From eef6a3c887d16a71a1acff97ede9764a74b9a7f4 Mon Sep 17 00:00:00 2001
From: Victor Giers <mail@victorgiers.com>
Date: Sat, 18 Apr 2026 20:27:13 +0200
Subject: [PATCH] Add terrain brush functionality in ViewportHost

---
 src/viewport-three/viewport-host.ts | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/src/viewport-three/viewport-host.ts b/src/viewport-three/viewport-host.ts
index 38f01820..c46d3ef9 100644
--- a/src/viewport-three/viewport-host.ts
+++ b/src/viewport-three/viewport-host.ts
@@ -7909,6 +7909,10 @@ export class ViewportHost {
       return;
     }
 
+    if (this.beginTerrainBrushStroke(event)) {
+      return;
+    }
+
     const candidates = this.getSelectionCandidates(event);
 
     if (candidates.length === 0) {
@@ -8004,6 +8008,20 @@ export class ViewportHost {
       return;
     }
 
+    if (this.continueTerrainBrushStroke(event)) {
+      return;
+    }
+
+    if (this.isTerrainBrushActive()) {
+      this.setHoveredSelection({
+        kind: "none"
+      });
+      this.setTerrainBrushHover(
+        this.getTerrainBrushHitAtClientPosition(event.clientX, event.clientY)
+      );
+      return;
+    }
+
     if (this.toolMode === "select") {
       const hoveredCandidate = this.getSelectionCandidates(event)[0]
         ?.selection ?? { kind: "none" };
@@ -8058,6 +8076,10 @@ export class ViewportHost {
       return;
     }
 
+    if (this.finishTerrainBrushStroke(event)) {
+      return;
+    }
+
     if (this.activeCameraDragPointerId !== event.pointerId) {
       return;
     }
@@ -8079,6 +8101,7 @@ export class ViewportHost {
     this.setHoveredSelection({
       kind: "none"
     });
+    this.setTerrainBrushHover(null);
 
     // Keep the shared creation preview alive across panel boundaries; the next
     // viewport panel will update it as the pointer continues moving.