update spirit

assets/scripts/logic/PlayerMotionModel.ts

@@ -44,6 +44,8 @@ export interface IPlayerMotionOptions {
     platforms: IPlatform[];
     /** Starting color state. */
     initialColorState?: PlayerColorState;
+    /** Level horizontal extent (px). Used to clamp player X so they cannot leave the level. */
+    levelLengthPx: number;
 }
 
 export const DEFAULT_GRAVITY = 2500; // px/s² — tuned so a 250px jump peaks in ~0.45s
@@ -63,12 +65,14 @@ export class PlayerMotionModel {
     private _aabb: IAxisAlignedBox;
     private _platforms: IPlatform[];
     private readonly gravity: number;
+    private readonly _levelLengthPx: number;
 
     constructor(options: IPlayerMotionOptions) {
         this._aabb = { ...options.aabb };
         this._platforms = options.platforms.slice();
         this._colorState = options.initialColorState ?? PlayerColorState.Red;
         this.gravity = options.gravity ?? DEFAULT_GRAVITY;
+        this._levelLengthPx = options.levelLengthPx;
     }
 
     // -- accessors ----------------------------------------------------------
@@ -130,6 +134,9 @@ export class PlayerMotionModel {
      * ground; mid-air `_vx` is preserved (起跳定型).
      */
     public update(dt: number): void {
+        // Remember feet position before integration (for sweep test).
+        const prevFeetY = this._aabb.y - this._aabb.h / 2;
+
         if (this._grounded) {
             this._vx = this._horizontalInput * MOVE_SPEED[this._colorState];
             this._vy = 0;
@@ -143,16 +150,34 @@ export class PlayerMotionModel {
             x: this._aabb.x + this._vx * dt,
             y: this._aabb.y + this._vy * dt,
         };
-        // Resolve against platforms (basic AABB vs. top-surface only).
+
+        const curFeetY = this._aabb.y - this._aabb.h / 2;
+
+        // Resolve against platforms using sweep test.
+        // If the feet crossed a platform surface this frame (prev above → cur below),
+        // snap the player onto that platform — prevents tunneling at high fall speeds.
         this._grounded = false;
         for (const p of this._platforms) {
-            if (this.isRestingOn(p)) {
+            const withinHorizontal = this._aabb.x >= p.leftX && this._aabb.x <= p.rightX;
+            if (!withinHorizontal) continue;
+            if (this._vy > 0) continue; // moving upward — cannot land
+
+            // Sweep test: feet were above topY last frame, now at or below topY.
+            const crossedSurface = prevFeetY >= p.topY - 0.5 && curFeetY <= p.topY + 0.5;
+            // Also catch the small-window case (slow fall, feet near surface).
+            const nearSurface = curFeetY <= p.topY + 0.5 && curFeetY >= p.topY - 6;
+
+            if (crossedSurface || nearSurface) {
                 this._grounded = true;
                 this._aabb = { ...this._aabb, y: p.topY + this._aabb.h / 2 };
                 if (this._vy < 0) this._vy = 0;
                 break;
             }
         }
+
+        // Clamp AABB X within level boundaries so the player cannot leave the level.
+        const halfW = this._aabb.w / 2;
+        this._aabb.x = Math.max(halfW, Math.min(this._aabb.x, this._levelLengthPx - halfW));
     }
 
     // -- helpers ------------------------------------------------------------