User:Nan Wang/counting
function unit () {
// a single housing unit ctx.beginPath(); ctx.arc(5, 5, 5, 0, Math.PI, false); ctx.closePath(); ctx.stroke(); // ctx.strokeRect(0, 0, 10, 10);
}
function street () {
// a linear row of houses
ctx.save();
for (c=0; c<10; c++) {
unit();
ctx.translate(10, 0);
}
ctx.restore();
}
function street (r) {
// a curved row of houses
var length = Math.PI * r,
numunits = length/10,
step = length/numunits,
turn = Math.PI/(numunits-1);
ctx.save();
ctx.translate(-r, 0);
ctx.rotate(-Math.PI/2);
for (c=0; c<numunits; c++) {
unit();
ctx.translate(step, 0);
ctx.rotate(turn);
}
ctx.restore();
}
function city (l) {
// rows of streets
ctx.translate(125, 125);
for (var r=30; r<120; r+=20) {
street(r);
}
}
var c, ctx; function draw() {
c = document.getElementById("c3");
ctx = c.getContext("2d");
city();
}
