Code viewer for World: Assignment_1_W_clone_by_Sh...

// Cloned by Sharjil Dhanani on 11 Nov 2023 from World "Assignment_1_W_clone_by_Sharjil Dhanani" by Sharjil Dhanani 
// Please leave this clone trail here.
 


// Cloned by Sharjil Dhanani on 3 Nov 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.
// =============================================================================================


 





// ===================================================================================================================
// === 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?


// Sharjil Dhanani - changed speed

AB.clockTick       = 100; //  20;    

	// Speed of run: Step every n milliseconds. Default 100.
	
AB.maxSteps        = 8000;    

	// 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) 

//Sharjil Dhanani - changed door image
 const TEXTURE_WALL 	= '/uploads/sharjil12/door_2.jpg' ; 

//Sharjil Dhanani - changed maze image
 const TEXTURE_MAZE 	= '/uploads/sharjil12/maze_3.png' ;
 
//Sharjil Dhanani - changed pacman image
 const TEXTURE_AGENT 	= '/uploads/sharjil12/pacman_2.jpg' ;

//Sharjil Dhanani - changed ghost image 
 const TEXTURE_ENEMY 	= '/uploads/sharjil12/enemy_3.png' ;

// credits:
// https://pixabay.com/photos/door-knocker-door-entry-lock-wall-7913270/
// https://pixabay.com/photos/computer-game-pac-man-nostalgia-3258455/
// https://pixabay.com/vectors/pirate-skull-crossed-bones-47705/
// https://pixabay.com/vectors/geometrical-maze-round-net-145062/

//Sharjil Dhanani - changed background music 
	const MUSIC_BACK  = '/uploads/sharjil12/Sound_2.mp4' ;
//Sharjil Dhanani - changed captured music
	const SOUND_ALARM = '/uploads/sharjil12/captured_2.mp3' ;

// credits:
// https://pixabay.com/music/trap-what-you-want-phonk-soundtrack-171335/
// https://uppbeat.io/browse/sfx/fail

	
//Sharjil Dhanani - changed gridsize

const gridsize = 40;  // 30;						// number of squares along side of world	   

//Sharjil Dhanani - changed density

const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 4 );   // 12
    // 200 
    
		// density of maze - number of internal boxes
		// (bug) use trunc or can get a non-integer 

const squaresize = 300;					// 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

// Changed background image
 const SKYBOX_ARRAY = [										 
                "/uploads/sharjil12/posx_3.jpg",
                "/uploads/sharjil12/negx_3.jpg",
                "/uploads/sharjil12/posy_3.jpg",
                "/uploads/sharjil12/negy_3.jpg",
                "/uploads/sharjil12/posz_3.jpg",
                "/uploads/sharjil12/negz_3.jpg"
                ];


// night skybox, credit:
// https://opengameart.org/content/forest-skyboxes
// 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"
                ];
*/				
//https://pixabay.com/photos/mount-st-helens-washington-state-51027/

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


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

var badsteps;
var goodsteps;


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


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

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

	
function occupied ( i, j )		// is this square occupied
{
 if ( ( ei == i ) && ( ej == j ) ) return true;		// variable objects 
 if ( ( ai == i ) && ( aj == j ) ) return true;

//  if ( GRID[i][j] == GRID_WALL ) return true;		// fixed objects	 
//  if ( GRID[i][j] == GRID_MAZE ) return true;		 
	 
 if(GRID[i][j].wall == true) 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;
}



var openSet=[];
var closedSet=[];
var start;
var end;

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


	// set up walls
	 
	 for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ ) 
		if ( ( i==0 ) || ( i==gridsize-1 ) || ( j==0 ) || ( j==gridsize-1 ) )
		{
			//GRID[i][j] = GRID_WALL;	
			GRID[i][j] = new Spot(i, j, true);	 
			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;
   	
GRID[i][j] = new Spot(i, j, false); // Leaves the i,j spot 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 ;

		GRID[i][j].wall = true;
		
		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 
    
    //also setting up in fixed position to check the steps when no boxes, few boxes and many boxes    
	 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 
    
     //also setting up in fixed position to check the steps when no boxes, few boxes and many boxes    
	 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
	 });

	  // All the neighbors
	  for (var i = 0; i < gridsize; i++) 
	  	for (var j = 0; j < gridsize; j++) 
	  		GRID[i][j].addneighbors();


	  // Start and end at random position
	  // When checking for fixed positions of enemy and agent, checking for noboxes, many boxes 
	  start     = GRID[ei][ej];
	  end       = GRID[ai][aj];
	  start.wall    = false;
	  end.wall      = false;

	  // openSet checks every posibility from start
	  openSet.push(start);
}
 
 
 


// --- 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 -----------------------------------
//Sharjil Dhanani -changed code so that enemy cannot move diagonally
// function moveLogicalEnemy(e)
// { 
// // move towards agent 
// // put some randomness in so it won't get stuck with barriers 

//  var i=ei;
//  var j=ej;
 
 
 
//  if ( ei < ai ) i++; 
//  if( ei == ai ) i = ei;
//  if ( ei > ai ) i--; 

//  if ( ej < aj ) j++; 
//  if ( ej == aj ) j = ej; 
//  if ( ej > aj ) j--;
 
//  if ( !occupied(i,j) )  	// if no obstacle then move, else just miss a turn
//  {
//   ei = i;
//   ej = j;
//  }
 
// }

// --- draw moving objects -----------------------------------
var old_path = []


/*
  A* Algorithm
  
  Referred from the following YouTube tutorial:
  Title: "A* Pathfinding Algorithm (Coding Challenge 51 - Part 1)"
  Author: TheCodingTrain
  URL: https://www.youtube.com/watch?v=aKYlikFAV4k&list=PLRqwX-V7Uu6YJ3XfHhT2Mm4Y5I99nrIKX&index=11
*/
class Spot{
	constructor(i, j, wall){
		this.i = i;
		this.j = j;
		this.f = 0;
		this.g = 0;
		this.h = 0;
		this.neighbors = [];
		
		this.previous = undefined;
		
		this.wall = wall;
	}

	checkWall(){
		return this.wall;
	}



  //  drawing the paths on screen
  display() 
  {
      //shape of path
  	var geometry    = new THREE.CylinderGeometry( 60, 60, 35, 32 );	
  	//color and shape of path
  	var material =    new THREE.MeshBasicMaterial( { color: 0xFFFF00} );
  	this.shapes=  new THREE.Mesh( geometry, material );
  	
  	this.shapes.position.copy(translate(this.i, this.j));
  	
  	
  	ABWorld.scene.add(this.shapes);
  }
// geometry shape reference: https://threejs.org/docs/#api/en/geometries/CylinderGeometry
  
//removing path after each step
  removePath()
  {
  	if (this.shapes) {
    ABWorld.scene.remove(this.shapes);
    this.shapes = undefined;
  }
  }
  

  
  addneighbors()
  {
  	var i = this.i;
  	var j = this.j;
  	
  		if (i < gridsize - 1 && !GRID[i + 1][j].wall) this.neighbors.push(GRID[i + 1][j]);
  		
  		if (i > 0 && !GRID[i - 1][j].wall) this.neighbors.push(GRID[i - 1][j]);
  		
  		if (j < gridsize - 1 && !GRID[i][j + 1].wall)  this.neighbors.push(GRID[i][j + 1]);
  		
  		if (j > 0 && !GRID[i][j - 1].wall) this.neighbors.push(GRID[i][j - 1]);
  }
}
// Removes an element 'elt' from 'arr'
function removeFromArray(arr, elt) 
{
  for (var i = arr.length - 1; i >= 0; i--) 
  	if (arr[i] == elt) 
  		arr.splice(i, 1);
  }

// Heuristic function to estimate the cost from node 'a' to node 'b'

function heuristic(a, b) 
{   //Euclidian distance
    //return (Math.sqrt(Math.pow(a.i-b.i,2) + Math.pow(a.j-b.j,2)));
    //Manhattan distance
	return ( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
	
	//bad h function
	//return 10;
	//return -4;
	//bfs
	//return 0;
	
	
}
// Resets parameters for each node in the grid
function resetFunctions()
{
for (var i = 0; i < gridsize; i++) 

	for (var j = 0; j < gridsize; j++) 
	
		if(!GRID[i][j].wall){
		    
  		GRID[i][j].f = 0;
  		GRID[i][j].g = 0;
  		GRID[i][j].h = 0;
  		
  		GRID[i][j].previous = undefined;
		}
}
var statesSearchedCount = 0;



function moveLogicalEnemy()
{ 

// Initialize starting and ending points for the pathfinding algorithm
let start = GRID[ei][ej];
let end = GRID[ai][aj];
resetFunctions();  // Reset some parameters for pathfinding

for (var i = 0; i < old_path.length; i++){
	old_path[i].removePath();  // Remove previous path drawing shapes
	
} 



openSet = [start];  // set of nodes to be evaluated - h
//console.log("start",start)
closedSet = []; // set of nodes already evaluated - g


var current = null;


let path = [];  //final path


 // A* Pathfinding algorithm

while(openSet.length > 0){
	// Finding node with the lowest cost in the openSet
	
	if (openSet.length > 0) 
	{

    
    
    var win = 0;
    for (var i = 0; i < openSet.length; i++)
    //console.log("openset[i].f",openSet[i].f)
    //console.log("openset[win].f",openSet[win].f)
    	if (openSet[i].f < openSet[win].f) 
    	
    		win = i;
    	
    	var current = openSet[win];
    	

    
    
    if (current === end) 
    {
    
        // End the loop when the destination is reached
    	break;    
    }

    
    removeFromArray(openSet, current);
    closedSet.push(current);

    
    var neighbors = current.neighbors;
    
    
    // Explore neighboring nodes
    
    for (var i = 0; i < neighbors.length; i++) 
    {
    	var neighbor = neighbors[i];

      
      if (!closedSet.includes(neighbor) && !neighbor.checkWall()) 
      {
      	var tempG = current.g + heuristic(neighbor, current);

        
        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);
        }

        
        if (newPath) 
        {
        	
        	neighbor.h = heuristic(neighbor, end);
        	
        	//neighbor.f = neighbor.g + neighbor.h;
        	neighbor.f = neighbor.g + neighbor.h;
        	
        	neighbor.previous = current;
        }
      }
    }
    
    
  }
  
  else 
  {
  	// No path found
  	return;
  }
}
statesSearchedCount=openSet.length+closedSet.length;
//console.log("openset",openSet)
//console.log("closedSet",closedSet)
console.log("A* bfs walls",statesSearchedCount);
var temp = current;

path.push(temp);
while (temp && temp.previous) 
{
	path.push(temp.previous);
	
	temp = temp.previous;
}

old_path = path

// Draw the new path
for (var i = 0; i < path.length; i++){
    
	path[i].display();

} 


// Move the enemy to the next step in the path
if(path.length > 2)
{
	i = path[path.length - 2].i;
	j = path[path.length - 2].j;
}
else
{
	i = ei;
	j = ej;
}
 // Move the enemy if the next square is not occupied
 if ( ! occupied(i,j) )
 {
 	
 	ei = i;
 	ej = j;
 }
}




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; States Searched: " + statesSearchedCount, 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 
}