ActionScript3学习记录边界反弹平行轴位移

 1 var left:Number = 0;
 2 var top:Number = 0;
 3 var right:Number = stage.stageWidth;
 4 var bottom:Number = stage.stageHeight;
 5 
 6 var angle:Number = Math.atan2(ball.vy, ball.vx);
 7 var dist:Number = 0;
 8 if (ball.x - ball.radius < left)
 9 {
10     dist = (ball.x - ball.radius) / Math.cos(angle);
11     ball.y -= Math.sin(angle) * dist;
12     ball.x = ball.radius;
13     ball.vx *= bounce;
14 }
15 else if (ball.x + ball.radius > right)
16 {
17     dist = (ball.radius - (right - ball.x)) / Math.cos(angle);
18     ball.y -= Math.sin(angle) * dist;
19     ball.x = right - ball.radius;
20     ball.vx *= bounce;
21 }
22 
23 if (ball.y - ball.radius < top)
24 {
25     dist = (ball.y - ball.radius) / Math.sin(angle);
26     ball.x -= Math.cos(angle) * dist;
27     ball.y = ball.radius;
28     ball.vy *= bounce;
29 }
30 else if (ball.y + ball.radius > bottom)
31 {
32     dist = (ball.radius - (bottom - ball.y)) / Math.sin(angle);
33     ball.x -= Math.cos(angle) * dist;
34     ball.y = bottom - ball.radius;
35     ball.vy *= bounce;
36 }