Merge pull request #2007 from rdbtCVS/fix/1962-passenger-animation

🤖 Agent: contrib-gate-17 verified this head (26.3 sources, integration tree build, clippy, tests, parity; details in the PR comment). Thanks @rdbtCVS!

crates/horizon-client/examples/probe/entity_anim_fixture.rs

@@ -393,7 +393,7 @@ pub fn main() -> horizon_client::Result<()> {
             mob.extra.age = -24000;
         }
         mob.age = f("ageInTicks") as u32;
-        let state = State {
+        let mut state = State {
             pos: f("walkAnimationPos"),
             speed: f("walkAnimationSpeed"),
             age: f("ageInTicks"),
@@ -405,6 +405,20 @@ pub fn main() -> horizon_client::Result<()> {
         };
         let mut poses = Poses::new(&model);
         entity_state(&mut mob, def.species, case);
+        if let Some(ticks) = case["@walkTicks"].as_array() {
+            for speed in ticks {
+                mob.previous_limb_speed = mob.limb_speed;
+                mob.limb_speed += (speed.as_f64().unwrap() as f32 - mob.limb_speed) * 0.4;
+                mob.limb_position += mob.limb_speed;
+            }
+            if !case["@alive"].as_bool().unwrap() {
+                mob.health = 0.0;
+            }
+            let extracted = anim::state(&mob, f("@partial"));
+            state.pos = extracted.pos;
+            state.speed = extracted.speed;
+        }
+
         let flag = |k: &str| case[k].as_bool().unwrap_or(false);
         let num = |k: &str| case[k].as_f64().unwrap_or(0.0) as f32;
         let started = |k: &str| AnimationState {
@@ -598,7 +612,11 @@ pub fn main() -> horizon_client::Result<()> {
             }
             _ => anim::setup(&mob, s, p, &animations),
         }
-        out.push_str(&format!("{}\n", emit(&model, &mut poses, case, layer)));
+        let mut result = emit(&model, &mut poses, case, layer);
+        if case["@walkTicks"].is_array() {
+            result["walk"] = json!([state.pos, state.speed]);
+        }
+        out.push_str(&format!("{result}\n"));
     }
     fs::write(&args[2], out)?;
     Ok(())

crates/horizon-client/src/mobs/anim.rs

@@ -189,14 +189,15 @@ pub fn state(m: &Mob, alpha: f32) -> State {
         swing += 1.0;
     }
     let swing = m.anim.attack_anim_o + swing * alpha;
-    let alive = m.alive();
+    // LivingEntityRenderer.extractRenderState: riding motion is not walking.
+    let walking = m.alive() && !m.extra.passenger;
     State {
-        pos: if alive {
+        pos: if walking {
             m.limb_position - m.limb_speed * (1.0 - alpha)
         } else {
             0.0
         },
-        speed: if alive {
+        speed: if walking {
             (m.previous_limb_speed + (m.limb_speed - m.previous_limb_speed) * alpha).min(1.0)
         } else {
             0.0

mods/horizon/src/test/java/dev/horizonlab/parity/VanillaEntityAnimOracle.java

@@ -312,6 +312,19 @@ public final class VanillaEntityAnimOracle {
                 state.getClass();
                 for (var entry : kase.entrySet())
                     if (!entry.getKey().startsWith("@")) set(state, entry.getKey(), entry.getValue());
+                if (kase.has("@walkTicks")) {
+                    var walk = new net.minecraft.world.entity.WalkAnimationState();
+                    for (var speed : kase.getAsJsonArray("@walkTicks"))
+                        walk.update(speed.getAsFloat(), 0.4F, 1.0F);
+                    // LivingEntity.calculateEntityAnimation stops passengers/dead entities;
+                    // LivingEntityRenderer.extractRenderState also zeros both fields.
+                    if (kase.get("isPassenger").getAsBoolean() || !kase.get("@alive").getAsBoolean())
+                        walk.stop();
+                    float partial = kase.get("@partial").getAsFloat();
+                    set(state, "walkAnimationPos", gson.toJsonTree(walk.position(partial)));
+                    set(state, "walkAnimationSpeed", gson.toJsonTree(walk.speed(partial)));
+                    result.add("walk", gson.toJsonTree(new float[]{walk.position(partial), walk.speed(partial)}));
+                }
                 hooks(state, kase);
                 if (state instanceof net.minecraft.client.renderer.entity.state.ArmedEntityRenderState armed && armed.swingAnimation > 0)
                     armed.currentSwing = new net.minecraft.world.entity.LivingEntity.SwingDescription(net.minecraft.world.InteractionHand.MAIN_HAND, net.minecraft.world.item.component.SwingAnimation.DEFAULT, 6);

tools/test_entity_model_parity.py

@@ -164,6 +164,15 @@ def cases(layer, model=None):
     cases_out = [{**c, **DEFAULTS.get(name, {})} for c in cases_out]
     yield from cases_out
     yield from species_cases(layer, cases_out)
+    # Exercise render-state extraction with a live walk clock, including the
+    # first mounted frame. Existing setupAnim cases bypass anim::state.
+    if name == 'skeleton':
+        for passenger in [False, True]:
+            for alive in [False, True]:
+                for partial in [0.0, 0.5, 1.0]:
+                    yield {**cases_out[2], 'isPassenger': passenger,
+                           '@walkTicks': [0.5, 1.0, 0.75],
+                           '@alive': alive, '@partial': partial}
     part = model and scaled_part(model)
     if part:
         for index, scale in enumerate(PART_SCALES):
@@ -387,6 +396,10 @@ def main():
             skipped.add(layer); continue
         checked += 1
         bad = []
+        if 'walk' in v:
+            for a, b in zip(v['walk'], r['walk']):
+                if abs(a - b) > args.tolerance * (1.0 + abs(a)):
+                    bad.append(('@walk', f'{v["walk"]} != {r["walk"]}'))
         for path, expected in v['parts'].items():
             got = r['parts'].get(path)
             if got is None: