ludic.base, ludic.wildlife, ludic.npc: fact records reused, not made per fact

wl_fact made a new WildFact per fact, about one a frame, and Ludic never gives one back. ludic.base's q_unheld(q, pool, out) lists the records a queue no longer holds: neither waiting nor handed out by its last drain, which is good until the next drain. ludic.wildlife and ludic.npc now keep a pool, hand out a free record, and make a new one only when every record is held. Taking a record writes the state, so wl_fact / np_fact and the few callers holding their state read-only take it mut. Tests: q_unheld's rules (an empty drain holds on, the safe side); 3000 prints drained frame by frame use at most 4 records; 500 arrivals drained turn by turn use at most 4. base 37, wildlife 27, npc 17; all packages 420.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.npc/act.ludic

@@ -30,7 +30,7 @@ function np_turns(act: int) -> bool {
 }
 
 # a player who came within notice since the last look is greeted - once, until they walk off
-export function npc_notice(npc_st: NpcState, p: NpcPerson) -> void {
+export function npc_notice(npc_st: mut NpcState, p: NpcPerson) -> void {
   let reach = NpcKinds[p.kind].notice
   for i in 0 .. NpcWorld.players() {
     if i >= 30 { break }

packages/ludic.npc/person.ludic

@@ -13,6 +13,9 @@ export state NpcState {
   np_n: int = 0                 # walkers about
   np_dice: Rng = rng_new(20260925)
   np_facts: Queue<NpcFact> = np_facts__new()
+  np_fpool: []NpcFact = new []NpcFact      # every fact record made, reused once no drain holds it
+  np_ffree: []NpcFact = new []NpcFact
+  np_fnext: int = 0
   np_next_h: float = 0.0        # the hour the census is next looked at
   np_hold: bool = false         # held where they stand (a shot of their poses)
   np_mirror: bool = false       # a guest drawing a host's: no routine runs here
@@ -29,8 +32,8 @@ export function npc_facts(npc_st: NpcState) -> Queue<NpcFact> {
   return npc_st.np_facts
 }
 
-function np_fact(npc_st: NpcState, what: int, p: NpcPerson, player: int) -> NpcFact {
-  let f = new NpcFact
+function np_fact(npc_st: mut NpcState, what: int, p: NpcPerson, player: int) -> NpcFact {
+  let f = np_fact_record(npc_st)
   f.what = what
   f.person = p.id
   f.slot = p.slot

packages/ludic.npc/tests/way_test.ludic

@@ -101,4 +101,20 @@ program NpcWayTest {
     expect_eq(p.act, NPCA_SIT)
     expect(p.phase > 100.0)
   }
+
+  test "an arrival a turn, drained each turn, makes a few fact records and then reuses them" (npc_st: mut NpcState, npc_tests_fake_st: mut NpcTestsFakeState, way_test_st: WayTestState) {
+    fk_setup(npc_st, npc_tests_fake_st)
+    npc_tests_fake_st.fk_want = 1
+    let p = npc_spawn(npc_st, NPCK_HIKER)
+    var arrived = 0
+    for k in 0 .. 500 {
+      npc_set_at(p, 0.0, 0.0)
+      npc_go(npc_st, p, 0.5, 0.0, NPCA_SIT, 30.0)
+      npc_tick(npc_st, 0.05)
+      let fs = q_drain(npc_facts(npc_st))
+      for i in 0 .. len(fs) { if fs[i].what == NPC_F_ARRIVED { arrived += 1 } }
+    }
+    expect(arrived > 400)
+    expect(npc_fact_records(npc_st) <= 4)
+  }
 }

packages/ludic.npc/way.ludic

@@ -4,7 +4,7 @@
 export const NPC_STUCK_DETOUR: int = 0     # a step round what was in front of it
 export const NPC_STUCK_RETRY: int = 1      # no closer for twenty seconds, or no step round: planned again
 export const NPC_STUCK_GAVE_UP: int = 2    # the third of those: the target given up
-function np_stuck_fact(npc_st: NpcState, p: NpcPerson, how: int) -> void {
+function np_stuck_fact(npc_st: mut NpcState, p: NpcPerson, how: int) -> void {
   let f = np_fact(npc_st, NPC_F_STUCK, p, -1)
   f.how = how
   f.x = p.x
@@ -77,3 +77,26 @@ export function npc_moved(p: NpcPerson, x: float, z: float, vx: float, vz: float
   if vx * vx + vz * vz > 0.01 { p.yaw = Math.atan2(-vx, -vz) }
   p.phase = p.phase + Math.sqrt(dx * dx + dz * dz) * 2.6
 }
+
+# a fact record no drain holds any more, made fresh (and kept) only when every one is held
+function np_fact_record(npc_st: mut NpcState) -> NpcFact {
+  if npc_st.np_fnext >= len(npc_st.np_ffree) {
+    q_unheld(npc_st.np_facts, npc_st.np_fpool, npc_st.np_ffree)
+    npc_st.np_fnext = 0
+  }
+  if npc_st.np_fnext < len(npc_st.np_ffree) {
+    let f = npc_st.np_ffree[npc_st.np_fnext]
+    npc_st.np_fnext += 1
+    f.line = -1
+    f.choice = -1
+    f.how = 0
+    f.x = 0.0
+    f.z = 0.0
+    return f
+  }
+  let f = new NpcFact
+  push(npc_st.np_fpool, f)
+  return f
+}
+# how many fact records have ever been made: the peak held at once, not the facts pushed
+export function npc_fact_records(npc_st: NpcState) -> int { return len(npc_st.np_fpool) }