org.mini2Dx.core.util

Class FastXYSorter<T extends java.lang.Comparable<T>>

java.lang.Object

org.mini2Dx.core.util.FastXYSorter<T>

Type Parameters:

T -

public class FastXYSorter<T extends java.lang.Comparable<T>>
extends java.lang.Object

Utility class for fast sorting of objects to be rendered Works by combining an grid with a bitset. For per-pixel games, it is recommended to decide on a grid cell size (e.g. 8 x 8) and divide your screen size by this size. For tile-based games, your entities should already be conforming to a grid. For best performance, pre-calculate everything according to the grid.

Constructor Summary

Constructors

Constructor and Description
FastXYSorter(int gridWidth, int gridHeight, int expectedElementsPerCell) Constructor
FastXYSorter(int screenWidth, int screenHeight, int cellWidth, int cellHeight, int expectedElementsPerCell) Constructor

Method Summary

Modifier and Type	Method and Description
void	add(int screenX, int screenY, int cellWidth, int cellHeight, T obj)
void	add(int gridX, int gridY, T obj) Add an object to be sorted
void	begin() Must be called after all calls to add(int, int, Comparable) are done
int	getHeight()
int	getOriginX()
int	getOriginY()
int	getWidth()
T	poll() Returns the next object to render
void	setOrigin(int originX, int originY) Useful for setting an origin that is subtracted from values added to the sorter (e.g.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FastXYSorter

public FastXYSorter(int screenWidth,
                    int screenHeight,
                    int cellWidth,
                    int cellHeight,
                    int expectedElementsPerCell)

Constructor

Parameters:

screenWidth - The screen width in pixels

screenHeight - The screen height in pixels

cellWidth - The cell width in pixels to divide the screen width by

cellHeight - The cell height in pixels to divide the screen height by

expectedElementsPerCell - The expected amount of entities per cell

FastXYSorter

public FastXYSorter(int gridWidth,
                    int gridHeight,
                    int expectedElementsPerCell)

Constructor

Parameters:

gridWidth - The width of the grid

gridHeight - The height of the grid

expectedElementsPerCell - The expected amount of entities per cell

Method Detail

setOrigin

public void setOrigin(int originX,
                      int originY)

Useful for setting an origin that is subtracted from values added to the sorter (e.g. camera position)

Parameters:

originX - The X value to subtract

originY - The Y value to subtract

add

public void add(int screenX,
                int screenY,
                int cellWidth,
                int cellHeight,
                T obj)

Parameters:

screenX - The pixel X coordinate of the object

screenY - The pixel Y coordinate of the object

cellWidth - The width of the cells in pixels

cellHeight - The height of the cells in pixels

obj - The object to be added

add

public void add(int gridX,
                int gridY,
                T obj)

Add an object to be sorted

Parameters:

gridX - The grid X coordinate of the object

gridY - The grid Y coordinate of the object

obj - The object to be added

begin

public void begin()

Must be called after all calls to add(int, int, Comparable) are done

poll

public T poll()

Returns the next object to render

Returns:

Null if no more objects

getWidth

public int getWidth()

getHeight

public int getHeight()

getOriginX

public int getOriginX()

getOriginY

public int getOriginY()