From: Martin DeMello <martindemello@...>
Date: 2013-06-06T07:08:00+09:00
Subject: Re: My car is "falling" off the screen green shoes

Hint: Check out the mod function (%). For instance, if you have a
screen of width 20, a car at position 10, and it moves 15 units in
either direction:

irb(main):001:0> a = 10
=> 10
irb(main):002:0> b = a + 15
=> 25  # <--- gone off the right edge
irb(main):003:0> c = (a + 15) % 20
=> 5  # <--- wrapped around
irb(main):004:0> d = a - 15
=> -5  # <--- gone off the left edge
irb(main):005:0> e = (a - 15) % 20
=> 15  # <--- wrapped around

martin

On Wed, Jun 5, 2013 at 9:08 AM, Ruby Student <ruby.student@gmail.com> wrote:
> Team,
>
> I am having so much fun with shoes!!!!!!!!!!!!!!!!
>
> But, I have a problem. I finally made my car image moves from left to right.
> But it reaches the end of the screen on the right and it disappears. Can
> anyone help me keep my car return back to the starting pint, which is the
> left bottom of the screen? I want for that to happen continuously. The
> following is the actual code I'm using:
>
>
>     @carim = image  "/home/rstudent/MyData/Programs/shoes/car1.png"
>     every 6 do
>        animate do |i|
>           @carim.left += (-20..50).rand
>        end
>     end
>
> Any help will be appreciated.
>
> --
> Ruby Student