schani/gol.html

## gol.html
<html>
<head>
    <title>Game of Life</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
    <canvas id="canvas" width="300" height="300"></canvas>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script>
        // draw 2d array of booleans to canvas efficiently
        function draw(canvas, array) {
            var ctx = canvas.getContext("2d");
            var w = canvas.width;
            var h = canvas.height;


        // cells is a 2D array of booleans
        function drawCells(ctx, cells) {
            ctx.clearRect(0, 0, 300, 300);
            for (var i = 0; i < cells.length; i++) {
                for (var j = 0; j < cells[i].length; j++) {
                    if (cells[i][j]) {
                        ctx.fillStyle = "black";
                    } else {
                        ctx.fillStyle = "white";
                    }
                    ctx.fillRect(j, i, 1, 1);
                }
            }
        }

        function gameOfLifeStep(cells) {
            var nextCells = new Array(cells.length);
            for (var i = 0; i < cells.length; i++) {
                nextCells[i] = new Array(cells[i].length);
                for (var j = 0; j < cells[i].length; j++) {
                    var liveNeighbors = 0;
                    for (var k = -1; k <= 1; k++) {
                        for (var l = -1; l <= 1; l++) {
                            if ((k === 0 && l === 0) || i + k < 0 || i + k >= cells.length || j + l < 0 || j + l >= cells[i].length) {
                                continue;
                            }
                            if (cells[i + k][j + l]) {
                                liveNeighbors++;
                            }
                        }
                    }
                    if (cells[i][j]) {
                        if (liveNeighbors < 2) {
                            nextCells[i][j] = false;
                        } else if (liveNeighbors > 3) {
                            nextCells[i][j] = false;
                        } else {
                            nextCells[i][j] = true;
                        }
                    } else {
                        if (liveNeighbors == 3) {
                            nextCells[i][j] = true;
                        } else {
                            nextCells[i][j] = false;
                        }
                    }
                }
            }
            return nextCells;
        }

        // init cells randomly
        var cells = [];
        for (var i = 0; i < 300; i++) {
            cells[i] = [];
            for (var j = 0; j < 300; j++) {
                cells[i][j] = Math.random() > 0.7;
            }
        }

        var canvas = $("#canvas")[0];
        var ctx = canvas.getContext("2d");
        var width = canvas.width;
        var height = canvas.height;
        var cellX, cellY;
        var cellColor = "#111";
        var cellColorActive = "#444";

        console.log("script");

        // draw on each animation frame
        requestAnimationFrame(function draw() {
            drawCells(ctx, cells);
            var nextCells = gameOfLifeStep(cells);
            cells = nextCells;
            requestAnimationFrame(draw);
        });

    </script>
</body>
</html>
	<html>
	<head>
	<title>Game of Life</title>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	</head>
	<body>
	<canvas id="canvas" width="300" height="300"></canvas>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
	<script>
	// draw 2d array of booleans to canvas efficiently
	function draw(canvas, array) {
	var ctx = canvas.getContext("2d");
	var w = canvas.width;
	var h = canvas.height;


	// cells is a 2D array of booleans
	function drawCells(ctx, cells) {
	ctx.clearRect(0, 0, 300, 300);
	for (var i = 0; i < cells.length; i++) {
	for (var j = 0; j < cells[i].length; j++) {
	if (cells[i][j]) {
	ctx.fillStyle = "black";
	} else {
	ctx.fillStyle = "white";
	}
	ctx.fillRect(j, i, 1, 1);
	}
	}
	}

	function gameOfLifeStep(cells) {
	var nextCells = new Array(cells.length);
	for (var i = 0; i < cells.length; i++) {
	nextCells[i] = new Array(cells[i].length);
	for (var j = 0; j < cells[i].length; j++) {
	var liveNeighbors = 0;
	for (var k = -1; k <= 1; k++) {
	for (var l = -1; l <= 1; l++) {
	if ((k === 0 && l === 0) \|\| i + k < 0 \|\| i + k >= cells.length \|\| j + l < 0 \|\| j + l >= cells[i].length) {
	continue;
	}
	if (cells[i + k][j + l]) {
	liveNeighbors++;
	}
	}
	}
	if (cells[i][j]) {
	if (liveNeighbors < 2) {
	nextCells[i][j] = false;
	} else if (liveNeighbors > 3) {
	nextCells[i][j] = false;
	} else {
	nextCells[i][j] = true;
	}
	} else {
	if (liveNeighbors == 3) {
	nextCells[i][j] = true;
	} else {
	nextCells[i][j] = false;
	}
	}
	}
	}
	return nextCells;
	}

	// init cells randomly
	var cells = [];
	for (var i = 0; i < 300; i++) {
	cells[i] = [];
	for (var j = 0; j < 300; j++) {
	cells[i][j] = Math.random() > 0.7;
	}
	}

	var canvas = $("#canvas")[0];
	var ctx = canvas.getContext("2d");
	var width = canvas.width;
	var height = canvas.height;
	var cellX, cellY;
	var cellColor = "#111";
	var cellColorActive = "#444";

	console.log("script");

	// draw on each animation frame
	requestAnimationFrame(function draw() {
	drawCells(ctx, cells);
	var nextCells = gameOfLifeStep(cells);
	cells = nextCells;
	requestAnimationFrame(draw);
	});

	</script>
	</body>
	</html>