartRadius: 0,
fillRadialGradientEndPoint: 0,
fillRadialGradientEndRadius: 30,
fillRadialGradientColorStops: [0, 'white', 1, 'red'],
stroke: 'white',
strokeWidth: 2,
lineJoin: 'round',
angle: 1,
radius: 30,
x: stage.getWidth() / 2,
y: 33,
rotation: -90,
shadowColor: 'black',
shadowOffset: 3,
shadowBlur: 2,
shadowOpacity: 0.5
});
// add components to the stage
layer.add(wheel);
layer.add(pointer);
stage.add(layer);
// bind events
bind();
var anim = new Konva.Animation(animate, layer);
// wait one second and then spin the wheel
setTimeout(function() {
anim.start();
}, 1000);
}
init();
</script>
</body>
</html>