Code viewer for World: Final Assignment Submission

// Cloned by Mohamed Hafez on 24 Nov 2020 from World "Final version" by Mohamed Hafez 
// Please leave this clone trail here.
 


// Cloned by Mohamed Hafez on 13 Nov 2020 from World "Complex World (clone by Mohamed Hafez)" by Mohamed Hafez 
// Please leave this clone trail here.
 


// Cloned by Mohamed Hafez on 8 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?

const enemyalgorithm=2;     // 1 for Default , 2 for A* , 3 for Random , 4 for firstneigbour with best heuristic
const agentalgorithm=3;    // 1 for Default , 2 for A*  ,3 for goingfar 
const heuristicmethod=2; // 1 for Manhattan distance , 2 for Eucledean distance


AB.clockTick       = 10;    

	// 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/mhafez/purpleflame.jpg' ;
 const TEXTURE_MAZE 	= '/uploads/mhafez/redflame.jpg' ;
 const TEXTURE_AGENT 	= '/uploads/mhafez/ball.jpg' ;
 const TEXTURE_ENEMY 	= '/uploads/mhafez/mosalah3.jpg' ;

// 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  //[MH] Grid changed to 50x50  

const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 3 ); //[MH] Grid density changed to be divided by 3
		// 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/mhafez/stad_modified.jpg",
                "/uploads/mhafez/stad_modified.jpg",
                "/uploads/mhafez/stad_modified.jpg",
                "/uploads/mhafez/black_background.jpg",
                "/uploads/mhafez/stad_modified.jpg",
                "/uploads/mhafez/stad_modified.jpg"
                ];





 /*const SKYBOX_ARRAY = [                                                                          
                "/uploads//bluecloud_dn.jpg",
                "/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 GRIDMIND = new Array(gridsize);			// [MH] Array for A* Algorithm for Agent  


var theagent, theenemy, thepath,theagentpath, astarpath;
  
var wall_texture, agent_texture, enemy_texture, maze_texture; 
var fi=0;
var fim=0;

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

var badsteps;
var goodsteps;

//[MH] Openset and Closeset for Enemy A* 

var openSet = [];
var closedSet = [];
var path=[];
var newpath2=[];
var start;
var end;
var previousei=0;
var previousej=0;
var previousai=0;
var previousaj=0;
var ariko=[];  //[MH] Array to save three.js objects while drawing to delete them in next search



//[MH] heuristic function for A*
function heuristic(a, b) 
{
 if (heuristicmethod==1)    return ( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );  //[MH] Manhattan distance heuristic
 if (heuristicmethod==2)    return ( Math.sqrt(Math.pow((a.i - b.i),2) + Math.pow((a.j - b.j),2)) ); //[MH] Euclidean distance heuristic
}
	
//[MH] Function to delete element from the Openset array
function removeFromArray(arr, elt) 
{
  // Could use indexOf here instead to be more efficient
  for (var i = arr.length - 1; i >= 0; i--) 
    if (arr[i] == elt) 
      arr.splice(i, 1);
}

//[MH] Object for location on grid 

function Spot(i, j) 
{

  // Location
  this.i = i;
  this.j = j;
  this.value=0;

  // f, g, and h values for A*
  this.f = 0;
  this.g = 0;
  this.h = 0;
  

  // Neighbors
  this.neighbors = [];
  this.previou = undefined;
  
  // Figure out who my neighbors are
  this.addNeighbors = function(GRID) 
  {
    var i = this.i;
    var j = this.j;
    
    if (i < gridsize - 1)   this.neighbors.push(GRID[i + 1][j]);
    if (i > 0)          this.neighbors.push(GRID[i - 1][j]);
    if (j < gridsize - 1)   this.neighbors.push(GRID[i][j + 1]);
    if (j > 0)          this.neighbors.push(GRID[i][j - 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].value == GRID_WALL ) return true;		// fixed objects //[MH] Adding .value since we are dealing with object now	 
 if ( GRID[i][j].value == GRID_MAZE ) return true;		//[MH] Adding .value since we are dealing with object now
	 
 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,text;
	 
	// set up GRID as 2D array
	 
	 for ( i = 0; i < gridsize ; i++ ) 
	{
		GRID[i] = new Array(gridsize);
		GRIDMIND[i] = new Array(gridsize);		 
    }

    for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ )
	    {
	    GRID[i][j] = new Spot(i, j); //[MH] Define grid position as an object
	    GRIDMIND[i][j] = new Spot(i, j); //[MH] Define grid position of Mind as an object
	    }
	
	 // All the neighbors
    for (var i = 0; i < gridsize; i++)
      for (var j = 0; j < gridsize; j++) 
        {
        GRID[i][j].addNeighbors(GRID); //[MH] Adding neigbours for each point in Grid
        GRIDMIND[i][j].addNeighbors(GRIDMIND); //[MH] Adding neigbours for each point in Mind Grid
        }
    

	// 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].value = GRID_WALL;  //[MH] Adding .value since we are dealing with object now
		    GRIDMIND[i][j].value = GRID_WALL;  //[MH] Adding .value since we are dealing with object now 		 
			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].value = GRID_BLANK;  //[MH] Adding .value since we are dealing with object now
   		    GRIDMIND[i][j].value = GRID_BLANK;  //[MH] Adding .value since we are dealing with object now
		}
 

		
   // 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].value = GRID_MAZE ; //[MH] Adding .value since we are dealing with object now
		GRIDMIND[i][j].value = GRID_MAZE ; //[MH] Adding .value since we are dealing with object now

		
		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();	
	 start = GRID[ei][ej]; //[MH] start point of A* Alogrithm is enemy position
     

	// 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(); 
	 end= GRID[ai][aj]; //[MH] End point of A* Path is Agent position
  

    // [MH] Start point of A* Algorithm
     openSet.push(start);


  // 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
	 });
 

 		
}
 
 
 


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

 //[MH] Function to draw path from Enemy to Agent with blue color
 
 function drawpath(i,j)
  {
    shape    = new THREE.BoxGeometry ( squaresize, 0, squaresize );	
    astarpath = new THREE.Mesh( shape );
    astarpath.material =  new THREE.MeshBasicMaterial( {color: 0x0000ff} );
    ABWorld.scene.add(astarpath);
    astarpath.position.copy ( translate(i,j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
    ABWorld.lookat.copy ( astarpath.position );// if camera moving, look back at where the enemy is
  }

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)
}

//[MH] Function to draw the path in Enemy path in green
function drawenemypath()
{
    shape    = new THREE.BoxGeometry ( squaresize, 0, squaresize );	
	thepath = new THREE.Mesh( shape );
    thepath.material =  new THREE.MeshBasicMaterial( {color: 0x00ff00} );
    ABWorld.scene.add(thepath);
    thepath.position.copy ( translate(previousei,previousej) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
    ABWorld.lookat.copy ( thepath.position );	 		// if camera moving, look back at where the enemy is 
}	
    
function drawagentpath()
{
    shape    = new THREE.BoxGeometry ( squaresize, 0, squaresize );			 
	theagentpath = new THREE.Mesh( shape );
    theagentpath.material =  new THREE.MeshBasicMaterial( {color: 0xff0000} );
    ABWorld.scene.add(theagentpath);
    theagentpath.position.copy ( translate(previousai,previousaj) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
    ABWorld.lookat.copy ( theagentpath.position );	 		// if camera moving, look back at where the enemy is 
}	



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

function moveLogicalEnemy()
{
    
//[MH] A* star alogrithm for Enemy
if (enemyalgorithm==2)
{

//[MH] Delete old drawn Path
for (var i=0 ; i<ariko.length;i++)
{
ABWorld.scene.remove(ariko[i]);
}    

//[MH] Clear all values for next A* Run
openSet=[];
closedSet=[];
start = GRID[ei][ej];
end= GRID[ai][aj];
openSet.push(start);

for ( i = 0; i < gridsize ; i++ )
{
    for ( j = 0; j < gridsize ; j++ )
    {
      GRID[i][j].g=0;
	  GRID[i][j].f=0;
	  GRID[i][j].h=0;
	  GRID[i][j].previou=undefined;
    }
}	  

//[MH] A* Algorithm start
while (openSet.length > 0) 
  {

    // Best next option
    var winner = 0;
    
   for (var i = 0; i < openSet.length; i++) 
      if (openSet[i].f < openSet[winner].f)  // [MH] Choose lowest cost
        winner = i;
        
    var current = openSet[winner];
    // Did I finish?
    if (current === end) 
    {
     console.log("success - found path");
     break;
    }

    // Best option moves from openSet to closedSet
    removeFromArray(openSet, current);
    closedSet.push(current); //[MH] paths explored
    // Check all the neighbors
    var neighbors = current.neighbors;

    //--- start of for loop -----------
    for (var i = 0; i < neighbors.length; i++) 
    {
      var neighbor = neighbors[i];
      // Valid next spot?
        if (!closedSet.includes(neighbor) && (neighbor.value)!==2 && (neighbor.value)!==1)  // [MH] Discard walls and mazes from being neighbors
        {
        var tempG = current.g + heuristic(neighbor, current);
        // Is this a better path than before?
        var newPath = false;
        if (openSet.includes(neighbor)) 
        {
          if (tempG < neighbor.g) 
          {
            neighbor.g = tempG;
            newPath = true;
          }
        }
        else 
        {
          neighbor.g = tempG;
          newPath = true;
          openSet.push(neighbor);
        }

        // Yes, it's a better path
        if (newPath) 
        {
          neighbor.h = heuristic(neighbor, end); //[MH] Calculate heuristic to agent
          neighbor.f = neighbor.g + neighbor.h; //[MH] Caclulate cost to agent
          neighbor.previou = current; //[MH] Save previous node to be used for drawing the path
        }
        }
    }
  }
 
 //[MH] Get shortest Path from Enemy to Agent
 
  path = [];
  var temp = current;
  path.push(temp);
  while (temp.previou) 
  {
    path.push(temp.previou);
    temp = temp.previou;
  }
  i=path[path.length-2].i;   //[MH] Lenght-2 to discard myself otherwise will not move as array first point is own location
  j=path[path.length-2].j;   //[MH] Lenght-2 to discard myself otherwise will not move
  previousei=ei;
  previousej=ej;
  
  if ( ! occupied(i,j) )  	// if no obstacle then move, else just miss a turn
    {
    ei = i;
    ej = j;
    }

// [MH] Draw Path from Enemy to Agent

   for (var f = 0; f < path.length-1; f++) 
    {
    drawpath(path[f].i,path[f].j);
    ariko.push(astarpath);  //[MH] Put each drawing object in an array so I can delete it for next run
    }
    
    
}   

//[MH] Default algorithm 
if (enemyalgorithm==1)
{
// move towards agent 
// put some randomness in so it won't get stuck with barriers 
var i, j;
if ( ei < ai ) i = AB.randomIntAtoB(ei, ei+1); 
if ( ei == ai ) i = ei;  
if ( ei > ai ) i = AB.randomIntAtoB(ei-1, ei); 

 if ( ej < aj ) j = AB.randomIntAtoB(ej, ej+1); 
 if ( ej == aj ) j = ej; 
 if ( ej > aj ) j = AB.randomIntAtoB(ej-1, ej); 
 
 if ( ! occupied(i,j) )         // if no obstacle then move, else just miss a turn
 {
  ei = i;
  ej = j;
 }
}
 
 
 //[MH] Algorithm for Enemy moving in random
 if (enemyalgorithm==3)
 {
 // very random algorithm
 var i,j;
 i=ei + AB.randomIntAtoB (-1,1);
 j=ej + AB.randomIntAtoB (-1,1);
 
 if ( ! occupied(i,j) )         // if no obstacle then move, else just miss a turn
 {
  ei = i;
  ej = j;
 }
 
}


//[MH] Algorithm for enemy moving by picking the box with the shortest distance to Agent
if (enemyalgorithm==4)
{
 var i,j;
 var z=[];
 var bfs=[];
 var min2=[];

//[MH] Calculate distance from all Enemy neighbors to Agent
if( ! occupied(ei,ej+1)) bfs[0]=Math.sqrt(Math.pow(ei-ai,2 )  + Math.pow(ej+1-aj,2)) ; else bfs[0]=5;
if( ! occupied(ei+1,ej)) bfs[1]=Math.sqrt(Math.pow(ei+1-ai,2 )  + Math.pow(ej-aj,2)) ; else bfs[1]=5;
if( ! occupied(ei,ej-1)) bfs[2]=Math.sqrt(Math.pow(ei-ai,2 )  + Math.pow(ej-1-aj,2)) ; else bfs[2]=5;
if( ! occupied(ei-1,ej)) bfs[3]=Math.sqrt(Math.pow(ei-1-ai,2 )  + Math.pow(ej-aj,2)) ; else bfs[3]=5;

//choose neighbors with min. distance to agent
var min = Math.min.apply(null, bfs);
 for (var f = 0; f < bfs.length; f++ )
 {
     if (bfs[f]==min)
     {
      min2.push(f);
     }
 }
 f= AB.randomElementOfArray ( min2 );
 console.log(fi);
 //[MH] If enemy stucked in same place , give him some random
if (fi>=2) f = AB.randomIntAtoB (0,3);

// [MH] choose next hop with minimum distance to agent
if (f==0) i=ei , j= ej+1;
if (f==1) i=ei+1 , j= ej;
if (f==2) i=ei , j= ej-1;
if (f==3) i=ei-1 , j= ej;

if ( ! occupied(i,j) )         // if no obstacle then move, else just miss a turn
 {
  ei = i;
  ej = j;
  fi=0;
 }
 else 
{
//[MH] Count if enemy is stucked for 3 rounds
 fi++  ;   
 }
}


}




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

//[MH] Action to move based on Mind (applies for default and A* Mind)
if (agentalgorithm<3)
{
      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;
 }

}


//[MH] Agent algorithm to escape from Enemy by going far and avoid being stucked by the wall
if (agentalgorithm==3)
{
// [MH] if agent got stucked , give it some random
if (fim>=2) a = AB.randomIntAtoB (0,3);

if (a==0) i=ai , j= aj+1;
if (a==1) i=ai+1 , j= aj;
if (a==2) i=ai , j= aj-1;
if (a==3) i=ai-1 , j= aj;

if ( ! occupied(i,j) )         // if no obstacle then move, else just miss a turn
 {
  ai = i;
  aj = j;
  fim=0;
 }
 else 
 {
 fim++  ;   
 }
  
} 

//[MH] When enemy leaves its positon , clear the value of its spot marking it as enemy 
GRIDMIND[ei][ej].value=0;

}




// --- 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.slice(0,4).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.slice(0,4).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()
{
//[MH] Passing more parameters to Mind to be able to build the other 2 algorithms
 var x = [ ai, aj, ei, ej , agentalgorithm , GRID[ai][aj-1].value ,GRID[ai+1][aj].value , GRID[ai-1][aj].value , GRID[ai][aj+1].value ,gridsize ,GRIDMIND]; //[MH] Giving more informaiton for the agent mind
  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();
  }




};



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 
}