JS viewer

Syntax-highlighted view of JS of World: Pokemon Chase





// Cloned by StevenMacManus on 18 Nov 2020 from World "Complex World" by Starter user 
// Please leave this clone trail here.
 



// ==== Starter World =================================================================================================
// This code is designed for use on the Ancient Brain site.
// This code may be freely copied and edited by anyone on the Ancient Brain site.
// To include a working run of this program on another site, see the "Embed code" link s 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 = false;						// Switch between 3d and 2d view (both using Three.js) 


 const TEXTURE_WALL 	= '/uploads/themacmac/Screenshot2020-11-17at09.40.42.png' ;
 const TEXTURE_MAZE 	= '/uploads/themacmac/Screenshot2020-11-17at09.40.55.png' ;
 const TEXTURE_AGENT 	= '/uploads/themacmac/Screenshot2020-11-16at17.57.44.png' ;
 const TEXTURE_ENEMY 	= '/uploads/themacmac/1605547622.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/themacmac/PokemonThemeQuiet.mp3' ;
	const SOUND_ALARM = '/uploads/themacmac/PokemonCaught.mp3' ;

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

	
	
const gridsize = 25;						// number of squares along side of world	   

const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 5);
		// 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 theagent, theenemy;
  
var wall_texture, agent_texture, enemy_texture, maze_texture; 


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

// USER CODE: start and end points----------------------------------------------
var start;
var end;

// The road taken
var path = [];

// List of holes on the board
var holelist = []

// USER CODE:Open and closed set
var openSet = [];
var closedSet = [];

// USER CODE:Loop Constant
var flag;
var Draw;

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

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;
}	
	
	
 // --- USER CODE: Simple Heuristic Function -----------
function heuristic(a,b) 
{
    a = new THREE.Vector2(a.i, a.j);
    b = new THREE.Vector2(b.i, b.j);
    dist = a.distanceTo( b );
    return (dist)
}

//--- 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].obstacle == GRID_WALL ) return true;		// fixed objects	 
 if ( GRID[i][j].obstacle == 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 )			
{
	var v = new THREE.Vector3();
	
	v.y = 0;	
	v.x = ( i * squaresize ) - ( MAXPOS/2 );   		 
	v.z = ( j * squaresize ) - ( MAXPOS/2 );   	
	
	return v;
}

// USER CODE: remove function taken from previous world ------------------------
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);
}

// USER CODE: Spot function taken from previous world and modified--------------
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;
  
  // Walls etc
  this.obstacle = 0;
  
  // Is this space a hole?
  this.hole = false;

  // 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 (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]);
  }
  
  // Am I a hole?
  this.addHoles = function(grid)
  {
    var i = this.i;
    var j = this.j;
    
    var COUNT = 0;
        
    if((grid[i + 1][j].obstacle == GRID_WALL) || (grid[i + 1][j].obstacle == GRID_MAZE)) COUNT++;
    if((grid[i - 1][j].obstacle == GRID_WALL) || (grid[i - 1][j].obstacle == GRID_MAZE)) COUNT++;
    if((grid[i][j + 1].obstacle == GRID_WALL) || (grid[i][j + 1].obstacle == GRID_MAZE)) COUNT++;
    if((grid[i][j - 1].obstacle == GRID_WALL) || (grid[i][j - 1].obstacle == GRID_MAZE)) COUNT++;
    
    if (COUNT == 3) 
    {
        this.hole = true;
        holelist.push(this)
    }
  }
  
// USER CODE: Function to remove links to previous neighbour after a move has been decided

  this.removelinks = function(grid) 
  {
      
    var i = this.i;
    var j = this.j;
    
    grid[i][j].previous = undefined;
  }

  
}

//------------------------------------------------------------------------------
	
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);	

// USER CODE: Initialise Grid as per previous World ----------------------------
		
     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);
        }

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

	// 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].obstacle = 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].obstacle = 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].obstacle = 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);		
	}
	
	// Add the holes
	
	 for ( i = 1; i < gridsize-1 ; i++ ) 
	  for ( j = 1; j < gridsize-1 ; j++ )
	  {	    
            GRID[i][j].addHoles(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;
	 

// USER CODE: Define start position --------------------------------------------
	 
	 start = GRID[ei][ej];

//------------------------------------------------------------------------------
	 
	 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;
	 
	 
// USER CODE: Define end position ----------------------------------------------

	 end     = GRID[ai][aj];

//------------------------------------------------------------------------------
 
	 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)
}

function drawPath(path)
{
    const material = new THREE.LineBasicMaterial({
	color: '#F10B0B' , linewidth: 1000});
	
	var a;
    var b;
    var geometry;
    var line;
    var points = [];
    
    for (c = path.length; c>0; c--) 
    {
        a = path[c-1].i;
        b = path[c-1].j;
        points.push(translate(a,b));
      
    }

    geometry = new THREE.BufferGeometry().setFromPoints( points );
    line = new THREE.Line( geometry, material );
    
    
  ABWorld.scene.add( line );
  
  return line;
  
}


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

function moveLogicalEnemy()
{ 

  if (Draw)
    ABWorld.scene.remove( Draw );
    
  openSet.push(start);
  console.log("Enemy is at: " + start.i + ", " + start.j);
  console.log("Agent is at: " + end.i + ", " + end.j);
  
  while(true)
  {
      
      
      
      if (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 (heuristic(current,end) == 1) 
        {
          console.log("Success - Found Shortest Path to Agent");
          flag = 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) && (!occupied(neighbor.i,neighbor.j))) 
          {
            var tempG = current.g + heuristic(neighbor, current);
    
            // Is this a better path than before?
            var newPath = false;
            if (openSet.includes(neighbor)) 
            {
              if (tempG < neighbor.g) 
              {
                neighbor.g = tempG;
                newPath = true;
              }
            }
            else 
            {
              neighbor.g = tempG;
              newPath = true;
              openSet.push(neighbor);
            }
    
            // Yes, it's a better path
            if (newPath) 
            {
              neighbor.h = heuristic(neighbor, end);
              neighbor.f = neighbor.g + neighbor.h;
              neighbor.previous = current;
            }
          }
        }
      }
        else 
      {
        console.log('fail - no path exists');
        break;
      }

}

    //Find the path by working backwards
    path = [];
    var temp = flag;
    path.push(temp);
    while (temp.previous) 
    {
        path.push(temp.previous);
        temp = temp.previous;
    }
    
    Draw = drawPath(path) 

// move towards agent 
// put some randomness in so it won't get stuck with barriers 

console.log("Now We Move");

if(path.length > 1)
{
    var nextmove = path[path.length-2];
    console.log("Next Move is: " + nextmove.i + ", " + nextmove.j)
}
else
{
     console.log("No Move: Adjacent to Agent")
}

openSet = [];
closedSet = [];
 
 if(path.length > 1)
     if ( ! occupied(nextmove.i,nextmove.j))  	// if no obstacle then move, else just miss a turn
     {
      ei = nextmove.i;
      ej = nextmove.j;
      start = GRID[ei][ej];
     }
     
 // Remove All Path Links Between Nodes
for (var i = 0; i < gridsize; i++) 
    for (var j = 0; j < gridsize; j++) 
    {
        GRID[i][j].removelinks(GRID);
    }  
 
 }

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;
  end = GRID[ai][aj];
 }
}

// --- 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();
	console.log("Agent Is Trapped, Enemy Wins")
  }

};



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 
}