Add source files for scene (graph + frustum culling) guest article.

src/8.guest/2021/1.scene/1.scene_graph/1.model_loading.fs

@@ -0,0 +1,11 @@
+#version 330 core
+out vec4 FragColor;
+
+in vec2 TexCoords;
+
+uniform sampler2D texture_diffuse1;
+
+void main()
+{    
+    FragColor = texture(texture_diffuse1, TexCoords);
+}

src/8.guest/2021/1.scene/1.scene_graph/1.model_loading.vs

@@ -0,0 +1,16 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    TexCoords = aTexCoords;    
+    gl_Position = projection * view * model * vec4(aPos, 1.0);
+}

src/8.guest/2021/1.scene/1.scene_graph/scene_graph.cpp

@@ -0,0 +1,227 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+#include <learnopengl/filesystem.h>
+#include <learnopengl/shader_m.h>
+#include <learnopengl/camera.h>
+#include <learnopengl/model.h>
+#include <learnopengl/entity.h>
+
+#ifndef ENTITY_H
+#define ENTITY_H
+
+#include <list> //std::list
+#include <memory> //std::unique_ptr
+
+class Entity : public Model
+{
+public:
+	list<unique_ptr<Entity>> children;
+	Entity* parent;
+};
+#endif
+
+
+#include <iostream>
+
+void framebuffer_size_callback(GLFWwindow* window, int width, int height);
+void mouse_callback(GLFWwindow* window, double xpos, double ypos);
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
+void processInput(GLFWwindow* window);
+
+// settings
+const unsigned int SCR_WIDTH = 800;
+const unsigned int SCR_HEIGHT = 600;
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = SCR_WIDTH / 2.0f;
+float lastY = SCR_HEIGHT / 2.0f;
+bool firstMouse = true;
+
+// timing
+float deltaTime = 0.0f;
+float lastFrame = 0.0f;
+
+int main()
+{
+	// glfw: initialize and configure
+	// ------------------------------
+	glfwInit();
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+#ifdef __APPLE__
+	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+#endif
+
+	// glfw window creation
+	// --------------------
+	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+	if (window == NULL)
+	{
+		std::cout << "Failed to create GLFW window" << std::endl;
+		glfwTerminate();
+		return -1;
+	}
+	glfwMakeContextCurrent(window);
+	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+	glfwSetCursorPosCallback(window, mouse_callback);
+	glfwSetScrollCallback(window, scroll_callback);
+
+	// tell GLFW to capture our mouse
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	// glad: load all OpenGL function pointers
+	// ---------------------------------------
+	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+	{
+		std::cout << "Failed to initialize GLAD" << std::endl;
+		return -1;
+	}
+
+	// tell stb_image.h to flip loaded texture's on the y-axis (before loading model).
+	stbi_set_flip_vertically_on_load(true);
+
+	// configure global opengl state
+	// -----------------------------
+	glEnable(GL_DEPTH_TEST);
+
+	// build and compile shaders
+	// -------------------------
+	Shader ourShader("1.model_loading.vs", "1.model_loading.fs");
+
+	// load entities
+	// -----------
+	Entity ourEntity(FileSystem::getPath("resources/objects/planet/planet.obj"));
+	ourEntity.transform.setLocalPosition({ 10, 0, 0 });
+	const float scale = 0.75;
+	ourEntity.transform.setLocalScale({ scale, scale, scale });
+
+	{
+		Entity* lastEntity = &ourEntity;
+
+		for (unsigned int i = 0; i < 10; ++i)
+		{
+			lastEntity->addChild(FileSystem::getPath("resources/objects/planet/planet.obj"));
+			lastEntity = lastEntity->children.back().get();
+
+			//Set tranform values
+			lastEntity->transform.setLocalPosition({ 10, 0, 0 });
+			lastEntity->transform.setLocalScale({ scale, scale, scale });
+		}
+	}
+	ourEntity.updateSelfAndChild();
+
+	// draw in wireframe
+	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+
+	// render loop
+	// -----------
+	while (!glfwWindowShouldClose(window))
+	{
+		// per-frame time logic
+		// --------------------
+		float currentFrame = glfwGetTime();
+		deltaTime = currentFrame - lastFrame;
+		lastFrame = currentFrame;
+
+		// input
+		// -----
+		processInput(window);
+
+		// render
+		// ------
+		glClearColor(0.05f, 0.05f, 0.05f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		// don't forget to enable shader before setting uniforms
+		ourShader.use();
+
+		// view/projection transformations
+		glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+		glm::mat4 view = camera.GetViewMatrix();
+		ourShader.setMat4("projection", projection);
+		ourShader.setMat4("view", view);
+
+		// draw our scene graph
+		Entity* lastEntity = &ourEntity;
+		while (lastEntity->children.size())
+		{
+			ourShader.setMat4("model", lastEntity->transform.getModelMatrix());
+			lastEntity->Draw(ourShader);
+			lastEntity = lastEntity->children.back().get();
+		}
+
+		ourEntity.transform.setLocalRotation({ 0.f, ourEntity.transform.getLocalRotation().y + 20 * deltaTime, 0.f });
+		ourEntity.updateSelfAndChild();
+
+		// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+		// -------------------------------------------------------------------------------
+		glfwSwapBuffers(window);
+		glfwPollEvents();
+	}
+
+	// glfw: terminate, clearing all previously allocated GLFW resources.
+	// ------------------------------------------------------------------
+	glfwTerminate();
+	return 0;
+}
+
+// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
+// ---------------------------------------------------------------------------------------------------------
+void processInput(GLFWwindow* window)
+{
+	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
+		glfwSetWindowShouldClose(window, true);
+
+	if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
+		camera.ProcessKeyboard(FORWARD, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
+		camera.ProcessKeyboard(BACKWARD, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
+		camera.ProcessKeyboard(LEFT, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
+		camera.ProcessKeyboard(RIGHT, deltaTime);
+}
+
+// glfw: whenever the window size changed (by OS or user resize) this callback function executes
+// ---------------------------------------------------------------------------------------------
+void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+{
+	// make sure the viewport matches the new window dimensions; note that width and 
+	// height will be significantly larger than specified on retina displays.
+	glViewport(0, 0, width, height);
+}
+
+// glfw: whenever the mouse moves, this callback is called
+// -------------------------------------------------------
+void mouse_callback(GLFWwindow* window, double xpos, double ypos)
+{
+	if (firstMouse)
+	{
+		lastX = xpos;
+		lastY = ypos;
+		firstMouse = false;
+	}
+
+	float xoffset = xpos - lastX;
+	float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
+
+	lastX = xpos;
+	lastY = ypos;
+
+	camera.ProcessMouseMovement(xoffset, yoffset);
+}
+
+// glfw: whenever the mouse scroll wheel scrolls, this callback is called
+// ----------------------------------------------------------------------
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
+{
+	camera.ProcessMouseScroll(yoffset);
+}

src/8.guest/2021/1.scene/2.frustum_culling/1.model_loading.fs

@@ -0,0 +1,11 @@
+#version 330 core
+out vec4 FragColor;
+
+in vec2 TexCoords;
+
+uniform sampler2D texture_diffuse1;
+
+void main()
+{    
+    FragColor = texture(texture_diffuse1, TexCoords);
+}

src/8.guest/2021/1.scene/2.frustum_culling/1.model_loading.vs

@@ -0,0 +1,16 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    TexCoords = aTexCoords;    
+    gl_Position = projection * view * model * vec4(aPos, 1.0);
+}

src/8.guest/2021/1.scene/2.frustum_culling/frustum_culling.cpp

@@ -0,0 +1,236 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+#include <learnopengl/filesystem.h>
+#include <learnopengl/shader_m.h>
+#include <learnopengl/camera.h>
+#include <learnopengl/model.h>
+#include <learnopengl/entity.h>
+
+#ifndef ENTITY_H
+#define ENTITY_H
+
+#include <list> //std::list
+#include <memory> //std::unique_ptr
+
+class Entity : public Model
+{
+public:
+	list<unique_ptr<Entity>> children;
+	Entity* parent;
+};
+#endif
+
+
+#include <iostream>
+
+void framebuffer_size_callback(GLFWwindow* window, int width, int height);
+void mouse_callback(GLFWwindow* window, double xpos, double ypos);
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
+void processInput(GLFWwindow* window);
+
+// settings
+const unsigned int SCR_WIDTH = 800;
+const unsigned int SCR_HEIGHT = 600;
+
+// camera
+Camera camera(glm::vec3(0.0f, 10.0f, 0.0f));
+Camera cameraSpy(glm::vec3(0.0f, 10.0f, 0.f));
+float lastX = SCR_WIDTH / 2.0f;
+float lastY = SCR_HEIGHT / 2.0f;
+bool firstMouse = true;
+
+// timing
+float deltaTime = 0.0f;
+float lastFrame = 0.0f;
+
+int main()
+{
+	// glfw: initialize and configure
+	// ------------------------------
+	glfwInit();
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+#ifdef __APPLE__
+	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+#endif
+
+	// glfw window creation
+	// --------------------
+	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
+	if (window == NULL)
+	{
+		std::cout << "Failed to create GLFW window" << std::endl;
+		glfwTerminate();
+		return -1;
+	}
+	glfwMakeContextCurrent(window);
+	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+	glfwSetCursorPosCallback(window, mouse_callback);
+	glfwSetScrollCallback(window, scroll_callback);
+
+	// tell GLFW to capture our mouse
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	// glad: load all OpenGL function pointers
+	// ---------------------------------------
+	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+	{
+		std::cout << "Failed to initialize GLAD" << std::endl;
+		return -1;
+	}
+
+	// tell stb_image.h to flip loaded texture's on the y-axis (before loading model).
+	stbi_set_flip_vertically_on_load(true);
+
+	// configure global opengl state
+	// -----------------------------
+	glEnable(GL_DEPTH_TEST);
+
+	camera.MovementSpeed = 20.f;
+
+	// build and compile shaders
+	// -------------------------
+	Shader ourShader("1.model_loading.vs", "1.model_loading.fs");
+
+	// load entities
+	// -----------
+	Model model(FileSystem::getPath("resources/objects/planet/planet.obj"));
+	Entity ourEntity(model);
+	ourEntity.transform.setLocalPosition({ 0, 0, 0 });
+	const float scale = 1.0;
+	ourEntity.transform.setLocalScale({ scale, scale, scale });
+
+	{
+		Entity* lastEntity = &ourEntity;
+
+		for (unsigned int x = 0; x < 20; ++x)
+		{
+			for (unsigned int z = 0; z < 20; ++z)
+			{
+				ourEntity.addChild(model);
+				lastEntity = ourEntity.children.back().get();
+
+				//Set tranform values
+				lastEntity->transform.setLocalPosition({ x * 10.f - 100.f,  0.f, z * 10.f - 100.f });
+			}
+		}
+	}
+	ourEntity.updateSelfAndChild();
+
+	// draw in wireframe
+	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+
+	// render loop
+	// -----------
+	while (!glfwWindowShouldClose(window))
+	{
+		// per-frame time logic
+		// --------------------
+		float currentFrame = glfwGetTime();
+		deltaTime = currentFrame - lastFrame;
+		lastFrame = currentFrame;
+
+		// input
+		// -----
+		processInput(window);
+
+		// render
+		// ------
+		glClearColor(0.05f, 0.05f, 0.05f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		// don't forget to enable shader before setting uniforms
+		ourShader.use();
+
+		// view/projection transformations
+		glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+		const Frustum camFrustum = createFrustumFromCamera(camera, (float)SCR_WIDTH / (float)SCR_HEIGHT, glm::radians(camera.Zoom), 0.1f, 100.0f);
+
+		cameraSpy.ProcessMouseMovement(2, 0);
+		//static float acc = 0;
+		//acc += deltaTime * 0.0001;
+		//cameraSpy.Position = { cos(acc) * 10, 0.f, sin(acc) * 10 };
+		glm::mat4 view = camera.GetViewMatrix();
+
+		ourShader.setMat4("projection", projection);
+		ourShader.setMat4("view", view);
+
+		// draw our scene graph
+		unsigned int total = 0, display = 0;
+		ourEntity.drawSelfAndChild(camFrustum, ourShader, display, total);
+		std::cout << "Total process in CPU : " << total << " / Total send to GPU : " << display << std::endl;
+
+		//ourEntity.transform.setLocalRotation({ 0.f, ourEntity.transform.getLocalRotation().y + 20 * deltaTime, 0.f });
+		ourEntity.updateSelfAndChild();
+
+		// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+		// -------------------------------------------------------------------------------
+		glfwSwapBuffers(window);
+		glfwPollEvents();
+	}
+
+	// glfw: terminate, clearing all previously allocated GLFW resources.
+	// ------------------------------------------------------------------
+	glfwTerminate();
+	return 0;
+}
+
+// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
+// ---------------------------------------------------------------------------------------------------------
+void processInput(GLFWwindow* window)
+{
+	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
+		glfwSetWindowShouldClose(window, true);
+
+	if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
+		camera.ProcessKeyboard(FORWARD, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
+		camera.ProcessKeyboard(BACKWARD, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
+		camera.ProcessKeyboard(LEFT, deltaTime);
+	if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
+		camera.ProcessKeyboard(RIGHT, deltaTime);
+}
+
+// glfw: whenever the window size changed (by OS or user resize) this callback function executes
+// ---------------------------------------------------------------------------------------------
+void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+{
+	// make sure the viewport matches the new window dimensions; note that width and 
+	// height will be significantly larger than specified on retina displays.
+	glViewport(0, 0, width, height);
+}
+
+// glfw: whenever the mouse moves, this callback is called
+// -------------------------------------------------------
+void mouse_callback(GLFWwindow* window, double xpos, double ypos)
+{
+	if (firstMouse)
+	{
+		lastX = xpos;
+		lastY = ypos;
+		firstMouse = false;
+	}
+
+	float xoffset = xpos - lastX;
+	float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
+
+	lastX = xpos;
+	lastY = ypos;
+
+	camera.ProcessMouseMovement(xoffset, yoffset);
+}
+
+// glfw: whenever the mouse scroll wheel scrolls, this callback is called
+// ----------------------------------------------------------------------
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
+{
+	camera.ProcessMouseScroll(yoffset);
+}