Tile-based worlds are a happy incorporation between fully dynamically created worlds and worlds that use a large image for the background. With large images, you create a very detailed and predictable world, but it is very difficult to change. Dynamically created worlds are easy to generate but are often too random. Tile-based worlds let you easily create detailed, predictable worlds in a way such that they are easy to change or modify.

Actors as tiles

Artists can create amazing images using small pieces of tile or glass. Figure 8 shows a simple tile mosaic. By strategically placing small pieces of colored tiles, you can generate many different types of images.

Figure 8: This is a simple mosaic, courtesy of pixabay.com at http://pixabay.com/en/uzbekistan-mosaic-pattern-artfully-196875/

We will use a similar technique to create a world in Greenfoot, but we will use small actors instead of tiles. Figure 9 demonstrates how we will do this. We will create a set of actors that will...