Code viewer for World: Adrian's A* Assignment
 // Cloned by Adrian Sweeney on 29 Oct 2019 from World "Complex World" by Starter user 
 // Please leave this clone trail here.
 
 // Check out my World, which now has cool glow effects!
 // View the console and you can see it runs and how it outputs logs during run
 
 AB.clockTick       = 100;   
 AB.maxSteps        = 1000;    
 AB.screenshotStep  = 50;   

 // Global Constants
 const show3d = true;
 const TEXTURE_WALL 	= '/uploads/ajsweeney/blueglow.png' ;
 const TEXTURE_MAZE 	= '/uploads/ajsweeney/pinkglow.png' ;
 const TEXTURE_AGENT 	= '/uploads/ajsweeney/agentglow.png' ;
 const TEXTURE_ENEMY 	= '/uploads/ajsweeney/enemyglow.png' ;

 const MUSIC_BACK  = '/uploads/starter/Defense.Line.mp3' ;
 const SOUND_ALARM = '/uploads/starter/air.horn.mp3' ;
 const gridsize = 20;   
 const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 10 );

 // size of square in pixels
 const squaresize = 100;		
 
 // length of one side in pixels 
 const MAXPOS = gridsize * squaresize;	
 
 // a number, not a string
 const SKYCOLOR 	= 0xddffdd;				

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

 // ABWorld Defaults
 ABHandler.MAXCAMERAPOS 	= maxRadiusConst ;
 ABHandler.GROUNDZERO		= true;		
 
 // "ground" exists at altitude zero
 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"
                ];


 // 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;


 // Contents of Grid
 const GRID_BLANK 	= 0;
 const GRID_WALL 	= 1;
 const GRID_MAZE 	= 2;

 // 3d or 2d box height
 var BOXHEIGHT;		 
 
 // can query GRID about whether squares are occupied, will in fact be initialised as a 2D array 
 var GRID 	= new Array(gridsize);			  
 var openList = [];
 var closedList = [];
 var start;
 var end;

 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;

 var path = [];
 var pathlength; 
 var previouslength = 0;
 var fullPathFound = false;
 var pathRun = 0;

 // Heuristic function
 function heuristic(a, b) 
 {
   var first = a.i - b.i;
   var second = a.j - b.j;
   
   if ( diagonal ) return ( Math.sqrt( first*first + second*second))
   console.log('Heuristic function calculaution is: ' + Math.sqrt( first*first + second*second));
}

 // Spot function
 function Spot(i, j, type) 
 {
  // Location
  this.i = i;
  this.j = j;

  // f, g, and h values for A* algorith
  this.f = 0;
  this.g = 0;
  this.h = 0;
  
  // Type of grid position (grid/wall/blank)
  this.type = type;

  // Neighbors
  this.neighbors = [];

  // Where did I come from?
  this.previous = 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]);
    
    if (diagonal)
    // diagonals are also neighbours:
    {
        if (i > 0 && j > 0)                 this.neighbors.push(GRID[i - 1][j - 1]);
        if (i < gridsize - 1 && j > 0)          this.neighbors.push(GRID[i + 1][j - 1]);
        if (i > 0 && j < gridsize - 1)          this.neighbors.push(GRID[i - 1][j + 1]);
        if (i < gridsize - 1 && j < gridsize - 1)   this.neighbors.push(GRID[i + 1][j + 1]);
    }
    
  }
  
 }


 // Function to delete element from array
 function removeFromArray(arr, elt) 
 {
  for (var i = arr.length - 1; i >= 0; i--) {
      if (arr[i] == elt) {
          arr.splice(i, 1);
      }
      
  }
    
 }

 function searchNew(openList,start,end) 
 // search continues over timesteps
 {
  if (openList.length > 0) 
  {
    console.log('Start of searchNew function');
    
    // Best next option
    var winner = 0;
    
    for (var i = 0; i < openList.length; i++) {
        if (openList[i].f < openList[winner].f) {
           winner = i; 
        }
    }
     
    var current= openList[winner];

    console.log('after current assignment to openList[winner] j is ' + current.j + current.type + current.i + 'end j and i' + end.j + end.i );
    // Did I finish?
    if (current == end) 
    {
        console.log("success - found path");

    }
    else
    {
        console.log("path not yet found");
    }

    // Best option to closedset
    removeFromArray(openList, current);
    closedList.push(current);
    console.log('No. of items in closedList is:' + closedList.length);

    // Check all the neighbors
    var neighbors = current.neighbors;
    
    
    // Start of for loop
    for (i = 0; i < neighbors.length; i++) 
    {
      console.log('neighbors.length is: ' + neighbors.length);
      var neighbor = neighbors[i];

      // Valid next spot?
      if (!closedList.includes(neighbor) && neighbor.type!=GRID_WALL && neighbor.type!=GRID_MAZE && neighbor.type!=GRID_MAZE) 
      {
        var tempG = current.g + heuristic(neighbor, current);
        console.log('tempG value is: ' + tempG );

        // Is this a better path on this loop?
        var newPath = false;
        if (openList.includes(neighbor)) 
        {
          if (tempG < neighbor.g) 
          {
            neighbor.g = tempG;
            newPath = true;
          }
        }
        else 
        {
          console.log('Neighbor is not in the openList: ' + neighbor.i );
          neighbor.g = tempG;
          newPath = true;
          openList.push(neighbor);
          console.log('openList length is: ' + openList.length );
        }

        // Yes, it's a better path
        if (newPath) 
        {
          console.log('newPath is true');
          neighbor.h = heuristic(neighbor, end);
          neighbor.f = neighbor.g + neighbor.h;
          neighbor.previous = current;
          console.log('neighbor h value is: '+ neighbor.h );
          console.log('neighbor f value is: '+ neighbor.f );
        }
      }
    }
  }
  else 
  {
    console.log('No path exists');
    //noLoop();
    return;
  }

  // Find the path by working backwards
  path = [];
  var temp = current;
  path.push(temp);
  while (temp.previous) 
  {
    console.log('Finding path.....');
    path.push(temp.previous);
    temp = temp.previous;
  }
  pathlength = path.length;
  
  if (current.i == end.i && current.j == end.j)
  {
      fullPathFound = true;
      console.log('full path length: ' + path.length ); 
  }
  
   /* if (diagonal)
    {
      // path as continuous line
      noFill();
      stroke(pathcolor);
      strokeWeight(w / 8);
      beginShape();
      for (i = 0; i < path.length; i++) 
            vertex (    (path[i].i * w) + w / 2,     (path[i].j * h) + h / 2   );
      endShape();
    }
    else 
    {
        // path as solid blocks 
       for (i = 0; i < path.length; i++) 
         path[i].show(pathcolor);
    }*/

}


 //Function to load files
 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 all file loads have returned 
		if ( asynchFinished() )	initScene();		
	});
		
	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();		 
	});
	
 }


 // all file loads returned 
 function asynchFinished()		 
 {
	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 )		
 {
 // Variable objects 
 if ( ( ei == i ) && ( ej == j ) ) return true;		
 if ( ( ai == i ) && ( aj == j ) ) return true;

 // Fixed objects
 if ( GRID[i][j].type == GRID_WALL ) return true;			 
 if ( GRID[i][j].type == GRID_MAZE ) return true;		 
	 
 return false;
 }


 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;
 }

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

			shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
			thecube  = new THREE.Mesh( shape );
			thecube.material = new THREE.MeshBasicMaterial( { map: wall_texture } );
			
			// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates
			thecube.position.copy ( translate(i,j) ); 		  	 
			ABWorld.scene.add(thecube);
		}
		else 
		{
		    GRID[i][j] = new Spot(i,j,GRID_BLANK);
		}
   
   // set up maze 
   for ( var c=1 ; c <= NOBOXES ; c++ )
	{
	    // inner squares are 1 to gridsize-2
		i = AB.randomIntAtoB(1,gridsize-2);		
		j = AB.randomIntAtoB(1,gridsize-2);
		
		GRID[i][j] = new Spot(i,j,GRID_MAZE);

		shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
		thecube  = new THREE.Mesh( shape );
		thecube.material = new THREE.MeshBasicMaterial( { map: maze_texture } );		  

        // translate my (i,j) grid coordinates to three.js (x,y,z) coordinates
		thecube.position.copy ( translate(i,j) ); 		  	 
		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;
	 
	for ( i = 0; i < gridsize; i++) {
        for (j = 0; j < gridsize; j++) {
           GRID[i][j].addNeighbors(GRID); 
        }
	}

	 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(); 

    // Setting start and end grid positions
    start = GRID[ai][aj]; 
    end= GRID[ei][ej];
    
    openList.push(start);

    //searchNew(openList,start,end); 
    
    /*while (!fullPathFound){
       searchNew(openList,start,end);
    }*/
  
  // Draw skybox
  ABWorld.scene.background = new THREE.CubeTextureLoader().load ( SKYBOX_ARRAY, 	function() 
	 { 
		ABWorld.render(); 
	 
		AB.removeLoading();
		
	    // start the run loop
		AB.runReady = true; 		
	 });
 
 }
 
 // Draw moving objects
 // Draw enemy function
 function drawEnemy()		
 {
    // translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
	theenemy.position.copy ( translate(ei,ej) ); 		  	

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


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

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


 // Enemy move function
 function moveLogicalEnemy()
 { 
    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 no obstacle then move, else just miss a turn PROBLEM - IF NEXT BEST MOVE IS AN OBSTACLE IT STOPS
    //if ( ! occupied(i,j) )  	
    {
        ei = i;
        ej = j;
    }
 
 }


 // Function to move the Agent
 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) ) 
    {
    ai = i;
    aj = j;
    }
 }

 // Agent move function
 function newMoveAgent(list){
   var i = list.i;
   var j = list.j;
   
   if ( ! occupied(i,j) ) 
     {
      ai = i;
      aj = j;
     } 
 }


 //Key Handling

 // 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; 		

    // 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;
 } 


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

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


 function updateStatusBefore(a)
 {
 var x 		= AB.world.getState();
 AB.msg ( " Step: " + AB.step + " &nbsp; x = (" + x.toString() + ") &nbsp; a = (" + a + ") " ); 
 }


 // Function to update score after move
 function   updateStatusAfter()	
 {
 // 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 ); 
 }


 // Function for new run
 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;	
		 
 };


 // Function to get state of world
 AB.world.getState = function()
 {
 var x = [ ai, aj, ei, ej ];
  return ( x );  
 };


 // Function to take Action if Agent gets trapped CHECK HERE
 AB.world.takeAction = function ( a )
 {
  // show status line before moves 
  updateStatusBefore(a);			

  // New functions to move loop A* and move enemy one space PROBLEM IS HERE
  searchNew(openList,start,end);
  newMoveAgent(path[pathlength-1]);
  
  start.i = ai;
  start.j = aj;
  
  moveLogicalEnemy();
  
  end.i = ei;
  end.j = ej;
  
  
  /*if (pathlength>=0){
      if ( ( AB.step % 2 ) == 0 )	{
          newMoveAgent(path[pathlength-1]);
          pathlength--;
      }
       
  }*/
  
  /*for (var i=path.length-1; i>0; i--){
      if ( ( AB.step % 2 ) == 0 )	{
          newMoveAgent(path[i]);
      }
  }*/
  
 /* if (pathlength > previouslength) 
  {
      previouslength = pathlength;
      searchNew(openList,start,end); 
  }
  else{

  }*/
    

  moveLogicalAgent(a); 
  

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


  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();
  }

 };


 // Function to End Run
 AB.world.endRun = function()
 {
  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  );
 };


 // Function to get Score
 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;    
    var x = Math.round (s * 100);                
    return ( x / 100 );                          
 };


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