Add basic background rendering

js/graphics/background.mjs

@@ -0,0 +1,21 @@
+import {SeededRandom} from '../util.mjs';
+import {context, view, getVisibleSectors} from './index.mjs';
+import {STAR_DENSITY} from '../consts.mjs';
+
+export function render() {
+	context.fillStyle = '#000';
+
+	getVisibleSectors().forEach(s => renderSectorStars(s));
+}
+
+function renderSectorStars(sector) {
+	let rand = new SeededRandom(sector.numId);
+
+	context.fillStyle = '#fff';
+
+	for (let i = 0; i < STAR_DENSITY; i++) {
+		let sx = rand.next() * sector.size + sector.wx;
+		let sy = rand.next() * sector.size + sector.wy;
+		context.fillRect(sx, sy, 1.5, 1.5);
+	}
+}