ludic.wildlife (18.2): a walker a crowd moves

wildlife_set_crowd(a, true) hands a walker to a crowd. Its step no longer moves it, and its want is two fields on it: goal_x / goal_z (the point it heads for or faces) and goal_speed (0 when it stands). A route reads those and hands back where the crowd put it through wildlife_moved(a, x, z, vx, vz). That sets its place, its ground, its heading from its velocity and its prints, and updates its row's columns so the spatial index finds it there. Nothing allocates per animal per frame: the want is the animal's own fields, and moved writes in place. The prints and the turn counters moved to walked.ludic (steer.ludic was at the 100-line limit). crowd_test holds it; with crowd off every old test is unchanged. wildlife 26/26.

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

packages/ludic.wildlife/tests/crowd_test.ludic

@@ -0,0 +1,83 @@
+# crowd_test.ludic - a walker a crowd moves (phase 18): it says where it is going and how fast and
+# stays where it is, standing still is a speed of 0, and where the crowd puts it is its place,
+# its heading and its prints, found there by the table's index
+import "ludic.wildlife"
+import "ludic.base"
+import "fake"
+program WildCrowdTest {
+  numbers float
+  bind WildlifeWorld {
+    ground: fn fk_ground
+    water: fn fk_water
+    forest: fn fk_forest
+    sight: fn fk_sight
+    push: fn fk_push
+    pushed_x: fn fk_pushed_x
+    pushed_z: fn fk_pushed_z
+    players: fn fk_players
+    player_on: fn fk_player_on
+    player_x: fn fk_x
+    player_y: fn fk_y
+    player_z: fn fk_z
+    hidden: fn fk_is_hidden
+    noise: fn fk_noise_of
+    scent: fn fk_scent_of
+    stillness: fn fk_still_of
+    wind: fn fk_wind_of
+    wind_dir: fn fk_wind_to
+    winterness: fn fk_winter_of
+    about: fn fk_about_of
+    per_range: fn fk_one
+    lures: fn fk_count
+    lure: fn fk_lure
+    present: fn fk_present
+    born: fn fk_on_born
+    spot: fn fk_spot
+  }
+
+
+  function walker(wildlife_st: mut WildlifeState, wildlife_tests_fake_st: mut WildlifeTestsFakeState) -> WildAnimal {
+    fk_setup(wildlife_st, wildlife_tests_fake_st)
+    let a = wildlife_make(wildlife_st, 0, 0.0, 0.0, false, 0.0, 0, 1.0, 1)
+    wildlife_tests_fake_st.fk_px[0] = 400.0
+    wildlife_tests_fake_st.fk_pz[0] = 0.0
+    wildlife_tests_fake_st.fk_hidden = true
+    wildlife_set_crowd(a, true)
+    return a
+  }
+
+  test "a crowd walker says where and how fast, and does not move itself" (wildlife_st: mut WildlifeState, wildlife_tests_fake_st: mut WildlifeTestsFakeState) {
+    let a = walker(wildlife_st, wildlife_tests_fake_st)
+    a.state = WILD_WANDER
+    a.tx = 0.0
+    a.tz = -100.0
+    a.timer = 300.0
+    for k in 0 .. 120 { wildlife_tick(wildlife_st, 1.0 / 60.0, 0.0) }
+    expect_eq(a.x, 0.0)
+    expect_eq(a.z, 0.0)
+    expect_eq(a.goal_x, 0.0)
+    expect_eq(a.goal_z, -100.0)
+    expect(a.goal_speed > 0.5)
+    a.state = WILD_IDLE
+    a.timer = 300.0
+    wildlife_tick(wildlife_st, 1.0 / 60.0, 0.0)
+    expect_eq(a.goal_speed, 0.0)
+  }
+
+  test "where the crowd puts it is its place, its heading, its prints, and the index finds it there" (wildlife_st: mut WildlifeState, wildlife_tests_fake_st: mut WildlifeTestsFakeState) {
+    let a = walker(wildlife_st, wildlife_tests_fake_st)
+    q_clear(wildlife_facts(wildlife_st))
+    for k in 1 .. 41 { wildlife_moved(wildlife_st, a, 0.0, -0.1 * float(k), 0.0, -1.2) }
+    expect_near(a.z, -4.0, 0.0001)
+    expect_near(a.y, 10.0, 0.0001)
+    expect_near(Math.sin(a.yaw), 0.0, 0.0001)
+    expect(Math.cos(a.yaw) > 0.99)
+    var prints = 0
+    let fs = q_drain(wildlife_facts(wildlife_st))
+    for i in 0 .. len(fs) { if fs[i].what == WILD_PRINT { prints += 1 } }
+    expect_eq(prints, 1)
+    let out = new []WildAnimal
+    expect_eq(wildlife_near(wildlife_st, 0.0, -4.0, 1.0, out), 1)
+    expect_eq(wildlife_near(wildlife_st, 0.0, 0.0, 1.0, out), 0)
+  }
+}