| java.lang.Object
 javax.microedition.lcdui.game.Layer
javax.microedition.lcdui.game.TiledLayer
| TiledLayer | | public class TiledLayer extends Layer (Code) | | A TiledLayer is a visual element composed of a grid of cells that
can be filled with a set of
tile images. This class allows large virtual layers to be created
without the need for an
extremely large Image. This technique is commonly used in 2D
gaming platforms to create
very large scrolling backgrounds,
Tiles
The tiles used to fill the TiledLayer's cells are provided in a
single Image object which
may be mutable or immutable. The Image is broken up into a series
of equally-sized tiles;
the tile size is specified along with the Image. As shown in the
figure below, the same
tile set can be stored in several different arrangements depending
on what is the most
convenient for the game developer.
Each tile is assigned a unique index number. The tile located in
the upper-left corner
of the Image is assigned an index of 1. The remaining tiles are
then numbered consecutively
in row-major order (indices are assigned across the first row, then
the second row, and so on).
These tiles are regarded as static tiles because there is
a fixed link between
the tile and the image data associated with it.
A static tile set is created when the TiledLayer is instantiated;
it can also be updated
at any time using the
TiledLayer.setStaticTileSet method.
In addition to the static tile set, the developer can also define
several animated tiles.
An animated tile is a virtual tile that is dynamically associated
with a static tile; the appearance
of an animated tile will be that of the static tile that it is
currently associated with.
Animated tiles allow the developer to change the appearance of a
group of cells
very easily. With the group of cells all filled with the animated
tile, the appearance
of the entire group can be changed by simply changing the static
tile associated with the
animated tile. This technique is very useful for animating large
repeating areas without
having to explicitly change the contents of numerous cells.
Animated tiles are created using the
TiledLayer.createAnimatedTile method, which returns the
index to be used for the new animated tile. The animated tile
indices are always negative
and consecutive, beginning with -1. Once created, the static tile
associated with an
animated tile can be changed using the
TiledLayer.setAnimatedTile method.
Cells
The TiledLayer's grid is made up of equally sized cells; the number
of rows and
columns in the grid are specified in the constructor, and the
physical size of the cells
is defined by the size of the tiles.
The contents of each cell is specified by means of a tile index; a
positive tile index refers
to a static tile, and a negative tile index refers to an animated
tile. A tile index of 0
indicates that the cell is empty; an empty cell is fully
transparent and nothing is drawn
in that area by the TiledLayer. By default, all cells contain tile
index 0.
The contents of cells may be changed using
TiledLayer.setCell and
TiledLayer.fillCells . Several
cells may contain the same tile; however, a single cell cannot
contain more than one tile.
The following example illustrates how a simple background can be
created using a TiledLayer.
In this example, the area of water is filled with an animated tile
having an index of -1, which
is initially associated with static tile 5. The entire area of
water may be animated by simply
changing the associated static tile using setAnimatedTile(-1,
7).
Rendering a TiledLayer
A TiledLayer can be rendered by manually calling its paint method;
it can also be rendered
automatically using a LayerManager object.
The paint method will attempt to render the entire TiledLayer
subject to the
clip region of the Graphics object; the upper left corner of the
TiledLayer is rendered at
its current (x,y) position relative to the Graphics object's
origin. The rendered region
may be controlled by setting the clip region of the Graphics object
accordingly.
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| Constructor Summary | |
| public | TiledLayer(int columns, int rows, Image image, int tileWidth, int tileHeight)
Creates a new TiledLayer. |
| Method Summary | |
| public int | createAnimatedTile(int staticTileIndex)
Creates a new animated tile and returns the index that refers
to the new animated tile. | | public void | fillCells(int col, int row, int numCols, int numRows, int tileIndex)
Fills a region cells with the specific tile. | | public int | getAnimatedTile(int animatedTileIndex)
Gets the tile referenced by an animated tile. | | public int | getCell(int col, int row)
Gets the contents of a cell. | | final public int | getCellHeight()
Gets the height of a single cell, in pixels. | | final public int | getCellWidth()
Gets the width of a single cell, in pixels. | | final public int | getColumns()
Gets the number of columns in the TiledLayer grid. | | final public int | getRows()
Gets the number of rows in the TiledLayer grid. | | final public void | paint(Graphics g)
Draws the TiledLayer. | | public void | setAnimatedTile(int animatedTileIndex, int staticTileIndex)
Associates an animated tile with the specified static tile. | | public void | setCell(int col, int row, int tileIndex)
Sets the contents of a cell. | | public void | setStaticTileSet(Image image, int tileWidth, int tileHeight)
Change the static tile set. |
| sourceImage | | Image sourceImage(Code) | | Source image for tiles
|
| tileSetX | | int[] tileSetX(Code) | | X co-ordinate definitions for individual frames into the source image
|
| tileSetY | | int[] tileSetY(Code) | | Y co-ordinate definitions for individual frames into the source image
|
| TiledLayer | | public TiledLayer(int columns, int rows, Image image, int tileWidth, int tileHeight)(Code) | | Creates a new TiledLayer.
The TiledLayer's grid will be rows cells high and
columns cells wide. All cells in the grid are initially
empty (i.e. they contain tile index 0). The contents of the grid may
be modified through the use of
TiledLayer.setCell and
TiledLayer.fillCells .
The static tile set for the TiledLayer is created from the specified
Image with each tile having the dimensions of tileWidth x tileHeight.
The width of the source image must be an integer multiple of
the tile width, and the height of the source image must be an integer
multiple of the tile height; otherwise, an IllegalArgumentException
is thrown;
The entire static tile set can be changed using
TiledLayer.setStaticTileSet(Image,int,int) .
These methods should be used sparingly since they are both
memory and time consuming.
Where possible, animated tiles should be used instead to
animate tile appearance.
Parameters:
columns - the width of the TiledLayer,expressed as a number of cells
Parameters:
rows - the height of the TiledLayer,expressed as a number of cells
Parameters:
image - the Image to use for creatingthe static tile set
Parameters:
tileWidth - the width in pixels of a single tile
Parameters:
tileHeight - the height in pixels of a single tile
throws:
NullPointerException - if image is null
throws:
IllegalArgumentException - if the number of rowsor columns is less than 1
throws:
IllegalArgumentException - if tileHeightor tileWidth is less than 1
throws:
IllegalArgumentException - if the imagewidth is not an integer multiple of the tileWidth
throws:
IllegalArgumentException - if the imageheight is not an integer multiple of the tileHeight |
| createAnimatedTile | | public int createAnimatedTile(int staticTileIndex)(Code) | | Creates a new animated tile and returns the index that refers
to the new animated tile. It is initially associated with
the specified tile index (either a static tile or 0).
The indices for animated tiles are always negative. The first
animated tile shall have the index -1, the second, -2, etc.
Parameters:
staticTileIndex - the index of the associated tile (must be 0 or a valid static tile index) the index of newly created animated tile
throws:
IndexOutOfBoundsException - if the staticTileIndex is invalid |
| fillCells | | public void fillCells(int col, int row, int numCols, int numRows, int tileIndex)(Code) | | Fills a region cells with the specific tile. The cells may be filled
with a static tile index, an animated tile index, or they may be left
empty (index 0).
Parameters:
col - the column of top-left cell in the region
Parameters:
row - the row of top-left cell in the region
Parameters:
numCols - the number of columns in the region
Parameters:
numRows - the number of rows in the region
Parameters:
tileIndex - the Index of the tile to place in all cells in the specified region
throws:
IndexOutOfBoundsException - if the rectangular regiondefined by the parameters extends beyond the bounds of theTiledLayer grid
throws:
IllegalArgumentException - if numCols is lessthan zero
throws:
IllegalArgumentException - if numRows is lessthan zero
throws:
IndexOutOfBoundsException - if there is no tile withindex tileIndex
See Also: TiledLayer.setCell
See Also: TiledLayer.getCell |
| getAnimatedTile | | public int getAnimatedTile(int animatedTileIndex)(Code) | | Gets the tile referenced by an animated tile.
Returns the tile index currently associated with the
animated tile.
Parameters:
animatedTileIndex - the index of the animated tile the index of the tile reference by the animated tile
throws:
IndexOutOfBoundsException - if the animated tile indexis invalid
See Also: TiledLayer.setAnimatedTile |
| getCell | | public int getCell(int col, int row)(Code) | | Gets the contents of a cell.
Gets the index of the static or animated tile currently displayed in
a cell. The returned index will be 0 if the cell is empty.
Parameters:
col - the column of cell to check
Parameters:
row - the row of cell to check the index of tile in cell
throws:
IndexOutOfBoundsException - if row orcol is outside the bounds of the TiledLayer grid
See Also: TiledLayer.setCell
See Also: TiledLayer.fillCells |
| getCellHeight | | final public int getCellHeight()(Code) | | Gets the height of a single cell, in pixels.
the height in pixels of a single cell in the TiledLayer grid |
| getCellWidth | | final public int getCellWidth()(Code) | | Gets the width of a single cell, in pixels.
the width in pixels of a single cell in the TiledLayer grid |
| getColumns | | final public int getColumns()(Code) | | Gets the number of columns in the TiledLayer grid.
The overall width of the TiledLayer, in pixels,
may be obtained by calling
TiledLayer.getWidth .
the width in columns of the TiledLayer grid |
| getRows | | final public int getRows()(Code) | | Gets the number of rows in the TiledLayer grid. The overall
height of the TiledLayer, in pixels, may be obtained by
calling
TiledLayer.getHeight .
the height in rows of the TiledLayer grid |
| paint | | final public void paint(Graphics g)(Code) | | Draws the TiledLayer.
The entire TiledLayer is rendered subject to the clip region of
the Graphics object.
The TiledLayer's upper left corner is rendered at the
TiledLayer's current
position relative to the origin of the Graphics object. The current
position of the TiledLayer's upper-left corner can be retrieved by
calling
TiledLayer.getX() and
TiledLayer.getY() .
The appropriate use of a clip region and/or translation allows
an arbitrary region
of the TiledLayer to be rendered.
If the TiledLayer's Image is mutable, the TiledLayer is rendered
using the current contents of the Image.
Parameters:
g - the graphics object to draw the TiledLayer
throws:
NullPointerException - if g is null |
| setAnimatedTile | | public void setAnimatedTile(int animatedTileIndex, int staticTileIndex)(Code) | | Associates an animated tile with the specified static tile.
Parameters:
animatedTileIndex - the index of the animated tile
Parameters:
staticTileIndex - the index of the associated tile(must be 0 or a valid static tile index)
throws:
IndexOutOfBoundsException - if the staticTileIndex is invalid
throws:
IndexOutOfBoundsException - if the animated tile indexis invalid
See Also: TiledLayer.getAnimatedTile |
| setCell | | public void setCell(int col, int row, int tileIndex)(Code) | | Sets the contents of a cell.
The contents may be set to a static tile index, an animated
tile index, or it may be left empty (index 0)
Parameters:
col - the column of cell to set
Parameters:
row - the row of cell to set
Parameters:
tileIndex - the index of tile to place in cell
throws:
IndexOutOfBoundsException - if there is no tile with indextileIndex
throws:
IndexOutOfBoundsException - if row orcol is outside the bounds of the TiledLayer grid
See Also: TiledLayer.getCell
See Also: TiledLayer.fillCells |
| setStaticTileSet | | public void setStaticTileSet(Image image, int tileWidth, int tileHeight)(Code) | | Change the static tile set.
Replaces the current static tile set with a new static tile set.
See the constructor
TiledLayer.TiledLayer(int,int,Image,int,int) for information on how the tiles are created from the
image.
If the new static tile set has as many or more tiles than the
previous static tile set,
the the animated tiles and cell contents will be preserve. If
not, the contents of
the grid will be cleared (all cells will contain index 0) and
all animated tiles
will be deleted.
Parameters:
image - the Image to use for creating thestatic tile set
Parameters:
tileWidth - the width in pixels of a single tile
Parameters:
tileHeight - the height in pixels of a single tile
throws:
NullPointerException - if image is null
throws:
IllegalArgumentException - if tileHeightor tileWidth is less than 1
throws:
IllegalArgumentException - if the imagewidth is not an integer multiple of the tileWidth
throws:
IllegalArgumentException - if the imageheight is not an integer multiple of the tileHeight |
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