// Cloned by Evans Kipchaui on 29 Oct 2023 from World "Complex World" by Starter user
// Please leave this clone trail here.
// Clone from complex world, making the enemy smarter using A Star algorithm - Practical 1
// ==== 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; // 200;
// Speed of run: Step every n milliseconds. Default 100.
AB.maxSteps = 500;
// 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)
//Changed the images using the ones uploaded to my ancient brain account
const TEXTURE_WALL = '/uploads/ekipchau/whitesquare.png' ;
const TEXTURE_MAZE = '/uploads/ekipchau/square.png' ;
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
// http://en.wikipedia.org/wiki/File:Inscription_displaying_apices_(from_the_shrine_of_the_Augustales_at_Herculaneum).jpg
// Changed the background music to ireland's call (I love it) and used rooster crowing for sound alarm
const MUSIC_BACK = '/uploads/ekipchau/IrelandsCall.mp3' ;
const SOUND_ALARM = '/uploads/ekipchau/mixkit-rooster-crowing-in-the-morning-2462.wav' ;
// credits:
// http://www.dl-sounds.com/royalty-free/defense-line/
// http://soundbible.com/1542-Air-Horn.html
// Changed number of squares along side of world, can be changed to any value
const gridsize = 40; // 15;
// Changed the denominator, can be changed to any value
const NOBOXES = Math.trunc ( (gridsize * gridsize) / 4 ); // 5
// density of maze - number of internal boxes
// (bug) use trunc or can get a non-integer
const squaresize = 200; // 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
// purple-yeti-cartoon-sitting-chair, credit:
// https://www.freepik.com/free-photo/purple-yeti-cartoon-sitting-chair_39425707.htm
// https://matheowis.github.io/HDRI-to-CubeMap/
const SKYBOX_ARRAY = [
'/uploads/ekipchau/1px.png',
'/uploads/ekipchau/1nx.png',
'/uploads/ekipchau/1py.png',
'/uploads/ekipchau/1ny.png',
'/uploads/ekipchau/1pz.png',
'/uploads/ekipchau/1nz.png'
];
// ===================================================================================================================
// === 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] == 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++ )
{
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 );
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)
}
// --------------------Start of adding A-Star without diagonal moves--------------------
// Nodes used in the A* algorithm
function pathNode(i, j) {
// Row and column indices of the node
this.i = i;
this.j = j;
// Cost from the start node (initially set to infinity)
this.g = Infinity;
// Heuristic, initially set to 0
this.h = 0;
// Reference to the parent node in the path
this.parent = null;
// Comparing nodes based on f cost
this.compareTo = function(comparisonNode) {
return (this.g + this.h) - (comparisonNode.g + comparisonNode.h);
};
}
// Explore adjacent tiles around the current parent node
function exploreAdjacentTiles(centerNode, grid, closedPositions, totalRows, totalCols) {
const relativePositions = [
[0, 1], // right
[1, 0], // down
[0, -1], // left
[-1, 0], // up
];
// Check if tile is unoccupied and not in closed list
function isTileUnoccupied(rowIdx, colIdx) {
return (
rowIdx >= 0 && rowIdx < totalRows &&
colIdx >= 0 && colIdx < totalCols &&
grid[rowIdx][colIdx] === 0 &&
!closedPositions.has(`${rowIdx},${colIdx}`)
);
}
// Generate array of neighboring tiles
return relativePositions
.map(([rowDelta, colDelta]) => ({
i: centerNode.i + rowDelta,
j: centerNode.j + colDelta,
}))
.filter(({ i, j }) => isTileUnoccupied(i, j))
.map(({ i, j }) => new pathNode(i, j));
}
// A* algorithm to find the shortest path from start to end on a grid
function aStarPath(grid, start, goal) {
// Calculate Manhattan distance between two tiles
function computeManhattanDistance(start, end) {
return Math.abs(start.i - end.i) + Math.abs(start.j - end.j);
}
// Generate backtracing coordinates from the end to the start
function generatePath(currentTile) {
const pathCoordinates = [];
while (currentTile !== null) {
pathCoordinates.push([currentTile.i, currentTile.j]);
currentTile = currentTile.parent;
}
return pathCoordinates.reverse();
}
// Initialize open and closed lists
const openList = [];
const closedList = new Set();
// Number of rows and columns in the grid
const numRows = grid.length;
const numCols = grid[0].length;
// Create start and goal tiles
const startTile = new pathNode(start[0], start[1]);
const goalTile = new pathNode(goal[0], goal[1]);
// Set initial values for the first tile
startTile.g = 0;
startTile.h = computeManhattanDistance(startTile, goalTile);
// Add the start tile to the open list
openList.push(startTile);
// A* algorithm loop
while (openList.length > 0) {
// Sort openlist based on the f cost
openList.sort((a, b) => a.compareTo(b));
// Identify the tile with the lowest f cost from the open list
const currentTile = openList.shift();
// Check if the goal is reached
if (currentTile.i === goalTile.i && currentTile.j === goalTile.j) {
// Generate and return the path
return generatePath(currentTile);
}
// Add the current tile to the closed list
closedList.add(`${currentTile.i},${currentTile.j}`);
// Get neighbors of the current tile
const neighbors = exploreAdjacentTiles(currentTile, grid, closedList, numRows, numCols);
// Process each neighbor
for (const neighborTile of neighbors) {
// Calculate tentative g value
const tentativeG = currentTile.g + 1;
// Check if the tentative g value is better than the current g value
if (tentativeG < neighborTile.g) {
// Update neighbor values
neighborTile.g = tentativeG;
neighborTile.h = computeManhattanDistance(neighborTile, goalTile);
neighborTile.parent = currentTile;
// Add neighbor to open list if not already present
if (!openList.some(tile => tile.i === neighborTile.i && tile.j === neighborTile.j)) {
openList.push(neighborTile);
}
}
}
}
// If open list is blank and goal is not reached, return null
return null;
}
// Visualize path on 3D grid
function visualizePath(newPath) {
// Existing path visualization object from the scene
const existingPathVisual = ABWorld.scene.getObjectByName("pathVisual");
// Remove current path visualization if it exists
if (existingPathVisual) {
ABWorld.scene.remove(existingPathVisual);
}
// Create a new buffer geometry for the path
const newPathGeometry = new THREE.BufferGeometry();
// Path coordinates to 3D positions
const newPathPositions = newPath.map(([i, j]) => [(i - gridsize / 2) * squaresize, BOXHEIGHT / 2, (j - gridsize / 2) * squaresize]).flat();
// 'position' attribute of the geometry
newPathGeometry.setAttribute('position', new THREE.Float32BufferAttribute(newPathPositions, 3));
// New material for path visualization
const newPathMaterial = new THREE.LineBasicMaterial({ color: 0xFF0000 });
// New line object for path visualization
const newPathVisual = new THREE.Line(newPathGeometry, newPathMaterial);
// Name for the path visualization object
newPathVisual.name = "pathVisual";
// Put the new path visualization to the scene
ABWorld.scene.add(newPathVisual);
}
// --------------------End of adding A-Star without diagonal moves--------------------
// --- take actions -----------------------------------
//Modified move enemy code to use A*
// Move the enemy logically using the A* pathfinding algorithm
function moveLogicalEnemy()
{
// Starting position of the enemy
const start = [ei, ej];
// Set the goal position as the current position of the agent
const goal = [ai, aj];
// Find the path using the A* pathfinding algorithm
const path = aStarPath(GRID, start, goal);
// Check if valid path is found
if (path === null) {
console.log("There is no path to agent.");
} else {
if ( ! occupied(path[1][0] , path[1][1]) )
{
// Move the enemy to the second position in the path (following the agent)
// Note: path[0] is the current position, so path[1] is the next position to move to
ei = path[1][0];
ej = path[1][1];
}
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;
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
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();
}
// Added this piece to visualize path
const start = [ei, ej];
const goal = [ai, aj];
const path = aStarPath(GRID,start, goal);
if (path !== null) {
visualizePath(path);
}
};
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
}