// Cloned by rohan on 13 Nov 2021 from World "A star (clone by Tom McAllister)" by Tom McAllister
// Please leave this clone trail here.
// Cloned by Tom McAllister on 16 Nov 2020 from World "A star" by "Coding Train" project
// Please leave this clone trail here.
// is diagonal move allowed
const diagonal = false;
// canvas size
const cw = 900;
const ch = 600;
// How many columns and rows
// different each time
var rando = AB.randomIntAtoB(1, 5);
var cols = 9 * rando;
var rows = 6 * rando;
// how many walls to make, from 0 to 1
// different each time
const wallAmount = AB.randomFloatAtoB(0, 0.2);
const sandAmount = AB.randomFloatAtoB(0, 0.4);
const backcolor = 'white';
const wallcolor = 'black';
const pathcolor = 'darkred';
const opencolor = 'white';
const closedcolor = 'white';
const beginEndColor = 'blue';
const sandColor = 'orange';
// 2D array
var grid = new Array(cols);
// Open and closed set
var openSet = [];
var closedSet = [];
// Start and end
var start;
var end;
var startCell = {x: 0, y: AB.randomIntAtoB(0, rows-1)}
var endCell = {x: cols -1 , y: AB.randomIntAtoB(0, rows-1)}
// Width and height of each cell of grid
var w, h;
// The road taken
var path = [];
//=== heuristic ===========================
// this must be always optimistic - real time will be this or longer
function heuristic(a, b) {
if (diagonal) return (dist(a.i, a.j, b.i, b.j));
// 2D distance
// dist is a P5 function
else return (abs(a.i - b.i) + abs(a.j - b.j));
// else not diagonal, can only go across and down
// so this is optimistic
// not this is not optimistic if we can do diagonal move
}
// Function to delete element from the array
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);
}
// An object to describe a spot in the grid
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;
// Neighbors
this.neighbors = [];
// Where did I come from?
this.previous = undefined;
// Am I an wall?
if (random(1) < wallAmount) this.wall = true;
else this.wall = false;
// Am I sand
if (random(1) < sandAmount) this.sand = true;
// Display me
this.show = function(col) {
if (this.wall) {
fill(wallcolor);
noStroke();
rect(this.i * w, this.j * h, w, h);
} else if (this.sand) {
fill(sandColor);
noStroke();
rect(this.i * w, this.j * h, w , h);
} else if (col) {
fill(col);
if(isStartOrFinish(this.i, this.j)) {
ellipse (this.i * w + w / 2, this.j * h + h / 2, w * 0.7, h * 0.7);
} else{
rect(this.i * w, this.j * h, w, h);
}
}
};
// Figure out who my neighbors are
this.addNeighbors = function(grid) {
var i = this.i;
var j = this.j;
if (i < cols - 1) this.neighbors.push(grid[i + 1][j]);
if (i > 0) this.neighbors.push(grid[i - 1][j]);
if (j < rows - 1) this.neighbors.push(grid[i][j + 1]);
if (j > 0) this.neighbors.push(grid[i][j - 1]);
if (diagonal)
// diagonals are also neighbours:
{
if (i > 0 && j > 0) this.neighbors.push(grid[i - 1][j - 1]);
if (i < cols - 1 && j > 0) this.neighbors.push(grid[i + 1][j - 1]);
if (i > 0 && j < rows - 1) this.neighbors.push(grid[i - 1][j + 1]);
if (i < cols - 1 && j < rows - 1) this.neighbors.push(grid[i + 1][j + 1]);
}
}
}
function setup() {
// slower frame rate to see how it is working
// frameRate (2);
createCanvas(cw, ch);
// Grid cell size
w = width / cols;
h = height / rows;
console.log('width '+ width);
console.log('height'+ height);
console.log('w '+ cols);
console.log('h '+ rows);
// Making a 2D array
for (var i = 0; i < cols; i++)
grid[i] = new Array(rows);
for (var i = 0; i < cols; i++)
for (var j = 0; j < rows; j++)
grid[i][j] = new Spot(i, j);
// All the neighbors
for (var i = 0; i < cols; i++)
for (var j = 0; j < rows; j++)
grid[i][j].addNeighbors(grid);
// Start and end
start = grid[startCell.x][startCell.y];
end = grid[endCell.x][endCell.y];
start.wall = false;
end.wall = false;
start.sand = false;
end.sand = false;
// openSet starts with beginning only
openSet.push(start);
console.log('start search');
}
function draw()
// the search goes on over many timesteps
// each timestep, check one more square and draw current partial solution
{
// --- begin still searching -----------------------------
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 (current === end) {
noLoop();
console.log("success - found path");
}
// 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) && !neighbor.wall) {
var tempG = current.g + heuristic(neighbor, current);
if(current.sand) tempG += 5
// 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;
}
}
}
//--- end of for loop -----------
}
// --- end still searching -----------------------------
else {
console.log('fail - no path exists');
noLoop();
return;
}
// Draw current state of everything
background(backcolor);
for (var i = 0; i < cols; i++)
for (var j = 0; j < rows; j++)
grid[i][j].show();
for (var i = 0; i < closedSet.length; i++)
closedSet[i].show(closedcolor);
for (var i = 0; i < openSet.length; i++)
openSet[i].show(opencolor);
for (var i = 0; i < cols; i++)
for (var j = 0; j < rows; j++)
if(isStartOrFinish(i, j))
grid[i][j].show(beginEndColor);
// Find the path by working backwards
path = [];
var temp = current;
path.push(temp);
while (temp.previous) {
path.push(temp.previous);
temp = temp.previous;
}
if (diagonal) {
// path as continuous line
noFill();
stroke(pathcolor);
strokeWeight(w / 8);
beginShape();
for (var i = 0; i < path.length; i++)
vertex((path[i].i * w) + w / 2, (path[i].j * h) + h / 2);
endShape();
} else {
// path as solid blocks
for (var i = 0; i < path.length; i++)
path[i].show(pathcolor);
}
}
function isStartOrFinish(x, y) {
if( (startCell.x === x && startCell.y === y) || (endCell.x === x && endCell.y === y) ){
return true;
}
return false;
}