Motorola C450 ユーザーズマニュアル

 

raceCar.setPaletteEntry(0, 0x0000FF); 

Image blueRaceCar = raceCar.getImage(); 

 

// Set the car color to green and retrieve the Image 

raceCar.setPaletteEntry(0, 0x00FF00); 

Image greenRaceCar = raceCar.getImage(); 

 

// The PaletteImage can now be discarded since we have the 

// Image objects that we need 

raceCar = null; 

  

PlayField Class 

A 

PlayField

 is a rectangular grid of cells with a set of available tiles to place in those 

cells and a set of associated Sprites. 
The 

PlayField

 grid is made up of (rows * columns) cells, where the number of rows 

and columns are defined by parameters to the constructor. The cells are equally sized. 
The size of the cells is defined by the size of the tiles, or if the 

PlayField

 has no tiles, 

by arguments to the constructor. Each cell is either empty or contains a single tile whose 

image will be drawn in that cell. An empty cell is fully transparent - Nothing will be drawn 
in that area by the 

PlayField

. 

The tiles used to fill the 

PlayField

 cells can be either static tiles or animated tiles. Tiles 

are referred to using index numbers. Tile 0 (tile with index 0) refers to the special empty 

tile. Any cell assigned the tile 0 will be considered empty and will be effectively 
transparent.  
The static tile indices are non-negative (>=0) and the animated tiles indices are negative 

(<0). 

Using Static and Animated Tiles 

Static tiles are called static because their image does not often change, i.e., any cell that 
contains the static Tile 1 will always be drawn as the unchanging image of Tile 1. Tile 0 is 

a special static tile. It represents an empty cell. Any cell containing tile 0 will be 
transparent, it will not have a tile image drawn in it. 
Animated tiles are called animated because their appearance changes easily over time. 
At any given time, each animated tile is associated with a particular static tile. When a cell 
containing an animated tile is drawn, the image of the static tile currently referenced by 

that animated tile will be drawn in that cell. In effect, the animated tiles provide indirect 
references to the set of static tiles, and therefore allow many cells to be animated 

simultaneously. For example, cells (0,0) and (0,1) both contain animated Tile -2. Animated 
Tile -2 currently references static Tile 1. Cells (0,0) and (0,1) will then be drawn with the 
image of static Tile 1. If animated Tile -2 is subsequently set to reference static Tile 2 by