Code viewer for World: Complex World (2020-C686I:...

// Cloned by Andrey Totev on 20 Oct 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/atotev/stone.png' ;
 const TEXTURE_MAZE 	= '/uploads/atotev/timber.png' ;
 const TEXTURE_AGENT 	= '/uploads/atotev/spot-centaur3.png' ;
 const TEXTURE_ENEMY 	= '/uploads/atotev/zeus2.png' ;
 const TEXTURE_TILE 	= '/uploads/atotev/tile.png' ;
 const TEXTURE_TILE_OPEN 	= '/uploads/atotev/tile-open.png' ;
 const TEXTURE_TILE_CLOSED 	= '/uploads/atotev/tile-closed.png' ;
 const TEXTURE_TILE_PATH 	= '/uploads/atotev/tile-path2.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 );
		// 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/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 GRID_TILES = new Array(gridsize)        // AGT:holds three types of floor tiles

var theagent, theenemy;
  
var wall_texture, agent_texture, enemy_texture, maze_texture, tile_texture, tile_open_texture, tile_closed_texture, tile_path_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();
	var loader5 = new THREE.TextureLoader();
	var loader6 = new THREE.TextureLoader();
	var loader7 = new THREE.TextureLoader();
	var loader8 = 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();		 
	});
	
	loader5.load ( TEXTURE_TILE, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		tile_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	loader6.load ( TEXTURE_TILE_OPEN, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		tile_open_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	loader7.load ( TEXTURE_TILE_CLOSED, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		tile_closed_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	loader8.load ( TEXTURE_TILE_PATH, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		tile_path_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
}


function asynchFinished()		 // all file loads returned 
{
	if ( wall_texture && agent_texture && enemy_texture && maze_texture && tile_texture && tile_open_texture && tile_closed_texture && tile_path_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, k )			
{
	var v = new THREE.Vector3();
	
	v.y = !!k ? -squaresize/2-1 : 0; // AGT:tiles are one pixel thick each
	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);
		GRID_TILES[i] = new Array(gridsize);
	 }
		

	 // AGT:create all tiles
     // AGT:lay down the regular ones
	 for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ ) 
        {
            GRID_TILES[i][j] = new Array(4);
            
        	shape    = new THREE.BoxGeometry ( squaresize, 1, squaresize );			 
        	thecube  = new THREE.Mesh( shape );
        	thecube.material = new THREE.MeshBasicMaterial( { map: tile_texture } );
        	thecube.position.copy ( translate(i,j,true) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
        	GRID_TILES[i][j][0] = thecube;
        	
        	shape    = new THREE.BoxGeometry ( squaresize, 1, squaresize );			 
        	thecube  = new THREE.Mesh( shape );
        	thecube.material = new THREE.MeshBasicMaterial( { map: tile_open_texture } );
        	thecube.position.copy ( translate(i,j,true) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
        	GRID_TILES[i][j][1] = thecube;
        	
        	shape    = new THREE.BoxGeometry ( squaresize, 1, squaresize );			 
        	thecube  = new THREE.Mesh( shape );
        	thecube.material = new THREE.MeshBasicMaterial( { map: tile_closed_texture } );
        	thecube.position.copy ( translate(i,j,true) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
        	GRID_TILES[i][j][2] = thecube;
        	
        	shape    = new THREE.BoxGeometry ( squaresize, 1, squaresize );			 
        	thecube  = new THREE.Mesh( shape );
        	thecube.material = new THREE.MeshBasicMaterial( { map: tile_path_texture } );
        	thecube.position.copy ( translate(i,j,true) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
        	GRID_TILES[i][j][3] = thecube;
        	
        	ABWorld.scene.add(GRID_TILES[i][j][0]);
        }
		
	// 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
	 });
 		
}
 
 
 


// --- 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 -----------------------------------

// AGT:BEGIN
// AGT:The final state of the A* algorithm is visualised by adding tint to all visited tiles
// AGT:0-unvisited: yellow, 1-open: green, 2-closed: red, 3-shortest path: special tint

function moveLogicalEnemy()
{
    runAStar();
}

// AGT:only show a particular type of TILE: 0-regular, 1-open, 2-closed, 3-path
function showTile(i, j, show) {
    for ( hide = 0; hide < 4 ; hide++ ) 
    {
      ABWorld.scene.remove(GRID_TILES[i][j][hide]);
    }
    ABWorld.scene.add(GRID_TILES[i][j][show]);
}

// AGT: A spot on the grid along with a list of neighbours,
// AGT: previous spot in the path, and isWall atribute
function Spot(i, j) 
{
    // Location
    this.i = i;
    this.j = j;
    
    // f, g, and h values for A*
    this.f = 0;
    this.g = 0;
    this.h = 0;
    
    // Neighbors
    this.neighbors = [];
    
    // Where did I come from?
    this.previous = undefined;
    
    this.wall = (GRID[i][j] !== GRID_BLANK);

    // 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 (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 heuristic( a, b ) {
    return ( Math.sqrt(Math.pow((a.i-b.i), 2) + Math.pow((a.j-b.j), 2)) );
}

// Function to delete element from the 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);
}

function runAStar() {
  	// AGT:clean up the floor
	 for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ ) 
        {
            showTile(i, j, 0);
        }
        
    
    var grid = [];
    
    // Making a 2D array
    for (var i = 0; i < gridsize; i++) 
        grid[i] = new Array(gridsize);
    
    for (var i = 0; i < gridsize; i++) 
        for (var j = 0; j < gridsize; j++) 
            grid[i][j] = new Spot(i, j);
    
    // All the neighbors
    for (var i = 0; i < gridsize; i++) 
        for (var j = 0; j < gridsize; j++) 
            grid[i][j].addNeighbors(grid);

    // Open and closed set
    var openSet = [];
    var closedSet = [];
    openSet.push(grid[ei][ej]);
    
    // AGT:While more open tiles are left to visit and agent is not found
    var agentSpot = undefined;
    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) 
            winner = i;
            
        var current = openSet[winner];
        
        // Did I finish?
        if (current.i === ai && current.j === aj) 
        {
          agentSpot = current;
          break;
        }

        // Best option moves from openSet to closedSet
        removeFromArray(openSet, current);
        closedSet.push(current);
    
        // 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.wall) 
          {
            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, grid[ai][aj]);
              neighbor.f = neighbor.g + neighbor.h;
              neighbor.previous = current;
            }
          }
        }
    }
    
	// mark open tiles
	 for ( i = 0; i < openSet.length ; i++ ) {
	     showTile(openSet[i].i, openSet[i].j, 1);
    }
	// mark closed tiles
	 for ( i = 0; i < closedSet.length ; i++ ) {
	    showTile(closedSet[i].i, closedSet[i].j, 2);
    }
        
    if (agentSpot) {
        if (agentSpot.previous!==grid[ei][ej]) 
        {
        	// AGT: Trace back the path to the first move and use that.
            var nextSpot = undefined;
            var temp = agentSpot;
            while (temp.previous) 
            {
                nextSpot = temp;
                temp = temp.previous;
                showTile(nextSpot.i, nextSpot.j, 3);
            }
            ei = nextSpot.i;
            ej = nextSpot.j;
        }
        else
        {
            /*
            	AGT:
                "Trapping" works by Enemy standing beside Agent while Agent
                is in a hole. That is, Enemy cannot trap Agent by standing
                diagonally to it. Therefore, the final move of the agent needs
                to be right next to one of Agent's sides.
            */
            var i, j;
            
            /*
            	AGT:
                "Intimidation" tactic -
                Enemy always moves next to Agent as this is how "trapping"
                works. This implementation mostly leads to low-score run-overs
                as Agent cannot move diagonally.
            */
            // if ( ei < ai ) i = ei+1;
            // if ( ei == ai ) i = ei; 
            // if ( ei > ai ) i = ei-1;
            
            // if ( ej < aj ) j = ej+1;
            // if ( ej == aj ) j = ej; 
            // if ( ej > aj ) j = ej-1;
            
            /*
            	AGT:
                Leeway tactic -
                Without utilising *any* knowledge about the surroundings,
                with just some stochasticity, Enemy is occasionally letting
                Agent to move past. This allows the game to move to other
                parts of the grid and increases the chances of Agent entering
                a hole.
            */
            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;
            }
        }
    }
}
// AGT:END

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 + ") " ); 
}


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;

	
	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();
  }

};



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 
}