Blit Scrolling in a Tile-Based World - The Essential Guide to Flash Games - page 440

* ...
* @author Jeff Fulton
*/
public class DriveSheSaid extends Game {
public static const KEY_UP:int = 38;
public static const KEY_DOWN:int = 40;
public static const KEY_LEFT:int = 37;
public static const KEY_RIGHT:int = 39;
public static const TILE_WALL:int = 0;
public static const TILE_MOVE:int = 1
public static const SPRITE_PLAYER:int = 2;
public static const SPRITE_GOAL:int = 3;
public static const SPRITE_CLOCK:int = 4;
public static const SPRITE_SKULL:int = 5;
public static const SPRITE_HEART:int = 6;
public static const STATE_SYSTEM_GAMEPLAY:int = 0;
public static const STATE_SYSTEM_LEVELOUT:int = 1;
private var systemFunction:Function;
private var currentSystemState:int;
private var nextSystemState:int;
private var lastSystemState:int;
private var level:int = 0;
private var levelData:Level;
private var levels:Array = [undefined,new Level1()];
//tiles
private var mapTileWidth:int=32;
private var mapTileHeight:int=32;
//display
private var canvasBitmapData:BitmapData;
private var backgroundBitmapData:BitmapData;
private var canvasBitmap:Bitmap;
private var backgroundBitmap:Bitmap;
//world
private var world:Array=new Array();
private var worldCols:int=50;
private var worldRows:int=50;
private var worldWidth:int=worldCols*mapTileWidth;;
private var worldHeight:int=worldRows*mapTileHeight;
//camera
private var camera:Camera2D = new Camera2D();
//for drawing cameraAreaTiles
private var tileRect:Rectangle;
private var tilePoint:Point;
private var tileSheetData:Array;