from visual import *
from integrate import *

scene.autoscale=0
scene.range=1.0

ball1=sphere(radius=0.05)
ball2=sphere(radius=0.05)
ball1.track=curve(radius=0.01,color=color.red)
ball2.track=curve(radius=0.01,color=color.red)
ball1.pos=vector(0.0,0.25,0)
ball2.pos=vector(0.1,-0.5,0)
ball1.vel=vector(0.5,0.1,0.0)
ball2.vel=vector(-0.5,0.0,0.0)
ball1.acc=vector(0,0,0)
ball2.acc=vector(0,0,0)
ball1.acc2=vector(0,0,0)
ball2.acc2=vector(0,0,0)

ball1.mass=1.0
ball2.mass=1.0

L=0.95
system=[ball1,ball2]
dt=0.01
t=0

while(1):
    rate(500)
    t=t+dt
    for balla in system:                
        balla.acc=(1.0/balla.mass)*totalforce(balla,system)
        
    for balla in system:
        balla.pos=balla.pos+balla.vel*dt+balla.acc*dt*dt*0.5
        balla.track.append(pos=balla.pos)
        
    for balla in system:
        balla.acc2=(1.0/balla.mass)*totalforce(balla,system)

    for balla in system:
        balla.vel=balla.vel+(balla.acc+balla.acc2)*dt*0.5
        
# put in box with elastic walls 
    for balla in system:
        if((balla.pos.x>L) or (balla.pos.x<-L)):
            balla.vel.x=-balla.vel.x
        if((balla.pos.y>L) or (balla.pos.y<-L)):
            balla.vel.y=-balla.vel.y
        if((balla.pos.z>L) or (balla.pos.z<-L)):
            balla.vel.z=-balla.vel.z