perf opt

frontend/src/game/renderer.ts

@@ -56,6 +56,13 @@ const MAX_STATIC_GRAPHICS_CACHE_AREA = 2_500_000;
 
 const TERRAIN_SEAM_BLEED_SCALE = 1.002;
 
+/**
+ * Snap camera center (px, same space as worldToScreen) when computing visible tile indices.
+ * Without this, sub-pixel camera follow changes floor(minWX)/ceil(maxWX) often and forces a full
+ * tile/object pass + pool scans every frame while walking.
+ */
+const GROUND_CAMERA_BOUNDS_QUANTIZE_PX = TILE_HEIGHT;
+
 /** Convert world (tile) coordinates to screen (pixel) coordinates */
 export function worldToScreen(wx: number, wy: number): ScreenPoint {
   return {
@@ -136,6 +143,8 @@ export class GameRenderer {
         endY: number;
       }
     | null = null;
+  /** Incremented on each full ground rebuild; used to throttle eviction passes. */
+  private _groundRebuildCounter = 0;
 
   // Reusable Graphics (avoid GC). UI/combat overlays; world tiles are sprite-only.
   private _heroGfx: Graphics | null = null;
@@ -173,7 +182,8 @@ export class GameRenderer {
   private _usedNearbyHeroSprites = new Set<string>();
 
   private _lastEntitySortMs = 0;
-  private _entitySortIntervalMs = 120;
+  /** Depth sort is O(n log n) on entityLayer; ~8 Hz is enough for walking fights. */
+  private _entitySortIntervalMs = 200;
   private _townDrawDirty = true;
   private _lastTownDrawMs = 0;
   private _townDrawIntervalMs = 120;
@@ -502,17 +512,20 @@ export class GameRenderer {
   drawGround(camera: Camera, screenWidth: number, screenHeight: number): void {
     const cx = camera.finalX;
     const cy = camera.finalY;
+    const q = GROUND_CAMERA_BOUNDS_QUANTIZE_PX;
+    const qcx = Math.round(cx / q) * q;
+    const qcy = Math.round(cy / q) * q;
     const halfW = screenWidth / (2 * MAP_ZOOM) + TILE_WIDTH * 2;
     const halfH = screenHeight / (2 * MAP_ZOOM) + TILE_HEIGHT * 2;
 
     const worldCorners = [
-      screenToWorld(cx - halfW, cy - halfH),
-      screenToWorld(cx + halfW, cy - halfH),
-      screenToWorld(cx - halfW, cy + halfH),
-      screenToWorld(cx + halfW, cy + halfH),
+      screenToWorld(qcx - halfW, qcy - halfH),
+      screenToWorld(qcx + halfW, qcy - halfH),
+      screenToWorld(qcx - halfW, qcy + halfH),
+      screenToWorld(qcx + halfW, qcy + halfH),
     ];
 
-    const renderPaddingTiles = 4;
+    const renderPaddingTiles = 5;
     let minWX = Number.POSITIVE_INFINITY;
     let maxWX = Number.NEGATIVE_INFINITY;
     let minWY = Number.POSITIVE_INFINITY;
@@ -548,6 +561,8 @@ export class GameRenderer {
 
     this._groundDirty = false;
     this._lastGroundBounds = { startX, endX, startY, endY };
+    this._groundRebuildCounter += 1;
+    const runTileEviction = (this._groundRebuildCounter & 1) === 0;
 
     const hw = TILE_WIDTH / 2;
     const hh = TILE_HEIGHT / 2;
@@ -556,10 +571,10 @@ export class GameRenderer {
     const usedObjectSprites = this._usedObjectSprites;
     usedTileSprites.clear();
     usedObjectSprites.clear();
-    const tileMinX = cx - (halfW + hw);
-    const tileMaxX = cx + (halfW + hw);
-    const tileMinY = cy - (halfH + hh);
-    const tileMaxY = cy + (halfH + hh);
+    const tileMinX = qcx - (halfW + hw);
+    const tileMaxX = qcx + (halfW + hw);
+    const tileMinY = qcy - (halfH + hh);
+    const tileMaxY = qcy + (halfH + hh);
 
     // Pass 2 needs slightly expanded bounds for oversized props.
     const objectPaddingTiles = 4;
@@ -623,10 +638,10 @@ export class GameRenderer {
 
     // Pass 2: objects (drawn after tiles so they layer on top)
     // Slightly expanded object bounds prevent enlarged props from edge clipping.
-    const objectMinX = cx - (halfW + TILE_WIDTH * 1.5);
-    const objectMaxX = cx + (halfW + TILE_WIDTH * 1.5);
-    const objectMinY = cy - (halfH + TILE_HEIGHT * 2);
-    const objectMaxY = cy + (halfH + TILE_HEIGHT * 2);
+    const objectMinX = qcx - (halfW + TILE_WIDTH * 1.5);
+    const objectMaxX = qcx + (halfW + TILE_WIDTH * 1.5);
+    const objectMinY = qcy - (halfH + TILE_HEIGHT * 2);
+    const objectMaxY = qcy + (halfH + TILE_HEIGHT * 2);
     for (let wx = objectStartX; wx <= objectEndX; wx++) {
       let isoX = (wx - objectStartY) * hw;
       let isoY = (wx + objectStartY) * hh;
@@ -684,6 +699,7 @@ export class GameRenderer {
       this._objectSpriteFreeList,
       1800,
     );
+    if (runTileEviction) {
       const evictPaddingTiles = 8;
       this._evictSpritesOutsideTileBounds(
         this._tileSpritePool,
@@ -704,6 +720,7 @@ export class GameRenderer {
         1800,
       );
     }
+  }
 
   /**
    * Draw the hero (sprite only).
@@ -717,7 +734,6 @@ export class GameRenderer {
     let cy = iso.y;
 
     if (texture) {
-      gfx.clear();
       const entry = this._ensureSprite(
         this._characterSpritePool,
         'hero',
@@ -766,7 +782,6 @@ export class GameRenderer {
       return;
     }
 
-    gfx.clear();
     const entry = this._ensureSprite(
       this._characterSpritePool,
       'meet_partner',
@@ -824,7 +839,6 @@ export class GameRenderer {
       return;
     }
 
-    gfx.clear();
     const place = (
       poolKey: string,
       textureKey: string,