Time for action – moving the character

Eggs will be falling in all different areas of the screen from the sky. Let's prepare our main character to move through all the potential areas on the screen:

Set up a new local function called moveChar() with an event parameter:
```
local moveChar = function(event)
```

Add in the accelerometer movement for the character:

  charObject.x = display.contentCenterX - (display.contentCenterX* (event.yGravity*3))

Create character boundaries where it moves on the screen. This enables the character to stay within the game screen and not go past the offscreen boundaries:

  if((charObject.x - charObject.width * 0.5) < 0) then charObject.x = charObject.width * 0.5
  elseif((charObject.x + charObject.width * 0.5) > display.contentWidth) then
  charObject.x = display.contentWidth - charObject.width * 0.5
  end
end

What just happened?

To make the accelerometer movement work with a device, we have to use yGravity.

Note

Accelerometer events are based on portrait scale when xGravity and yGravity are used accordingly. When display objects are designated for the landscape mode, the xGravity and yGravity values are switched to compensate for the events to work properly.

Notice that the code in step 3 keeps the charObject display object from going past any wall border boundaries.

Have a go hero – adding touch events

The character is currently controlled by the accelerometer. Another option to control the character is through a touch event. Try replacing the event listener with "touch" and using event parameters so that the touch event works properly.

If you remember how we incorporated the paddle movement with Breakout in Chapter 3, Building Our First Game – Breakout and Chapter 4, Game Controls, for the simulator, it should be very similar.

Updating the score

When the score is updated, it refers to our text display objects and translates the value from the number into a string.

Here is an example:

gameScore = 100
scoreText = display.newText( "Score: " .. gameScore, 0, 0, "Arial", 45 )
scoreText:setTextColor( 1, 1, 1)
scoreText.x = 160; scoreText.y = 100

In the previous example, you will notice that we set a value of 100 to gameScore. In the following lines for scoreText, gameScore is used to concatenate the "Score: " string and the value of gameScore. Doing so displays the value of gameScore in a string format by scoreText.