Fix gate facing so gates sit on the destination side of system center

- Sort gate candidates by destination-side before tier, so an on-ray point behind the center loses to any destination-side aimed/scan point
- Add a new soft "facing from the center" check in tests: when some anchor's tether circle reaches the destination side (maxProj + tether > 0), the gate must lie there; a single far planet may still take the best aimed point
- Prefer a destination-side aimed candidate in the clearance fallback

dev/jumps.test.mjs

@@ -21,9 +21,14 @@
  *   - ANCHORED systems (a planet — or the home world in the starting
  *     system): every gate is within level-1 tether (tether.level1Radius)
  *     of a planet anchor and FACES its destination star on the 2-D map
- *     (soft rule — within 90° of the system→star bearing from the
+ *     (soft rule — the gate sits on the DESTINATION SIDE of the system
- *     anchoring object); stations are NOT anchors (the player must be
+ *     center whenever some anchor can reach that side (maxProj + tether
- *     able to build out from a world), but they DO get clearance;
+ *     > 0), and from the anchoring object it is within 90° of the
+ *     system→star bearing; when the only anchor sits farther than the
+ *     tether opposite the destination — a single far planet — the gate
+ *     takes the best aimed point instead); stations are NOT anchors (the
+ *     player must be able to build out from a world), but they DO get
+ *     clearance;
  *   - every non-barren system holds at least ONE planet (the gate's
  *     anchor is guaranteed to exist);
  *   - BARREN systems (objectCount → 0 — the network's dead-end leaves):
@@ -243,9 +248,21 @@ const norm = (a) => ((a % (2 * Math.PI)) + 3 * Math.PI) % (2 * Math.PI) - Math.P
           tether++;
           if (!tWhy) tWhy = `${sys.id}: gate ${j.id} is ${Math.round(bestD)} px from its nearest anchor (> ${TETHER})`;
         }
-        // FACING (soft): from the anchoring object, the gate is on the
+        // FACING (soft, from the CENTER): the gate sits on the DESTINATION
-        // target side — within 90° of the system→star bearing (some anchor
+        // side of the system center — dot(gate, destDir) > 0 — whenever
-        // must satisfy BOTH the tether and the facing).
+        // geometry allows it: some anchor's tether circle reaches that side
+        // (maxProj + tether > 0). When every anchor sits farther than the
+        // tether opposite the destination (a single far planet), the gate
+        // takes the best aimed point — the tether rule (hard) outranks the
+        // facing rule (soft).
+        const maxProj = Math.max(...anchors.map((a) => a.x * Math.cos(th) + a.y * Math.sin(th)));
+        if (maxProj + TETHER > 0 && j.x * Math.cos(th) + j.y * Math.sin(th) <= 1e-6) {
+          facing++;
+          if (!fWhy) fWhy = `${sys.id}: gate ${j.id} faces AWAY from its destination (wrong side of the center)`;
+        }
+        // FACING (soft, from the anchor): from the anchoring object, the
+        // gate is on the target side — within 90° of the system→star
+        // bearing (some anchor must satisfy BOTH the tether and the facing).
         let onSide = false;
         for (const a of anchors) {
           const d = Math.hypot(j.x - a.x, j.y - a.y);

js/galaxy/SystemGenerator.js

@@ -458,7 +458,13 @@ function bestRotation(place, targetAngles) {
  *     target star, (3) a forward-hemisphere scan of the circle (±75°).
  *     Every candidate is exactly `range` from its anchor, so
  *     tether-reachability holds by construction and the facing deviation
- *     never exceeds 90° (in practice a few degrees). Anchors are PLANETS
+ *     never exceeds 90° (in practice a few degrees). Candidates on the
+ *     DESTINATION SIDE of the system center sort first — before every
+ *     tier — so the gate faces its destination FROM THE CENTER (the rule
+ *     the map reads) and is never placed on the far side; an on-ray
+ *     intersection behind the center loses to any destination-side
+ *     aimed/scan point.
+ *     Anchors are PLANETS
  *     only (plus the home world at home) — free-space stations are
  *     deliberately excluded: the build console lives on a world, so every
  *     gate must be tether-reachable from a planet the player can build
@@ -575,25 +581,32 @@ function layoutGates(seed, record, planets, freeSpace, isHome, targets) {
       //            (32 points, ± up to 75° from the target direction) — the
       //            clearance search for tight systems.
       // Every candidate is exactly `range` from an anchor, so the level-N
-      // tether rule (hard) is met by construction; the direction rule (soft)
+      // tether rule (hard) is met by construction. The facing rule (soft —
-      // is honored by the tier order: on-ray → aimed → near-aimed.
+      // the gate faces its destination FROM THE SYSTEM CENTER) is honored
+      // by the sort: destination-side candidates (side 0) come FIRST —
+      // before every tier — so a gate is never placed on the far side of
+      // the center (an on-ray intersection behind the center loses to any
+      // destination-side aimed/scan point); then on-ray → aimed →
+      // near-aimed.
       const cands = [];
+      const add = (tier, order, px, py) =>
+        cands.push({ tier, order, side: px * ux + py * uy > 0 ? 0 : 1, px, py });
       anchors.forEach((a, ai) => {
         const proj = a.x * ux + a.y * uy; // signed distance along the ray
         const h = Math.abs(a.x * uy - a.y * ux); // perpendicular distance
         if (h <= range) {
           const off = Math.sqrt(Math.max(0, range * range - h * h));
-          cands.push({ tier: 1, order: h * 1e6 + ai * 1000, px: (proj + off) * ux, py: (proj + off) * uy });
+          add(1, h * 1e6 + ai * 1000, (proj + off) * ux, (proj + off) * uy);
         }
-        cands.push({ tier: 2, order: h * 1e6 + ai * 1000, px: a.x + range * ux, py: a.y + range * uy });
+        add(2, h * 1e6 + ai * 1000, a.x + range * ux, a.y + range * uy);
         for (let k = 0; k < 32; k++) {
           const phi = -1.3089 + (2.6179 * k) / 31; // ±75° around the target direction
           const dx = ux * Math.cos(phi) - uy * Math.sin(phi);
           const dy = ux * Math.sin(phi) + uy * Math.cos(phi);
-          cands.push({ tier: 3, order: Math.abs(phi) * 1e6 + h + ai * 1e-3, px: a.x + range * dx, py: a.y + range * dy });
+          add(3, Math.abs(phi) * 1e6 + h + ai * 1e-3, a.x + range * dx, a.y + range * dy);
         }
       });
-      cands.sort((p, q) => p.tier - q.tier || p.order - q.order);
+      cands.sort((p, q) => p.side - q.side || p.tier - q.tier || p.order - q.order);
 
       const ok = (c) => {
         const d2c = c.px * c.px + c.py * c.py;
@@ -622,9 +635,12 @@ function layoutGates(seed, record, planets, freeSpace, isHome, targets) {
       if (!chosen) {
         // Every candidate failed clearance (nearly impossible — an anchor's
         // tether circle is 5120 px across, the discs under a thousand): take
-        // the first anchor's aimed point anyway — the tether and facing rules
+        // the first DESTINATION-SIDE aimed point anyway — the tether and
-        // outrank cosmetics.
+        // facing rules outrank cosmetics.
-        chosen = cands.find((c) => c.tier === 2) ?? cands[0];
+        chosen =
+          cands.find((c) => c.tier === 2 && c.side === 0) ??
+          cands.find((c) => c.tier === 2) ??
+          cands[0];
         console.warn(
           `[orbit] ${record.id}: gate ${i + 1} fell back to its first aimed candidate (clearance)`,
         );