Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
Conway's Game of Life with JS and D3
function Cell(initialState) {
this.isAlive = initialState;
this.willBeAlive = false;
}
Cell.prototype.computeNextState = function(aliveNeighborsCount) {
if(aliveNeighborsCount == 3){
this.willBeAlive = true;
} else if(aliveNeighborsCount > 3 || aliveNeighborsCount < 2) {
this.willBeAlive = false;
} else {
this.willBeAlive = this.isAlive;
}
return this.willBeAlive;
};
Cell.prototype.nextState = function(){
this.isAlive = this.willBeAlive;
}
function CellGrid(rows, columns) {
this.cells = new Array(rows);
var n = 0;
for(var i = -1; ++i < rows;){
this.cells[i] = new Array(columns);
for(var j = -1; ++j < columns; ){
var cell = new Cell(false);
cell.n = n++;
cell.x = i;
cell.y = j;
this.cells[i][j] = cell;
}
}
}
CellGrid.prototype.aliveNeighborsFor = function(x, y) {
var self = this,
neighbors = [[-1,-1],[-1,0],[-1,1],[0,-1],[0,1],[1,-1],[1,0],[1,1]];
function isAliveAt(i, j){
if(i < 0 || i >= self.cells.length || j < 0 || j >= self.cells[0].length){
return false;
}
return self.cells[i][j].isAlive;
}
var count = 0;
for(var i = 0; i < neighbors.length; i++){
count += (isAliveAt(x+neighbors[i][0],y+neighbors[i][1]))?1:0;
}
return count;
};
CellGrid.prototype.eachCell = function(callback){
var rows = this.cells.length,
columns = this.cells[0].length,
x,y;
for(var i = 0; i < rows * columns; i++){
x = i%rows; y = Math.floor(i/rows);
callback.apply(this,[this.cells[x][y],x,y]);
}
};
CellGrid.prototype.reset = function(){
this.eachCell(function(cell,x,y){
cell.isAlive = (Math.random() > 0.5);
});
};
CellGrid.prototype.prepareStep = function() {
this.eachCell(function(cell,x,y){
cell.computeNextState(this.aliveNeighborsFor(x,y));
});
};
CellGrid.prototype.step = function() {
this.prepareStep();
this.eachCell(function(cell,x,y){
cell.nextState();
});
};
CellGrid.prototype.aliveCells = function() {
var alive = [];
this.eachCell(function(cell){
cell.isAlive && alive.push(cell);
});
return alive;
};
<!doctype html>
<html>
<body>
<a href="http://github.com/sylvaingi/d3-life"><img style="position: absolute; top: 0; right: 0; border: 0;" src="https://a248.e.akamai.net/assets.github.com/img/abad93f42020b733148435e2cd92ce15c542d320/687474703a2f2f73332e616d617a6f6e6177732e636f6d2f6769746875622f726962626f6e732f666f726b6d655f72696768745f677265656e5f3030373230302e706e67" alt="Fork me on GitHub"></a>
<style type="text/css">
html,body{
margin: 0;
overflow: hidden;
}
circle {
fill: #1f77b4;
}
</style>
<script type="text/javascript" src="Cell.js"></script>
<script type="text/javascript" src="CellGrid.js"></script>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?2.8.1"></script>
<script type="text/javascript">
(function(){
var w = window.innerWidth,
h = window.innerHeight,
columns = 10,
rows = 10,
wRatio = w/columns,
hRatio = h/rows,
radius = Math.min(Math.floor(w/(2*columns)),Math.floor(h/(2*rows)));
var grid = new CellGrid(rows,columns);
grid.reset();
var svg = d3.select("body").append("svg:svg")
.attr("width", w)
.attr("height", h);
var circle = svg.selectAll("circle");
(function(){
grid.step();
circle = circle.data(grid.aliveCells(),function(d){return d.n});
circle.enter().append("circle")
.attr("cx", function(d){return d.x*wRatio + radius})
.attr("cy", function(d){return d.y*hRatio + radius})
.transition().duration(500)
.attr("r", radius)
.style("fill","#2ca02c");;
circle.exit()
.style("fill","#d62728")
.transition().duration(500)
.attr("r", 0)
.remove();
setTimeout(arguments.callee,500);
})();
})();
</script>
</body>
</html>
Owner

sylvaingi commented Apr 12, 2012

Github repo here

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment