Time for action – adding the config.lua file

If no content size is specified, the content width and height returned will be the same as the physical screen width and height of the device. If you specify a different content width and height in config.lua, the content width and height will take on those values. To add the config.lua file in your project folder, perform the following steps:

1. In your text editor, create a new file called config.lua and save it to your project folder.
2. Type in the following lines:

   application =
   {
     content =
     {
       width = 320,
       height = 480, 
       scale = "letterbox",
       fps = 60,
     },
   }

3. Save and close your file.

What just happened?

The content width and height allow you to choose a virtual screen size that is independent of the physical device screen size. We have set the size to target the iPhone 3GS since it displays one of the common dimensions across most devices for both iOS and Android platforms.

The scale used for this application is set to letterbox. It will uniformly scale up content as much as possible while still displaying all content on the screen.

We set fps to 60. By default, the frame rate is 30 fps. In this application, this will make the movement of the ball appear faster and allow us to increase the speed conveniently. We can stretch the frame rate to 60 fps, which is the maximum that Corona can allow.