by Mike Davis. This program is a simple version of Conway's game of Life. A lit point turns off if there are fewer than two or more than three surrounding lit points. An unlit point turns on if there are exactly three lit neighbors. The 'density' parameter determines how much of the board will start out lit.
Original Processing.org Example: Conway
// All Examples Written by Casey Reas and Ben Fry // unless otherwise stated. int sx, sy; float density = 0.5; int[][][] world; void setup() { size(100, 100); frameRate(12); sx = width; sy = height; world = new int[sx][sy][2]; stroke(255); // Set random cells to 'on' for (int i = 0; i < sx * sy * density; i++) { world[(int)random(sx)][(int)random(sy)][1] = 1; } } void draw() { background(0); // Drawing and update cycle for (int x = 0; x < sx; x=x+1) { for (int y = 0; y < sy; y=y+1) { //if (world[x][y][1] == 1) // Change recommended by The.Lucky.Mutt if ((world[x][y][1] == 1) || (world[x][y][1] == 0 && world[x][y][0] == 1)) { world[x][y][0] = 1; point(x, y); } if (world[x][y][1] == -1) { world[x][y][0] = 0; } world[x][y][1] = 0; } } // Birth and death cycle for (int x = 0; x < sx; x=x+1) { for (int y = 0; y < sy; y=y+1) { int count = neighbors(x, y); if (count == 3 && world[x][y][0] == 0) { world[x][y][1] = 1; } if ((count < 2 || count > 3) && world[x][y][0] == 1) { world[x][y][1] = -1; } } } } // Count the number of adjacent cells 'on' int neighbors(int x, int y) { return world[(x + 1) % sx][y][0] + world[x][(y + 1) % sy][0] + world[(x + sx - 1) % sx][y][0] + world[x][(y + sy - 1) % sy][0] + world[(x + 1) % sx][(y + 1) % sy][0] + world[(x + sx - 1) % sx][(y + 1) % sy][0] + world[(x + sx - 1) % sx][(y + sy - 1) % sy][0] + world[(x + 1) % sx][(y + sy - 1) % sy][0]; }