Game Development Reference
In-Depth Information
Chapter 10
Blit Scrolling in a Tile-Based World
In this chapter, we will start with the tile-based single screen game theory we covered in Chapters
6 and 7 and extend it to a scrolling tile-based world. The game we are going to create is called
Drive She Said. Drive She Said includes a top-down perspective and will feature a physics-based
car that will navigate through the scrolling world. The car will be an extension of the
BlitSprite
class we created in Chapter 7, and the world will be a fully blit
BitmapData
canvas much like the
one discussed in Chapter 6. Only this time, it will be much bigger than a single screen and will
require us to scroll the viewable window as user navigates the car through the world.
Designing and getting started with Drive She Said
Let's get started by taking a look at a screenshot (see Figure 10-1), sample outline game design,
and technical specification document for our game.
These are the basic game design specifications for this game:
Game name
: Drive She Said
Game type
: Driving through a tile-based world
Game inspiration
: The first scrolling world driving game we played was Auto Racing on
the Mattel Intellivision. This was a great game, hampered by the deficiencies of the
Intellivision control disc. We (Jeff in particular) were always interested in how the world
was created and was especially excited when I found Rally Speedway on the Atari 800
and Super Cars on the Atari ST—both similar games that intrigued us with their simple
premise: Race around a top-down scrolling world. Drive She Said is actually a driving
adventure style game rather than a racing game, but the technical concept is the same.
Game objective
: You have made your girlfriend or boyfriend mad (once again). Before
time runs out, collect all of the hearts on the level. If you collect enough before time runs
out and make it to the finish, your date might accept your apology.
