ludic.anim: animset_choice names the playing choice's clip as the set does, animset_can says whether the rig carries any of a state's clips (a one-shot with none is not asked for)

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

packages/ludic.anim/README.md

@@ -68,7 +68,9 @@ and transitions (from a state or `"*"`, with a fade; with `@frame when: fn() ->
 own the frame it answers true). The code binds an `AnimPlayer` to a set and a rig
 (`animset_bind`), sets parameters (`animset_param`), asks for a state (`animset_request`, taken once
 however often it is asked) and ticks it into a skin (`animset_tick`). A one-shot (`loop: false`)
-holds its last pose and hands on to `next`. Clip names are made once per rig; a tick makes nothing.
+holds its last pose and hands on to `next`. `animset_choice` names the playing choice's clip as the set
+does ("sit_seat", no rig), and `animset_can(key)` says whether the rig carries any of a state's clips, so a
+one-shot with none yet is not asked for. Clip names are made once per rig; a tick makes nothing.
 
 ## Tests
 

packages/ludic.anim/set_pick.ludic

@@ -15,6 +15,17 @@ export function animset_request(pl: AnimPlayer, key: string) -> void {
   pl.want = i
 }
 
+# the state is in the set and the rig carries one of its clips: a one-shot with none is not asked for
+export function animset_can(pl: AnimPlayer, key: string) -> bool {
+  if pl.set < 0 or pl.clips == null { return false }
+  let i = as_state(AnimSets[pl.set], key)
+  if i < 0 { return false }
+  let d = AnimSets[pl.set].states[i]
+  if d.choices == null { return false }
+  for c in 0 .. len(d.choices) { if pl.clips[pl.base[i] + c] != null { return true } }
+  return false
+}
+
 function as_param_at(pl: AnimPlayer, name: string) -> int {
   if pl.set < 0 { return -1 }
   let s = AnimSets[pl.set]

packages/ludic.anim/set_player.ludic

@@ -20,10 +20,16 @@ export property AnimPlayer {
   mix: float = 1.0
   fade: float = 0.2
   rate: float = 1.0
+  pick: int = -1            # which of the state's choices plays
 }
 
 export function animset_clip(pl: AnimPlayer) -> Clip { return pl.clip }
 export function animset_time(pl: AnimPlayer) -> float { return pl.t }
 export function animset_rate(pl: AnimPlayer) -> float { return pl.rate }
+# the playing choice's clip as the set names it, without the rig ("sit_seat"); "" before a tick
+export function animset_choice(pl: AnimPlayer) -> string {
+  if pl.set < 0 or pl.pick < 0 { return "" }
+  return AnimSets[pl.set].states[pl.state].choices[pl.pick].clip
+}
 export function animset_ready(pl: AnimPlayer) -> bool { return pl.ready }
 export function animset_bound(pl: AnimPlayer, set: int, rig: string) -> bool { return pl.set == set and pl.rig == rig and pl.names != null }

packages/ludic.anim/set_tick.ludic

@@ -6,6 +6,7 @@ export function animset_tick(anim_st: mut AnimState, pl: AnimPlayer, sk: Skin, d
   let d = AnimSets[pl.set].states[pl.state]
   let k = as_pick(pl, d)
   if k < 0 { return false }
+  pl.pick = k
   pl.rate = as_rate(pl, d, d.choices[k])
   as_switch(pl, d, pl.clips[pl.base[pl.state] + k])
   let adv = dt * pl.rate

packages/ludic.anim/tests/animset_test.ludic

@@ -113,4 +113,15 @@ program AnimSetTest {
     }
     expect(playing(pl) == "rig_idle")
   }
+  test "the playing choice is named as the set names it; a state the rig has no clip for cannot be asked" (anim_st: mut AnimState, render3d_st: mut Render3dState) {
+    let sk = skin(render3d_st)
+    let pl = rig(anim_st)
+    expect(animset_choice(pl) == "")
+    animset_param(pl, "speed", 1.0)
+    animset_tick(anim_st, pl, sk, 0.016)
+    expect(animset_choice(pl) == "walk")
+    expect(animset_can(pl, "wave"))
+    expect(not animset_can(pl, "bow"))
+    expect(not animset_can(pl, "nope"))
+  }
 }

packages/ludic.anim/tests/sets.lres

@@ -1,5 +1,5 @@
 # sets.lres - the test's one set: a ground state picking by speed bands, a one-shot that hands back,
-# and a hop the code never asks for, taken when toy_hops says so
+# a hop the code never asks for, taken when toy_hops says so, and a bow no rig carries
 toy {
   entry: "ground"
   params: ["speed"]
@@ -14,7 +14,8 @@ toy {
       ]
     },
     { key: "wave", loop: false, next: "ground", choices: [{ clip: "wave" }] },
-    { key: "hop", choices: [{ clip: "hop" }] }
+    { key: "hop", choices: [{ clip: "hop" }] },
+    { key: "bow", loop: false, next: "ground", choices: [{ clip: "bow" }] }
   ]
   transitions: [{ from: "ground", to: "hop", blend: 0.1, when: fn toy_hops }]
 }