Time for action – animate the Paddle

  1. Jump back into your MouseFollow Script if you're not there already by double-clicking on it in the Project panel.
  2. Change the line of code in the Update function ever so slightly so that it reads as follows: 
        function Update () {
       transform.position.x += 0.2;
    }

The changes are very subtle. We added a plus sign (+) before the equals to sign (=), and we made the number smaller by adding a zero and a decimal place in front of it, changing it from 2 to 0.2.

Save the Script and test your game. The Paddle should scoot out the way, and fly straight off the right-edge of the screen!

What just happened – what witchcraft is this?

We made the 2 smaller, because the Paddle would have just rocketed off the screen in a twinkling and we may not have seen it. But, there's a tiny bit of code magic going on in that += bit.

By changing the transform.position.x property with += instead of =, we're saying that we want to add 0.2 to the x property on every update. The special built-in Update function automatically gets called again and again by Unity as your game plays. While this happens, the x position constantly increases. Let's follow the following logic:

  • The first time Update is called, x is 0. We add 0.2, and the Paddle moves to 0.2.
  • The second time Update is called, x is 0.2. We add 0.2, and the Paddle moves to 0.4.
  • Every time Update is called, the Paddle's x position increases. We get a real sense of how often the Update function is called by how quickly the Paddle moves across the screen in tiny 0.2 increments.

Tip

Any excuse to work less

+= is a bit of programmer shorthand. It's the same as typing:

transform.position.x = transform.position.x + 0.2;

But that's way more typing, and the less you have to type the better. Excessive typing kills 80 percent of computer programmers before their 40th birthdays. I just made that stat up, so it's probably off by a few percentage points.

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