feat: Add useSpawnHandler hook to manage material spawning for conveyor actions in the simulation, including pause/resume logic.

app/src/modules/simulation/actions/conveyor/actionHandler/useSpawnHandler.ts

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useState } from "react";
+import { useCallback, useEffect, useRef } from "react";
 import * as THREE from "three";
 import { useFrame } from "@react-three/fiber";
 import { usePlayButtonStore, useAnimationPlaySpeed, usePauseButtonStore, useResetButtonStore } from "../../../../../store/ui/usePlayButtonStore";
@@ -29,7 +29,7 @@ export function useSpawnHandler() {
     const { speed } = useAnimationPlaySpeed();
     const { isReset } = useResetButtonStore();
 
-    const [activeSpawns, setActiveSpawns] = useState<Map<string, SpawnInstance>>(new Map());
+    const activeSpawns = useRef<Map<string, SpawnInstance>>(new Map());
 
     const getConveyorPausedState = useCallback(
         (action: ConveyorAction) => {
@@ -51,7 +51,7 @@ export function useSpawnHandler() {
     );
 
     const clearAllSpawns = useCallback(() => {
-        setActiveSpawns(new Map());
+        activeSpawns.current.clear();
     }, []);
 
     useEffect(() => {
@@ -109,7 +109,7 @@ export function useSpawnHandler() {
         const completedActions: string[] = [];
         let hasChanges = false;
 
-        activeSpawns.forEach((spawn) => {
+        activeSpawns.current.forEach((spawn) => {
             const isPausedNow = shouldPauseSpawn(spawn.params.action);
 
             if (isPausedNow && !spawn.isPaused) {
@@ -136,12 +136,16 @@ export function useSpawnHandler() {
         });
 
         if (isPlaying && !isReset && !isPaused) {
-            activeSpawns.forEach((spawn, actionUuid) => {
+            activeSpawns.current.forEach((spawn, actionUuid) => {
                 if (spawn.isPaused) return;
 
                 const { material, intervalMs, totalCount, action } = spawn.params;
 
-                if (spawn.spawnCount >= totalCount) return;
+                if (spawn.spawnCount >= totalCount) {
+                    completedActions.push(actionUuid);
+                    return;
+                }
+
                 // intervalMs is in simulation time, and currentTime is simulation time. No speed adjustment needed.
                 const adjustedInterval = intervalMs;
                 const isFirstSpawn = spawn.lastSpawnTime === null;
@@ -186,15 +190,9 @@ export function useSpawnHandler() {
             });
         }
 
-        if (hasChanges || completedActions.length > 0) {
-            setActiveSpawns((prevSpawns) => {
-                const newSpawns = new Map(prevSpawns);
-
-                completedActions.forEach((actionUuid) => {
-                    newSpawns.delete(actionUuid);
-                });
-
-                return newSpawns;
+        if (completedActions.length > 0) {
+            completedActions.forEach((actionUuid) => {
+                activeSpawns.current.delete(actionUuid);
             });
         }
     });
@@ -205,29 +203,23 @@ export function useSpawnHandler() {
         const { material, spawnInterval = 0, spawnCount = 1, actionUuid } = action;
         const intervalMs = spawnInterval * 1000;
 
-        setActiveSpawns((prevSpawns) => {
-            const newSpawns = new Map(prevSpawns);
+        if (activeSpawns.current.has(actionUuid)) {
+            activeSpawns.current.delete(actionUuid);
+        }
 
-            if (newSpawns.has(actionUuid)) {
-                newSpawns.delete(actionUuid);
-            }
-
-            newSpawns.set(actionUuid, {
-                lastSpawnTime: null,
-                startTime: getSimulationTime(),
-                spawnCount: 0,
-                params: {
-                    material,
-                    intervalMs,
-                    totalCount: spawnCount,
-                    action: action,
-                },
-                pauseStartTime: 0,
-                remainingTime: 0,
-                isPaused: false,
-            });
-
-            return newSpawns;
+        activeSpawns.current.set(actionUuid, {
+            lastSpawnTime: null,
+            startTime: getSimulationTime(),
+            spawnCount: 0,
+            params: {
+                material,
+                intervalMs,
+                totalCount: spawnCount,
+                action: action,
+            },
+            pauseStartTime: 0,
+            remainingTime: 0,
+            isPaused: false,
         });
     }, []);