// Cloned by Paul R on 23 Oct 2022 from World "Hound and Hare (complex world)" by Paul R
// Please leave this clone trail here.
// Cloned by Paul R on 8 Oct 2022 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?
AB.clockTick = 1000; // 1000;
// 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 = 100;
// 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/paul79/wall2.jpg' ;
const TEXTURE_MAZE = '/uploads/starter/latin.jpg' ;
const TEXTURE_AGENT = '/uploads/paul79/rabbit-128.png' ;
const TEXTURE_ENEMY = '/uploads/paul79/greyhound-silhouette.jpg' ;
// 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
// https://freestocktextures.com/texture/brick-renovated-closeup,740.html
// https://www.iconspng.com/images/greyhound-silhouette/greyhound-silhouette.jpg
//https://www.iconsdb.com/orange-icons/rabbit-icon.html
const MUSIC_BACK = '/uploads/starter/Defense.Line.mp3' ;
const SOUND_ALARM = '/uploads/starter/air.horn.mp3' ;
// credits:
// http://www.dl-sounds.com/royalty-free/defense-line/
// http://soundbible.com/1542-Air-Horn.html
//Paul Ryan parameters to control moving walls
const WALLMOVENO = 150 ; // 150;
const WALLMOVETICK = 4 ; // 4;
const gridsize = 40; // 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 * 1 ; // 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;
const VERBOSE_LOG = false;
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 MAZE_BLOCKS = [];
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;
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++ )
{
//Paul Ryan bug fix ensure a block is not placed on existing block
do {
i = AB.randomIntAtoB(1,gridsize-2); // inner squares are 1 to gridsize-2
j = AB.randomIntAtoB(1,gridsize-2);
} while(occupied(i,j));
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);
//Paul Ryan
MAZE_BLOCKS.push({i:i, j:j, cube:thecube});
}
if (VERBOSE_LOG){ //Paul Ryan logging to help diagnose a bug
let str = "Initial block pos: ";
for (var k=0; k<MAZE_BLOCKS.length; k++){
str = str + "[" + MAZE_BLOCKS[k].i + "," + MAZE_BLOCKS[k].j + "]";
}
console.log (str);
}
// set up enemy
// start in random location
//Paul Ryan ensure enemy and agent start at opposite corners
do
{
i = AB.randomIntAtoB(1,10);
j = AB.randomIntAtoB(1,10);
}
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
//Paul Ryan ensure enemy and agent start at opposite corners
do
{
i = AB.randomIntAtoB(gridsize-10,gridsize-2);
j = AB.randomIntAtoB(gridsize-10,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();
//Paul Ryan set up for the A* search
//only needs to be done once because maze does not change.
aStarSetup();
// 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 -----------------------------------
////////////////////////////////////////////////////////////////////////////////
//Paul Ryan START: Move the enemy ////
//First, call "getPathToAgent" to get the shortest path ////
//Second, move the enemy to the second element in the path (1st is current pos)/
//Third, show the trail ////
////////////////////////////////////////////////////////////////////////////////
var trail_lights = new Array(); //a trail showing the path
function moveEnemyA_Star()
{
console.log("Search for shortest path");
//Paul Ryan get shortest path by using A* search
let path = getPathToAgent (ai, aj, ei, ej);
if (VERBOSE_LOG){ //Paul Ryan logging to help diagnose a bug
console.log("agent pos:" +ai + " " + aj + " enemy pos:" + ei + " " + ej);
var logStr = "[";
for (var b=0; b<path.length; b++){
let occ = false;
for (var c=0; c<MAZE_BLOCKS.length; c++){
if (MAZE_BLOCKS[c].i == path[b].i && MAZE_BLOCKS[c].j == path[b].j){
occ = true;
}
}
logStr = logStr + "[" + path[b].i + "," + path[b].j + "," + occ + "]";
}
logStr = logStr + "]";
console.log(logStr);
}
//Paul Ryan move the enemy to the second step in the path
if (path.length>=2 && !occupied(path[1].i, path[1].j)){
ei = path[1].i;
ej = path[1].j;
}
//Paul Ryan remove any old trail_lights that exist
while (trail_lights.length>0){
let trail_light = trail_lights.pop();
ABWorld.scene.remove(trail_light);
}
//Paul Ryan add trail_lights to all steps of returned path except first and last steps
for (let a=1; a<path.length-1; a++){
const geometry = new THREE.SphereGeometry( 20, 32 );
const material = new THREE.MeshBasicMaterial( { color: 0x0000FF } );
let trail_light = new THREE.Mesh( geometry, material );
ABWorld.scene.add( trail_light );
trail_light.position.copy ( translate(path[a].i, path[a].j) );
trail_lights.push(trail_light);
}
}
////////////////////////////////////////////////////////////////////////////////
//Paul Ryan END: Move the enemy ////
////////////////////////////////////////////////////////////////////////////////
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 + " x = (" + x.toString() + ") 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 ( " y = (" + y.toString() + ") <br>" +
" Bad steps: " + badsteps +
" Good steps: " + goodsteps +
" 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
console.log("Move some blocks");
var str;
//Paul Ryan move some blocks - just take the first WALLMOVENO blocks
if (AB.step % WALLMOVETICK == 0){
for (var i=0; i<Math.min(WALLMOVENO, NOBOXES); i++){
let blockInfo = MAZE_BLOCKS[i];
let newI, newJ;
do {
newI = AB.randomIntAtoB(1,gridsize-2);
newJ = AB.randomIntAtoB(1,gridsize-2);
}
while ( occupied(newI, newJ) ); // search for empty square
//Paul Ryan update the main grid to take account of the new block pos
GRID[newI][newJ] = GRID_MAZE;
GRID[blockInfo.i][blockInfo.j] = GRID_BLANK;
if (VERBOSE_LOG){ //Paul Ryan logging to help diagnose a bug
str = str + "[" + blockInfo.i + "," + blockInfo.j + "] -> [" + newI + "," + newJ + "]";
}
//Paul Ryan move the block to the new position and update MAZE_BLOCK element
blockInfo.cube.position.copy ( translate(newI, newJ) ); // translate grid coordinates to three.js (x,y,z) coordinates
blockInfo.i = newI;
blockInfo.j = newJ;
}
if (VERBOSE_LOG) { //Paul Ryan logging to help diagnose a bug
console.log("Position changes: " + str);
str = "New block pos: ";
for (var i=0; i<MAZE_BLOCKS.length; i++){
str = str + "[" + MAZE_BLOCKS[i].i + "," + MAZE_BLOCKS[i].j + "]";
}
console.log(str);
}
}
moveLogicalAgent(a);
// if ( ( AB.step % 2 ) == 0 ) // slow the enemy down to every nth step
moveEnemyA_Star();
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
}
////////////////////////////////////////////////////////////////////////////////
// Paul Ryan START: A* funcs & structures ////
// This is the start of the code for the A* search ////
////////////////////////////////////////////////////////////////////////////////
const aStarGrid = new Array(gridsize-2); //a grid to hold A* cells. It's smaller than grid because no need to search walls
//Paul Ryan
//Set up the A*grid. This is based on the main grid
function aStarSetup(){
for (var x=0; x < gridsize-2; x++){
aStarGrid[x] = new Array(gridsize-2);
}
for (var x = 0; x < gridsize-2 ; x++ ) {
for (var y = 0; y < gridsize-2 ; y++ )
{
aStarGrid[x][y] = new AStarCell(x, y, GRID[x+1][y+1] == GRID_MAZE);
//Paul Ryan set up neighbour relationships
if (x > 0){
aStarGrid[x][y].addNeighbour(aStarGrid[x-1][y]);
aStarGrid[x-1][y].addNeighbour(aStarGrid[x][y]);
}
if (y > 0){
aStarGrid[x][y].addNeighbour(aStarGrid[x][y-1]);
aStarGrid[x][y-1].addNeighbour(aStarGrid[x][y]);
}
}
}
}
//Paul Ryan structure used for the A* search
function AStarCell(i, j, isMaze){
// Location
this.i = i;
this.j = j;
// f, g, and h values for A*
this.f = 0;
this.g = 0;
this.h = 0;
// Neighbours
this.neighbours = [];
// Where did I come from?
this.previous = undefined;
this.maze = isMaze;
//Set another cell as a neighbour of this cell
this.addNeighbour = function(neighbour){
this.neighbours.push(neighbour);
}
//Paul Ryan reset the cell for a new search
//Unlike world1, the "maze" boolean must also be reset.
this.reset = function(isMaze){
this.f = 0;
this.g = 0;
this.h = 0;
this.previous = undefined;
this.maze = isMaze;
}
}
//Paul Ryan The manhattan distance as the heuristic func
function heuristic(a, b) {
return ( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
}
//Paul Ryan
//The main A* search routine
//Agent and enemy positions are passed in as parameters
//The A* grid is reset and set up again for new search
//Search is executed
//Returns an array which describes the path from enemy to agent.
function getPathToAgent(agentPosI, agentPosJ, enemyPosI, enemyPosJ){
////////////////////////////////
//Initialisation for the search
////////////////////////////////
let ai = agentPosI-1, aj=agentPosJ-1, ei=enemyPosI-1,ej=enemyPosJ-1;
// Open and closed set
let openSet = [];
let closedSet = [];
// Start and end are the enemy and agent positions respectively
let start = aStarGrid[ei][ej];
let end = aStarGrid[ai][aj];
//Reset the grid elements from previous search
for (let x = 0; x < gridsize-2 ; x++ ) {
for (let y = 0; y < gridsize-2 ; y++ ) {
aStarGrid[x][y].reset(GRID[x+1][y+1] == GRID_MAZE);
}
}
openSet.push(start);
//////////////////////////////////
//Paul Ryan START: The A* search
/////////////////////////////////
let current;
let isCurrent = (element) => element == current;
while (openSet.length > 0){ //Iterate while there is something in the openSet
let winner = 0;
for (let i = 0; i < openSet.length; i++) {
if (openSet[i].f < openSet[winner].f)
winner = i;
}
current = openSet[winner];
if (current === end) {
console.log("success - found path");
break;
}
//remove current from openSet and push into closedSet
openSet.splice(openSet.findIndex( isCurrent ), 1);
closedSet.push(current);
for (let i = 0; i < current.neighbours.length; i++) {
let neighbour = current.neighbours[i];
// Paul Ryan Do not look at maze cells or previously completed cells
if (!closedSet.includes(neighbour) && !neighbour.maze) {
//Paul Ryan A temporary g is stored as we do not know that the
//path to this neighbour is better than a previous path
let tempG = current.g + heuristic(neighbour, current);
let neighbourAlreadySearched = openSet.includes(neighbour);
if (!neighbourAlreadySearched || tempG < neighbour.g){
//Paul Ryan If it's a new path or a better path
//then set h and f values and record path in neighbour
neighbour.g = tempG;
neighbour.h = heuristic(neighbour, end);
neighbour.f = neighbour.g + neighbour.h;
neighbour.previous = current;
}
if (!neighbourAlreadySearched){
//only push neighbour into open set if not already there
openSet.push(neighbour);
}
}
}
}
//////////////////////////////////
//Paul Ryan END: The A* search
/////////////////////////////////
if (openSet.length == 0){
console.log("failure - no path found.");
return [];
}
////////////////////////////////////////////////////////////////////////////
// Paul Ryan Create a path from start to current; current == end if search was success
// Find the path by working backwards
let path = [];
let temp = current;
path.push(temp);
while (temp.previous) {
path.push(temp.previous);
temp = temp.previous;
}
let transformedPath = new Array();
for (let a=path.length-1; a>=0; a--){
transformedPath.push({i : path[a].i + 1, j : path[a].j + 1});
}
return transformedPath;
}
////////////////////////////////////////////////////////////////////////////////
// Paul Ryan END: A* funcs & structures ////
////////////////////////////////////////////////////////////////////////////////