| inozemcev |
14.09.2011 14:27 |
actionscript и физика
Ребята помогите разобраться с физикой и реализовать задачу пересечения двух векторов.
Задача при пересечении дух векторов - вектора мяча и вектора стены - получить новый вектор мяча.
Сам ориентировался на данную статью. Смог разобраться в терминологии, смог найти точку пересечения, но построить новый вектор не получается. К автору топика уже не обратится. статья старая.
В статье используется ationscript 1 Поэтому сделал несколько отличный код, ввел понятия VectorDara VectorView
Код AS3:
public class VectorData
{
private var _start:Point;
private var _end:Point;
private var _delta:Point;
private var _ort:Point;
private var _normal_l:VectorData;
private var _normal_r:VectorData;
public static const END_POINT:Boolean = true;
public static const DELTA_POINT:Boolean = false;
public function VectorData(start:Point, endOrDelta:Point, type:Boolean = END_POINT)
{
_start = start;
if (type)
{
_end = endOrDelta;
_delta = new Point (_end.x - _start.x, _end.y - _start.y);
} else {
_delta = endOrDelta;
_end = new Point (_start.x + _delta.x, _start.y + _delta.y);
}
}
public function get start () :Point
{
return _start;
}
public function get delta () :Point
{
return _delta;
}
public function get end () :Point
{
return _end;
}
public function get length () :Number
{
return Math.sqrt (delta.x * delta.x + delta.y * delta.y);
}
public function get ort () :Point
{
if (!_ort)
{
_ort = new Point (delta.x / length, delta.y / length);
}
return _ort;
}
public function get rad () :Number
{
return Math.atan2 (ort.y, ort.x);
}
public function get gradus () :Number
{
return rad * 180 / Math.PI;
}
public function get normal_l () :VectorData
{
if (!_normal_l)
{
_normal_l = new VectorData(start,new Point (-delta.y, delta.x), VectorData.DELTA_POINT);
}
return _normal_l;
}
public function get normal_r () :VectorData
{
if (!_normal_r)
{
_normal_r = new VectorData(start,new Point (delta.y, - delta.x), VectorData.DELTA_POINT);
}
return _normal_r;
}
public static function add (vector1:VectorData, vector2:VectorData) :VectorData
{
var newDelta:Point = new Point (vector1.delta.x + vector2.delta.x, vector1.delta.y + vector2.delta.y);
var newVector:VectorData = new VectorData (vector1.start, newDelta, false);
return newVector;
}
public static function cosA (vector1:VectorData, vector2:VectorData) :Number
{
return (vector1.ort.x * vector2.ort.x + vector1.ort.y * vector2.ort.y);
}
public static function scalar (vector1:VectorData, vector2:VectorData) :Number
{
return (vector1.length * vector2.length * VectorData.cosA (vector1, vector2))
}
public static function proection (vector:VectorData, scalarDot:int ) :Point
{
var newDelta:Point = new Point (vector.ort.x * scalarDot / vector.length, vector.ort.y * scalarDot / vector.length);
return newDelta;
}
public static function intersection (vector1:VectorData, vector2:VectorData) :Point
{
var delta3:Point = new Point (vector2.start.x - vector1.start.x, vector2.start.y-vector1.start.y);
var vector3:VectorData = new VectorData (vector1.start, delta3, DELTA_POINT);
var t:Number = scalarNV (vector3, vector2) / scalarNV (vector1, vector2);
return new Point (vector1.start.x + vector1.delta.x * t, vector1.start.y + vector1.delta.y * t);
}
public static function scalarNV (vector1:VectorData, vector2:VectorData) :int
{
return vector1.delta.x * vector2.delta.y - vector1.delta.y* vector2.delta.x;
}
public static function dot (vector1:VectorData, vector2:VectorData) :int
{
return vector1.delta.x * vector2.delta.x + vector1.delta.y * vector2.delta.y;
}
}
И собственно главный класс Main
Код AS3:
public class Main extends Sprite
{
private var start:Point;
private var vectorDatas:Array = [];
public function Main():void
{
if (stage) init();
else addEventListener(Event.ADDED_TO_STAGE, init);
}
private function init(e:Event = null):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
// entry point
stage.addEventListener (MouseEvent.CLICK, onClick);
}
private function onClick (event:MouseEvent) :void
{
if (numChildren == 3)
{
vectorDatas = [];
while (numChildren) removeChildAt (0);
start = null;
}
var end:Point = new Point (event.stageX, event.stageY);
if (start)
{
var vectorData:VectorData = new VectorData (start, end);
//trace ('Vector length : ' + vectorData.length);
vectorDatas.push(vectorData);
var vectorView:VectorView = new VectorView (vectorData);
addChild (vectorView);
vectorView.draw ();
start = null;
} else {
start = end;
}
if (numChildren == 2)
{
vectorData = makeBounce (vectorDatas[0], vectorDatas[1]);
vectorView = new VectorView (vectorData);
vectorView.draw (1, 0xCCCC00, 1);
addChild (vectorView);
}
}
private function makeBounce (vector1:VectorData, vector2:VectorData) :VectorData
{
var iPoint:Point = VectorData.intersection (vector1, vector2);
var dot_v1_v2:int = VectorData.dot (vector1, vector2);
var dot_v1_v2_left:int = VectorData.dot (vector1, vector2.normal_l);
var proectionV2:Point = VectorData.proection (vector2, dot_v1_v2);
var proectionV2left:Point = VectorData.proection (vector2, dot_v1_v2_left);
proectionV2left.x *= -1;
proectionV2left.y *= -1;
var newVectorDelta:Point = new Point(proectionV2.x + proectionV2left.x, proectionV2.y + proectionV2left.y);
var newVector:VectorData = new VectorData (iPoint, newVectorDelta, VectorData.DELTA_POINT);
return newVector;
}
/*
private function createVector (start:Point, endOrDelta:Point, color:int, type:Boolean = VectorData.END_POINT) :VectorView
{
var vectorData:VectorData = new VectorData (start, endOrDelta, type);
var vectorView:VectorView = new VectorView (vectorData);
vectorView.draw (1, color, 1);
return vectorView;
}
*/
}
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