Pastebin

// Include Sordie's "wonderful" libraries
include("bitmap");
include("timer");

// Width/height constants
var GOL_WIDTH = 60;
var GOL_HEIGHT = 60;

// Creates an array large enough to hold the board ...
var gol = new Array(GOL_HEIGHT);

// ... and it's sub-arrays
for (var i = 0; i < GOL_HEIGHT; ++i)
	gol[i] = new Array(GOL_WIDTH);

// Puts the initial board state
// Loops over each row ...
for (var y = 0; y < GOL_HEIGHT; ++y)
{
	// ... and every cell ...
	for (var x = 0; x < GOL_WIDTH; ++x)
	{
		// Set every cell with a random 5% chance
		if (Math.random() < 0.05)
			gol[y][x] = 1
	}
}

// Creates the image to draw the board state on
var gol_bmp = new bitmap(GOL_WIDTH, GOL_HEIGHT);

// Counts the number of living neighbours a cell has
function gol_neighbours(x, y)
{
	var neighbours = 0;

	// Loops over the 3 rows surrounding the cell ...
	for (var oy = -1; oy <= 1; ++oy)
	{
		// ... and the 3 columns
		for (var ox = -1; ox <= 1; ++ox)
		{
			// Don't count the cell we're looking at
			if (ox == 0 && oy == 0)
				continue; // Skips the current "for" iteration
			
			// Holds the absolute value on the board
			var nx = x + ox;
			var ny = y + oy;
			
			// Make sure the cell we check is inside the board
			if (nx >= 0 && nx < GOL_WIDTH && ny >= 0 && ny < GOL_HEIGHT)
			{
				// If the cell is alive, add 1 to the neighbour count
				if (gol[ny][nx])
					++neighbours; // Increase neighbours by 1
			}
		}
	}
	
	return neighbours;
}

// Draws the base grid data to the bitmap
function gol_init()
{
	// Loops over each row ...
	for (var y = 0; y < GOL_HEIGHT; ++y)
	{
		// ... and every cell ...
		for (var x = 0; x < GOL_WIDTH; ++x)
		{
			// Sets the appropriate pixel depending on the cell state
			if (gol[y][x])
				gol_bmp.setPixel(x, y, "white");
			else
				gol_bmp.setPixel(x, y, "black");
		}
	}
}

// Ticks one game logic step
function gol_step()
{
	// Creates a temporary array to write the new state to
	var new_gol = new Array(GOL_HEIGHT);

	// Copies each index of the original array
	for (var i = 0; i < GOL_HEIGHT; ++i)
		new_gol[i] = gol[i].slice(0); // Array copy
	
	// Loops over each row ...
	for (var y = 0; y < GOL_HEIGHT; ++y)
	{
		// ... and every cell ...
		for (var x = 0; x < GOL_WIDTH; ++x)
		{
			// Calls the neighbour counting function
			var neighbours = gol_neighbours(x, y);
			
			// The rules of the game state that a cell with 3 neighbours will
			// become living, and a cell with less than 2 or more than 3 dies.
			if (neighbours < 2 || neighbours > 3)
			{
				new_gol[y][x] = 0;
				gol_bmp.setPixel(x, y, "black");
			}
			else if (neighbours == 3)
			{
				new_gol[y][x] = 1;
				gol_bmp.setPixel(x, y, "white");
			}
		}
	}

	// Copies the temporary array over the original
	gol = new_gol;
}

// Call the initialize function
gol_init();

// Create a timer to tick the simulator every 250ms and start it
tick = new timer(100);
tick.event = function() { gol_step(); }; // Creates a closure that calls gol_step()
tick.start();