AMOS TOME Series IV Manual  Index Prev Page Next Page 6

when you hit the tile, it is easy to find out what tile to change it into.

How many points you should get for hitting the tile, when you hit the tile, multiply this tile value by 10 say, and add it to the score.

Whether the tile has any special effects or not, This can be combined with the Solid/Non-Solid value. e.g..

Non-Solid Tile with no effects = 0
Non-Solid Tile with Ice on it  = 1
Non-Solid Tile with Bomb on it = 2
Non-Solid Bonus Tile           = 3
Solid Tile with no effects     = 128
Solid Tile with Ice on it      = 129
Solid Tile with Bomb on it     = 130
Solid Bonus Tile               = 131

With values like this you can see if the tile is solid or not (Value>127) and which special effects the tile has (Value Mod 128). These values are examples, as you can assign any value (0-255) to each tile.

Tile Values are one of TOME's more powerful features, and although you may not need to use them straight away, you will probably find all sorts of uses for them !

First Steps 1, "What is a map ?"

Put simply, a map is a grid of tiles, which is normally used to display huge background areas in games. If, for instance, you wanted a game that scrolled horizontally over 20 screens, you could do it the difficult way, and somehow draw 20 screens and cram them into memory which would take up 640K (each screen takes up 32K in 16 colours). O.k, so you could compact them, but even assuming that you can get each screen down to 6K (Very reasonable compaction), you are still looking at 120K, and you still have to de-compact the screens (Very slow)! Now imagine designing the background as a grid. Each point on the grid can use one of 256 tiles selected from a set you have designed. Each point on the grid only takes up 1 byte of memory, and the only overhead you have is the size of the icon bank (not usually more than one screen).

You can design all your screens from these tiles, rather like a collage or jigsaw puzzle (depending on how you draw your tiles !). The end result. Even assuming you use 32K for your tiles, the 20 screen map can be done in 4.8K, so you would only be using 36.8K for the 20 screens ! (Even less if you are using larger 32x32 pixel tiles) . Now you can see why about 90% of games use map based backgrounds, and why AMOS TOME was