Game Development Reference
In-Depth Information
Let's take the sheet row by row and describe each of the tiles:
Row1
(tiles 0-7): Tile 0 is the road or floor tile. It is used as a background and as a
walkable tile; this means a tile that the player and enemy tanks can move on. This row
also contains the first seven frames for the player tank. On each of the frames, the tank
tracks are slightly different. When played in succession this causes the tank to appear to
be driving rather than sliding across the game screen.
Row2
(tiles 8-15): This row contains the eighth frame for the player tank and then the first
seven frames for the enemy tank. On each of the frames, the tank tracks are slightly
different. Just like the player tank, this causes the tank to appear to be driving rather
than sliding across the game screen.
Row3
(tiles 16-23):
Tile 16 is the eighth and final frame for the enemy tank.
Tiles 17-19 are used for explosions.
Tile 20 is the ammunition pick up object.
Tile 21 is the missile that both the player and the enemy will fire at one another.
Tile 22 is the object representing extra tank pick-ups in the game.
Tile 23 is the artifact that the player seeks to find on each level.
Row4
(tiles 24-31): This row contains eight tiles that can be used for walls. Neither the
player nor the enemy can move onto these tiles.
Sprites vs. tiles vs. background
We will be using the term “sprite” to refer to any interactive object in our game. These sprites will
not be part of the background of our level. They will be in the foreground. Sprites are made up of
tiles in our tile sheet just the same as the background. The background for our game will be the
walls and walkable tiles that the tanks can move on. The sprites will be the tanks, ammunition,
missiles, explosions, and other objects in the game.
Creating the tile sheet
A tile sheet is basically the same as any other image, but it is set up in a unique manner. Our tile
sheet will be 256 pixels in width and 128 in height. This will allow us to have four rows of 8 32
32 tiles to use. For the look of the tiles, we will copy images directly from the Spritelib GPL files
and place them on to our new sheet. For this example, I wanted to choose tools that everyone
would have at their disposal. The tool we are going to use to create the tile sheet is called GIMP.
Photoshop and Fireworks are also tools used by many professionals for the same purpose. We
will stop to give hints for those tools also along the way where we can.
GIMP is a free, community supported tool with many of the same features as Photoshop and
Fireworks. You can download the latest version at
http://www.gimp.org
.
Detailed instructions on GIMP are beyond the scope of this topic, but what follows are the steps
necessary to create and save a tile sheet that we can use for our No Tanks! game.
