数学常用公式

三角学：

弧度(radians) = 角度(degrees) * Math.PI / 180

角度(degrees) =弧度(radians)  * 180 / Math.PI

角的正炫值 = Math.sin(-角度 * Math.PI / 180)角的对边长除以斜边长

角的余炫值 = Math.cos(-角度 * Math.PI / 180)角的对邻边长除以斜边长

角的正切值 = Math.tan(-角度 * Math.PI / 180)角的对边长除以邻边长

 

向鼠标旋转(或向某点旋转)

dx = mouseX - sprite.x;

dy = mouseY - sprite.y;

sprite.rotation = Math.atan2(dy,dx) * 180 / Math.PI

 

创建波形

public function onEnterFrame(event:Event)

{

  value = center + Math.sin(angle) * range;

  angle += speed;

}

 

计算两点间的距离

dx = x2 - x1;

dy = y2 = y1;

dist = Math.sqrt(dx * dx + dy * dy);

 

 

根本鼠标座标取到该座标某个半径内的位置

var angle:Number = Math.random() * Math.PI * 2;//360度
var radius:Number = Math.random() * 10;//半径大小范围
var xpos:Number = mouseX + Math.cos(angle) * radius;
var ypos :Number = mouseY + Math.sin(angle) * radius;

 

addEventListener(Event.ENTER_FRAME, onEnterFrame);function onEnterFrame(event:Event){mc.rotation = Math.atan2(mouseY - mc.y,mouseX-mc.x) * 180 / Math.PI;trace(Math.atan2(mouseY-mc.y,mouseX-mc.x) * 180 / Math.PI);mc.x +=5* Math.cos(Math.atan2(mouseY-mc.y,mouseX-mc.x) * 180 / Math.PI);mc.y +=5* Math.sin(Math.atan2(mouseY-mc.y,mouseX-mc.x) * 180 / Math.PI); }