multiple of the tile width. The height of the source image must be an integer multiple of the tile height.
The tiles in the source image will have indices as follows:
The static tiles are indexed like words are read on a page; left-to-right, then top-to- bottom. The top-left tile is assigned index 1. If there is a tile to its right, this tile is assigned index 2, and so on, across the first row of tiles. If there is a second row of tiles, the index of the left-most tile in this row is one greater than the right-most tile in the preceding row. The table below is a diagrammatic depiction:
| 1 | 2 | . . . | N |
| | | | |
| N+1 | N + 2 | . . . | 2N |
| | | | |
| 2N+1 | 2N + 2 | . . . | |
| | | | |
| . . . | . . . | . . . | . . . |
| | | | |
| [(M – 1) * | [(M-1) * N )] + 2 | . . . | (M * N ) |
| N]+1 |
| | | |
| | | | |
So the total number of tiles is M * N, where:
−N = (image width) / (tile width);
−M = (image height) / (tile height).
The indices for the static tile set will be non-negative (>=0) and the indices for animated tiles will be negative (<0). The index sets do not overlap and therefore indices for static and animated tiles can be used interchangeably in the methods that set or move the contents of the PlayField cells. The static Tile set shall behave as if the image used in creation were cached. If a mutable image is used to create the tiles, the tiles' appearances should not reflect changes to the mutable source image. The appearance of individual static tiles can be changed with setStaticTileImage(). The entire static tile set can be changed using setStaticTileSet(). These methods should be used sparingly since they are both memory and time consuming.
PlayField (int columns, int rows, int cellWidth,
int cellHeight) throws IllegalArgumentException - Creates a new PlayField without a tile set. The parameter are the following:
−columns - width of the PlayField in number of cells;
−rows - height of the PlayField in number of cells;
−cellWidth - Pixel width of each cell;
−cellHeight - Pixel height of each cell.
It creates a new PlayField, rows cells high and columns cells wide. A PlayField created with this constructor will not have any tiles (animated or static) associated with it. The primary use of a PlayField without tiles is expected to be as a container for managing sprites. The on-screen pixel dimensions of cells is defined by the parameters cellWidth and cellHeight. The cells in the
