-
Notifications
You must be signed in to change notification settings - Fork 0
/
index.html
189 lines (150 loc) · 3.9 KB
/
index.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Canvas</title>
<style>
body {
margin: 0;
overflow: hidden;
background: #222;
}
.toolbar {
width: 150px;
height: 75px;
background: #222;
padding: 5px;
}
input[type="color"], button {
width: 90%;
margin: 0 auto;
display: block;
}
input[type="range"] {
width: 70%;
}
span {
position: relative;
bottom: 5px;
}
</style>
</head>
<body>
<div class="toolbar">
<!-- <input type="range" min="2" max="50" value="30" aria-label="select pen size"><span class="output">30</span> -->
<button class="reset">Reset</button>
<button class="start">Start</button>
<button class="stop">Stop</button>
</div>
<canvas class="myCanvas">
<p>Add suitable fallback here.</p>
</canvas>
<script>
const canvas = document.querySelector('.myCanvas');
const ctx = canvas.getContext('2d');
const width = canvas.width = window.innerWidth;
const height = canvas.height = window.innerHeight-85;
const startBtn = document.querySelector('.start');
const stopBtn = document.querySelector('.stop');
const resetBtn = document.querySelector('.reset');
let balls = [];
// function to generate random number
function random(min, max) {
const num = Math.floor(Math.random() * (max - min + 1)) + min;
return num;
}
// define Ball constructor
function Ball(x, y, velX, velY, color, size) {
this.x = x;
this.y = y;
this.velX = velX;
this.velY = velY;
this.color = color;
this.size = size;
}
// define ball draw method
Ball.prototype.draw = function() {
ctx.beginPath();
ctx.fillStyle = this.color;
ctx.arc(this.x, this.y, this.size, 0, 2 * Math.PI);
ctx.fill();
};
// define ball update method
Ball.prototype.update = function() {
if((this.x + this.size) >= width) {
this.velX = -(this.velX);
}
if((this.x - this.size) <= 0) {
this.velX = -(this.velX);
}
if((this.y + this.size) >= height) {
this.velY = -(this.velY);
}
if((this.y - this.size) <= 0) {
this.velY = -(this.velY);
}
this.x += this.velX;
this.y += this.velY;
};
// define ball collision detection
/*Ball.prototype.collisionDetect = function() {
for(let j = 0; j < balls.length; j++) {
if(!(this === balls[j])) {
const dx = this.x - balls[j].x;
const dy = this.y - balls[j].y;
const distance = Math.sqrt(dx * dx + dy * dy);
if (distance < this.size + balls[j].size) {
balls[j].color = this.color = 'rgb(' + random(0,255) + ',' + random(0,255) + ',' + random(0,255) +')';
}
}
}
};*/
let pressed = false;
startBtn.onclick = function() {
pressed = true;
}
stopBtn.onclick = function() {
pressed = false;
}
// define array to store balls and populate it
reset = function() {
ctx.fillStyle = 'rgba(0,0,0,1)';
ctx.fillRect(0,0,width,height);
balls = [];
while(balls.length < 25) {
const size = 10;
let ball = new Ball(
// ball position always drawn at least one ball width
// away from the edge of the canvas, to avoid drawing errors
random(0 + size,width/2 - size),
random(0 + size,height - size),
random(-7,7),
random(-7,7),
'rgb(' + 100 + ',' + 255 + ',' + 100 +')',
size
);
ball.draw();
balls.push(ball);
}
}
reset();
resetBtn.onclick = function() {
reset();
}
// define loop that keeps drawing the scene constantly
function loop() {
if(pressed) {
ctx.fillStyle = 'rgba(0,0,0,1)';
ctx.fillRect(0,0,width,height);
for(let i = 0; i < balls.length; i++) {
balls[i].draw();
balls[i].update();
// balls[i].collisionDetect();
}
}
requestAnimationFrame(loop);
}
loop();
</script>
</body>
</html>