Code viewer [Ancient Brain]

Code viewer for World: Practical A* - Rajasi
// ==== 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; // 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/rajasi/Screenshot2022-11-11at10.15.41PM.png' ;
 const TEXTURE_MAZE 	= '/uploads/rajasi/Screenshot2022-11-11at10.19.41PM.png' ;
 const TEXTURE_AGENT 	= '/uploads/rajasi/1668273550.png' ;
 const TEXTURE_ENEMY 	= '/uploads/rajasi/Batman1.png' ;
// credits:

//RC : joker https://www.pinterest.com/pin/528258231263446011/
//RC : batman https://www.pinterest.com/pin/how-to-draw-batmans-head--810296157935326268/

//https://stock.adobe.com/nl/images/arrangement-of-beautiful-shiny-black-golden-brick-wall-high-contrast-background-dark-yellow-gold-foil-texture-background-square-brick-wall-decorated-with-golden-high-light-painting/243842799
//https://www.dreamstime.com/gold-brick-wall-texture-brick-wall-background-gold-brick-wall-texture-brick-wall-background-goldenbrick-wall-interior-image144138696
// 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

 //RC : Credits https://www.zedge.net/
	const MUSIC_BACK  = '/uploads/rajasi/batman2_1.mp3' ;
	const SOUND_ALARM = '/uploads/rajasi/Winning.mp3' ;

// credits:
// http://www.dl-sounds.com/royalty-free/defense-line/
// http://soundbible.com/1542-Air-Horn.html 

	
	
const gridsize = 20; // 20;						// 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
///uploads/starter/dawnmountain-xpos.png

//RC : https://www.pngwing.com/en/free-png-kfuqd
 const SKYBOX_ARRAY = [										 
                "/uploads/rajasi/xpos.png",
                "/uploads/rajasi/xneg.png",
                "/uploads/rajasi/ypos.png",
                "/uploads/rajasi/yneg.png",
                "/uploads/rajasi/zpos.png",
                "/uploads/rajasi/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 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].isWall ) return true;		// fixed objects	 
 if ( GRID[i][j].isMaze ) return true;		 
	 
 return false;
}

 
// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates
// logically, coordinates are: y=0, x and z all positive (no negative)    
// logically my dimensions are all positive 0 to MAXPOS
// to centre everything on origin, subtract (MAXPOS/2) from all dimensions 

function translate ( i, j )			
{
	var v = new THREE.Vector3();
	
	v.y = 0;	
	v.x = ( i * squaresize ) - ( MAXPOS/2 );   		 
	v.z = ( j * squaresize ) - ( MAXPOS/2 );   	
	
	return v;
}



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


	// set up 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);		
	}
	 
	// RC : Making all points in the grid object of Spot and assigning the blank,maze,wall status according to variables. 
	for ( i = 0; i < gridsize ; i++ ){ 
	  for ( j = 0; j < gridsize ; j++ ) {
	      
	     if(GRID[i][j] == GRID_WALL){
	        GRID[i][j] = new Spot(i,j);
	        GRID[i][j].isWall = true;
	      }
	      
	      if(GRID[i][j] == GRID_MAZE){
	        GRID[i][j] = new Spot(i,j);
	        GRID[i][j].isMaze = true;
	      } 
	      
	      if(GRID[i][j] == GRID_BLANK){
	        GRID[i][j] = new Spot(i,j);
	        GRID[i][j].isBlank = true;
	      }
	      
	      
	  }
    }
    
    //RC : Adding Neighbours for each Spot
    for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ )
	          GRID[i][j].addNeighbours(GRID);	 
    
    
	// 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 -----------------------------------
function Spot(i,j){
    
    this.x = i;
    this.y = j;
    
    //RC : To evaluate the A* heuristic function
    this.h = 0;
    this.g = 0;
    this.f = 0;
    
    //RC : To keep track of all neighbours for particular point
    this.neighbours = [];
    
    this.isWall = false;
    this.isMaze = false;
    this.isBlank = false;
    
    //RC : To keep track of the previous spot before the current spot
    this.previous= undefined;
    
    this.addNeighbours = function(GRID) 
    {
        var xi = this.x;
        var yj = this.y;
    
        if (xi < gridsize - 1)
            this.neighbours.push(GRID[xi + 1][yj]);
        if (xi > 0)          
            this.neighbours.push(GRID[xi - 1][yj]);
        if (yj < gridsize - 1)   
            this.neighbours.push(GRID[xi][yj + 1]);
        if (yj > 0)          
            this.neighbours.push(GRID[xi][yj - 1]);
    
    }
}


function heuristic ( a, b ) 
{
    /*if ( diagonal ) return ( dist(a.i, a.j, b.i, b.j) );

        // 2D distance
        // dist is a P5 function 

    else   */         return ( Math.abs(a.x - b.x) + Math.abs(a.y - b.y) );

}

function gfn ( a, b ) 
{
    /*if ( diagonal ) return ( dist(a.i, a.j, b.i, b.j) );            // 2D distance

    else*/            return ( Math.abs(a.x - b.x) + Math.abs(a.y - b.y) );     // else go across and down 
}

function removeFromArray(array,element){
    for(var i=array.length-1;i>=0;i--){
        if(array[i] == element) {
            array.splice(i,1);
        }
    }
}

//RC : To show the best path for the enemy
function highlightPath(path) {
    for (var t = 0; t < path.length - 1; t++) {
        var show = path[t];
        shape    = new THREE.BoxGeometry ( squaresize, 0, squaresize );			 
    	thePath  = new THREE.Mesh( shape );
    	thePath.material = new THREE.MeshBasicMaterial( { color: 'blue' } );		  
        
        ABWorld.scene.add(thePath);
    	thePath.position.copy ( translate(show.x,show.y) );  
    	ABWorld.lookat.copy(thePath.position); 	
    	shownPath.push(thePath);
    	
    }
}

var shownPath = [];
var path = [];

function moveLogicalEnemy()
{ 
    
    console.log("Start of Logical enemy");
    
    //RC : to remove the existing path and show new path towards the agent
    for (var i = 0; i < shownPath.length ; i++ ) {
        ABWorld.scene.remove(shownPath[i]);
    }
    
    var closedSet = []; //RC : Keep track of already evaluated spots
    var openSet = [];   //RC : Keep track of paths yet to be evaluated 

    //RC : Intialising the heuristics and previous again after every enemy move
    for (var i = 0; i < gridsize ; i++ ){ 
	  for (var j = 0; j < gridsize ; j++ ) {
	      GRID[i][j].f=0;
	      GRID[i][j].g=0;
	      GRID[i][j].h=0;
	      GRID[i][j].previous=undefined;
	      
	  }
    }
    
    var start=GRID[ei][ej];
    var goal=GRID[ai][aj];
    
    openSet.push(start);

    //RC : Loop till all spots possible towards the agent are evaluated
    while(openSet.length > 0){
        var winner=0;

        //RC : To pickup the next spot to evaluate with lowest score
        for( var i = 0;i < openSet.length; i++){
            if(openSet[i].f < openSet[winner].f)
                winner=i;
        }
        var current= openSet[winner];
        
        //RC : If you have reached goal spot, break out of the loop
        if(current == goal){
            console.log("AGENT TRAPPED!!"+"Current cordinates"+current.x+" : "+current.y);
            break;
        }
    
        removeFromArray(openSet,current);
        closedSet.push(current);
        var neighbours  = current.neighbours;
        for( i = 0; i< neighbours.length; i++ ) {
            var evaluateNeighbour = neighbours[i];
            var tentative_g=0;
            
            //RC : The neighbour spot is not already evaluated and the spot is not wall or Maze
            if(!closedSet.includes(evaluateNeighbour) && !(evaluateNeighbour.isWall) && !(evaluateNeighbour.isMaze) ){
                tentative_g = current.g +  gfn ( evaluateNeighbour, current ); 
    
                //RC :If the spot is already evaluated and if its current 'g' value is less than previous 'g', if not do not update
                var newPath=false;
                if(openSet.includes(evaluateNeighbour)){
                    if(tentative_g < evaluateNeighbour.g){
                        evaluateNeighbour.g = tentative_g;
                        newPath=true;
                    }
                }else{
            
                    //RC : Evaluating this spot first time ever
                    evaluateNeighbour.g = tentative_g;
                    openSet.push(evaluateNeighbour);
                    newPath=true;
                }
                
                //RC : If its best spot then calculate heuristics and attach the current spot as previous for this neighbour 
                if(newPath){
                    evaluateNeighbour.h = heuristic(evaluateNeighbour,goal);
                    evaluateNeighbour.f = evaluateNeighbour.g + evaluateNeighbour.h;
                    evaluateNeighbour.previous = current;
    
                }
            }
        }
    }
    
    //RC : To backtrack the best path from agent to enemy
    path =[];
    var trace = current;
    while(trace.previous){
        path.push(trace.previous);
        trace = trace.previous;
    }
    
    //RC : To show the path in maze
    highlightPath(path);
       
         
    var tlength= path.length-2; //RC : The last spot is where enemy is and the second last is where the enemy should move
    var newei=path[tlength].x;
    var newej=path[tlength].y;
    
    //RC : Check if the new spot calculated in not occupied else, miss a turn
    if (!occupied(newei, newej)) 
    {
        ei = newei;
        ej = newej;
        //console.log("Pointa New points : "+ei +": "+ej);
    }
}


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> Joker 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 
}