from visual import *

##establishes what value the x,y, and z will have
positionNum = 20
##size of each side is twice the position
size = 2*positionNum
rad = positionNum/20

##velocity should be kept at <(1/20)*position because any higher and numerous problems may occur with bounces
##weird bounces will still occur occasionally regardless of velocity
xVelocity = .5
yVelocity = .2
zVelocity = .3

##creates the walls using the positions and size
xzBottomWall = box (pos=(0,-positionNum,0), length=size, height=0.01, width=size, color=color.blue)
xzTopWall = box (pos=(0,positionNum,0), length=size, height=0.01, width=size, color=color.blue)

yzRightWall = box (pos=(positionNum,0,0), length=.01, height=size, width=size, color=color.red)
yzLeftWall = box (pos=(-positionNum,0,0), length=.01, height=size, width=size, color=color.red)

##creates front wall as invisible wall so user can see inside
xyFrontWall = box (pos=(0,0,positionNum), length=size, height=size, width=0.01, color=color.white, opacity=0)
xyBackWall = box (pos=(0,0,-positionNum), length=size, height=size, width=0.01, color=color.white, opacity=0.2)

##creates ball and establishes velocity
ball = sphere (pos=(0,0,0), radius=rad, color=color.green)
ball.velocity = vector(xVelocity,yVelocity,zVelocity)

while True:
    ##halts computations briefly
    rate(100)
    ##changes ball position by adding velocity to position
    ##this is why a big velocity causes problems, makes position beyond borders
    ball.pos = ball.pos + ball.velocity
    ##conditionals check to see if the ball's x,y or z position is beyond the wall
    ##if one of them is, it flips that component of the velocity
    if ball.y - ball.radius < -positionNum:
        ball.velocity.y = -ball.velocity.y
    if ball.y + ball.radius> positionNum:
        ball.velocity.y = -ball.velocity.y
    if ball.x - ball.radius< -positionNum:
        ball.velocity.x = -ball.velocity.x
    if ball.x + ball.radius> positionNum:
        ball.velocity.x = -ball.velocity.x
    if ball.z - ball.radius< -positionNum:
        ball.velocity.z = -ball.velocity.z
    if ball.z + ball.radius> positionNum:
        ball.velocity.z = -ball.velocity.z