Code viewer for World: Tom and Jerry in Complex World

// Cloned by bo on 6 Nov 2020 from World "Complex World" by Starter user 
// Please leave this clone trail here.
 



// ==== Starter World =================================================================================================
// This code is designed for use on the Ancient Brain site.
// This code may be freely copied and edited by anyone on the Ancient Brain site.
// To include a working run of this program on another site, see the "Embed code" links provided on Ancient Brain.
// ====================================================================================================================



// =============================================================================================
// More complex starter World 
// 3d-effect Maze World (really a 2-D problem)
// Movement is on a semi-visible grid of squares 
//
// This more complex World shows:
// - Skybox
// - Internal maze (randomly drawn each time)
// - Enemy actively chases agent
// - Music/audio
// - 2D world (clone this and set show3d = false)
// - User keyboard control (clone this and comment out Mind actions to see)
// =============================================================================================


// =============================================================================================
// Scoring:
// Bad steps = steps where enemy is within one step of agent.
// Good steps = steps where enemy is further away. 
// Score = good steps as percentage of all steps.
//
// There are situations where agent is trapped and cannot move.
// If this happens, you score zero.
// =============================================================================================


 





// ===================================================================================================================
// === Start of tweaker's box ======================================================================================== 
// ===================================================================================================================

// The easiest things to modify are in this box.
// You should be able to change things in this box without being a JavaScript programmer.
// Go ahead and change some of these. What's the worst that could happen?


AB.clockTick       = 100;    

	// Speed of run: Step every n milliseconds. Default 100.
	
AB.maxSteps        = 1000;    

	// Length of run: Maximum length of run in steps. Default 1000.

AB.screenshotStep  = 50;   
  
	// Take screenshot on this step. (All resources should have finished loading.) Default 50.



//---- global constants: -------------------------------------------------------

	const show3d = true;						// Switch between 3d and 2d view (both using Three.js) 


 const TEXTURE_WALL 	= '/uploads/bow2/Spike.png' ;
 const TEXTURE_MAZE 	= '/uploads/bow2/shrubs-trees.jpg' ;
 const TEXTURE_AGENT 	= '/uploads/bow2/Jerry.png' ;
 const TEXTURE_ENEMY 	= '/uploads/bow2/Tom.png' ;

// credits:
// http://commons.wikimedia.org/wiki/File:Old_door_handles.jpg
// https://commons.wikimedia.org/wiki/Category:Pac-Man_icons
// https://commons.wikimedia.org/wiki/Category:Skull_and_crossbone_icons
// http://en.wikipedia.org/wiki/File:Inscription_displaying_apices_(from_the_shrine_of_the_Augustales_at_Herculaneum).jpg

 
	const MUSIC_BACK  = '/uploads/starter/Defense.Line.mp3' ;
	const SOUND_ALARM = '/uploads/starter/air.horn.mp3' ;

// credits:
// http://www.dl-sounds.com/royalty-free/defense-line/
// http://soundbible.com/1542-Air-Horn.html 

	
	
const gridsize = 50;						// number of squares along side of world	   

const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 3 );
console.log("Box density" + NOBOXES);
		// density of maze - number of internal boxes
		// (bug) use trunc or can get a non-integer 

const squaresize = 100;					// size of square in pixels

const MAXPOS = gridsize * squaresize;		// length of one side in pixels 
	
const SKYCOLOR 	= 0xddffdd;				// a number, not a string 

 
const startRadiusConst	 	= MAXPOS * 0.8 ;		// distance from centre to start the camera at
const maxRadiusConst 		= MAXPOS * 10  ;		// maximum distance from camera we will render things  



//--- change ABWorld defaults: -------------------------------

ABHandler.MAXCAMERAPOS 	= maxRadiusConst ;

ABHandler.GROUNDZERO		= true;						// "ground" exists at altitude zero



//--- skybox: -------------------------------
// skybox is a collection of 6 files 
// x,y,z positive and negative faces have to be in certain order in the array 
// https://threejs.org/docs/#api/en/loaders/CubeTextureLoader 

// mountain skybox, credit:
// http://stemkoski.github.io/Three.js/Skybox.html
/*
 const SKYBOX_ARRAY = [										 
                "/uploads/bow2/shrubs-trees.jpg",
                "/uploads/bow2/shrubs-trees.jpg",
                "/uploads/bow2/shrubs-trees.jpg",
                "/uploads/bow2/shrubs-trees.jpg",
                "/uploads/bow2/shrubs-trees.jpg",
                "/uploads/bow2/shrubs-trees.jpg"
                ];

*/
// space skybox, credit:
// http://en.spaceengine.org/forum/21-514-1
// x,y,z labelled differently

/*
 const SKYBOX_ARRAY = [										 
                "/uploads/starter/sky_pos_z.jpg",
                "/uploads/starter/sky_neg_z.jpg",
                "/uploads/starter/sky_pos_y.jpg",
                "/uploads/starter/sky_neg_y.jpg",
                "/uploads/starter/sky_pos_x.jpg",
                "/uploads/starter/sky_neg_x.jpg"
                ];
*/				


// urban photographic skyboxes, credit:
// http://opengameart.org/content/urban-skyboxes


 const SKYBOX_ARRAY = [										 
                "/uploads/starter/posx.jpg",
                "/uploads/starter/negx.jpg",
                "/uploads/starter/posy.jpg",
                "/uploads/starter/negy.jpg",
                "/uploads/starter/posz.jpg",
                "/uploads/starter/negz.jpg"
                ];




// ===================================================================================================================
// === End of tweaker's box ==========================================================================================
// ===================================================================================================================


// You will need to be some sort of JavaScript programmer to change things below the tweaker's box.


//--- Mind can pick one of these actions -----------------

const ACTION_LEFT 			= 0;		   
const ACTION_RIGHT 			= 1;
const ACTION_UP 			= 2;		 
const ACTION_DOWN 			= 3;
const ACTION_STAYSTILL 		= 4;

// in initial view, (smaller-larger) on i axis is aligned with (left-right)
// in initial view, (smaller-larger) on j axis is aligned with (away from you - towards you)


// contents of a grid square

const GRID_BLANK 	= 0;
const GRID_WALL 	= 1;
const GRID_MAZE 	= 2;
//***********************************************Bo Wang's code*********************************************************************************************
const GRID_ENEMY    = 3;
const GRID_AGENT    = 4;
//***********************************************End of my code*********************************************************************************************
 
 

var BOXHEIGHT;		// 3d or 2d box height 

var GRID 	= new Array(gridsize);			// can query GRID about whether squares are occupied, will in fact be initialised as a 2D array   

var theagent, theenemy;
  
var wall_texture, agent_texture, enemy_texture, maze_texture; 


// enemy and agent position on squares
var ei, ej, ai, aj;

var badsteps;
var goodsteps;


	
function loadResources()		// asynchronous file loads - call initScene() when all finished 
{
	var loader1 = new THREE.TextureLoader();
	var loader2 = new THREE.TextureLoader();
	var loader3 = new THREE.TextureLoader();
	var loader4 = new THREE.TextureLoader();
	
	loader1.load ( TEXTURE_WALL, function ( thetexture )  		
	{
		thetexture.minFilter  = THREE.LinearFilter;
		wall_texture = thetexture;
		if ( asynchFinished() )	initScene();		// if all file loads have returned 
	});
		
	loader2.load ( TEXTURE_AGENT, function ( thetexture )  	 
	{
		thetexture.minFilter  = THREE.LinearFilter;
		agent_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});	
	
	loader3.load ( TEXTURE_ENEMY, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		enemy_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	loader4.load ( TEXTURE_MAZE, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		maze_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
}


function asynchFinished()		 // all file loads returned 
{
	if ( wall_texture && agent_texture && enemy_texture && maze_texture )   return true; 
	else return false;
}	
	
	
 

//--- grid system -------------------------------------------------------------------------------
// my numbering is 0 to gridsize-1

	
function occupied ( i, j )		// is this square occupied
{
 //if ( ( ei == i ) && ( ej == j ) ) return true;		// variable objects 
 //if ( ( ai == i ) && ( aj == j ) ) return true;
//***********************************************Bo Wang's code*********************************************************************************************
 if ( GRID[i][j] == GRID_ENEMY ) return true;
 if ( GRID[i][j] == GRID_AGENT ) return true;
//***********************************************End of my code*********************************************************************************************
 if ( GRID[i][j] == GRID_WALL ) return true;		// fixed objects	 
 if ( GRID[i][j] == GRID_MAZE ) return true;		 
	 
 return false;
}

 
// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates
// logically, coordinates are: y=0, x and z all positive (no negative)    
// logically my dimensions are all positive 0 to MAXPOS
// to centre everything on origin, subtract (MAXPOS/2) from all dimensions 

function translate ( i, j )			
{
	var v = new THREE.Vector3();
	
	v.y = 0;	
	v.x = ( i * squaresize ) - ( MAXPOS/2 );   		 
	v.z = ( j * squaresize ) - ( MAXPOS/2 );   	
	
	return v;
}



	
function initScene()		// all file loads have returned 
{
	 var i,j, shape, thecube;
	 
	// set up GRID as 2D array
	 
	 for ( i = 0; i < gridsize ; i++ ) 
		GRID[i] = new Array(gridsize);		 


	// set up walls
	 
	 for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ ) 
		if ( ( i==0 ) || ( i==gridsize-1 ) || ( j==0 ) || ( j==gridsize-1 ) )
		{
			GRID[i][j] = GRID_WALL;		 
			shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
			thecube  = new THREE.Mesh( shape );
			thecube.material = new THREE.MeshBasicMaterial( { map: wall_texture } );
			
			thecube.position.copy ( translate(i,j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
			ABWorld.scene.add(thecube);
		}
		else 
   			GRID[i][j] = GRID_BLANK;

		
   // set up maze 
   
    for ( var c=1 ; c <= NOBOXES ; c++ )
	{
		i = AB.randomIntAtoB(1,gridsize-2);		// inner squares are 1 to gridsize-2
		j = AB.randomIntAtoB(1,gridsize-2);
			
		GRID[i][j] = GRID_MAZE ;
		
		shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
		thecube  = new THREE.Mesh( shape );
		thecube.material = new THREE.MeshBasicMaterial( { map: maze_texture } );		  

		thecube.position.copy ( translate(i,j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
		ABWorld.scene.add(thecube);		
	}
	 	 
   
	// set up enemy 
	// start in random location
	
	 do
	 {
	  i = AB.randomIntAtoB(1,gridsize-2);
	  j = AB.randomIntAtoB(1,gridsize-2);
	 }
	 while ( occupied(i,j) );  	  // search for empty square 

	 ei = i;
	 
	 ej = j;
	 console.log("Set up enemy"+ei+"**"+ej)
	 
	 shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
	 theenemy = new THREE.Mesh( shape );
 	 theenemy.material =  new THREE.MeshBasicMaterial( { map: enemy_texture } );
	 ABWorld.scene.add(theenemy);
	 drawEnemy();		  

	 
	
	// set up agent 
	// start in random location
	
	 do
	 {
	  i = AB.randomIntAtoB(1,gridsize-2);
	  j = AB.randomIntAtoB(1,gridsize-2);
	 }
	 while ( occupied(i,j) );  	  // search for empty square 

	 ai = i;
	 aj = j;
 
	 shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
	 theagent = new THREE.Mesh( shape );
	 theagent.material =  new THREE.MeshBasicMaterial( { map: agent_texture } );
	 ABWorld.scene.add(theagent);
	 drawAgent();
	 
//***********************************************Bo Wang's code*********************************************************************************************
	GRID[ai][aj] = GRID_AGENT;
    GRID[ei][ej] = GRID_ENEMY;
//***********************************************End of my code*********************************************************************************************

  // finally skybox 
  // setting up skybox is simple 
  // just pass it array of 6 URLs and it does the asych load 
  
  	 ABWorld.scene.background = new THREE.CubeTextureLoader().load ( SKYBOX_ARRAY, 	function() 
	 { 
		ABWorld.render(); 
	 
		AB.removeLoading();
	
		AB.runReady = true; 		// start the run loop
	 });
 		
}

//***********************************************Bo Wang's code*********************************************************************************************

//move diagonal or not
var diagonal = true;
//show the path or not
var showPath = true;
var showPathArray = [];



//coordinates class for creating variables containing i and j values
class coordinates {
    constructor(i, j) {
        this.i = i;
        this.j = j;
    }
}

var start = new coordinates();
var target = new coordinates();

var aStarGrid = [];
var closedSet, openSet;

function aStarSpot(i,j){
     // fields for a spot object
     //i and j for coordinates
     this.i = i;
     this.j = j;
     //f, g and h values for evaluation
     this.f = 0;
     this.g = 0;
     this.h = 0;
     //an array of near neighbors
     this.neighbors = [];
     //the previous spot
     this.parent = undefined;
     this.addNeighbors = function(){
         
        var i = this.i;
        var j = this.j;
        //add the four neighbors by deafult
        if(i < gridsize - 1){
                   this.neighbors.push(aStarGrid[i + 1][j]);
        }
        if(i > 0){
                   this.neighbors.push(aStarGrid[i - 1][j]);
        }
        if(j < gridsize - 1){
                   this.neighbors.push(aStarGrid[i][j + 1]);
        }
        if(j > 0){
                   this.neighbors.push(aStarGrid[i][j - 1]);
        }
        
        if (diagonal){
            //if the diagonal is enabled
            //add other four neighbors
            if(i > 0 && j > 0){
                this.neighbors.push(aStarGrid[i - 1][j - 1]);
            }
         
            if (i < gridsize - 1 && j > 0){
                this.neighbors.push(aStarGrid[i + 1][j - 1]);
            }
         
            if (i > 0 && j < gridsize - 1){
                this.neighbors.push(aStarGrid[i - 1][j + 1]);
            }
            if (i < gridsize - 1 && j < gridsize - 1){
                this.neighbors.push(aStarGrid[i + 1][j + 1]);
            }
        }
     }
 }
 
function initialAStarGrid() {
     console.log("initialAStarGrid function");
     var i, j;
     //create a 2D array
     for( i = 0;i < gridsize;i++){
         aStarGrid[i] = [];
         for( j = 0;j<gridsize;j++){
             aStarGrid[i][j] = new aStarSpot(i,j);
         }
     }
     //add neighbors for each spot
     for(i = 0; i< gridsize;i++){
         for(j = 0; j < gridsize; j++){
             aStarGrid[i][j].addNeighbors();
         }
     }

 }
 function isOccupied(i, j) {
     //function to check is the spot available or not
    switch (GRID[i][j]) {
        case GRID_WALL:
        case GRID_MAZE:
            return true;
        default:
            return false;
    }
}
 
function sortFunction(a, b) {
    //a sort function for sorting the openSet based on spots' f values
    if (a.f === b.f) {
        return 0;
    }
    else {
        return (a.f > b.f) ? 1 : -1;
    }
}

function heuristic(start, end){
    if (diagonal){
        //if diagonal is enabled
        //returns sum of horizontal distance to the power of two and vertical distance to the power of two
        //avoid decimal numbers
        return (Math.pow(start.i - end.i, 2) + Math.pow((start.j - end.j), 2));
    } else{
        //if diagonal is disabled
        //an absolute number of spots in the shortest path ignoring the obstacles
        return (Math.abs(start.i - start.i) + Math.abs(start.j - end.j));
    }
        
}

 //this is the a star function to determine the next move
function nextMove(start, target){
    var targetNode = aStarGrid[target.i][target.j];
    var startNode = aStarGrid[start.i][start.j];
    var currentNode;
    //initialize the openSet and closedSet
    openSet = [];
    closedSet = [];
    var neighbor;
    //create a variable for return value
    var nextMove = new coordinates(start.i, start.j);
    //push the first spot into the openSet
    openSet.push(startNode);
    //this function will run multiple times
    //we need to remove old values for each spot before doing any evaluation for the new path to get the next move
    for (i = 0; i < gridsize; i++) {
        for (j = 0; j < gridsize; j++) {
            currentNode = aStarGrid[i][j];
            currentNode.f = currentNode.h = currentNode.g = 0;
            currentNode.parent = null;
        }
    }

    // loop through the openSet until the target is found 
    //or length of the openSet reaches 0 could not find the target
    while ((openSet.length > 0) && currentNode !== targetNode) {
        //sort the openSet using sortFunction
        openSet.sort(sortFunction);
        //remove the first element from the openSet
        currentNode = openSet.shift();
        //push it into the closedSet, no more evaluation for it in this run
        closedSet.push(currentNode);

        //it has not reached the target then keep pushing spots into openSet to evaluate
        for (n = 0; n < currentNode.neighbors.length; n++) {
            //calculate the f value for each neighbor and push it into the openSet if it is available
            neighbor = currentNode.neighbors[n];
            if (closedSet.includes(neighbor)) {
                //if the neighbor is already in the closedSet then do nothing
            } else if (isOccupied(neighbor.i, neighbor.j)) {
                //check if the neighbor is available
                closedSet.push(neighbor);
            } else {
                if ((neighbor.i == currentNode.i) || (neighbor.j == currentNode.j)){
                    //if any one of the i or j value is the same as currentNode
                    //then it must not be the diagonal movement
                    //assign the cost of each non diagonal movement is 10
                    neighbor.g = currentNode.g + 10;
                } else{
                    //if it is diagonal movement
                    //according to the cost of non diagonal movement
                    //the cost of each diagonal movement should be the square root of the sum of 10 to the power of 2 and 10 to the power of 2
                    //roughly equal to 14
                    neighbor.g = currentNode.g + 14;
                }
                //calculate the h value using heuristic function
                neighbor.h = heuristic(neighbor, targetNode);
                //add the h and g values together as the f value
                neighbor.f = neighbor.g + neighbor.h;
                //assign the parent spot
                neighbor.parent = currentNode;
                if (!openSet.includes(neighbor)) {
                    // if this spot is not in the openSet
                    //push it into the openSet
                    openSet.push(neighbor);
                }
            }
        }
    }
    
    // make sure that the algorithm reached targetNode rather than the length of the openSet reached 0
    if (currentNode == targetNode) {
        //backtrack to get only the next spot from the starting spot
        while (currentNode.parent != startNode) {
            // if the showPath is enabled
            if (showPath){
                //push the node into the showPathArray for drawing the line later
                showPathArray.push(currentNode);
            }
                
            //backtrack to get only the next spot from the starting spot
            currentNode = currentNode.parent;
        }
        if (showPath){
            //we do not have the startNode in the showPathArray then push it in
            showPathArray.push(startNode);
        }
    }else{
        //in case the algorithm cannot reach the targetNode
        return nextMove;
    }
    
    //now we have the next move before the startNode
    //return it
    nextMove.i = currentNode.i;
    nextMove.j = currentNode.j;
    return nextMove;
}


function drawPath(){
    //declear variables
    var ele;
    var line;
    // material and geometry for drawing the line in the world
    var mat = new THREE.LineBasicMaterial({color:'red', linewidth:2 });
    var geo = new THREE.Geometry();
    //loop through the array containing the spots
    for ( i = showPathArray.length; i > 1; i--) {
        //get the first element from the array and remove from it
        ele = showPathArray.shift();
        if (ele.parent){
            //if it has a parent
            ele = ele.parent;
            geo.vertices.push( translate(ele.i, ele.j) );
        }
        else {
            //if it does not have parent
            geo.vertices.push( translate(ele.i, ele.j) );
        }        
    }
    //draw the line
    line = new THREE.Line(geo, mat);
    ABWorld.scene.add(line);
}


//***********************************************End of my code*********************************************************************************************


// --- draw moving objects -----------------------------------


function drawEnemy()		// given ei, ej, draw it 
{
	theenemy.position.copy ( translate(ei,ej) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 

	ABWorld.lookat.copy ( theenemy.position );	 		// if camera moving, look back at where the enemy is  
}

function drawAgent()		// given ai, aj, draw it 
{
	theagent.position.copy ( translate(ai,aj) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 

	ABWorld.follow.copy ( theagent.position );			// follow vector = agent position (for camera following agent)
}






// --- take actions -----------------------------------

function moveLogicalEnemy()
{ 
//***********************************************Bo Wang's code*********************************************************************************************


    //get the coordinates of the enemy as start node
    start.i=ei;
    start.j=ej;
    //get the coordinates of the agent as target node
    target.i = ai;
    target.j = aj;
    //get the next move
    nextMoveByAStar = nextMove(start, target);
    //if that coordinates is avaliable then move
    if ( ! occupied(nextMoveByAStar.i,nextMoveByAStar.j) ) {
        GRID[ei][ej] = GRID_BLANK;
        ei = nextMoveByAStar.i;
        ej = nextMoveByAStar.j;
        GRID[ei][ej] = GRID_ENEMY;
    }
 
//***********************************************End of my code*********************************************************************************************
}


function moveLogicalAgent( a )	
{ 
 var i = ai;
 var j = aj;		 

      if ( a == ACTION_LEFT ) 	i--;
 else if ( a == ACTION_RIGHT ) 	i++;
 else if ( a == ACTION_UP ) 		j++;
 else if ( a == ACTION_DOWN ) 	j--;

    if (!occupied(i, j)) {
        GRID[ai][aj] = GRID_BLANK;
        ai = i;
        aj = j;
        GRID[ai][aj] = GRID_AGENT;

    }
}


// --- key handling --------------------------------------------------------------------------------------
// This is hard to see while the Mind is also moving the agent:
// AB.mind.getAction() and AB.world.takeAction() are constantly running in a loop at the same time 
// have to turn off Mind actions to really see user key control 

// we will handle these keys: 

var OURKEYS = [ 37, 38, 39, 40 ];

function ourKeys ( event ) { return ( OURKEYS.includes ( event.keyCode ) ); }
	

function keyHandler ( event )		
{
	if ( ! AB.runReady ) return true; 		// not ready yet 

   // if not one of our special keys, send it to default key handling:
	
	if ( ! ourKeys ( event ) ) return true;
	
	// else handle key and prevent default handling:
	
	if ( event.keyCode == 37 )   moveLogicalAgent ( ACTION_LEFT 	);   
    if ( event.keyCode == 38 )   moveLogicalAgent ( ACTION_DOWN  	); 	 
    if ( event.keyCode == 39 )   moveLogicalAgent ( ACTION_RIGHT 	); 	 
    if ( event.keyCode == 40 )   moveLogicalAgent ( ACTION_UP		);   
	
	// when the World is embedded in an iframe in a page, we want arrow key events handled by World and not passed up to parent 

	event.stopPropagation(); event.preventDefault(); return false;
}





// --- score: -----------------------------------


function badstep()			// is the enemy within one square of the agent
{
 if ( ( Math.abs(ei - ai) < 2 ) && ( Math.abs(ej - aj) < 2 ) ) return true;
 else return false;
}


function agentBlocked()			// agent is blocked on all sides, run over
{
 return ( 	occupied (ai-1,aj) 		&& 
		occupied (ai+1,aj)		&&
		occupied (  ai,aj+1)		&&
		occupied (  ai,aj-1) 	);		
} 


function updateStatusBefore(a)
// this is called before anyone has moved on this step, agent has just proposed an action
// update status to show old state and proposed move 
{
 var x 		= AB.world.getState();
 AB.msg ( " Step: " + AB.step + " &nbsp; x = (" + x.toString() + ") &nbsp; a = (" + a + ") " ); 
}


function   updateStatusAfter()		// agent and enemy have moved, can calculate score
{
 // new state after both have moved
 
 var y 		= AB.world.getState();
 var score = ( goodsteps / AB.step ) * 100; 

 AB.msg ( " &nbsp; y = (" + y.toString() + ") <br>" +
		" Bad steps: " + badsteps + 
		" &nbsp; Good steps: " + goodsteps + 
		" &nbsp; Score: " + score.toFixed(2) + "% ", 2 ); 
}





AB.world.newRun = function() 
{
	AB.loadingScreen();

	AB.runReady = false;  

	badsteps = 0;	
	goodsteps = 0;
	initialAStarGrid();

	
	if ( show3d )
	{
	 BOXHEIGHT = squaresize;
	 ABWorld.init3d ( startRadiusConst, maxRadiusConst, SKYCOLOR  ); 	
	}	     
	else
	{
	 BOXHEIGHT = 1;
	 ABWorld.init2d ( startRadiusConst, maxRadiusConst, SKYCOLOR  ); 		     
	}
	
	
	loadResources();		// aynch file loads		
							// calls initScene() when it returns 

	document.onkeydown = keyHandler;	
		 
};



AB.world.getState = function()
{
 var x = [ ai, aj, ei, ej ];
  return ( x );  
};



AB.world.takeAction = function ( a )
{
  updateStatusBefore(a);			// show status line before moves 

  moveLogicalAgent(a);

  if ( ( AB.step % 2 ) == 0 )		// slow the enemy down to every nth step
    moveLogicalEnemy();


  if ( badstep() )  badsteps++;
  else   			goodsteps++;

   drawAgent();
   drawEnemy();
   updateStatusAfter();			// show status line after moves  


  if ( agentBlocked() )			// if agent blocked in, run over 
  {
	AB.abortRun = true;
	goodsteps = 0;			// you score zero as far as database is concerned 			 
	musicPause();
	soundAlarm();
  }
  
//***********************************************Bo Wang's code*********************************************************************************************
  if (showPath){
        drawPath();
    }
//***********************************************End of my code*********************************************************************************************

};



AB.world.endRun = function()
{
  musicPause(); 
  if ( AB.abortRun ) AB.msg ( " <br> <font color=red> <B> Agent trapped. Final score zero. </B> </font>   ", 3  );
  else    				AB.msg ( " <br> <font color=green> <B> Run over. </B> </font>   ", 3  );
};

 
AB.world.getScore = function()
{
    // only called at end - do not use AB.step because it may have just incremented past AB.maxSteps
    
    var s = ( goodsteps / AB.maxSteps ) * 100;   // float like 93.4372778 
    var x = Math.round (s * 100);                // 9344
    return ( x / 100 );                          // 93.44
};


 




// --- music and sound effects ----------------------------------------

var backmusic = AB.backgroundMusic ( MUSIC_BACK );

function musicPlay()   { backmusic.play();  }
function musicPause()  { backmusic.pause(); }

											 
function soundAlarm()
{
	var alarm = new Audio ( SOUND_ALARM );
	alarm.play();							// play once, no loop 
}