Optimize Debug Draw performance of splines to use frustum culling

Source/Editor/Viewport/MainEditorGizmoViewport.cs

@@ -340,6 +340,13 @@ namespace FlaxEditor.Viewport
         {
             _debugDrawData.Clear();
 
+            if (task is SceneRenderTask sceneRenderTask)
+            {
+                // Sync debug view to avoid lag on culling/LODing
+                var view = sceneRenderTask.View;
+                DebugDraw.SetView(ref view);
+            }
+
             // Collect selected objects debug shapes and visuals
             var selectedParents = TransformGizmo.SelectedParents;
             if (selectedParents.Count > 0)
@@ -374,7 +381,7 @@ namespace FlaxEditor.Viewport
             // Draw selected objects debug shapes and visuals
             if (DrawDebugDraw && (renderContext.View.Flags & ViewFlags.DebugDraw) == ViewFlags.DebugDraw)
             {
-                _debugDrawData.DrawActors();
+                _debugDrawData.DrawActors(true);
                 DebugDraw.Draw(ref renderContext, target.View(), targetDepth.View(), true);
             }
         }

Source/Editor/Viewport/PrefabWindowViewport.cs

@@ -243,7 +243,12 @@ namespace FlaxEditor.Viewport
                     _tempDebugDrawContext = DebugDraw.AllocateContext();
                 DebugDraw.SetContext(_tempDebugDrawContext);
                 DebugDraw.UpdateContext(_tempDebugDrawContext, 1.0f);
-
+                if (task is SceneRenderTask sceneRenderTask)
+                {
+                    // Sync debug view to avoid lag on culling/LODing
+                    var view = sceneRenderTask.View;
+                    DebugDraw.SetView(ref view);
+                }
                 for (int i = 0; i < selectedParents.Count; i++)
                 {
                     if (selectedParents[i].IsActiveInHierarchy)

Source/Editor/Viewport/Previews/AssetPreview.cs

@@ -264,6 +264,7 @@ namespace FlaxEditor.Viewport.Previews
             {
                 DebugDraw.SetContext(_debugDrawContext);
                 DebugDraw.UpdateContext(_debugDrawContext, 1.0f / Mathf.Max(Engine.FramesPerSecond, 1));
+                DebugDraw.SetView(ref renderContext.View);
                 CustomDebugDraw?.Invoke(context, ref renderContext);
                 OnDebugDraw(context, ref renderContext);
                 DebugDraw.Draw(ref renderContext, target.View(), targetDepth.View(), true);

Source/Engine/Debug/DebugDraw.cpp

@@ -357,7 +357,8 @@ struct DebugDrawContext
     DebugDrawData DebugDrawDefault;
     DebugDrawData DebugDrawDepthTest;
     Float3 LastViewPos = Float3::Zero;
-    Matrix LastViewProj = Matrix::Identity;
+    Matrix LastViewProjection = Matrix::Identity;
+    BoundingFrustum LastViewFrustum;
 
     inline int32 Count() const
     {
@@ -779,9 +780,23 @@ Vector3 DebugDraw::GetViewPos()
     return Context->LastViewPos;
 }
 
+BoundingFrustum DebugDraw::GetViewFrustum()
+{
+    return Context->LastViewFrustum;
+}
+
+void DebugDraw::SetView(const RenderView& view)
+{
+    Context->LastViewPos = view.Position;
+    Context->LastViewProjection = view.Projection;
+    Context->LastViewFrustum = view.Frustum;
+}
+
 void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTextureView* depthBuffer, bool enableDepthTest)
 {
     PROFILE_GPU_CPU("Debug Draw");
+    const RenderView& view = renderContext.View;
+    SetView(view);
 
     // Ensure to have shader loaded and any lines to render
     const int32 debugDrawDepthTestCount = Context->DebugDrawDepthTest.Count();
@@ -791,7 +806,6 @@ void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTe
     if (renderContext.Buffers == nullptr || !DebugDrawVB)
         return;
     auto context = GPUDevice::Instance->GetMainContext();
-    const RenderView& view = renderContext.View;
     if (Context->Origin != view.Origin)
     {
         // Teleport existing debug shapes to maintain their location
@@ -800,8 +814,6 @@ void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTe
         Context->DebugDrawDepthTest.Teleport(delta);
         Context->Origin = view.Origin;
     }
-    Context->LastViewPos = view.Position;
-    Context->LastViewProj = view.Projection;
     TaaJitterRemoveContext taaJitterRemove(view);
 
     // Fallback to task buffers
@@ -1383,7 +1395,7 @@ void DebugDraw::DrawWireSphere(const BoundingSphere& sphere, const Color& color,
     int32 index;
     const Float3 centerF = sphere.Center - Context->Origin;
     const float radiusF = (float)sphere.Radius;
-    const float screenRadiusSquared = RenderTools::ComputeBoundsScreenRadiusSquared(centerF, radiusF, Context->LastViewPos, Context->LastViewProj);
+    const float screenRadiusSquared = RenderTools::ComputeBoundsScreenRadiusSquared(centerF, radiusF, Context->LastViewPos, Context->LastViewProjection);
     if (screenRadiusSquared > DEBUG_DRAW_SPHERE_LOD0_SCREEN_SIZE * DEBUG_DRAW_SPHERE_LOD0_SCREEN_SIZE * 0.25f)
         index = 0;
     else if (screenRadiusSquared > DEBUG_DRAW_SPHERE_LOD1_SCREEN_SIZE * DEBUG_DRAW_SPHERE_LOD1_SCREEN_SIZE * 0.25f)

Source/Engine/Debug/DebugDraw.h

@@ -76,6 +76,11 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
 
     // Gets the last view position when rendering the current context. Can be used for custom culling or LODing when drawing more complex shapes.
     static Vector3 GetViewPos();
+    // Gets the last view frustum when rendering the current context. Can be used for custom culling or LODing when drawing more complex shapes.
+    static BoundingFrustum GetViewFrustum();
+
+    // Sets the rendering view information beforehand.
+    API_FUNCTION() static void SetView(API_PARAM(ref) const RenderView& view);
 
     /// <summary>
     /// Draws the collected debug shapes to the output.

Source/Engine/Level/Actors/Spline.cpp

@@ -3,6 +3,7 @@
 #include "Spline.h"
 #include "Engine/Serialization/Serialization.h"
 #include "Engine/Animations/CurveSerialization.h"
+#include "Engine/Core/Math/BoundingFrustum.h"
 #include "Engine/Core/Math/Matrix.h"
 #include "Engine/Scripting/ManagedCLR/MCore.h"
 
@@ -520,7 +521,8 @@ namespace
 
 void Spline::OnDebugDraw()
 {
-    DrawSpline(this, GetSplineColor().AlphaMultiplied(0.7f), _transform, true);
+    if (DebugDraw::GetViewFrustum().Intersects(_sphere))
+        DrawSpline(this, GetSplineColor().AlphaMultiplied(0.7f), _transform, true);
 
     // Base
     Actor::OnDebugDraw();