ludic.physics, ludic.character, ludic.vehicles: fact records reused, and phys_sink allocates nothing

The per-frame sweep over physics, character, vehicles and nav found three fact makers that made a record per fact: contacts and splashes, the character's and the vehicles'. Each keeps a pool now, as wildlife's and npc's do (q_unheld). phys_sink, asked on every removal, built two new lists each time; it filters into a kept spare pair and swaps. ludic.nav's paths and crowds already allocate nothing, and none of the four builds a string per call. What remains at load, reset or a world swap is not per frame. vehicle_feed takes its state mut. vehicles_test: 1000 fed facts, drained turn by turn, use at most 4 records. All packages 421.

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

packages/ludic.physics/shapes.ludic

@@ -32,8 +32,8 @@ export function phys_close(physics_st: mut PhysicsState) -> void {
     }
   }
   physics_st.ph_shapes = new []pointer
-  physics_st.ph_floats = new []int
-  physics_st.ph_float_k = new []float
+  List.clear(physics_st.ph_floats)
+  List.clear(physics_st.ph_float_k)
   if physics_st.ph_facts != null { q_clear(physics_st.ph_facts) }
 }
 

packages/ludic.physics/state.ludic

@@ -46,12 +46,17 @@ export state PhysicsState {
   ph_hard: float = 2.0            # metres a second: a contact under this is not a fact
   ph_floats: []int = new []int         # buoyant bodies' ids
   ph_float_k: []float = new []float      # and theirs: buoyancy, linear drag, angular drag, wet
+  ph_floats2: []int = new []int        # the spare pair phys_sink filters into
+  ph_float_k2: []float = new []float
   ph_rx: float = 0.0               # where the last phys_resolve put a body
   ph_rz: float = 0.0
   ph_walkers: []pointer = new []pointer   # a walker id is its place here; null once removed
   ph_ids: []int = words(PH_CAP * 2)
   ph_vals: []float = floats(PH_CAP * 4)
   ph_facts: Queue<PhysFact> = ph_facts__new()
+  ph_fpool: []PhysFact = new []PhysFact   # every fact record made, reused once no drain holds it
+  ph_ffree: []PhysFact = new []PhysFact
+  ph_fnext: int = 0
 }
 
 # the facts, oldest first

packages/ludic.physics/system.ludic

@@ -33,12 +33,28 @@ export function phys_steps(physics_st: PhysicsState) -> int { return physics_st.
 # m/s2 down is negative
 export function phys_gravity(physics_st: mut PhysicsState, y: float) -> void { if physics_st.ph_world != null { jph_world_gravity(physics_st.ph_world, y) } }
 
+# a fact record no drain holds any more, made fresh (and kept) only when every one is held: a
+# fact can come every frame, and a record a frame is never given back
+function ph_fact_record(physics_st: mut PhysicsState) -> PhysFact {
+  if physics_st.ph_fnext >= len(physics_st.ph_ffree) {
+    q_unheld(phys_facts(physics_st), physics_st.ph_fpool, physics_st.ph_ffree)
+    physics_st.ph_fnext = 0
+  }
+  if physics_st.ph_fnext < len(physics_st.ph_ffree) {
+    let f = physics_st.ph_ffree[physics_st.ph_fnext]
+    physics_st.ph_fnext += 1
+    return f
+  }
+  let f = new PhysFact
+  push(physics_st.ph_fpool, f)
+  return f
+}
 function ph_contacts(physics_st: mut PhysicsState) -> void {
   let n = jph_contacts_drain(physics_st.ph_world, physics_st.ph_ids, physics_st.ph_vals, PH_CAP)
   for i in 0 .. n {
     let speed = physics_st.ph_vals[i * 4 + 3]
     if speed >= physics_st.ph_hard {
-      let f = new PhysFact
+      let f = ph_fact_record(physics_st)
       f.what = PHYS_HIT
       f.a = physics_st.ph_ids[i * 2]
       f.b = physics_st.ph_ids[i * 2 + 1]

packages/ludic.physics/water.ludic

@@ -13,17 +13,22 @@ export function phys_float(physics_st: mut PhysicsState, id: int, buoyancy: floa
   push(physics_st.ph_float_k, 0.0)
 }
 
-# no longer floats (it is still a body)
+# no longer floats (it is still a body); every removal asks, so the lists are filtered into a kept
+# spare pair and swapped, never made anew
 export function phys_sink(physics_st: mut PhysicsState, id: int) -> void {
   if physics_st.ph_floats == null { return }
-  let ids = new []int
-  let ks = new []float
+  let ids = physics_st.ph_floats2
+  let ks = physics_st.ph_float_k2
+  List.clear(ids)
+  List.clear(ks)
   for i in 0 .. len(physics_st.ph_floats) {
     if physics_st.ph_floats[i] != id {
       push(ids, physics_st.ph_floats[i])
       for k in 0 .. PH_K { push(ks, physics_st.ph_float_k[i * PH_K + k]) }
     }
   }
+  physics_st.ph_floats2 = physics_st.ph_floats
+  physics_st.ph_float_k2 = physics_st.ph_float_k
   physics_st.ph_floats = ids
   physics_st.ph_float_k = ks
 }
@@ -56,10 +61,12 @@ function ph_buoy_one(physics_st: mut PhysicsState, i: int, id: int, x: float, z:
   physics_st.ph_float_k[k + 3] = float(wet)
 }
 
-function ph_splash(physics_st: PhysicsState, id: int, x: float, y: float, z: float) -> void {
-  let f = new PhysFact
+function ph_splash(physics_st: mut PhysicsState, id: int, x: float, y: float, z: float) -> void {
+  let f = ph_fact_record(physics_st)
   f.what = PHYS_SPLASH
   f.a = id
+  f.b = -1
+  f.speed = 0.0
   f.x = x;  f.y = y;  f.z = z
   q_push(phys_facts(physics_st), f)
 }