From c86508ef5781a589fff07f24c9eb07eae0bff393 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Fri, 19 Feb 2021 11:01:21 +0100
Subject: [PATCH] Add support for updating particle effects in editor view when
 editing

---
 Source/Engine/Level/Level.cpp               |  6 +--
 Source/Engine/Level/Scene/SceneTicking.h    | 46 ++++++++++++++-------
 Source/Engine/Particles/ParticleEffect.cpp  | 14 +++++++
 Source/Engine/Particles/ParticleEffect.h    |  3 ++
 Source/Engine/Particles/ParticleManager.cpp | 10 +++++
 5 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/Source/Engine/Level/Level.cpp b/Source/Engine/Level/Level.cpp
index ba4ce4014..be07f56ec 100644
--- a/Source/Engine/Level/Level.cpp
+++ b/Source/Engine/Level/Level.cpp
@@ -194,7 +194,7 @@ void LevelService::Update()
         for (int32 i = 0; i < scenes.Count(); i++)
         {
             if (scenes[i]->GetIsActive())
-                scenes[i]->Ticking.Update.TickEditorScripts();
+                scenes[i]->Ticking.Update.TickExecuteInEditor();
         }
     }
 #endif
@@ -223,7 +223,7 @@ void LevelService::LateUpdate()
         for (int32 i = 0; i < scenes.Count(); i++)
         {
             if (scenes[i]->GetIsActive())
-                scenes[i]->Ticking.LateUpdate.TickEditorScripts();
+                scenes[i]->Ticking.LateUpdate.TickExecuteInEditor();
         }
     }
 #endif
@@ -255,7 +255,7 @@ void LevelService::FixedUpdate()
         for (int32 i = 0; i < scenes.Count(); i++)
         {
             if (scenes[i]->GetIsActive())
-                scenes[i]->Ticking.FixedUpdate.TickEditorScripts();
+                scenes[i]->Ticking.FixedUpdate.TickExecuteInEditor();
         }
     }
 #endif
diff --git a/Source/Engine/Level/Scene/SceneTicking.h b/Source/Engine/Level/Scene/SceneTicking.h
index bb26e83c1..8962f1810 100644
--- a/Source/Engine/Level/Scene/SceneTicking.h
+++ b/Source/Engine/Level/Scene/SceneTicking.h
@@ -17,15 +17,9 @@ public:
     /// <summary>
     /// Tick function type.
     /// </summary>
-    class Tick
+    struct Tick
     {
-    public:
-
-        /// <summary>
-        /// Signature of the function to call
-        /// </summary>
         typedef void (*Signature)();
-
         typedef void (*SignatureObj)(void*);
 
         template<class T, void(T::*Method)()>
@@ -51,8 +45,7 @@ public:
         /// <summary>
         /// Calls the binded function.
         /// </summary>
-        /// <returns>Function result</returns>
-        void Call() const
+        FORCE_INLINE void Call() const
         {
             (*FunctionObj)(Callee);
         }
@@ -63,10 +56,11 @@ public:
     public:
 
         Array<Script*> Scripts;
+        Array<Tick> Ticks;
 #if USE_EDITOR
         Array<Script*> ScriptsExecuteInEditor;
+        Array<Tick> TicksExecuteInEditor;
 #endif
-        Array<Tick> Ticks;
 
         TickData(int32 capacity)
             : Scripts(capacity)
@@ -81,18 +75,17 @@ public:
             TickScripts(Scripts);
 
             for (int32 i = 0; i < Ticks.Count(); i++)
-            {
                 Ticks[i].Call();
-            }
         }
 
 #if USE_EDITOR
-
-        void TickEditorScripts()
+        void TickExecuteInEditor()
         {
             TickScripts(ScriptsExecuteInEditor);
-        }
 
+            for (int32 i = 0; i < TicksExecuteInEditor.Count(); i++)
+                TicksExecuteInEditor[i].Call();
+        }
 #endif
 
         void AddScript(Script* script);
@@ -118,12 +111,35 @@ public:
             }
         }
 
+#if USE_EDITOR
+        template<class T, void(T::*Method)()>
+        void AddTickExecuteInEditor(T* callee)
+        {
+            SceneTicking::Tick tick;
+            tick.Bind<T, Method>(callee);
+            TicksExecuteInEditor.Add(tick);
+        }
+
+        void RemoveTickExecuteInEditor(void* callee)
+        {
+            for (int32 i = 0; i < TicksExecuteInEditor.Count(); i++)
+            {
+                if (TicksExecuteInEditor[i].Callee == callee)
+                {
+                    TicksExecuteInEditor.RemoveAt(i);
+                    break;
+                }
+            }
+        }
+#endif
+
         void Clear()
         {
             Scripts.Clear();
             Ticks.Clear();
 #if USE_EDITOR
             ScriptsExecuteInEditor.Clear();
+            TicksExecuteInEditor.Clear();
 #endif
         }
     };
diff --git a/Source/Engine/Particles/ParticleEffect.cpp b/Source/Engine/Particles/ParticleEffect.cpp
index b669eeabc..61f0ba8ae 100644
--- a/Source/Engine/Particles/ParticleEffect.cpp
+++ b/Source/Engine/Particles/ParticleEffect.cpp
@@ -373,6 +373,18 @@ void ParticleEffect::Update()
     UpdateSimulation();
 }
 
+#if USE_EDITOR
+
+#include "Editor/Editor.h"
+
+void ParticleEffect::UpdateExecuteInEditor()
+{
+    if (!Editor::IsPlayMode)
+        Update();
+}
+
+#endif
+
 void ParticleEffect::CacheModifiedParameters()
 {
     if (_parameters.IsEmpty())
@@ -649,6 +661,7 @@ void ParticleEffect::OnEnable()
     GetSceneRendering()->AddGeometry(this);
 #if USE_EDITOR
     GetSceneRendering()->AddViewportIcon(this);
+    GetScene()->Ticking.Update.AddTickExecuteInEditor<ParticleEffect, &ParticleEffect::UpdateExecuteInEditor>(this);
 #endif
 
     // Base
@@ -658,6 +671,7 @@ void ParticleEffect::OnEnable()
 void ParticleEffect::OnDisable()
 {
 #if USE_EDITOR
+    GetScene()->Ticking.Update.RemoveTickExecuteInEditor(this);
     GetSceneRendering()->RemoveViewportIcon(this);
 #endif
     GetSceneRendering()->RemoveGeometry(this);
diff --git a/Source/Engine/Particles/ParticleEffect.h b/Source/Engine/Particles/ParticleEffect.h
index 67d7ebd19..65004278c 100644
--- a/Source/Engine/Particles/ParticleEffect.h
+++ b/Source/Engine/Particles/ParticleEffect.h
@@ -366,6 +366,9 @@ protected:
 private:
 
     void Update();
+#if USE_EDITOR
+    void UpdateExecuteInEditor();
+#endif
     void CacheModifiedParameters();
     void ApplyModifiedParameters();
     void OnParticleSystemModified();
diff --git a/Source/Engine/Particles/ParticleManager.cpp b/Source/Engine/Particles/ParticleManager.cpp
index f2e70fee3..0ad96c74a 100644
--- a/Source/Engine/Particles/ParticleManager.cpp
+++ b/Source/Engine/Particles/ParticleManager.cpp
@@ -17,6 +17,9 @@
 #include "Engine/Profiler/ProfilerGPU.h"
 #include "Engine/Renderer/Utils/BitonicSort.h"
 #endif
+#if USE_EDITOR
+#include "Editor/Editor.h"
+#endif
 
 struct SpriteParticleVertex
 {
@@ -1155,6 +1158,13 @@ void ParticleManagerService::Update()
         // Simulation delta time can be based on a time since last update or the current delta time
         float dt = effect->UseTimeScale ? deltaTime : deltaTimeUnscaled;
         float t = effect->UseTimeScale ? time : timeUnscaled;
+#if USE_EDITOR
+        if (!Editor::IsPlayMode)
+        {
+            dt = deltaTimeUnscaled;
+            t = timeUnscaled;
+        }
+#endif
         const float lastUpdateTime = instance.LastUpdateTime;
         if (lastUpdateTime > 0 && t > lastUpdateTime)
         {