const width = 8 ** 3;
const height = 8 ** 3;

function validXY(x, y) {
	if (x < 0 || x >= width) return false;
	if (y < 0 || y >= height) return false;
	return true;
}

function getRGBA(data, i) {
	let out = new Uint8Array(4);
	for (let j = i * 4; j < i * 4 + 4; j++) {
		out[j - i*4] = data[j];
	}
	return out;
}

function setRGBA(data, i, input) {
	for (let j = i * 4; j < i * 4 + 4; j++) {
		data[j] = input[j - i * 4];
	}
}

function Game(inSize) {
	this.img = new Image();
	this.inSize = inSize;
	this.base = new Float32Array(inSize * inSize);
}

Game.prototype.main = function() {	
	var {base, inSize, ctx} = this;	

	var dat = ctx.getImageData(0,0,width,height);

	for (let i = 0; i < base.length; i++) {
		base[i] = Math.max(base[i] * 0.99999,0);
	}

	let exp = Math.ceil(Math.log(width) - Math.log(inSize));

	for (let i = 0; i < dat.data.length / 4; i++) {
		let x = i % width;
		let y = Math.floor(i / width);

		let x2 = x;
		let y2 = y;

		let isMask = 1;

		for (let j = 0; j < exp; j++) {
			isMask *= base[(y2 % inSize) * inSize + (x2 % inSize)];

			x2 /= inSize;
			y2 /= inSize;

			x2 = Math.floor(x2);
			y2 = Math.floor(y2);
		}

		isMask = (isMask - 0.5) * 100 + 0.5;
		isMask = Math.max(isMask,0);
		isMask = Math.min(isMask,1);
		isMask *= 255;

		setRGBA(dat.data,i,[isMask,isMask,isMask,255])
	}

	ctx.putImageData(dat,0,0,0,0,width,height);
}

Game.prototype.map = function() {
	var {base, inSize} = this;	

	//noise.seed(Math.random() * 1000);

	for (let i in base) {
		let x = i % inSize;
		let y = Math.floor(i / inSize);

		base[i] = Math.random();

		base[i] = Math.max(base[i],0);
		base[i] = Math.min(base[i],1);
		base[i] = Math.pow(base[i],0.3);
		base[i] = base[i] * 0.4 + 0.6;
		//base[i] = (Math.random() > 0.5) ? 0 : 1; 
	}
}

Game.prototype.loop = function() {
	let that = this;
	setInterval(function() { that.main() } ,1000 / 60);
}

Game.prototype.startGame = function() {
	var canvas = document.querySelector("#canvas");
	canvas.width = width;	
	canvas.height = height;

	var ctx = this.ctx =  canvas.getContext("2d",{ willReadFrequently: true });

	ctx.imageSmoothingEnabled = false;

	this.map();
	this.loop();
}

Game.prototype.init = function() { 	
	let that = this;
	that.startGame();
}

new Game(8).init();