From 85631a54331288b1418b20ce241b9c27fadb79b7 Mon Sep 17 00:00:00 2001
From: Panos Karabelas <panosconroe@hotmail.com>
Date: Thu, 24 Oct 2024 03:42:42 +0100
Subject: [PATCH] [renderer] cleaned up environment filtering code

---
 runtime/Rendering/Renderer.cpp        | 28 --------------
 runtime/Rendering/Renderer_Passes.cpp | 53 +++++++++++++++++----------
 runtime/World/Components/Light.h      |  5 ++-
 3 files changed, 36 insertions(+), 50 deletions(-)

diff --git a/runtime/Rendering/Renderer.cpp b/runtime/Rendering/Renderer.cpp
index ec68f3b62..12bd5b29b 100644
--- a/runtime/Rendering/Renderer.cpp
+++ b/runtime/Rendering/Renderer.cpp
@@ -599,34 +599,6 @@ namespace Spartan
 
         UpdateConstantBufferFrame(cmd_list_graphics);
         AddLinesToBeRendered();
-
-        // filter environment on directional light change
-        {
-            static Quaternion rotation;
-            static float intensity;
-            static Color color;
-
-            for (const shared_ptr<Entity>& entity : m_renderables[Renderer_Entity::Light])
-            {
-                if (const shared_ptr<Light>& light = entity->GetComponent<Light>())
-                {
-                    if (light->GetLightType() == LightType::Directional)
-                    {
-                        if (light->GetEntity()->GetRotation() != rotation ||
-                            light->GetIntensityLumens() != intensity ||
-                            light->GetColor() != color
-                            )
-                        {
-                            rotation  = light->GetEntity()->GetRotation();
-                            intensity = light->GetIntensityLumens();
-                            color     = light->GetColor();
-
-                            m_environment_mips_to_filter_count = GetRenderTarget(Renderer_RenderTarget::skysphere)->GetMipCount() - 1;
-                        }
-                    }
-                }
-            }
-        }
     }
 
     void Renderer::DrawString(const string& text, const Vector2& position_screen_percentage)
diff --git a/runtime/Rendering/Renderer_Passes.cpp b/runtime/Rendering/Renderer_Passes.cpp
index 7428d7862..85608e265 100644
--- a/runtime/Rendering/Renderer_Passes.cpp
+++ b/runtime/Rendering/Renderer_Passes.cpp
@@ -389,20 +389,17 @@ namespace Spartan
                 light_integration_brdf_speculat_lut_completed = true;
             }
 
-            if (m_environment_mips_to_filter_count > 0)
-            {
-                Pass_Light_Integration_EnvironmentPrefilter(cmd_list_graphics);
-            }
+            Pass_Light_Integration_EnvironmentPrefilter(cmd_list_graphics);
         }
 
         if (shared_ptr<Camera> camera = GetCamera())
         { 
             // shadow maps
             {
-                Pass_ShadowMaps(cmd_list_graphics, false);
+                //Pass_ShadowMaps(cmd_list_graphics, false);
                 if (mesh_index_transparent != -1)
                 {
-                    Pass_ShadowMaps(cmd_list_graphics, true);
+                   // Pass_ShadowMaps(cmd_list_graphics, true);
                 }
             }
 
@@ -1368,27 +1365,43 @@ namespace Spartan
 
     void Renderer::Pass_Light_Integration_EnvironmentPrefilter(RHI_CommandList* cmd_list)
     {
-        // acquire resources
-        RHI_Texture* tex_environment = GetRenderTarget(Renderer_RenderTarget::skysphere);
-        RHI_Shader* shader_c         = GetShader(Renderer_Shader::light_integration_environment_filter_c);
-        if (!shader_c || !shader_c->IsCompiled())
-            return;
-
-        // this pass is costly and can cause the engine to freeze for a few seconds
-        // so while the light is moving, we don't update the environment map
-        auto& entities = m_renderables[Renderer_Entity::Light];
-        for (shared_ptr<Entity> entity : entities)
+        // find a directional light, check if it has changed and update the mip count that we need to process
+        if (m_environment_mips_to_filter_count == 0)
         {
-            if (shared_ptr<Light> light = entity->GetComponent<Light>())
+            static Quaternion rotation;
+            static float intensity;
+            static Color color;
+
+            for (const shared_ptr<Entity>& entity : m_renderables[Renderer_Entity::Light])
             {
-                if (light->GetLightType() == LightType::Directional)
+                if (const shared_ptr<Light>& light = entity->GetComponent<Light>())
                 {
-                    if (light->GetEntity()->IsMoving())
-                        return;
+                    if (light->GetLightType() == LightType::Directional)
+                    {
+                        // filtering is very expensive hence why we try to minimize it
+                        if (!light->GetEntity()->IsMoving() && // has a rest time (a couple of seconds)
+                            (light->GetEntity()->GetRotation() != rotation || light->GetIntensityLumens() != intensity || light->GetColor() != color))
+                        {
+                            rotation  = light->GetEntity()->GetRotation();
+                            intensity = light->GetIntensityLumens();
+                            color     = light->GetColor();
+
+                            m_environment_mips_to_filter_count = GetRenderTarget(Renderer_RenderTarget::skysphere)->GetMipCount() - 1;
+                        }
+                    }
                 }
             }
         }
 
+        if (m_environment_mips_to_filter_count < 1)
+            return;
+
+        // acquire resources
+        RHI_Texture* tex_environment = GetRenderTarget(Renderer_RenderTarget::skysphere);
+        RHI_Shader* shader_c         = GetShader(Renderer_Shader::light_integration_environment_filter_c);
+        if (!shader_c || !shader_c->IsCompiled())
+            return;
+
         cmd_list->BeginTimeblock("light_integration_environment_filter");
 
         uint32_t mip_count = tex_environment->GetMipCount();
diff --git a/runtime/World/Components/Light.h b/runtime/World/Components/Light.h
index 7666039b6..59e5020a1 100644
--- a/runtime/World/Components/Light.h
+++ b/runtime/World/Components/Light.h
@@ -41,7 +41,8 @@ namespace Spartan
     {
         Directional,
         Point,
-        Spot
+        Spot,
+        Max
     };
 
     enum class LightIntensity
@@ -148,7 +149,7 @@ namespace Spartan
 
         // misc
         uint32_t m_flags           = 0;
-        LightType m_light_type     = LightType::Directional;
+        LightType m_light_type     = LightType::Max;
         Color m_color_rgb          = Color::standard_black;;
         float m_temperature_kelvin = 0.0f;
         float m_range              = 0.0f;