From 9179c90fb937976ea1ffdbc018c080325c36ea53 Mon Sep 17 00:00:00 2001
From: Simon Tippe <tippe.simon@gmail.com>
Date: Mon, 7 Mar 2022 01:15:45 +0100
Subject: [PATCH] DDGI probe count can now be changed

---
 CMakeLists.txt                    | 10 +++-
 README.md                         |  3 +-
 demo/App.cpp                      | 89 +++++++++++++++++++++----------
 demo/App.h                        |  5 +-
 demo/CMakeLists.txt               | 11 ++++
 src/System.h                      |  2 +-
 src/lighting/IrradianceVolume.cpp | 17 ++++++
 src/lighting/IrradianceVolume.h   |  2 +
 8 files changed, 107 insertions(+), 32 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 50d4bb9cc..8a289337d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,11 @@ endif()
 
 # Options and compiler settings ###################################################################
 option(ATLAS_DEMO "Build demo executable" OFF)
+option(ATLAS_IMGUI "Activate ImGui integration" OFF)
+
+if (ATLAS_DEMO)
+set (ATLAS_IMGUI ON)
+endif()
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
@@ -74,7 +79,10 @@ else()
 add_subdirectory(${GLAD_LOCATION})
 endif()
 add_subdirectory(${ATLAS_LOCATION})
-if (ATLAS_DEMO)
+
+if (ATLAS_IMGUI)
 add_subdirectory(${IMGUI_LOCATION})
+endif()
+if (ATLAS_DEMO)
 add_subdirectory(${DEMO_LOCATION})
 endif()
diff --git a/README.md b/README.md
index 3995d0993..8bc18c7b2 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,8 @@ Run CMake with the option ATLAS_DEMO=ON to include the demo application in the p
 that and launches Visual Studio afterwards. After launching the IDE, set AtlasEngineDemo as your target.
 ### Including the library into your own project
 It is possible to compile the engine either as a shared or static library. Set the ATLAS_BUILD_SHARED option accordingly. To make
-the library work with its dependencies, the root CMakeLists.txt of this repository has to be added as a subdirectory.
+the library work with its dependencies, the root CMakeLists.txt of this repository has to be added as a subdirectory. As an entry
+point to create an application from scratch take a look at the [Hello World tutorial](https://github.com/tippesi/Atlas-Engine/wiki/Hello-World). For reference, the source folder contains an empty [app header](https://github.com/tippesi/Atlas-Engine/blob/master/src/App.h) and an empty [app source](https://github.com/tippesi/Atlas-Engine/blob/master/src/App.cpp).
 <!---
 ### Android
 You can compile the engine using Gradle either with or without AndroidStudio.
diff --git a/demo/App.cpp b/demo/App.cpp
index add3d0715..c7a2f3bf5 100644
--- a/demo/App.cpp
+++ b/demo/App.cpp
@@ -19,6 +19,8 @@ void App::LoadContent() {
 
 	font = Atlas::Font("font/roboto.ttf", 44, 10);
 
+	DisplayLoadingScreen();
+
 	camera = Atlas::Camera(47.0f, 2.0f, 1.0f, 400.0f,
 		vec3(30.0f, 25.0f, 0.0f), vec2(-3.14f / 2.0f, 0.0f));
 
@@ -40,27 +42,20 @@ void App::LoadContent() {
 	directionalLight = Atlas::Lighting::DirectionalLight(AE_MOVABLE_LIGHT);
 	directionalLight.direction = vec3(0.0f, -1.0f, 1.0f);
 	directionalLight.color = vec3(253, 194, 109) / 255.0f;
-
-	// Cascaded shadow mapping
 	directionalLight.AddShadow(150.0f, 1.1f, 1024, 5, 0.8f);
 	directionalLight.AddVolumetric(10, 0.28f);
-
 	scene.Add(&directionalLight);
 
 	scene.ssao = new Atlas::Lighting::SSAO(32);
 
 	scene.fog = new Atlas::Lighting::Fog();
-
 	scene.fog->enable = true;
 	scene.fog->density = 0.0002f;
 	scene.fog->heightFalloff = 0.0284f;
 	scene.fog->height = 0.0f;
 	scene.fog->scatteringAnisotropy = 0.0f;
 
-	LoadScene();
-
 	scene.postProcessing.taa = Atlas::PostProcessing::TAA(0.99f);
-	// Use against TAA smoothing
 	scene.postProcessing.sharpen.enable = true;
 	scene.postProcessing.sharpen.factor = 0.15f;
 
@@ -70,22 +65,7 @@ void App::LoadContent() {
 	sphere.data.materials[0].metalness = 0.0;
 	sphere.data.materials[0].baseColor = vec3(1.0);
 
-	scene.Update(&camera, 1.0f);
-	scene.BuildRTStructures();
-	
-	auto volume = scene.irradianceVolume;
-	volume->hysteresis = 0.99f;
-
-	int32_t probeCount = volume->probeCount.x * volume->probeCount.y *
-		volume->probeCount.z;
-
-	for (int32_t j = 0; j < probeCount; j++) {
-		auto actor = new Atlas::Actor::MovableMeshActor(&sphere);
-		actor->visible = false;
-		sphereActors.push_back(actor);
-
-		scene.Add(actor);
-	}
+	LoadScene();
 
 	ImGui::CreateContext();
 	ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -128,9 +108,9 @@ void App::Update(float deltaTime) {
 		static bool renderSpheres = false;
 		if (renderSpheres != spheresVisible) {
 			renderSpheres = spheresVisible;
-			for (auto actor : sphereActors)
+			for (auto& actor : probeActors)
 			{
-				actor->visible = renderSpheres;
+				actor.visible = renderSpheres;
 			}
 		}
 		if (renderSpheres) {
@@ -153,7 +133,7 @@ void App::Update(float deltaTime) {
 				ivec3 offset = ivec3(x, y, z);
 				vec3 pos = scene.irradianceVolume->GetProbeLocation(offset);
 
-				sphereActors[j]->SetMatrix(glm::translate(pos));
+				probeActors[j].SetMatrix(glm::translate(pos));
 			}
 		}
 	}
@@ -271,7 +251,7 @@ void App::Render(float deltaTime) {
 				const char* items[] = { "1280x720", "1920x1080", "2560x1440", "3840x2160" };
 				static int resolution = 1;
 				int currentItem = resolution;
-				ImGui::Combo("Resolution", &currentItem, items, IM_ARRAYSIZE(items));
+				ImGui::Combo("Resolution##Rendering", &currentItem, items, IM_ARRAYSIZE(items));
 
 				if (currentItem != resolution) {
 					resolution = currentItem;
@@ -285,12 +265,33 @@ void App::Render(float deltaTime) {
 
 			}
 
-			if (ImGui::CollapsingHeader("Irradiance volume")) {
+			if (ImGui::CollapsingHeader("DDGI")) {
 				ImGui::Text(("Probe count: " + vecToString(volume->probeCount)).c_str());
 				ImGui::Checkbox("Enable volume", &volume->enable);
 				ImGui::Checkbox("Update volume", &volume->update);
 				ImGui::Checkbox("Visualize probes", &spheresVisible);
 				ImGui::Checkbox("Sample emissives", &volume->sampleEmissives);
+
+				const char* items[] = { "5x5x5", "10x10x10", "20x20x20", "30x30x30" };
+				int currentItem = 0;
+				if (volume->probeCount == ivec3(5)) currentItem = 0;
+				if (volume->probeCount == ivec3(10)) currentItem = 1;
+				if (volume->probeCount == ivec3(20)) currentItem = 2;
+				if (volume->probeCount == ivec3(30)) currentItem = 3;
+				auto prevItem = currentItem;
+				ImGui::Combo("Resolution##DDGI", &currentItem, items, IM_ARRAYSIZE(items));
+
+				if (currentItem != prevItem) {
+					RemoveProbeActors();
+					switch (currentItem) {
+					case 0: volume->SetProbeCount(ivec3(5)); break;
+					case 1: volume->SetProbeCount(ivec3(10)); break;
+					case 2: volume->SetProbeCount(ivec3(20)); break;
+					case 3: volume->SetProbeCount(ivec3(30)); break;
+					}
+					AddProbeActors();
+				}
+
 				ImGui::SliderFloat("Strength##DDGI", &volume->strength, 0.0f, 5.0f);
 				ImGui::Separator();
 				ImGui::Text("AABB");
@@ -411,6 +412,8 @@ bool App::LoadScene() {
 
 	DisplayLoadingScreen();
 
+	RemoveProbeActors();
+
 	Atlas::Texture::Cubemap sky;
 	//else sky = Atlas::Texture::Cubemap("moonlit_golf_4k.hdr", 1024);
 
@@ -537,6 +540,8 @@ bool App::LoadScene() {
 	scene.Update(&camera, 1.0f);
 	scene.BuildRTStructures();
 
+	AddProbeActors();
+
 	// Reset input handlers
 	keyboardHandler.Reset(&camera);
 	mouseHandler.Reset(&camera);
@@ -554,6 +559,34 @@ void App::UnloadScene() {
 
 }
 
+void App::AddProbeActors() {
+
+	auto volume = scene.irradianceVolume;
+	int32_t probeCount = volume->probeCount.x * volume->probeCount.y *
+		volume->probeCount.z;
+
+	for (int32_t j = 0; j < probeCount; j++) {
+		auto actor = Atlas::Actor::MovableMeshActor(&sphere);
+		actor.visible = spheresVisible;
+		probeActors.push_back(actor);
+	}
+
+	for (auto& actor : probeActors) {
+		scene.Add(&actor);
+	}
+
+}
+
+void App::RemoveProbeActors() {
+
+	for (auto& actor : probeActors) {
+		scene.Remove(&actor);
+	}
+
+	probeActors.clear();
+
+}
+
 void App::SetResolution(int32_t width, int32_t height) {
 
 	renderTarget->Resize(width, height);
diff --git a/demo/App.h b/demo/App.h
index ec37ec39b..0c068b2ce 100644
--- a/demo/App.h
+++ b/demo/App.h
@@ -40,6 +40,9 @@ class App : public Atlas::EngineInstance {
 	bool LoadScene();
 	void UnloadScene();
 
+	void AddProbeActors();
+	void RemoveProbeActors();
+
 	void SetResolution(int32_t width, int32_t height);
 
 	SceneSelection sceneSelection = SPONZA;
@@ -66,7 +69,7 @@ class App : public Atlas::EngineInstance {
 	Atlas::Input::MouseHandler mouseHandler;
 	Atlas::Input::KeyboardHandler keyboardHandler;
 
-	std::vector<Atlas::Actor::MovableMeshActor*> sphereActors;
+	std::vector<Atlas::Actor::MovableMeshActor> probeActors;
 
 	bool renderUI = true;
 	bool renderEnvProbe = true;
diff --git a/demo/CMakeLists.txt b/demo/CMakeLists.txt
index 040c405dc..c4a4b60e3 100644
--- a/demo/CMakeLists.txt
+++ b/demo/CMakeLists.txt
@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.7)
 project(AtlasEngineDemo)
 
+# Note: For this project, the root CMakeLists.txt turns
+# the ATLAS_IMGUI and ATLAS_EXPORT_MAIN options on.
+
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/)
 
 file(GLOB_RECURSE DEMO_SOURCE_FILES
@@ -10,6 +13,8 @@ file(GLOB_RECURSE DEMO_SOURCE_FILES
 		"*.hpp"
         )
 
+# Required: Set both the source and dependency directories 
+# as include directories
 include_directories(../src)
 include_directories(../dependencies)
 
@@ -24,6 +29,12 @@ foreach(SOURCE_FILE IN ITEMS ${DEMO_SOURCE_FILES})
     source_group("${SOURCE_PATH_CONVERTED}" FILES "${SOURCE_FILE}")
 endforeach()  
 
+# We use the exported main file from the AtlasEngine library to able to use
+# the app class. Alternatively, you can write a main function yourself.
+# To export the main file the ATLAS_EXPORT_MAIN option has to be turned on.
 add_executable(${PROJECT_NAME} ${DEMO_SOURCE_FILES} ${ATLAS_ENGINE_MAIN_FILE})
+# Required: Add the compile definitions of the library, such that includes work properly
 target_compile_definitions(${PROJECT_NAME} PUBLIC ${ATLAS_ENGINE_COMPILE_DEFINITIONS})
+# We want to use both ImGui and the AtlasEngine. For ImGui, the ATLAS_IMGUI option
+# needs to be turned on.
 target_link_libraries (${PROJECT_NAME} AtlasEngine Imgui)
\ No newline at end of file
diff --git a/src/System.h b/src/System.h
index 22efedc15..eacf73c11 100644
--- a/src/System.h
+++ b/src/System.h
@@ -10,7 +10,7 @@
 
 #define AE_SHOW_LOG
 // #define AE_SHOW_API_DEBUG_LOG
-#define AE_INSTANT_SHADER_RELOAD
+// #define AE_INSTANT_SHADER_RELOAD
 
 #include <stdint.h>
 #include <string>
diff --git a/src/lighting/IrradianceVolume.cpp b/src/lighting/IrradianceVolume.cpp
index 548a522f1..fc43208e2 100644
--- a/src/lighting/IrradianceVolume.cpp
+++ b/src/lighting/IrradianceVolume.cpp
@@ -64,6 +64,23 @@ namespace Atlas {
 		
 		}
 
+		void IrradianceVolume::SetProbeCount(ivec3 probeCount) {
+
+			this->probeCount = probeCount;
+
+			auto irrRes = ivec2(this->irrRes + 2);
+			irrRes.x *= probeCount.x;
+			irrRes.y *= probeCount.z;
+
+			auto momRes = ivec2(this->momRes + 2);
+			momRes.x *= probeCount.x;
+			momRes.y *= probeCount.z;
+
+			internal = InternalIrradianceVolume(irrRes, momRes, probeCount);
+			internal.SetRayCount(rayCount, rayCountInactive);
+
+		}
+
 		void IrradianceVolume::ClearProbes() {
 
 			auto irrRes = ivec2(this->irrRes + 2);
diff --git a/src/lighting/IrradianceVolume.h b/src/lighting/IrradianceVolume.h
index 9b261a26b..ceebc8ea5 100644
--- a/src/lighting/IrradianceVolume.h
+++ b/src/lighting/IrradianceVolume.h
@@ -65,6 +65,8 @@ namespace Atlas {
 
 			void SetRayCount(uint32_t rayCount, uint32_t rayCountInactive);
 
+			void SetProbeCount(ivec3 probeCount);
+
 			void ClearProbes();
 
 			Volume::AABB aabb;