Code viewer for World: Complex World a* (clone by...

// Cloned by Abdelshafa Abdala on 7 Nov 2021 from World "Complex World a*" by Brendan 
// Please leave this clone trail here.
 
// Cloned by Brendan on 28 Oct 2019 from World "Complex World" by Starter user
// Please leave this clone trail here.

/**
// MCM Foundations of AI
// Stucent Name: Brendan Bonner
// Code Submission for A* assignment

// Description: AB Starter World with addtional functions whenever the logicalMoveEnemy() function is called.
// The A* function uses a standalone grid made up of objects containg the A data elements, includeing the hueristic,
// distance, whether diagonal avaiable or not and the parent.

// The sets are managed by a sorted array containing the open set, while the closed set is based on a flag
// in the A* array.
// The  visuals and the sound have been replaced by blue boxes and a click that gets slightly louder and faster
// when the enemy and agent are close to each other.
**/

// ==== Starter World ===============================================================================================
// (c) Ancient Brain Ltd. All rights reserved.
// This code is only for use on the Ancient Brain site.
// This code may be freely copied and edited by anyone on the Ancient Brain site.
// This code may not be copied, re-published or used on any other website.
// To include a run of this code on another website, see the "Embed code" links provided on the Ancient Brain site.
// ==================================================================================================================

// =============================================================================================
// 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/brendanb/box_tron1.jpg';
const TEXTURE_MAZE = '/uploads/brendanb/box_tron1.jpg';
const TEXTURE_AGENT = '/uploads/brendanb/pacload.png';
const TEXTURE_ENEMY = '/uploads/starter/ghost.3.png';
//const TEXTURE_ENEMY = '/uploads/brendan/1570456293.png';

const gridsize = 20; // number of squares along side of world NB: Pacman was 28

const NOBOXES = Math.trunc((gridsize * gridsize) / 10);
// density of maze - number of internal boxes
// (bug) use trunc or can get a non-integer

const squaresize = 20; // 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

const SKYBOX_ARRAY = [
    "/uploads/brendanb/radial_gradient_blue.png",
    "/uploads/brendanb/radial_gradient_blue.png",
    "/uploads/brendanb/radial_gradient_lightblue.png",
    "/uploads/brendanb/radial_gradient_darkblue.png",
    "/uploads/brendanb/radial_gradient_blue.png",
    "/uploads/brendanb/radial_gradient_blue.png",

];

//--- 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;
const GRID_ENEMY = 10; // added information if grid contains the actors, rather than checking globals
const GRID_AGENT = 20; // added information if grid contains the actors, rather than checking globals

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;

// added new class to make it easier to pass coordinates
class coordinates {
    constructor(i, j) {
        this.i = i;
        this.j = j;
    }
}

var start = new coordinates();
var target = new coordinates();

var badsteps;
var goodsteps;

const MAX_OPENSET = gridsize * gridsize;

// diagonal option enabled significantly increases performance of the enemy bot
// and allows access to shorter routes
var diagonal = true;

// if you want to see A* in action
const PROOF = true;
var proofArray = [];


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
{
    // Added check to ensure that occupied square is in grid.
    if (i <= gridsize && j <= gridsize &&
        i >= 0 && j >= 0) {

        switch (GRID[i][j]) {
            case GRID_WALL:
            case GRID_MAZE:
            case GRID_ENEMY:
            case GRID_AGENT:
                return true;
            default:
                return false;
        }
    }
    // off the grid
    return true;
}



function iswall(i, j) // is this square occupied
{
    switch (GRID[i][j]) {
        case GRID_WALL:
        case GRID_MAZE:
            return true;
        default:
            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 = -squaresize;
    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);
    }


    // 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 );
    shape = new THREE.SphereGeometry(squaresize / 2, BOXHEIGHT / 2, squaresize / 2);
    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.SphereGeometry(squaresize / 2, BOXHEIGHT / 2, squaresize / 2);
    theagent = new THREE.Mesh(shape);
    theagent.material = new THREE.MeshBasicMaterial({
        map: agent_texture
    });
    ABWorld.scene.add(theagent);
    drawAgent();

    GRID[ai][aj] = GRID_AGENT;
    GRID[ei][ej] = GRID_ENEMY;



    // 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)
}

// A* Support Functions
// This is the set of new A* functions, the first is to create a spot location data type
// this contains the location, A* paramenters, as well as pointer array to the neighbours

function gridSpot(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.parent = undefined;
    this.closed = false; // are we in closed set

    // Figure out who my neighbors are
    this.addNeighbors = function () {
        var i = this.i;
        var j = this.j;


        if (i < gridsize - 1) this.neighbors.push(aStarGrid[i + 1][j]);
        if (i > 0) this.neighbors.push(aStarGrid[i - 1][j]);
        if (j < gridsize - 1) this.neighbors.push(aStarGrid[i][j + 1]);
        if (j > 0) this.neighbors.push(aStarGrid[i][j - 1]);

        if (diagonal)
        // diagonals are also neighbours:
        {
            if (i > 0 && j > 0) this.neighbors.push(aStarGrid[i - 1][j - 1]);
            if (i < gridsize - 1 && j > 0) this.neighbors.push(aStarGrid[i + 1][j - 1]);
            if (i > 0 && j < gridsize - 1) this.neighbors.push(aStarGrid[i - 1][j + 1]);
            if (i < gridsize - 1 && j < gridsize - 1) this.neighbors.push(aStarGrid[i + 1][j + 1]);
        }
    };
}

// Create Global A* Grid Array
var aStarGrid = [];

// initialise a astar grid in parallel to main "GRID"
function aStarInit() {
    var i, j;
    // create the aStarGrid
    for (i = 0; i < gridsize; i++) {
        aStarGrid[i] = [];
        for (j = 0; j < gridsize; j++) {
            aStarGrid[i][j] = new gridSpot(i, j);
            // console.log("A* Initialise: " + i + ", " + j);
        }
    }

    for (i = 0; i < gridsize; i++) {
        for (j = 0; j < gridsize; j++) {
            aStarGrid[i][j].addNeighbors();
        }
    }
    console.info("A* Initialise: Complete");
}

// A* function that returns the next position in the as a coordinate (i,j)
function aStar(grid, start, target) {

    // Initialize both open and closed list
    var openSet = [];
    var child;
    var completed = false;
    var targetNode = aStarGrid[target.i][target.j]; // define the target
    var startNode = aStarGrid[start.i][start.j]; // define the target
    var currentNode;
    var nextMove = new coordinates(start.i, start.j);

    // Push the start node onto the openlist to start the analysis
    openSet.push(startNode); // push startnode onto Openset

    // clearup previous search - need to be more efficient with memory
    console.info("cleaning up previous results");
    for (i = 0; i < gridsize; i++) {
        for (j = 0; j < gridsize; j++) {
            currentNode = aStarGrid[i][j];
            currentNode.f = currentNode.h = currentNode.g = 0;
            currentNode.closed = false;
            currentNode.parent = null;
        }
    }

    // loop through all of the a* openlist or until target or error found
    while ((openSet.length > 0) && !completed) {

        if (openSet.length > MAX_OPENSET) {
            // Prevent Memory Issues when debugging OpenSet
            console.error("there is a problem with the openset, bail out!");
            completed = true;
            return nextMove;
        }

        // Sort the list based on the f value
        openSet.sort((a, b) => (a.f > b.f) ? 1 : -1); //sort set by f
        currentNode = openSet.shift(); // shift the first entry of OpenSet
        currentNode.closed = true; // quick check for closed

        console.info("Current: " + currentNode.i + ", " + currentNode.j + " - (O/C) is " + openSet.length);
        if (currentNode == targetNode) {

            // Proof array
            if (PROOF){
                proofArray.push(targetNode);
            }

            // Found Target - now backtrack to get next node
            while (currentNode.parent != startNode) {

                 // if we require proof, push store path
                if (PROOF){
                    proofArray.push(currentNode);
                }
                
                // backtrack to return the next move                
                currentNode = currentNode.parent;
            }
            completed = true;

            // Proof array
            if (PROOF){
                proofArray.push(startNode);
            }


        } else {
            // if we are not at target, build openSet
            for (n = 0; n < currentNode.neighbors.length; n++) {
                // for each of the neighbours, calculate the children
                child = currentNode.neighbors[n];

                // check if in closedSet or occupied
                if (child.closed) {
                    // move to next child
                } else if (iswall(child.i, child.j)) {
                    // closedSet.push(child);
                    child.closed = true;
                } else {
                    // calculate values and add to openSet
                    if ((child.i == currentNode.i) || (child.j == currentNode.j))
                        child.g = currentNode.g + 10; // if not diagonal, use 10 as metric
                    else
                        child.g = currentNode.g + 14; // rougly the square path if diagonal

                    child.h = aStarHeuristics(child, targetNode);
                    child.f = child.g + child.h;
                    child.parent = currentNode;
                    if (openSet.indexOf(child) < 0) {
                        // if not in openSet
                        openSet.push(child);
                    }

                } // check if closedSet
            } // loop through neighbours
        } //check if we have reached target
    }

    nextMove.i = currentNode.i;
    nextMove.j = currentNode.j;

    console.info("returning form a*: ");
    return nextMove;
    // end of openSet, and not completed.
}


function aStarHeuristics(start, end) {
    if (diagonal)
        return (Math.pow(start.i - end.i, 2) + Math.pow((start.j - end.j), 2));
    else
        return (Math.abs(start.i - start.i) + Math.abs(start.j - end.j));
}



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

function moveLogicalEnemy() {
    // move towards agent
    // put some randomness in so it won't get stuck with barriers

    var i, j;

    start.i = ei;
    start.j = ej;
    target.i = ai;
    target.j = aj;

    // call the a* algorithm to provide the best path between targets (GRID not necessary, as globals used)
    bestPath = aStar(GRID, start, target);

    // Only Move if the space is empty
    if (!occupied(bestPath.i, bestPath.j)) {
        GRID[ei][ej] = GRID_BLANK; // Store Agents Position
        // move enemy to new position
        ei = bestPath.i;
        ej = bestPath.j;
        GRID[ei][ej] = GRID_ENEMY;
    }
    console.info("enemy moving to : " + ei + "," + ej)

}


function moveLogicalAgent(a) // this is called by the infrastructure that gets action a from the Mind
{
    var i = ai;
    var j = aj;

    // depending on the agent move, spin the sphere
    switch (a) {
        case ACTION_LEFT:
            i--;
            theagent.rotation.y = 0;
            break;
        case ACTION_RIGHT:
            i++;
            theagent.rotation.y = -1;
            break;
        case ACTION_UP:
            j++;
            theagent.rotation.y = -2;
            break;
        case ACTION_DOWN:
            j--;
            theagent.rotation.y = 2;
            break;
        default:
            break;
    }

    if (!occupied(i, j)) {
        GRID[ai][aj] = GRID_BLANK; // Clear Agents Previous Position
        ai = i;
        aj = j;
        GRID[ai][aj] = GRID_AGENT; // Store Agents Position

    }
}




// --- 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 + "<br>x = (" + x.toString() + ")");
    // <br>a = (" + a + ")<br>");
}


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("y = (" + y.toString() + ") <br>" +
    AB.msg(" Bad steps: " + badsteps +
        " &nbsp; Good steps: " + goodsteps +
        " &nbsp; Score: " + score.toFixed(2) + "% ", 2);
}

function playSound() // is the enemy within one square of the agent
{

    // load click sound & based on distance, speed up and change volume
    var sound = new Audio('/uploads/brendanb/click.ogg');
    var soundRate = 1 + (((Math.abs(ei - ai)) + Math.abs((ej - aj))) / (gridsize));
    console.log("PlaybackRate: " + soundRate);

    sound.playbackRate = soundRate;
    sound.volume = 1 / soundRate;
    if (Math.abs(ei - ai) + Math.abs(ej - aj) < 2) {
        sound.playbackRate = soundRate * 2;
        sound.play();
    }
    sound.play();

}

// Debugging using AB was not the friendliest, so created function to debug using node.js
// prints a 2D text grid containing elements
function consoleGrid() {
    var gridString = "";

    for (var i = gridsize - 1; i >= 0; i--) {
        gridString = "";
        for (var j = 0; j < gridsize; j++) {
            switch (GRID[i][j]) {
                case GRID_WALL:
                    gridString = gridString + ".";
                    break;
                case GRID_MAZE:
                    gridString = gridString + "+";
                    break;
                case GRID_AGENT:
                    gridString = gridString + "A";
                    break;
                case GRID_ENEMY:
                    gridString = gridString + "E";
                    break;
                default:
                    gridString = gridString + " ";
                    break;
            }

        }
        console.log(gridString);

    }
    start.i = ei;
    start.j = ej;
    target.i = ai;
    target.j = aj;

    // console.log("Heuristic: " + aStarHeuristics(start, target));
}


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

    badsteps = 0;
    goodsteps = 0;
    aStarInit();


    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

    // Initiailise A* Array
    document.onkeydown = keyHandler;

};



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

var enemyAngle = 0;
var cameraAngle;

AB.world.takeAction = function (a) {
    updateStatusBefore(a); // show status line before moves

    console.info("-: Agent: " + ai + "," + aj + " Enemy: " + ei + "," + ej);

    moveLogicalAgent(a);

    if ((AB.step % 2) === 0) { // slow the enemy down to every nth step
        playSound();
        moveLogicalEnemy();
    }

    console.info("+: Agent: " + ai + "," + aj + " Enemy: " + ei + "," + ej);

    // consoleGrid();

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

    // Spin the enemy around every turn
    enemyAngle += 0.2;
    theenemy.rotation.y = enemyAngle;
    // theagent.rotation.y -= 0.2;

    drawAgent();
    drawEnemy();
    updateStatusAfter(); // show status line after moves

    // enemy will agressively pin agen to wall, if score reaches 10%, generally pointless (and
    // and exponentially increasing time to claim run over
    if (agentBlocked() || ((goodsteps / AB.step) < 0.10)) // if agent blocked in, run over
    {
        AB.abortRun = true;
        goodsteps = 0; // you score zero as far as database is concerned
        //	musicPause();
        //	soundAlarm();
    }

    // Proof array
    if (PROOF){
        drawProof();
    }

};

AB.world.endRun = function () {
    //  musicPause();
    if (AB.abortRun) AB.msg(" <br> <font color=red> <B> Agent trapped.</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
};



// Draw the A* algortihm on the screen
// Needs more work in terms of the path changing and colours, but good enough
// To slow down the path and see it.

var lastProofLine = [];
var previousLine;

function drawProof()
{

var point1; // local "Spots"
var point2; // local "Spots"
var line;

var oldMaterial = new THREE.LineBasicMaterial({color:0x222222, linewidth:1 });
    
    // clear old line

    if (lastProofLine.length > 0){
        line = lastProofLine.shift();
        lastProofLine[0].material = oldMaterial;
        if (previousLine)
        {
            ABWorld.scene.remove(previousLine);
        }
        ABWorld.scene.add(line);
        previousLine = line;
    }
    
    var mat = new THREE.LineBasicMaterial({color:'blue', linewidth:2 });
    var geo = new THREE.Geometry();   
    
    // in the proofArray
    for ( i = proofArray.length; i > 1; i--)
    {
        point1 = proofArray.shift();

        // geo.vertices.push( translate(point1.i, point1.j) );
        if (point1.parent){
            
            point1 = point1.parent;
            // drawline between proofArrayPoints
            geo.vertices.push( translate(point1.i, point1.j) );
            console.log("Line between " + point1.i + "," + point1.j + " and ")
        }
        else {
            geo.vertices.push( translate(point1.i, point1.j) );
            console.log("Line between " + point1.i + "," + point1.j + " and ")

        }        

    }
	line = new THREE.Line(geo, mat);

	// line.castShadow = true;
    lastProofLine.push(line);
    ABWorld.scene.add(line);

}