-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathrotateBevel.html
158 lines (149 loc) · 4.31 KB
/
rotateBevel.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
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
<title></title>
<style id="stylesheet">
</style>
</head>
<body>
<div id="content">
<div class="point">
<button id="add">碰撞一下</button>
</div>
<canvas id="canvas" width="400" height="300" style="background:#333"></canvas>
</div>
<script src="scripts/tool.js?id=1"></script>
<script id="scripts">
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var centerX = Math.floor(canvas.width / 2);
var centerY = Math.floor(canvas.height / 2);
var requestID = null;
var balles = []; //存放页面上的球
var ball = null;
var gravity = 0.2;
var bounce = -0.6;
var line = null;
var sin = null;
var cos = null;
document.getElementById('add').addEventListener('click', function() {
var x = Math.random() * canvas.width;
var y = Math.random() * (canvas.height - 100);
ball = new Ball(x, y, 10);
animation();
});
// 球函数
function Ball(x, y, radius) {
this.x = x;
this.y = y;
this.radius = radius;
this.angle = 0;
this.vx = 0;
this.vy = 0;
};
Ball.prototype.draw = function(context) {
context.beginPath();
context.arc(this.x, this.y, this.radius, 0, 2 * Math.PI, true);
context.fill();
context.closePath();
};
function Line(x1, y1, x2, y2) {
this.x = 0;
this.y = 0;
this.x1 = (x1 === undefined) ? 0 : x1;
this.y1 = (y1 === undefined) ? 0 : y1;
this.x2 = (x2 === undefined) ? 0 : x2;
this.y2 = (y2 === undefined) ? 0 : y2;
this.rotation = 0;
this.scaleX = 1;
this.scaleY = 1;
this.lineWidth = 1;
};
Line.prototype.draw = function(context) {
context.save();
context.translate(this.x, this.y); //平移
context.rotate(this.rotation); // 旋转
context.scale(this.scaleX, this.scaleY);
context.lineWidth = this.lineWidth;
context.beginPath();
context.moveTo(this.x1, this.y1);
context.lineTo(this.x2, this.y2);
context.closePath();
context.stroke();
context.restore();
};
Line.prototype.getBounds = function() {
if(this.rotation === 0) {
var minX = Math.min(this.x1, this.x2);
var minY = Math.min(this.y1, this.y2);
var maxX = Math.max(this.x1, this.x2);
var maxY = Math.max(this.y1, this.y2);
return {
x: this.x + minX,
y: this.y + minY,
width: maxX - minX,
height: maxY - minY
};
} else {
//基于坐标系原点旋转
var sin = Math.sin(this.rotation);
var cos = Math.cos(this.rotation);
var x1r = cos * this.x1 + sin * this.y1;
var x2r = cos * this.x2 + sin * this.y2;
var y1r = cos * this.y1 + sin * this.x1;
var y2r = cos * this.y2 + sin * this.x2;
return {
x: this.x + Math.min(x1r, x2r),
y: this.y + Math.min(y1r, y2r),
width: Math.max(x1r, x2r) - Math.min(x1r, x2r),
height: Math.max(y1r, y2r) - Math.min(y1r, y2r)
};
}
}
function animation() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = '#fff';
ctx.strokeStyle = '#fff';
ball.vy += gravity;
ball.x += ball.vx;
ball.y += ball.vy;
//旋转后的坐标和速度
var x1 = ball.x - line.x;
var y1 = ball.y - line.y;
var x2 = x1 * cos + y1 * sin;
var y2 = y1 * cos - x1 * sin;
var vx1 = ball.vx * cos + ball.vy * sin;
var vy1 = ball.vy * cos - ball.vx * sin;
if(y2 > -ball.radius) {
y2 = -ball.radius;
vy1 *= bounce;
};
//旋转回来，计算坐标和速度
x1 = x2 * cos - y2 * sin;
y1 = y2 * cos + x2 * sin;
ball.vx = vx1 * cos - vy1 * sin;
ball.vy = vy1 * cos + vx1 * sin;
ball.x = line.x + x1;
ball.y = line.y + y1;
ball.draw(ctx);
line.draw(ctx);
if(ball.x > canvas.wdith || ball.y > canvas.height) {
cancelAnimationFrame(requestID);
}
requestID = requestAnimationFrame(animation);
};
window.onload = function() {
line = new Line(0, 0, 300, 0);
line.x = 50;
line.y = 200;
line.rotation = (10 * Math.PI / 180); //设置线的倾斜角度
cos = Math.cos(line.rotation);
sin = Math.sin(line.rotation);
ctx.strokeStyle = '#fff';
line.draw(ctx);
}
</script>
</body>
</html>