Flash制作红外线引导导弹爆炸视觉效果

Flash制作红外线引导导弹爆炸视觉效果(3)     fragment_mc.cacheAsBitmap = true;
 
    fragment_mc.onEnterFrame = function():Void {
      this._x += this.speedX;
      this._y += this.speedY;
 
      if (this._x < gLEFT this._x > gRIGHT this._y < gTOP this._y > gBOTTOM) {
        this.removeMovieClip();
      }
    };
  }
}

/* FUNCTION: Creates and initializes heat-seeking missiles */
createMissile.maxSpeed = 30;
createMissile.accel = 2;
function createMissile(target_mc:MovieClip, xPos:Number, yPos:Number):Void {
  var depth:Number = _root.getNextHighestDepth();
  var missile_mc:MovieClip = attachMovie("Missile", "missile" + depth, depth);
  missile_mc._x = xPos;
  missile_mc._y = yPos;
  missile_mc.speed = 0;
 
  missile_mc.setRotation = function():Void {
    var dy:Number = target_mc._y - this._y;
    var dx:Number = target_mc._x - this._x;
    this._rotation = rad2deg(Math.atan2(dy, dx));
  };
 
  missile_mc.onEnterFrame = function():Void {
    this.setRotation();
 
    if (this.speed < createMissile.maxSpeed) {
      this.speed += createMissile.accel;
    }
    this._x += Math.cos(deg2rad(this._rotation)) * this.speed;
    this._y += Math.sin(deg2rad(this._rotation)) * this.speed;
 
    if (this.hitTest(target_mc)) {
      explosion(target_mc._x, target_mc._y);
      this.removeMovieClip();
    }
  };
}

/* MAIN PROGRAM LOGIC */
var gameBG_mc:MovieClip = _root.createEmptyMovieClip("gameBG", 0);