The deep: a Portuguese man o' war drifts over in the sunlit water

components/OceanScene.tsx

@@ -32,7 +32,7 @@ import { Wash } from '@/lib/ocean/wash';
 import { outcropsInView } from '@/lib/ocean/outcrop';
 import { drawOutcrops, OutcropCache } from '@/lib/ocean/outcrop-sprite';
 import { drawDumbo, drawLure, drawWhaleFall } from '@/lib/ocean/sightings-deep';
-import { drawOarfish, drawSiphonophore, drawTurtle } from '@/lib/ocean/sightings-shallow';
+import { drawManOWar, drawOarfish, drawSiphonophore, drawTurtle } from '@/lib/ocean/sightings-shallow';
 import { jellyForBlock } from '@/lib/ocean/lineage';
 import { HUES, waterAt, type Ground, type Water } from '@/lib/ocean/palette';
 import { hash32 } from '@/lib/ocean/random';
@@ -348,6 +348,7 @@ export default function OceanScene({
         else if (event.kind === 'turtle') drawTurtle(bctx, W, H, age, event.seed, px, ambient, water.dark, jelly);
         else if (event.kind === 'siphonophore') drawSiphonophore(bctx, W, H, age, event.seed, px, ambient, water.dark);
         else if (event.kind === 'oarfish') drawOarfish(bctx, W, H, age, event.seed, px, ambient, water.dark);
+        else if (event.kind === 'manowar') drawManOWar(bctx, W, H, age, event.seed, px, ambient, water.dark);
         else if (event.kind === 'lure') drawLure(bctx, W, H, age, event.seed, px, ambient, water.dark);
         else if (event.kind === 'dumbo') drawDumbo(bctx, W, H, age, event.seed, px, ambient, water.dark);
       }

lib/ocean/events.ts

@@ -23,7 +23,8 @@ export type EventKind =
   | 'lure'
   | 'dumbo'
   | 'whalefall'
-  | 'oarfish';
+  | 'oarfish'
+  | 'manowar';
 
 interface Spec {
   zones: number[];
@@ -48,12 +49,17 @@ export const EVENTS: Record<EventKind, Spec> = {
   // Arrives over its span, then stays on the floor for the rest of the sitting.
   whalefall: { zones: [3, 4], perHour: 0.04, seconds: 20, phrase: 'a whale fall on the floor', weight: 800 },
   oarfish: { zones: [1, 2], perHour: 0.006, seconds: 60, phrase: 'an oarfish, hanging in the dark', weight: 1100 },
+  // A surface animal, so only in the first of the light.
+  manowar: { zones: [0], perHour: 0.8, seconds: 50, phrase: "a Portuguese man o' war drifted over", weight: 250 },
 };
 const ORDER: EventKind[] = ['leviathan', 'eye', 'storm', 'whale'];
 /* The second roll, added after the first had been out in the world: its
    events only land in minutes the first left well alone, so no saved
    sitting loses or moves anything it already had. */
 const LATER: EventKind[] = ['oarfish', 'whalefall', 'siphonophore', 'dumbo', 'lure', 'turtle'];
+/* The third, the same again: only in minutes both rolls before it left
+   well alone, so nothing either of them put in a sitting moves. */
+const LATEST: EventKind[] = ['manowar'];
 const GAP_MINUTES = 8;
 const MAX_SECONDS = 90;
 
@@ -71,10 +77,18 @@ function rawAt(biome: Biome, minute: number): EventKind | null {
 }
 
 function laterAt(biome: Biome, minute: number): EventKind | null {
+  return rollAt(biome, minute, 'event-later', LATER);
+}
+
+function latestAt(biome: Biome, minute: number): EventKind | null {
+  return rollAt(biome, minute, 'event-latest', LATEST);
+}
+
+function rollAt(biome: Biome, minute: number, salt: string, kinds: EventKind[]): EventKind | null {
   const zone = depthAt(minute * 60).zone;
-  const u = hash32(biome.key, 'event-later', minute) / 4294967296;
+  const u = hash32(biome.key, salt, minute) / 4294967296;
   let edge = 0;
-  for (const kind of LATER) {
+  for (const kind of kinds) {
     const spec = EVENTS[kind];
     if (!spec.zones.includes(zone)) continue;
     edge += spec.perHour / 60;
@@ -95,7 +109,7 @@ export interface OceanEvent {
 /** The event that begins in a given minute, if any. */
 export function eventAtMinute(biome: Biome, minute: number): OceanEvent | null {
   if (minute < 1) return null;
-  const kind = rawAt(biome, minute) ?? laterEventAt(biome, minute);
+  const kind = rawAt(biome, minute) ?? laterEventAt(biome, minute) ?? latestEventAt(biome, minute);
   if (!kind) return null;
   // Raw hits, not kept ones, so the rule never needs to look further back.
   if (rawAt(biome, minute)) for (let m = Math.max(1, minute - GAP_MINUTES); m < minute; m++) if (rawAt(biome, m)) return null;
@@ -112,6 +126,15 @@ function laterEventAt(biome: Biome, minute: number): EventKind | null {
   return kind;
 }
 
+/** The third roll's event, kept only with both rolls before it quiet for the gap either side (their raw hits, kept or not). */
+function latestEventAt(biome: Biome, minute: number): EventKind | null {
+  const kind = latestAt(biome, minute);
+  if (!kind) return null;
+  for (let m = Math.max(1, minute - GAP_MINUTES); m <= minute + GAP_MINUTES; m++) if (rawAt(biome, m) || laterAt(biome, m)) return null;
+  for (let m = Math.max(1, minute - GAP_MINUTES); m < minute; m++) if (latestAt(biome, m)) return null;
+  return kind;
+}
+
 /** The first event of a kind at or before `t`, for the ones that stay once they arrive. */
 export function firstEventUpTo(biome: Biome, kind: EventKind, t: number): OceanEvent | null {
   for (let m = 1; m * 60 <= t; m++) {

lib/ocean/ocean.test.ts

@@ -252,16 +252,29 @@ test('kelp only slides up the page, and is gone by the end of the sunlit water',
 
 test('the later sightings all turn up, and the first roll never hears of them', () => {
   const seen = new Set<EventKind>();
-  for (let k = 0; k < 600 && seen.size < 9; k++) {
+  for (let k = 0; k < 600 && seen.size < 10; k++) {
     for (const e of eventsUpTo(rollBiome(oceanKey('later', k), courseKey('later')), 4 * 3600)) seen.add(e.kind);
   }
-  for (const kind of ['turtle', 'siphonophore', 'lure', 'dumbo', 'whalefall'] as EventKind[]) assert.ok(seen.has(kind), `no ${kind} in 600 sittings`);
+  for (const kind of ['turtle', 'siphonophore', 'lure', 'dumbo', 'whalefall', 'manowar'] as EventKind[]) assert.ok(seen.has(kind), `no ${kind} in 600 sittings`);
   // Golden: a first-roll event that was there before the later roll existed is still there.
   const biome = rollBiome(oceanKey('gold', 1), courseKey('gold'));
   const first = eventsUpTo(biome, 4 * 3600).filter((e) => ['whale', 'storm', 'eye', 'leviathan'].includes(e.kind));
   for (const e of first) assert.equal(eventAtMinute(biome, Math.floor(e.start / 60))?.kind, e.kind);
 });
 
+test('a man o\' war only drifts over in the sunlit water, and never near another sighting', () => {
+  let seen = 0;
+  for (let k = 0; k < 400; k++) {
+    const all = eventsUpTo(rollBiome(oceanKey('war', k), courseKey('war')), 3 * 3600);
+    for (const e of all.filter((v) => v.kind === 'manowar')) {
+      seen++;
+      assert.ok(e.start < 15 * 60, `a man o' war at ${e.start}s`);
+      for (const o of all) if (o !== e) assert.ok(Math.abs(o.start - e.start) > 7 * 60, `a ${o.kind} within ${Math.abs(o.start - e.start)}s of a man o' war`);
+    }
+  }
+  assert.ok(seen > 20, `only ${seen} men o' war in 400 sittings`);
+});
+
 test('a whale fall stays on the floor once it has come', () => {
   for (let k = 0; k < 400; k++) {
     const biome = rollBiome(oceanKey('fall', k), courseKey('fall'));