Code viewer for World: Hardik Mangla Practical 1 ...
// Cloned by Hardik Mangla on 26 Oct 2023 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.
// =============================================================================================


 
// =============================================================================================

// To Learn the Working of A Star Algorithm I referred the videos by Daniel Shiffman (The Coding Train) present at

// https://www.youtube.com/watch?v=aKYlikFAV4k&list=PLRqwX-V7Uu6YJ3XfHhT2Mm4Y5I99nrIKX&index=11

// https://www.youtube.com/watch?v=EaZxUCWAjb0&list=PLRqwX-V7Uu6YJ3XfHhT2Mm4Y5I99nrIKX&index=12

// https://www.youtube.com/watch?v=jwRT4PCT6RU&list=PLRqwX-V7Uu6YJ3XfHhT2Mm4Y5I99nrIKX&index=13

// To learn about the Async/Await functions I looked at the video by CodeWithHarry and Article at mdn web docs_ website.

// https://www.youtube.com/watch?v=bLre6Uf4Op0

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function

// =============================================================================================




// ===================================================================================================================
// === 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 = 10; //  100;    
// Speed of run: Step every n milliseconds. Default 100.
	
AB.maxSteps = 1000;    
// Length of run: Maximum length of run in steps. Default 1000. This Works on AB.Step

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/hardik18/Fencing_1.jpeg'                          //const TEXTURE_WALL = '/uploads/starter/door.jpg' ;
const TEXTURE_MAZE = 'uploads/hardik18/Pond_1.jpeg'                             //const TEXTURE_MAZE = '/uploads/starter/latin.jpg' ;
const TEXTURE_AGENT = 'uploads/hardik18/Finish_2.png'                           //const TEXTURE_AGENT = '/uploads/starter/pacman.jpg' ;
const TEXTURE_ENEMY = 'uploads/hardik18/Runner_1.png'                           //const TEXTURE_ENEMY = '/uploads/starter/ghost.3.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 = 40; // 20;						                                    // number of squares along side of world	   

const NOBOXES =  Math.trunc( (gridsize * gridsize) / 4 );
// 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/hardik18/posx.jpg",
                "uploads/hardik18/negx.jpg",
                "uploads/hardik18/posy.jpg",
                "uploads/hardik18/negy.jpg",
                "uploads/hardik18/posz.jpg",
                "uploads/hardik18/negz.jpg"
];


//const SKYBOX_ARRAY = [										 
//                "/uploads/starter/dawnmountain-xpos.png",
//                "/uploads/starter/dawnmountain-xneg.png",
//                "/uploads/starter/dawnmountain-ypos.png",
//                "/uploads/starter/dawnmountain-yneg.png",
//                "/uploads/starter/dawnmountain-zpos.png",
//                "/uploads/starter/dawnmountain-zneg.png"
//];


// 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;




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 GridForSquares = new Array(gridsize - 2);                                   // Grid for A star Pieces Hardik 

var StartEnemyPos; var StartAgentPos;                                           //Start and End for A Star Hardik

var AStarFlag = true;                                                           //Flag to check wheather current A Star Calculation has comleted Hardik

var NoPathFlag = false;                                                         //Flag to Stop Algorithm if no path found. Hardik

var TotalSteps = 0;                                                             //Flag to calculate total steps and score. Hardik

var TotalStates = 0;

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;


//Main Function for Creating A Star Objects

function Squares(i,j){                                                          //This Function is For storing Squares and Values for Each Square. Hardik                       
    this.fn = 10000;
    this.gn;
    this.hn;
    this.x = i;
    this.y = j;
    
    this.neighbour = [];
    
    this.ParentSquare;
    
    this.AddNeighbour = function(GridForSquares){
        
        if(this.x > 0){
            this.neighbour.push(GridForSquares[this.x - 1][this.y]);
        }
        
        if(this.y > 0){
            this.neighbour.push(GridForSquares[this.x][this.y - 1]);
        }
        
        if(this.x < gridsize - 3){
            this.neighbour.push(GridForSquares[this.x + 1][this.y]);    
        }
        
        if(this.y < gridsize - 3){
            this.neighbour.push(GridForSquares[this.x][this.y + 1]);
        }
    }
}



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;

    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 GridForSquares as 2D Array Hardik
    
    for(i = 0; i < gridsize-2; i++)
    {
        GridForSquares[i] = new Array(gridsize - 2)
    }
    
	
	// 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;
	 
	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(); 


    // 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
	});
 	
 	
 	//Setting up values for each square for A Star Hardik
 	
 	for (i = 0; i < gridsize-2; i++)
	{
	    for (j = 0; j < gridsize-2; j++)
	    {
	        GridForSquares[i][j] = new Squares(i,j);
	    }
	}
	
	//Adding All the neighbours for each square Hardik
	
	for (i = 0; i < gridsize-2; i++)
	{
	    for (j = 0; j < gridsize-2; j++)
	    {
	        GridForSquares[i][j].AddNeighbour(GridForSquares);
	    }
	}
	
	//For Now Creating White Boxes on the Ground to see if A Star works Hardik
	
	ResetGrid();
}
 

async function ResetGrid(){                                                     //Function to Reset Blank Spots on the Grid to White Colour. Helps understand that enemy follows A Star
    
    var i, j, shape, thecube;
    
    for (i = 0; i < gridsize - 2 ; i++)
	{
	    for ( j = 0; j < gridsize - 2 ; j++)
	    {
		    if ((GRID[i+1][j+1] == GRID_BLANK))
		    {
			    shape = new THREE.BoxGeometry(squaresize, 10, squaresize);			 
			    
			    thecube  = new THREE.Mesh(shape);
			    
			    thecube.material = new THREE.MeshBasicMaterial({color: 0xffffff});
			
			    thecube.position.copy(translate(i+1,j+1));
			    
			    ABWorld.scene.add(thecube);
		    }
		    
		    GridForSquares[i][j].fn = 10000;
		    
		    GridForSquares[i][j].gn = undefined;
		    
		    GridForSquares[i][j].hn = undefined;
		    
		    GridForSquares[i][j].ParentSquare = undefined;
		}
	}
}
 


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


async 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  
}


async 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 RemoveCurrentSquareFromOpenSet(OpenSet, CurrentSquare){                //Removes a Square we have traversed from the OpenSet. Hardik
    for(var i = OpenSet.length - 1; i >= 0; i--){
        
        if(OpenSet[i] == CurrentSquare){
            OpenSet.splice(i,1);
        }
    }
    
    return OpenSet;
}

function HeuristicValue(NeighbourSquare, StartAgentPos){                        //Function to Calculate Heuristic Value. Hardik
    var dist;
    
    dist = Math.abs(NeighbourSquare.x - StartAgentPos.x) + Math.abs(NeighbourSquare.y - StartAgentPos.y)
    
    return dist;
}

async function MoveEnemyWithAStar(){                                            //Function to Implement A Star Algorithm Hardik
    
    var i, CurrentSquare, TempGValue, Winner, CurrentSquareNeighbours, TempSquare;
    
    var Path = [];
    
    var OpenSet = [];
    
    var ClosedSet = [];
    
    StartEnemyPos.gn = 0;
    
    StartEnemyPos.hn = HeuristicValue(StartEnemyPos, StartAgentPos);
    
    StartEnemyPos.fn = StartEnemyPos.gn + StartEnemyPos.hn;

    OpenSet.push(StartEnemyPos);
    
    if (OpenSet.length <= 0){
        console.log("No A Star Path Found !!")
    }
    
    console.log("Starting A Star");
    
    while(OpenSet.length > 0){
    
        if(CurrentSquare == StartAgentPos){
            console.log("Agent Found.");
            break;
        }
        
        await DrawOpenSet(OpenSet);
        
        await DrawClosedSet(ClosedSet);
        
        await new Promise((resolve,_)=>{
            setTimeout(resolve,100);
        })
        
        Winner = OpenSet[0];
        
        for(i = 0; i < OpenSet.length; i++){
            
            if(OpenSet[i].fn < Winner.fn){
                Winner = OpenSet[i];    
            }
        }
        
        CurrentSquare = Winner;
        
        if(Winner == StartAgentPos){
            console.log("Agent Found.")
            break;
        }
        else{
            OpenSet = RemoveCurrentSquareFromOpenSet(OpenSet,CurrentSquare);
            
            ClosedSet.push(CurrentSquare);
            
            CurrentSquareNeighbours = CurrentSquare.neighbour;
            
            for(i = 0; i < CurrentSquareNeighbours.length; i++){
                
                if( (! ClosedSet.includes(CurrentSquareNeighbours[i])) && (GRID[CurrentSquareNeighbours[i].x + 1][CurrentSquareNeighbours[i].y + 1] != GRID_MAZE)){
                    
                    TempGValue = CurrentSquare.gn + 1;
                    
                    if(OpenSet.includes(CurrentSquareNeighbours[i])){
                    
                        if(CurrentSquareNeighbours[i].gn > TempGValue){
                        
                            CurrentSquareNeighbours[i].gn = TempGValue;
                            
                            CurrentSquareNeighbours[i].hn = HeuristicValue(CurrentSquareNeighbours[i],StartAgentPos);
                            
                            CurrentSquareNeighbours[i].fn = CurrentSquareNeighbours[i].gn + CurrentSquareNeighbours[i].hn;
                            
                            CurrentSquareNeighbours[i].ParentSquare = CurrentSquare;
                            
                        }        
                    
                        
                    }
                    else{
                        CurrentSquareNeighbours[i].gn = CurrentSquare.gn + 1;
                        
                        CurrentSquareNeighbours[i].hn = HeuristicValue(CurrentSquareNeighbours[i],StartAgentPos);
                        
                        CurrentSquareNeighbours[i].fn = CurrentSquareNeighbours[i].gn + CurrentSquareNeighbours[i].hn;
                        
                        CurrentSquareNeighbours[i].ParentSquare = CurrentSquare;
                        
                        OpenSet.push(CurrentSquareNeighbours[i]);
                    }
                    
                }    
                
            }
        }
    
    }
    
    TempSquare = CurrentSquare;
        
    Path.push(TempSquare);
    
    while(TempSquare.ParentSquare !== undefined){
        TempSquare = TempSquare.ParentSquare;
        Path.push(TempSquare);
    }
    
    await DrawPath(Path);
    
    //console.log("Path.x = " + Path[0].x + " Path.y = " + Path[0].y + " ai = " + ai + " aj = " + aj);
    TotalStates = TotalStates + OpenSet.length + ClosedSet.length;
    console.log("TotalStates Covered in this step : " + TotalStates);
    
    if(Path[0].x + 1 != ai && Path[0].y + 1 !=aj){
        NoPathFlag = true;
    }
    
    if(Path.length > 1)
        return Path[Path.length - 2];
    else
        return Path[0];
}

async function DrawOpenSet(OpenSet){                                            //Function to Draw Squares in the Open Set. Hardik
    
    var i,j, shape, thecube;
    
    if(OpenSet.length > 0){
        
        for (i = 0; i < gridsize - 2 ; i++)
    	{
    	    for ( j = 0; j < gridsize - 2 ; j++)
    	    {
    		    if(OpenSet.includes(GridForSquares[i][j]))
    		    {
    			    shape = new THREE.BoxGeometry(squaresize, 10, squaresize);			 
    			    
    			    thecube  = new THREE.Mesh(shape);
    			    
    			    thecube.material = new THREE.MeshBasicMaterial({color: 0xe149a7});
    			
    			    thecube.position.copy(translate(i+1,j+1));
    			    
    			    ABWorld.scene.add(thecube);
    		    }
    		}
    	} 
    }
}


async function DrawClosedSet(ClosedSet){                                        //Function to Draw Squares present in the Closed Set. Hardik
    
    var i,j, shape, thecube;
    
    if(ClosedSet.length > 0){
        
        for (i = 0; i < gridsize - 2 ; i++)
    	{
    	    for ( j = 0; j < gridsize - 2 ; j++)
    	    {
    		    if(ClosedSet.includes(GridForSquares[i][j]))
    		    {
    			    shape = new THREE.BoxGeometry(squaresize, 10, squaresize);			 
    			    
    			    thecube  = new THREE.Mesh(shape);
    			    
    			    thecube.material = new THREE.MeshBasicMaterial({color: 0x2e5d4b});
    			
    			    thecube.position.copy(translate(i+1,j+1));
    			    
    			    ABWorld.scene.add(thecube);
    		    }
    		}
    	} 
    }
}

async function DrawPath(Path){                                                  //Function to Draw the Actual A Star Path. Hardik
    
    var i,j, shape, thecube;
    
    // if(Path.length > 0){
    //     for (i = 0; i < gridsize - 2 ; i++)
    // 	{
    // 	    for ( j = 0; j < gridsize - 2 ; j++)
    // 	    {
    // 		    if(Path.includes(GridForSquares[i][j]))
    // 		    {
    // 			    shape = new THREE.BoxGeometry(squaresize, 10, squaresize);			 
    			    
    // 			    thecube  = new THREE.Mesh(shape);
    			    
    // 			    thecube.material = new THREE.MeshBasicMaterial({color: 0xfadf00});
    			
    // 			    thecube.position.copy(translate(i+1,j+1));
    			    
    // 			    ABWorld.scene.add(thecube);
    			    
    // 			    await new Promise((resolve,_)=>{
    //                     setTimeout(resolve,100);
    //                 })
    // 		    }
    // 		}
    // 	} 
    // }
    
    if(Path.length > 0){
        for (i = Path.length-1; i >= 0 ; i--)
    	{
		    shape = new THREE.BoxGeometry(squaresize, 10, squaresize);			 
		    
		    thecube  = new THREE.Mesh(shape);
		    
		    thecube.material = new THREE.MeshBasicMaterial({color: 0xfadf00});
		
		    thecube.position.copy(translate(Path[i].x + 1,Path[i].y +1));
		    
		    ABWorld.scene.add(thecube);
		    
		    await new Promise((resolve,_)=>{
                setTimeout(resolve,100);
            })
    	} 
    }
}



async function moveLogicalEnemy()
{ 
    // move towards agent using A Star                                          //Function Changed to Implement A Star only. Hardik
    
    StartEnemyPos = GridForSquares[ei-1][ej-1];                                 //Start Enemy Position for A Star Hardik
    
    StartAgentPos = GridForSquares[ai-1][aj-1];                                 //Start Agent Position for A Star Hardik
    
    TotalStates = 0;
    
    var NextSquare = await MoveEnemyWithAStar();
    
    if (! occupied(NextSquare.x + 1, NextSquare.y + 1) ){
    
        ei = NextSquare.x + 1;
    
        ej = NextSquare.y + 1;
    }
    
    //await drawEnemy();
    
    //await ResetGrid();
}


function moveLogicalAgent( a )			                                        // this is called by the infrastructure that gets action a from the Mind 
{ 
    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) ) 
    {
        ai = i;
        aj = j;
    }
}




// --- 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 + ") " );
    AB.msg ( " Step: " + TotalSteps + " &nbsp; x = (" + x.toString() + ") &nbsp; a = (" + a + ") " ); // Hardik
}


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;
    var score = ( goodsteps / TotalSteps ) * 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;

	
	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 = async function ( a )
{
    
    if (AStarFlag){                                                             //Hardik
        
        AStarFlag = false;
        
        updateStatusBefore(a);			                                        // show status line before moves
        
        if (NoPathFlag){
            AB.abortRun = true;
            
            goodsteps = 0;
    	
    	    musicPause();
    	
    	    soundAlarm();
        }
        else{
            await moveLogicalEnemy();
        }
    
        await moveLogicalAgent(a);
        TotalSteps++;
        
        if ( badstep() )  
            badsteps++;
        else   			
            goodsteps++;
            
        await drawEnemy();
    
        await drawAgent();
        
        await ResetGrid();
        
        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();
        }
        
        AStarFlag = true;
    }

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



AB.world.endRun = function()
{
    musicPause(); 
    
    if ( AB.abortRun && ! NoPathFlag ) 
        AB.msg(" <br> <font color=red> <B> Agent trapped. Final score zero. </B> </font>   ", 3  );
    else if (AB.abortRun && NoPathFlag)
        AB.msg(" <br> <font color=red> <B> No Path from Agent to Enemy. </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 
}