初级物理模型的构建（AS）-力学1 三星系统的构建

function doV(mc1, mc2, mc3) {// r指的就是mc1的运动半径：

var r= Math.sqrt(mc2.m*mc2.m+mc3.m*mc3.m+mc2.m*mc3.m)/(mc1.m+mc2.m+mc3.m)*a;

mc1.v = Math.sqrt(mc1.fs*r/mc1.m); //根据向心力求匀速圆周运动速度

}

#include "Physics.as"

_root.onLoad=function(){

ball1.CreateBasicPhysicsFeature(1,0,0,0);

ball2.CreateBasicPhysicsFeature(1,0,0,0);

ball3.CreateBasicPhysicsFeature(1,0,0,0);

for(var i=1;i<4;i++){

eval("ball"+i).CreateExtendMotionFeature(0,0,0,0);

eval("ball"+i).ForceCondition(0,0,0,0);

eval("ball"+i).ForcedirectionX(0);

eval("ball"+i).ForcedirectionY(0);

eval("ball"+i).VdirectionX(0);

eval("ball"+i).VdirectionY(0);

eval("ball"+i).ForcedirectionX(0);

eval("ball"+i).ForcedirectionY(0);

eval("ball"+i).fs(0);

eval("ball"+i).fx(0);

eval("ball"+i).fy(0);

}

G = 1000;

a = 100;//三者呈三角状态时的参数。

}

///***Fundamental Function***///

function Getdistance(mc1, mc2) {

return Math.sqrt((mc1._x-mc2._x)*(mc1._x-mc2._x)+(mc1._y-mc2._y)*(mc1._y-mc2._y));

}

function StardandlizeAngle(mc1, mc2) {

var l = Getdistance(mc1, mc2);

mc1.ForcedirectionX=(mc2._x-mc1._x)/l;

mc1.ForcedirectionY=(mc2._y-mc1._y)/l;

}

function normal_vector(mc1){//求MC1沿顺时针绕MC2转的法向单位向量。

mc1.VdirectionX=mc1.ForcedirectionY;

mc1.VdirectionY=-mc1.ForcedirectionX;

}

function doForce(mc1,mc2) {//注意之里采用的累加力的方式

var r = Getdistance(mc1, mc2);

StardandlizeAngle(mc1, mc2);

var tempForce = G*mc1.m*mc2.m/(r*r);

mc1.fx += mc1.ForcedirectionX*tempForce;

mc1.fy += mc1.ForcedirectionY*tempForce;

}

function return_fx_fy(){//每一帧的最后，把力归零。

var i=1;

while(i<4){

eval("ball"+i).fx=0;

eval("ball"+i).fy=0;

i++;

}

}

function doFsum(mc){

mc.fs=Math.sqrt(mc.fx*mc.fx+mc.fy*mc.fy);

}

function doV(mc1,mc2,mc3){

var r=Math.sqrt(mc2.m*mc2.m+mc3.m*mc3.m+mc2.m*mc3.m)/(mc1.m+mc2.m+mc3.m)*a

mc1.v=Math.sqrt(mc1.fs*r/mc1.m);

}

function doMove_Circle(mc){

mc.ForcedirectionX=mc.fx/mc.fs;

mc.ForcedirectionY=mc.fy/mc.fs;

normal_vector(mc);

mc.vx=mc.v*mc.VdirectionX;

mc.vy=mc.v*mc.VdirectionY;

mc._x+=mc.vx;

mc._y+=mc.vy;

}

///Combine Functions and do Motions///

function sumForce(){

for(var i=1;i<4;i++){

var j=1;

while(j<4){

if(i!=j){

doForce(eval("ball"+i),eval("ball"+j));

}

j++;

};

}

}

function CaculateF(){

sumForce();

var j=1;

while(j<4){

doFsum(eval("ball"+j));

j++;

}

}

function CaculateV(){

doV(ball1,ball2,ball3);

doV(ball2,ball1,ball3);

doV(ball3,ball1,ball2);

}

function SumMove(){

var i=1;

while(i<4){

doMove_Circle(eval("ball"+i));

i++;

}

}

_root.onEnterFrame=function(){

CaculateF();

CaculateV();

SumMove();

return_fx_fy();

}