Moon Orbit

This project is in continuation of a tutorial of Flash AS 2.0 using some AS 3.0 practices given to us by Anna.

Essentially the tutorial was to create a moon orbiting the Earth within Flash.

I thought it would be interesting to extend this to being able to play with the settings that determine the orbit trajectory while the file is playing. I allowed the user to change the numbers that govern the trajectory, speed with the inclusion of the Earths own orbit.

Please view here.

This was a fun excursion into some techniques I hadn't before tried. For example the inclusion of the components that Flash offers as default in order to control the settings of the orbits.

Code:

angle = 0;
centerX = stage.width/2;
centerY = stage.height/2;
centerpos = {_x:300, _y:250};
i = 1;
earthSpeed = earthSpeed_com.value;
moonSpeed = moonSpeed_com.value;
earthXRadius = earthXRadius_com.value;
earthYRadius = earthYRadius_com.value;
moonXRadius = moonXRadius_com.value;
moonYRadius = moonYRadius_com.value;
var earthSpeed_com:mx.controls.NumericStepper;
var moonSpeed_com:mx.controls.NumericStepper;
var moonXRadius_com:mx.controls.NumericStepper;
var moonYRadius_com:mx.controls.NumericStepper;
var earthXRadius_com:mx.controls.NumericStepper;
var earthYRadius_com:mx.controls.NumericStepper;
var nstepListener:Object = new Object();
nstepListener.change = function(evt_obj:Object) {
trace("Value changed to "+evt_obj.target.value);
earthXRadius = earthXRadius_com.value;
earthYRadius = earthYRadius_com.value;
moonXRadius = moonXRadius_com.value;
moonYRadius = moonYRadius_com.value;
earthSpeed = earthSpeed_com.value;
moonSpeed = moonSpeed_com.value;
};
earthSpeed_com.addEventListener("change",nstepListener);
moonSpeed_com.addEventListener("change",nstepListener);
moonXRadius_com.addEventListener("change",nstepListener);
moonYRadius_com.addEventListener("change",nstepListener);
earthXRadius_com.addEventListener("change",nstepListener);
earthYRadius_com.addEventListener("change",nstepListener);
var moon_mc:MovieClip = _root.attachMovie("moon_mc", "moon_mc", i, centerpos);
i++;
var earth_mc:MovieClip = _root.attachMovie("earth_mc", "earth_mc", i, centerpos);
earth_mc.onEnterFrame = function():Void {
this._x = 300+Math.cos(angle)*earthXRadius;
this._y = 200+Math.sin(angle)*earthYRadius;
angle += earthSpeed;
earthpos = {_x:this._x, _y:this._y};
i++;
var trail_mc:MovieClip = _root.attachMovie("earth_mc", "earth_mc", i, earthpos);
trail_mc.onEnterFrame = function() {
this._alpha -= 1;
this._xscale -= 2;
this._yscale -= 2;
if (this._xscale<=0) {
this.removeMovieClip();
}
};
};
moon_mc.onEnterFrame = function():Void {
this._x = earth_mc._x+Math.cos(angle)*moonXRadius;
this._y = earth_mc._y+Math.sin(angle)*moonYRadius;
angle += moonSpeed;
moonpos = {_x:this._x, _y:this._y};
i++;
var trail_mc:MovieClip = _root.attachMovie("moon_mc", "trail_mc", i, moonpos);
trail_mc.onEnterFrame = function() {
this._alpha -= 0.75;
this._xscale -= 2;
this._yscale -= 2;
if (this._xscale<=0) {
this.removeMovieClip();
}
};
};