Reduce next.js example warnings (#324)

examples/nextjs/src/app/(demos)/presence/Presence.tsx

@@ -1,7 +1,7 @@
 'use client'
 
 import { usePresence, usePresenceSetter } from '@y-sweet/react'
-import { useCallback, useState } from 'react'
+import { useCallback, useRef, useState } from 'react'
 
 type Presence = { x: number; y: number; color: string; rotation: number }
 
@@ -34,8 +34,8 @@ export function Presence() {
   const [myColor, _] = useState(randomColor)
   const presence = usePresence<Presence>({ includeSelf: true })
   const setPresence = usePresenceSetter<Presence>()
+  const lastRotation = useRef(0)
 
-  let lastRotation = 0
   const updatePresence = useCallback(
     (e: React.MouseEvent<SVGSVGElement>) => {
       let rect = e.currentTarget.getBoundingClientRect()
@@ -47,12 +47,12 @@ export function Presence() {
       }
 
       let movementRotation = Math.atan2(deltaY, deltaX) * (180 / Math.PI)
-      let difference = ((movementRotation - lastRotation + 180) % 360) - 180
+      let difference = ((movementRotation - lastRotation.current + 180) % 360) - 180
       if (difference < -180) difference += 360
-      movementRotation = lastRotation + difference
+      movementRotation = lastRotation.current + difference
 
-      const rotation = 0.9 * lastRotation + 0.1 * movementRotation
-      lastRotation = rotation
+      const rotation = 0.9 * lastRotation.current + 0.1 * movementRotation
+      lastRotation.current = rotation
 
       setPresence({
         x: e.clientX - rect.left,
@@ -61,7 +61,7 @@ export function Presence() {
         rotation,
       })
     },
-    [setPresence],
+    [setPresence, myColor],
   )
 
   return (

examples/nextjs/src/app/(demos)/voxels/VoxelEditor.tsx

@@ -55,7 +55,7 @@ function MovingVoxel(props: { voxel: Voxel; name?: string }) {
     if (squaredDist > 0.00001) {
       destPositionRef.current = dest
     }
-  }, [props.voxel.position])
+  }, [props.voxel.position, position])
 
   return (
     <mesh name={props.name} position={position} scale={1}>
@@ -170,7 +170,7 @@ export function VoxelEditor() {
         color: color,
       })
     },
-    [setGhostPosition],
+    [setGhostPosition, updatePresence, color],
   )
 
   const handleClick = useCallback(