Gathering Resources - Learning LibGDX Game Development - page 153

Handling level data
It's now time to think about how we can handle level data to lay out our levels,
put objects into them at certain positions, define a starting position, and so on. This
usually implies a lot of work before visible results will appear because creating
levels require some kind of a tool to create, modify, save, and load their level data.
Furthermore, before we can even load or save levels, we will have to define an
appropriate file format to describe the data of a level.
Luckily, there is an easy route as long as we keep our requirements simple enough.
We will not have to build our own level editor. Instead, we will use a drawing
program such as GNU Image Manipulation Program ( GIMP ) ( http://www.gimp.
org/ ) or Paint.NET ( http://www.getpaint.net/ ) to draw an image, where each
pixel's color represents an object that is still to be defined. The position of a pixel
in this image will also represent the position in our game world. Job done! We just
defined our level format in a somewhat creative way by reusing an already existing
format and overlaying it with our way of interpreting the content.
The following is a level diagram to give you a better idea of how this works:
As we are dealing here with an image that is not going to be rendered to the screen,
we will not add it to the texture atlas. Therefore, we are bound to the power-of-two
rule once again, so be sure to keep this in mind. In the preceding screenshot, the
dimension of the level is 128 pixels x 32 pixels in width and height. The diagram has
been overlaid with a Cartesian coordinate system for better visibility of the position
of a pixel (or object in terms of our future interpretation of this information) inside
the level.