From d17e083c7738d9f1e4d88c914a44ea0925b73ff8 Mon Sep 17 00:00:00 2001
From: Wassim SAMAD <wass08@gmail.com>
Date: Thu, 14 May 2026 15:01:56 -0400
Subject: [PATCH] Add sfx:grid-snap on cursor cell-cross for shelf + spawn

Matches the wall / slab / curve-wall tool pattern: emit
sfx:grid-snap only when the snapped position changes (cursor crosses
a grid cell), not every frame of mouse movement within the same cell.
Tracked via a `previousSnapRef` per tool, reset when the tool
re-activates.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 packages/nodes/src/shelf/tool.tsx | 10 ++++++++++
 packages/nodes/src/spawn/tool.tsx | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/packages/nodes/src/shelf/tool.tsx b/packages/nodes/src/shelf/tool.tsx
index f79bcf8e..769c5045 100644
--- a/packages/nodes/src/shelf/tool.tsx
+++ b/packages/nodes/src/shelf/tool.tsx
@@ -50,13 +50,23 @@ const PREVIEW_BRACKET_DEPTH = PREVIEW_DEPTH * 0.7
 const ShelfTool = () => {
   const activeLevelId = useViewer((state) => state.selection.levelId)
   const cursorRef = useRef<Group>(null)
+  const previousSnapRef = useRef<[number, number] | null>(null)
 
   useEffect(() => {
     if (!activeLevelId) return
+    previousSnapRef.current = null
 
     const onGridMove = (event: GridEvent) => {
       const [sx, sz] = snapPointToGrid([event.localPosition[0], event.localPosition[2]], GRID_STEP)
       cursorRef.current?.position.set(sx, event.localPosition[1], sz)
+
+      // Fire grid-snap SFX only when the snapped position crosses a cell,
+      // matching the wall / slab / curve tools.
+      const prev = previousSnapRef.current
+      if (!prev || prev[0] !== sx || prev[1] !== sz) {
+        triggerSFX('sfx:grid-snap')
+        previousSnapRef.current = [sx, sz]
+      }
     }
 
     const onGridClick = (event: GridEvent) => {
diff --git a/packages/nodes/src/spawn/tool.tsx b/packages/nodes/src/spawn/tool.tsx
index e441750b..21f98a23 100644
--- a/packages/nodes/src/spawn/tool.tsx
+++ b/packages/nodes/src/spawn/tool.tsx
@@ -41,9 +41,11 @@ function getLevelLocalPosition(levelId: string, event: GridEvent): [number, numb
 const SpawnTool = () => {
   const activeLevelId = useViewer((state) => state.selection.levelId)
   const cursorRef = useRef<Group>(null)
+  const previousSnapRef = useRef<[number, number] | null>(null)
 
   useEffect(() => {
     if (!activeLevelId) return
+    previousSnapRef.current = null
 
     const onGridMove = (event: GridEvent) => {
       // Cursor lives in the ToolManager's building-local group. Use
@@ -52,6 +54,15 @@ const SpawnTool = () => {
       const nextX = roundToHalf(event.localPosition[0])
       const nextZ = roundToHalf(event.localPosition[2])
       cursorRef.current?.position.set(nextX, event.localPosition[1], nextZ)
+
+      // Fire grid-snap SFX only when the snapped position crosses a cell,
+      // not every frame the mouse moves within the same cell. Matches the
+      // wall / slab / curve tools.
+      const prev = previousSnapRef.current
+      if (!prev || prev[0] !== nextX || prev[1] !== nextZ) {
+        triggerSFX('sfx:grid-snap')
+        previousSnapRef.current = [nextX, nextZ]
+      }
     }
 
     const onGridClick = (event: GridEvent) => {