From 59ff42e52ba1988a0edd03d098ac2d26b84e0484 Mon Sep 17 00:00:00 2001
From: scamiv <6170744+scamiv@users.noreply.github.com>
Date: Tue, 25 Nov 2025 18:46:25 +0100
Subject: [PATCH] Refactor rendering and throttle based on backlog

- Refactor rendering and metrics emission in ClientGameRunner to ensure updates occur only after all processing is complete
- Throttle renderGame() based on the current backlog
---
 src/client/ClientGameRunner.ts      | 46 ++++++++++++++++-------------
 src/client/InputHandler.ts          |  7 +++++
 src/client/graphics/GameRenderer.ts | 34 ++++++++++++++++++++-
 3 files changed, 66 insertions(+), 21 deletions(-)

diff --git a/src/client/ClientGameRunner.ts b/src/client/ClientGameRunner.ts
index ce88d861a..4d70a3f3e 100644
--- a/src/client/ClientGameRunner.ts
+++ b/src/client/ClientGameRunner.ts
@@ -28,6 +28,7 @@ import { UserSettings } from "../core/game/UserSettings";
 import { WorkerClient } from "../core/worker/WorkerClient";
 import {
   AutoUpgradeEvent,
+  BacklogStatusEvent,
   DoBoatAttackEvent,
   DoGroundAttackEvent,
   InputHandler,
@@ -511,33 +512,35 @@ export class ClientGameRunner {
         this.pendingStart = 0;
       }
 
-      if (batch.length > 0 && lastTick !== undefined) {
+      // Only update view and render when ALL processing is complete
+      if (
+        this.pendingStart >= this.pendingUpdates.length &&
+        batch.length > 0 &&
+        lastTick !== undefined
+      ) {
         const combinedGu = this.mergeGameUpdates(batch);
         if (combinedGu) {
           this.gameView.update(combinedGu);
         }
 
-        // Only emit metrics when ALL processing is complete
-        if (this.pendingStart >= this.pendingUpdates.length) {
-          const ticksPerRender =
-            this.lastRenderedTick === 0
-              ? lastTick
-              : lastTick - this.lastRenderedTick;
-          this.lastRenderedTick = lastTick;
+        const ticksPerRender =
+          this.lastRenderedTick === 0
+            ? lastTick
+            : lastTick - this.lastRenderedTick;
+        this.lastRenderedTick = lastTick;
 
-          this.renderer.tick();
-          this.eventBus.emit(
-            new TickMetricsEvent(
-              lastTickDuration,
-              this.currentTickDelay,
-              this.backlogTurns,
-              ticksPerRender,
-            ),
-          );
+        this.renderer.tick();
+        this.eventBus.emit(
+          new TickMetricsEvent(
+            lastTickDuration,
+            this.currentTickDelay,
+            this.backlogTurns,
+            ticksPerRender,
+          ),
+        );
 
-          // Reset tick delay for next measurement
-          this.currentTickDelay = undefined;
-        }
+        // Reset tick delay for next measurement
+        this.currentTickDelay = undefined;
       }
 
       if (this.pendingStart < this.pendingUpdates.length) {
@@ -598,6 +601,9 @@ export class ClientGameRunner {
       this.serverTurnHighWater - this.lastProcessedTick,
     );
     this.backlogGrowing = this.backlogTurns > previousBacklog;
+    this.eventBus.emit(
+      new BacklogStatusEvent(this.backlogTurns, this.backlogGrowing),
+    );
   }
 
   private inputEvent(event: MouseUpEvent) {
diff --git a/src/client/InputHandler.ts b/src/client/InputHandler.ts
index bd95e7201..85039015d 100644
--- a/src/client/InputHandler.ts
+++ b/src/client/InputHandler.ts
@@ -136,6 +136,13 @@ export class TickMetricsEvent implements GameEvent {
   ) {}
 }
 
+export class BacklogStatusEvent implements GameEvent {
+  constructor(
+    public readonly backlogTurns: number,
+    public readonly backlogGrowing: boolean,
+  ) {}
+}
+
 export class InputHandler {
   private lastPointerX: number = 0;
   private lastPointerY: number = 0;
diff --git a/src/client/graphics/GameRenderer.ts b/src/client/graphics/GameRenderer.ts
index 1410cdbbd..97e4ad909 100644
--- a/src/client/graphics/GameRenderer.ts
+++ b/src/client/graphics/GameRenderer.ts
@@ -2,7 +2,10 @@ import { EventBus } from "../../core/EventBus";
 import { GameView } from "../../core/game/GameView";
 import { UserSettings } from "../../core/game/UserSettings";
 import { GameStartingModal } from "../GameStartingModal";
-import { RefreshGraphicsEvent as RedrawGraphicsEvent } from "../InputHandler";
+import {
+  BacklogStatusEvent,
+  RefreshGraphicsEvent as RedrawGraphicsEvent,
+} from "../InputHandler";
 import { FrameProfiler } from "./FrameProfiler";
 import { TransformHandler } from "./TransformHandler";
 import { UIState } from "./UIState";
@@ -292,6 +295,9 @@ export function createRenderer(
 
 export class GameRenderer {
   private context: CanvasRenderingContext2D;
+  private backlogTurns: number = 0;
+  private backlogGrowing: boolean = false;
+  private lastRenderTime: number = 0;
 
   constructor(
     private game: GameView,
@@ -309,6 +315,10 @@ export class GameRenderer {
 
   initialize() {
     this.eventBus.on(RedrawGraphicsEvent, () => this.redraw());
+    this.eventBus.on(BacklogStatusEvent, (event: BacklogStatusEvent) => {
+      this.backlogTurns = event.backlogTurns;
+      this.backlogGrowing = event.backlogGrowing;
+    });
     this.layers.forEach((l) => l.init?.());
 
     document.body.appendChild(this.canvas);
@@ -344,6 +354,28 @@ export class GameRenderer {
   }
 
   renderGame() {
+    const now = performance.now();
+
+    if (this.backlogTurns > 0) {
+      const BASE_FPS = 60;
+      const MIN_FPS = 20;
+      const BACKLOG_MAX_TURNS = 50;
+
+      const scale = Math.min(1, this.backlogTurns / BACKLOG_MAX_TURNS);
+      const targetFps = BASE_FPS - scale * (BASE_FPS - MIN_FPS);
+      const minFrameInterval = 1000 / targetFps;
+
+      if (this.lastRenderTime !== 0) {
+        const sinceLast = now - this.lastRenderTime;
+        if (sinceLast < minFrameInterval) {
+          requestAnimationFrame(() => this.renderGame());
+          return;
+        }
+      }
+    }
+
+    this.lastRenderTime = now;
+
     FrameProfiler.clear();
     const start = performance.now();
     // Set background