From 3958a4740f6b388e16e7f2fac474b0528d893897 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Wed, 14 Feb 2024 12:36:04 +0100
Subject: [PATCH] Add option to enable Depth Test on cloth painting debug
 preview (enabled by default)

---
 Source/Editor/Tools/ClothPainting.cs   | 15 +++++++++++++++
 Source/Engine/Physics/Actors/Cloth.cpp |  6 +++---
 Source/Engine/Physics/Actors/Cloth.h   |  5 +++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/Source/Editor/Tools/ClothPainting.cs b/Source/Editor/Tools/ClothPainting.cs
index 28536ea83..6a98a3b5f 100644
--- a/Source/Editor/Tools/ClothPainting.cs
+++ b/Source/Editor/Tools/ClothPainting.cs
@@ -43,6 +43,19 @@ namespace FlaxEngine.Tools
         /// Enables continuous painting, otherwise single paint on click.
         /// </summary>
         public bool ContinuousPaint;
+
+        /// <summary>
+        /// Enables drawing cloth paint debugging with Depth Test enabled (skips occluded vertices).
+        /// </summary>
+        public bool DebugDrawDepthTest
+        {
+            get => Gizmo.Cloth?.DebugDrawDepthTest ?? true;
+            set
+            {
+                if (Gizmo.Cloth != null)
+                    Gizmo.Cloth.DebugDrawDepthTest = value;
+            }
+        }
 #pragma warning restore CS0649
 
         public override void Init(IGizmoOwner owner)
@@ -62,6 +75,7 @@ namespace FlaxEngine.Tools
         public override void Dispose()
         {
             Owner.Gizmos.Remove(Gizmo);
+            Gizmo = null;
 
             base.Dispose();
         }
@@ -83,6 +97,7 @@ namespace FlaxEngine.Tools
         private EditClothPaintAction _undoAction;
 
         public bool IsPainting => _isPainting;
+        public Cloth Cloth => _cloth;
 
         public ClothPaintingGizmo(IGizmoOwner owner, ClothPaintingGizmoMode mode)
         : base(owner)
diff --git a/Source/Engine/Physics/Actors/Cloth.cpp b/Source/Engine/Physics/Actors/Cloth.cpp
index b2db80b0b..a35acb066 100644
--- a/Source/Engine/Physics/Actors/Cloth.cpp
+++ b/Source/Engine/Physics/Actors/Cloth.cpp
@@ -415,9 +415,9 @@ void Cloth::OnDebugDrawSelected()
                 c1 = Color::Lerp(Color::Red, Color::White, _paint[i1]);
                 c2 = Color::Lerp(Color::Red, Color::White, _paint[i2]);
             }
-            DebugDraw::DrawLine(v0, v1, c0, c1, 0, false);
-            DebugDraw::DrawLine(v1, v2, c1, c2, 0, false);
-            DebugDraw::DrawLine(v2, v0, c2, c0, 0, false);
+            DebugDraw::DrawLine(v0, v1, c0, c1, 0, DebugDrawDepthTest);
+            DebugDraw::DrawLine(v1, v2, c1, c2, 0, DebugDrawDepthTest);
+            DebugDraw::DrawLine(v2, v0, c2, c0, 0, DebugDrawDepthTest);
         }
         PhysicsBackend::UnlockClothParticles(_cloth);
     }
diff --git a/Source/Engine/Physics/Actors/Cloth.h b/Source/Engine/Physics/Actors/Cloth.h
index 6137ec3b6..1b97330e0 100644
--- a/Source/Engine/Physics/Actors/Cloth.h
+++ b/Source/Engine/Physics/Actors/Cloth.h
@@ -332,6 +332,11 @@ public:
     bool OnPreUpdate();
     void OnPostUpdate();
 
+private:
+#if USE_EDITOR
+    API_FIELD(Internal) bool DebugDrawDepthTest = true;
+#endif
+
 public:
     // [Actor]
     void Draw(RenderContext& renderContext) override;