orbit/js/galaxy/SystemChart.js

/**
 * SystemChart — the pure geometry + stats behind the deck's MAP console
 * (js/ui/MapWindow.js draws on it; GameScene feeds it).
 *
 *   chartBounds(objects, padding)   the system's chart frame: the furthest
 *                                   X/Y extents of EVERY object (planets,
 *                                   stations, jump gates AND asteroid
 *                                   clusters — discovered or not) plus
 *                                   `padding` px (data/map.json →
 *                                   bounds.padding, ~1024) on each edge.
 *   fitToRect(bounds, w, h)         the world → plate transform that fits
 *                                   that frame into the map plate, centred.
 *   navDiscoveryStats(d, sysId, c)  the SYSTEM DISCOVERY share — the NAV
 *                                   objects (planets + free-space stations
 *                                   + jump gates; the central body is the
 *                                   chart's anchor, not a count) vs. the
 *                                   player's Discovery state.
 *   resourceStats(d, sysId, c)      the SYSTEM RESOURCES share — the
 *                                   asteroid fields vs. Discovery (the only
 *                                   resource kind for now).
 *
 * Pure (no Phaser) — Node-testable (dev/system-chart.test.mjs). The NAV
 * point set is SystemCategory.navPoints (the same discoverable set the
 * jumpgate chart gate uses) minus the central body, per the readout's
 * rule: planets, stations, gates.
 */
import { navPoints } from '../research/SystemCategory.js';

/**
 * The chart's bounding frame from a list of objects.
 *
 * @param {Array<{x:number, y:number, radius:number}>} objects — the system's
 *   objects (any discoverable set; `radius` = the object's extent from its
 *   center — planet disc radius, station/gate keepout, cluster bound)
 * @param {number} [padding=1024] — px of margin added on every edge
 * @returns {{minX:number, minY:number, maxX:number, maxY:number,
 *            w:number, h:number, cx:number, cy:number}}
 *   (a degenerate empty list yields a `2×padding` box about the origin)
 */
export function chartBounds(objects, padding = 1024) {
  let minX = Infinity;
  let minY = Infinity;
  let maxX = -Infinity;
  let maxY = -Infinity;
  for (const o of objects ?? []) {
    if (!o || typeof o.x !== 'number' || typeof o.y !== 'number') continue;
    const r = Math.max(0, Number(o.radius) || 0);
    if (o.x - r < minX) minX = o.x - r;
    if (o.y - r < minY) minY = o.y - r;
    if (o.x + r > maxX) maxX = o.x + r;
    if (o.y + r > maxY) maxY = o.y + r;
  }
  if (!Number.isFinite(minX) || !Number.isFinite(maxX) || !Number.isFinite(minY) || !Number.isFinite(maxY)) {
    // No objects: a zero-size box about the origin (the padding then makes
    // the chart a 2×padding box about it).
    minX = 0;
    minY = 0;
    maxX = 0;
    maxY = 0;
  }
  minX -= padding;
  minY -= padding;
  maxX += padding;
  maxY += padding;
  return { minX, minY, maxX, maxY, w: maxX - minX, h: maxY - minY, cx: (minX + maxX) / 2, cy: (minY + maxY) / 2 };
}

/**
 * Fit a world-space rect into a plate of `w × h`, centred, uniform scale.
 *
 * @param {ReturnType<typeof chartBounds>} bounds
 * @param {number} w — plate width (px)
 * @param {number} h — plate height (px)
 * @returns {{scale:number, ox:number, oy:number, toX:(x:number)=>number,
 *            toY:(y:number)=>number}}
 *   `toX`/`toY` map world → plate; `scale` = plate px per world px.
 */
export function fitToRect(bounds, w = 100, h = 100) {
  const scale = Math.min(w, h) / Math.max(1, Math.max(bounds.w, bounds.h));
  const ox = w / 2 - bounds.cx * scale;
  const oy = h / 2 - bounds.cy * scale;
  return {
    scale,
    ox,
    oy,
    toX: (x) => x * scale + ox,
    toY: (y) => y * scale + oy,
  };
}

/**
 * The SYSTEM DISCOVERY share (data/map.json → stats): the player's found /
 * total over the system's NAV objects — planets, free-space stations and
 * jump gates (SystemCategory.navPoints minus the central body 'home',
 * which is the chart's anchor rather than a discoverable count — and
 * minus the asteroid clusters, which are the RESOURCE side of the readout).
 *
 * @param {object} discovery — the Discovery state (isDiscovered)
 * @param {string} systemId
 * @param {object} content — the generated system content
 * @returns {{total:number, found:number, pct:number}} — `pct` is 0..1
 *   (0 when the system has no NAV objects, which the readout renders as —)
 */
export function navDiscoveryStats(discovery, systemId, content) {
  const points = navPoints(content).filter((p) => p.kind !== 'home');
  const canQuery = typeof discovery?.isDiscovered === 'function';
  let found = 0;
  for (const p of points) if (canQuery && discovery.isDiscovered(systemId, p.id)) found++;
  const total = points.length;
  return { total, found, pct: total > 0 ? found / total : 0 };
}

/**
 * The SYSTEM RESOURCES share (data/map.json → stats): the player's found /
 * total over the system's asteroid fields (content.asteroids — the only
 * resource kind for now).
 *
 * @param {object} discovery — the Discovery state (isDiscovered)
 * @param {string} systemId
 * @param {object} content — the generated system content
 * @returns {{total:number, found:number, pct:number}}
 */
export function resourceStats(discovery, systemId, content) {
  const clusters = (content?.asteroids ?? []).filter((c) => c && typeof c.id === 'string');
  const canQuery = typeof discovery?.isDiscovered === 'function';
  let found = 0;
  for (const c of clusters) if (canQuery && discovery.isDiscovered(systemId, c.id)) found++;
  const total = clusters.length;
  return { total, found, pct: total > 0 ? found / total : 0 };
}