Flash AS实现的蝌蚪摆尾动画的教程

　　
function TentacleClass()
{
this.numNodes = 27;
this.head = 2 + random(4);
this.girth = 8 + random(12);
this.speedCoefficient = 9.000000E-002 + random(10) / 50;
this.friction = 9.000000E-001 + random(10) / 100;
this.muscleRange = 20 + random(50);
this.muscleFreq = 1.000000E-001 + random(100) / 250;
this.generateNodes();
this.onEnterFrame = this.move;
} // End of the function
TentacleClass.prototype = new MovieClip();
TentacleClass.prototype.generateNodes = function ()
{
this.node = new Array();
var n = 0;
while (n < this.numNodes)
{

var point = {x: 0, y: 0};
this.node.push(point);
++n;
} // end while
};
TentacleClass.prototype.move = function ()
{
this.tv = this.tv + 5.000000E-001 * (Math.random() - Math.random());
this.theta = this.theta + this.tv;
this.tv = this.tv * this.friction;
this.node[0].x = this.head * Math.cos(1.745329E-002 * this.theta);
this.node[0].y = this.head * Math.sin(1.745329E-002 * this.theta);
this.count = this.count + this.muscleFreq;
this.thetaMuscle = this.muscleRange * Math.sin(this.count);
this.node[1].x = -this.head * Math.cos(1.745329E-002 * (this.theta + this.thetaMuscle));
this.node[1].y = -this.head * Math.sin(1.745329E-002 * (this.theta + this.thetaMuscle));
var i = 2;
while (i < this.numNodes)
{
var dx = this.node.x - this.node[i - 2].x;
var dy = this.node.y - this.node[i - 2].y;
var d = Math.sqrt(dx * dx + dy * dy);
this.node.x = this.node[i - 1].x + dx * this.girth / d;
this.node.y = this.node[i - 1].y + dy * this.girth / d;
if (i == 2)
{
this._x = this._x - dx * this.speedCoefficient;
this._y = this._y - dy * this.speedCoefficient;
if (this._x + this._width < 0 this._x - this._width > 600 this._y + this._height < 0 this._y - this._height > 400)
{
--Object.environment.tents;
this.removeMovieClip();
} // end if
} // end if
++i;
} // end while
this.clear();
this.moveTo(this.node[1].x, this.node[1].y);
var i = 2;
while (i < this.numNodes)
{
this.lineStyle(int(this.numNodes - i) * (this.numNodes - i) / 20, 16777215, 100);
this.lineTo(this.node.x, this.node.y);
++i;
} // end while
};
Object.registerClass("tentacle", TentacleClass);
#endinitclip