Code viewer for World: Simple World

// ==== 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.
// ====================================================================================================================


// ==========================================================================
// Simple starter World 
// 3d-effect World (really a 2-D problem)
//
// Hero = agent = pacman. 
// Enemy moves randomly.
// Movement is on an invisible grid of squares 
//
// This simple World shows:
// - Texture load from files (asynchronous file reads)
// - Write status to <span> in run window
//
// It also shows functionality that is built-in to every World:
// - Camera control buttons  
// - Pause/step run
// ==========================================================================


// =============================================================================================
// Scoring:
// Bad steps = steps where enemy is within one step of agent.
// Good steps = steps where enemy is further away. 
// Score = good steps.
// =============================================================================================






// ===================================================================================================================
// === 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 TEXTURE_WALL 	= '/uploads/starter/door.jpg' ;
 const TEXTURE_AGENT 	= '/uploads/starter/pacman.jpg' ;
 const TEXTURE_ENEMY 	= '/uploads/starter/ghost.3.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


const gridsize 		= 15;							// number of squares along side of world	   
const squaresize 	= 100;							// size of square in pixels
	
const SKYCOLOR 		= 0xffffcc;						// a number, not a string 

const MAXPOS 		= gridsize * squaresize;		// length of one side in pixels 

const startRadiusConst	 	= MAXPOS * 0.8 ;		// distance from centre to start the camera at
const maxRadiusConst 		= MAXPOS * 3 ;			// maximum distance from camera we will render things  



//--- change ABWorld defaults: ----------------------------------------------

ABHandler.GROUNDZERO		= true;						// "ground" exists at altitude zero


// ===================================================================================================================
// === 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)


 

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; 

// 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();
	
	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();		 
	});
}


function asynchFinished()		 
{
	if ( wall_texture && agent_texture && enemy_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] == true ) return true;			// fixed object
 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
	// GRID = new Array(gridsize);
	// now make each element an 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] = true;		 
			shape    = new THREE.BoxGeometry ( squaresize, squaresize, 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] = false;

   
   // set up enemy 
   // start at same place every time:
   
	 ei = Math.trunc ( gridsize / 2 );		// this square will be free 
	 ej = Math.trunc ( gridsize / 2 );		// (bug) use Math.trunc or else you get a bad square number if gridsize is odd

	 shape    = new THREE.BoxGeometry ( squaresize, squaresize, squaresize );			 
	 theenemy = new THREE.Mesh( shape );
 	 theenemy.material =  new THREE.MeshBasicMaterial( { map: enemy_texture } );
	 ABWorld.scene.add(theenemy);
	 drawEnemy();		  
	
	
   // set up agent 
   // start at same place every time:
   
	 ai = Math.trunc ( gridsize / 2 ) + 1;		// this square will be free 
	 aj = Math.trunc ( gridsize / 2 ) + 1;

	 shape    = new THREE.BoxGeometry ( squaresize, squaresize, squaresize );			 
	 theagent = new THREE.Mesh( shape );
	 theagent.material =  new THREE.MeshBasicMaterial( { map: agent_texture } );
	 ABWorld.scene.add(theagent);
	 drawAgent(); 	

 
  // can start the run loop
  
	ABWorld.render();		
  
  	AB.runReady = true; 				 
}
 
 


// --- 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 moveLogicalEnemy()
{ 
// small random move

 var i = AB.randomIntAtoB ( ei-1, ei+1 );
 var j = AB.randomIntAtoB ( ej-1, ej+1 );
 
 if ( ! occupied(i,j) )  	// if no obstacle then move, else just miss a turn
 {
  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;
 }
}



// --- 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   updateStatus()		 
{
 var score = AB.world.getScore();
 AB.msg ( " Step: " + AB.step + " out of " + AB.maxSteps + ". Score: " + score ); 
}




AB.world.newRun = function() 
{
	AB.runReady = false;  

	badsteps = 0;		
	goodsteps = 0;

	ABWorld.init3d ( startRadiusConst, maxRadiusConst, SKYCOLOR  ); 

	loadResources();		// aynch file loads		
							// calls initScene() when it returns 	 
};


AB.world.getState = function()
{
	var x = [ ai, aj, ei, ej ];
	return ( x );  
};


AB.world.takeAction = function ( a )
{
  moveLogicalAgent(a);
  
  moveLogicalEnemy();

  if ( badstep() )  badsteps++;
  else   			goodsteps++;

   drawAgent();
   drawEnemy();
   updateStatus();
};



AB.world.getScore = function()
{
 return goodsteps;
};