From 24f3dfe2649e671fc44680a909d95ed7f767c883 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Fri, 31 Jan 2025 21:01:26 +0100
Subject: [PATCH] Fix selected spline points to be drawn relative to the view
 for greater readability

#2595
---
 Source/Engine/Debug/DebugDraw.cpp     |  5 +++++
 Source/Engine/Debug/DebugDraw.h       |  7 +++++--
 Source/Engine/Level/Actors/Spline.cpp | 15 +++++++++++----
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/Source/Engine/Debug/DebugDraw.cpp b/Source/Engine/Debug/DebugDraw.cpp
index 447e6cabc..d19737dbb 100644
--- a/Source/Engine/Debug/DebugDraw.cpp
+++ b/Source/Engine/Debug/DebugDraw.cpp
@@ -741,6 +741,11 @@ void DebugDraw::SetContext(void* context)
 
 #endif
 
+Vector3 DebugDraw::GetViewPos()
+{
+    return Context->LastViewPos;
+}
+
 void DebugDraw::Draw(RenderContext& renderContext, GPUTextureView* target, GPUTextureView* depthBuffer, bool enableDepthTest)
 {
     PROFILE_GPU_CPU("Debug Draw");
diff --git a/Source/Engine/Debug/DebugDraw.h b/Source/Engine/Debug/DebugDraw.h
index 6cfceca6d..e9d596aa1 100644
--- a/Source/Engine/Debug/DebugDraw.h
+++ b/Source/Engine/Debug/DebugDraw.h
@@ -39,7 +39,7 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
 
 #if USE_EDITOR
     /// <summary>
-    /// Allocates the context for Debug Drawing. Can be use to redirect debug shapes collecting to a separate container (instead of global state).
+    /// Allocates the context for Debug Drawing. Can be used to redirect debug shapes collecting to a separate container (instead of global state).
     /// </summary>
     /// <returns>The context object. Release it wil FreeContext. Returns null if failed.</returns>
     API_FUNCTION() static void* AllocateContext();
@@ -64,6 +64,9 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
     API_FUNCTION() static void SetContext(void* context);
 #endif
 
+    // Gets the last view position when rendering the current context. Can be sued for custom culling or LODing when drawing more complex shapes.
+    static Vector3 GetViewPos();
+
     /// <summary>
     /// Draws the collected debug shapes to the output.
     /// </summary>
@@ -717,7 +720,7 @@ API_CLASS(Static) class FLAXENGINE_API DebugDraw
     API_FUNCTION() static void Clear(void* context = nullptr);
 };
 
-#define DEBUG_DRAW_AXIS_FROM_DIRECTION(origin, direction, size, duration, depthTest)                 DebugDraw::DrawAxisFromDirection(origin, direction, size, duration, depthTest);
+#define DEBUG_DRAW_AXIS_FROM_DIRECTION(origin, direction, size, duration, depthTest)                        DebugDraw::DrawAxisFromDirection(origin, direction, size, duration, depthTest);
 #define DEBUG_DRAW_DIRECTION(origin, direction, color, duration, depthTest)                                 DebugDraw::DrawDirection(origin, direction, color, duration, depthTest);
 #define DEBUG_DRAW_RAY(origin, direction, color, length, duration, depthTest)                               DebugDraw::DrawRay(origin, direction, color, length, duration, depthTest);
 #define DEBUG_DRAW_RAY(ray, color, length, duration, depthTest)                                             DebugDraw::DrawRay(ray, color, length, duration, depthTest);
diff --git a/Source/Engine/Level/Actors/Spline.cpp b/Source/Engine/Level/Actors/Spline.cpp
index 37842a89d..22d13b6e5 100644
--- a/Source/Engine/Level/Actors/Spline.cpp
+++ b/Source/Engine/Level/Actors/Spline.cpp
@@ -490,19 +490,26 @@ void Spline::SetKeyframes(MArray* data, int32 keySize)
 
 namespace
 {
-    void DrawSpline(Spline* spline, const Color& color, const Transform& transform, bool depthTest)
+    FORCE_INLINE float NodeSizeByDistance(const Vector3& nodePosition, bool scaleByDistance)
+    {
+        if (scaleByDistance)
+            return (float)(Vector3::Distance(DebugDraw::GetViewPos(), nodePosition) / 100);
+        return 5.0f;
+    }
+
+    void DrawSpline(Spline* spline, const Color& color, const Transform& transform, bool depthTest, bool scaleByDistance = false)
     {
         const int32 count = spline->Curve.GetKeyframes().Count();
         if (count == 0)
             return;
         Spline::Keyframe* prev = spline->Curve.GetKeyframes().Get();
         Vector3 prevPos = transform.LocalToWorld(prev->Value.Translation);
-        DEBUG_DRAW_WIRE_SPHERE(BoundingSphere(prevPos, 5.0f), color, 0.0f, depthTest);
+        DEBUG_DRAW_WIRE_SPHERE(BoundingSphere(prevPos, NodeSizeByDistance(prevPos, scaleByDistance)), color, 0.0f, depthTest);
         for (int32 i = 1; i < count; i++)
         {
             Spline::Keyframe* next = prev + 1;
             Vector3 nextPos = transform.LocalToWorld(next->Value.Translation);
-            DEBUG_DRAW_WIRE_SPHERE(BoundingSphere(nextPos, 5.0f), color, 0.0f, depthTest);
+            DEBUG_DRAW_WIRE_SPHERE(BoundingSphere(nextPos, NodeSizeByDistance(nextPos, scaleByDistance)), color, 0.0f, depthTest);
             const float d = (next->Time - prev->Time) / 3.0f;
             DEBUG_DRAW_BEZIER(prevPos, prevPos + prev->TangentOut.Translation * d, nextPos + next->TangentIn.Translation * d, nextPos, color, 0.0f, depthTest);
             prev = next;
@@ -521,7 +528,7 @@ void Spline::OnDebugDraw()
 
 void Spline::OnDebugDrawSelected()
 {
-    DrawSpline(this, Color::White, _transform, false);
+    DrawSpline(this, Color::White, _transform, false, true);
 
     // Base
     Actor::OnDebugDrawSelected();