chart = {
const context = DOM.context2d(width, height);
const path = d3.geoPath(projection, context).pointRadius(2.5);
context.beginPath();
path(graticule);
context.lineWidth = 1;
context.strokeStyle = "#ccc";
context.stroke();
context.beginPath();
path(sphere);
context.strokeStyle = "#000";
context.stroke();
context.beginPath();
path(mesh);
context.stroke();
context.beginPath();
path({type: "MultiPoint", coordinates: points});
context.fillStyle = "#f00";
context.fill();
return context.canvas;
}