updated the collision for jumps and terrain

src/game/playerJump.ts

@@ -3,7 +3,8 @@ export const PLAYER_JUMP_COYOTE_MS = 100;
 export const PLAYER_JUMP_BUFFER_MS = 120;
 export const PLAYER_JUMP_LANDING_UNLOCK_MS = 80;
 export const PLAYER_LANDING_PRESENTATION_MS = 180;
-export const PLAYER_GROUND_PROBE_DISTANCE = 0.14;
+export const PLAYER_AIRBORNE_PRESENTATION_DELAY_MS = 100;
+export const PLAYER_GROUND_PROBE_DISTANCE = 0.22;
 export const PLAYER_GROUND_MIN_NORMAL_Y = 0.55;
 
 export type CharacterVerticalMotion = "grounded" | "rising" | "falling" | "landing";
@@ -15,6 +16,12 @@ export interface PlayerJumpTiming {
   lockedUntilLanding: boolean;
 }
 
+export interface CharacterVerticalPresentationTiming {
+  airborneStartedAtMs: number;
+  airbornePresented: boolean;
+  landingUntilMs: number;
+}
+
 export interface GroundProbeHit {
   readonly timeOfImpact: number;
   readonly normal: { readonly y: number };
@@ -29,6 +36,14 @@ export function createPlayerJumpTiming(nowMs = Number.NEGATIVE_INFINITY): Player
   };
 }
 
+export function createCharacterVerticalPresentationTiming(): CharacterVerticalPresentationTiming {
+  return {
+    airborneStartedAtMs: Number.NEGATIVE_INFINITY,
+    airbornePresented: false,
+    landingUntilMs: Number.NEGATIVE_INFINITY,
+  };
+}
+
 export function bufferPlayerJump(timing: PlayerJumpTiming, requestedAtMs: number): void {
   if (!Number.isFinite(requestedAtMs)) return;
   timing.bufferedUntilMs = requestedAtMs + PLAYER_JUMP_BUFFER_MS;
@@ -92,3 +107,38 @@ export function characterVerticalMotion(
   if (grounded) return nowMs < landingUntilMs ? "landing" : "grounded";
   return verticalVelocity > 0.15 ? "rising" : "falling";
 }
+
+/**
+ * Keeps tiny terrain gaps from interrupting locomotion with a fall/land pair.
+ * An intentional jump is presented immediately; an incidental loss of ground
+ * must persist before it becomes visible, and only visible airtime may land.
+ */
+export function updateCharacterVerticalPresentation(
+  timing: CharacterVerticalPresentationTiming,
+  grounded: boolean,
+  verticalVelocity: number,
+  nowMs: number,
+  intentionalJump: boolean,
+): CharacterVerticalMotion {
+  if (!Number.isFinite(nowMs)) {
+    return characterVerticalMotion(grounded, verticalVelocity, 0, Number.NEGATIVE_INFINITY);
+  }
+
+  if (!grounded) {
+    if (!Number.isFinite(timing.airborneStartedAtMs)) timing.airborneStartedAtMs = nowMs;
+    if (
+      intentionalJump
+      || nowMs - timing.airborneStartedAtMs >= PLAYER_AIRBORNE_PRESENTATION_DELAY_MS
+    ) timing.airbornePresented = true;
+    return timing.airbornePresented
+      ? characterVerticalMotion(false, verticalVelocity, nowMs, timing.landingUntilMs)
+      : "grounded";
+  }
+
+  if (timing.airbornePresented) {
+    timing.landingUntilMs = nowMs + PLAYER_LANDING_PRESENTATION_MS;
+  }
+  timing.airborneStartedAtMs = Number.NEGATIVE_INFINITY;
+  timing.airbornePresented = false;
+  return characterVerticalMotion(true, verticalVelocity, nowMs, timing.landingUntilMs);
+}