Lighting tutorial code updates.

src/2.lighting/1.colors/colors.cpp

@@ -1,6 +1,5 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
-#include <stb_image.h>
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>

src/2.lighting/2.1.basic_lighting_diffuse/basic_lighting_diffuse.cpp

@@ -1,6 +1,5 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
-#include <stb_image.h>
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>

src/2.lighting/2.2.basic_lighting_specular/basic_lighting_specular.cpp

@@ -1,6 +1,5 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
-#include <stb_image.h>
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>

src/2.lighting/3.1.materials/materials.cpp

@@ -1,6 +1,5 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
-#include <stb_image.h>
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>

src/2.lighting/3.2.materials_exercise1/materials_exercise1.cpp

@@ -1,6 +1,5 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
-#include <stb_image.h>
 
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>

src/2.lighting/4.1.lighting_maps_diffuse_map/4.1.lighting_maps.fs

@@ -0,0 +1,45 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    vec3 specular;    
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+  	
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(light.position - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * (spec * material.specular);  
+        
+    vec3 result = ambient + diffuse + specular;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/4.1.lighting_maps_diffuse_map/4.1.lighting_maps.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/4.1.lighting_maps_diffuse_map/lighting_maps_diffuse.cpp

@@ -0,0 +1,334 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+float lastFrame = 0.0f;
+
+// lighting
+glm::vec3 lightPos(1.2f, 1.0f, 2.0f);
+
+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);
+    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("4.1.lighting_maps.vs", "4.1.lighting_maps.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use(); 
+    lightingShader.setInt("material.diffuse", 0);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", lightPos);
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f); 
+        lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+
+        // material properties
+        lightingShader.setVec3("material.specular", 0.5f, 0.5f, 0.5f);
+        lightingShader.setFloat("material.shininess", 64.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+
+        // render the cube
+        glBindVertexArray(cubeVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // also draw the lamp object
+        lampShader.use();
+        lampShader.setMat4("projection", projection);
+        lampShader.setMat4("view", view);
+        model = glm::mat4();
+        model = glm::translate(model, lightPos);
+        model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        lampShader.setMat4("model", model);
+
+        glBindVertexArray(lightVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+    
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/4.2.lighting_maps_specular_map/4.2.lighting_maps.fs

@@ -0,0 +1,45 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+  	
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(light.position - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+        
+    vec3 result = ambient + diffuse + specular;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/4.2.lighting_maps_specular_map/4.2.lighting_maps.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/4.2.lighting_maps_specular_map/lighting_maps_specular.cpp

@@ -0,0 +1,338 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+float lastFrame = 0.0f;
+
+// lighting
+glm::vec3 lightPos(1.2f, 1.0f, 2.0f);
+
+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);
+    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("4.2.lighting_maps.vs", "4.2.lighting_maps.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", lightPos);
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
+        lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 64.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render the cube
+        glBindVertexArray(cubeVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // also draw the lamp object
+        lampShader.use();
+        lampShader.setMat4("projection", projection);
+        lampShader.setMat4("view", view);
+        model = glm::mat4();
+        model = glm::translate(model, lightPos);
+        model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        lampShader.setMat4("model", model);
+
+        glBindVertexArray(lightVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/4.3.lighting_maps_exercise4/4.3.lighting_maps.fs

@@ -0,0 +1,49 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    sampler2D emission;
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+  	
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(light.position - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+    
+      // emission
+    vec3 emission = texture(material.emission, TexCoords).rgb;
+        
+    vec3 result = ambient + diffuse + specular + emission;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/4.3.lighting_maps_exercise4/4.3.lighting_maps.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/4.3.lighting_maps_exercise4/lighting_maps_exercise4.cpp

@@ -0,0 +1,343 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+float lastFrame = 0.0f;
+
+// lighting
+glm::vec3 lightPos(1.2f, 1.0f, 2.0f);
+
+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);
+    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("4.3.lighting_maps.vs", "4.3.lighting_maps.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap  = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+    unsigned int emissionMap = loadTexture(FileSystem::getPath("resources/textures/matrix.jpg").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+    lightingShader.setInt("material.emission", 2);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", lightPos);
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
+        lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 64.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+        // bind emission map
+        glActiveTexture(GL_TEXTURE2);
+        glBindTexture(GL_TEXTURE_2D, emissionMap);
+
+        // render the cube
+        glBindVertexArray(cubeVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // also draw the lamp object
+        lampShader.use();
+        lampShader.setMat4("projection", projection);
+        lampShader.setMat4("view", view);
+        model = glm::mat4();
+        model = glm::translate(model, lightPos);
+        model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        lampShader.setMat4("model", model);
+
+        glBindVertexArray(lightVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/5.1.light_casters_directional/5.1.light_casters.fs

@@ -0,0 +1,47 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+}; 
+
+struct Light {
+    //vec3 position;
+    vec3 direction;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+  	
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    // vec3 lightDir = normalize(light.position - FragPos);
+    vec3 lightDir = normalize(-light.direction);  
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+        
+    vec3 result = ambient + diffuse + specular;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/5.1.light_casters_directional/5.1.light_casters.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/5.1.light_casters_directional/light_casters_directional.cpp

@@ -0,0 +1,361 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+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);
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("5.1.light_casters.vs", "5.1.light_casters.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // positions all containers
+    glm::vec3 cubePositions[] = {
+        glm::vec3( 0.0f,  0.0f,  0.0f),
+        glm::vec3( 2.0f,  5.0f, -15.0f),
+        glm::vec3(-1.5f, -2.2f, -2.5f),
+        glm::vec3(-3.8f, -2.0f, -12.3f),
+        glm::vec3( 2.4f, -0.4f, -3.5f),
+        glm::vec3(-1.7f,  3.0f, -7.5f),
+        glm::vec3( 1.3f, -2.0f, -2.5f),
+        glm::vec3( 1.5f,  2.0f, -2.5f),
+        glm::vec3( 1.5f,  0.2f, -1.5f),
+        glm::vec3(-1.3f,  1.0f, -1.5f)
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.direction", -0.2f, -1.0f, -0.3f);
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
+        lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 32.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render the cube
+        // glBindVertexArray(cubeVAO);
+        // glDrawArrays(GL_TRIANGLES, 0, 36);*/
+
+        // render containers
+        glBindVertexArray(cubeVAO);
+        for (unsigned int i = 0; i < 10; i++)
+        {
+            // calculate the model matrix for each object and pass it to shader before drawing
+            glm::mat4 model;
+            model = glm::translate(model, cubePositions[i]);
+            float angle = 20.0f * i;
+            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
+            lightingShader.setMat4("model", model);
+
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+
+
+        // a lamp object is weird when we only have a directional light, don't render the light object
+        // lampShader.use();
+        // lampShader.setMat4("projection", projection);
+        // lampShader.setMat4("view", view);
+        // model = glm::mat4();
+        // model = glm::translate(model, lightPos);
+        // model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        // lampShader.setMat4("model", model);
+
+        // glBindVertexArray(lightVAO);
+        // glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/5.2.light_casters_point/5.2.light_casters.fs

@@ -0,0 +1,57 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;  
+  
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+	
+    float constant;
+    float linear;
+    float quadratic;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+  	
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(light.position - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+    
+    // attenuation
+    float distance    = length(light.position - FragPos);
+    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
+
+    ambient  *= attenuation;  
+    diffuse   *= attenuation;
+    specular *= attenuation;   
+        
+    vec3 result = ambient + diffuse + specular;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/5.2.light_casters_point/5.2.light_casters.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/5.2.light_casters_point/light_casters_point.cpp

@@ -0,0 +1,363 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+float lastFrame = 0.0f;
+
+// lighting
+glm::vec3 lightPos(1.2f, 1.0f, 2.0f);
+
+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);
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("5.2.light_casters.vs", "5.2.light_casters.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // positions all containers
+    glm::vec3 cubePositions[] = {
+        glm::vec3( 0.0f,  0.0f,  0.0f),
+        glm::vec3( 2.0f,  5.0f, -15.0f),
+        glm::vec3(-1.5f, -2.2f, -2.5f),
+        glm::vec3(-3.8f, -2.0f, -12.3f),
+        glm::vec3( 2.4f, -0.4f, -3.5f),
+        glm::vec3(-1.7f,  3.0f, -7.5f),
+        glm::vec3( 1.3f, -2.0f, -2.5f),
+        glm::vec3( 1.5f,  2.0f, -2.5f),
+        glm::vec3( 1.5f,  0.2f, -1.5f),
+        glm::vec3(-1.3f,  1.0f, -1.5f)
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", lightPos);
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
+        lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("light.constant", 1.0f);
+        lightingShader.setFloat("light.linear", 0.09f);
+        lightingShader.setFloat("light.quadratic", 0.032f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 32.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render containers
+        glBindVertexArray(cubeVAO);
+        for (unsigned int i = 0; i < 10; i++)
+        {
+            // calculate the model matrix for each object and pass it to shader before drawing
+            glm::mat4 model;
+            model = glm::translate(model, cubePositions[i]);
+            float angle = 20.0f * i;
+            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
+            lightingShader.setMat4("model", model);
+
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+
+
+         // also draw the lamp object
+         lampShader.use();
+         lampShader.setMat4("projection", projection);
+         lampShader.setMat4("view", view);
+         model = glm::mat4();
+         model = glm::translate(model, lightPos);
+         model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+         lampShader.setMat4("model", model);
+
+         glBindVertexArray(lightVAO);
+         glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/5.3.light_casters_spot/5.3.light_casters.fs

@@ -0,0 +1,72 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;  
+    vec3 direction;
+    float cutOff;
+    float outerCutOff;
+  
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+	
+    float constant;
+    float linear;
+    float quadratic;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    vec3 lightDir = normalize(light.position - FragPos);
+    
+    // check if lighting is inside the spotlight cone
+    float theta = dot(lightDir, normalize(-light.direction)); 
+    
+    if(theta > light.cutOff) // remember that we're working with angles as cosines instead of degrees so a '>' is used.
+    {    
+        // ambient
+        vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+        
+        // diffuse 
+        vec3 norm = normalize(Normal);
+        float diff = max(dot(norm, lightDir), 0.0);
+        vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+        
+        // specular
+        vec3 viewDir = normalize(viewPos - FragPos);
+        vec3 reflectDir = reflect(-lightDir, norm);  
+        float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+        vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+        
+        // attenuation
+        float distance    = length(light.position - FragPos);
+        float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
+
+        // ambient  *= attenuation; // remove attenuation from ambient, as otherwise at large distances the light would be darker inside than outside the spotlight due the ambient term in the else branche
+        diffuse   *= attenuation;
+        specular *= attenuation;   
+            
+        vec3 result = ambient + diffuse + specular;
+        fragColor = vec4(result, 1.0f);
+    }
+    else 
+    {
+        // else, use ambient light so scene isn't completely dark outside the spotlight.
+        fragColor = vec4(light.ambient * texture(material.diffuse, TexCoords).rgb, 1.0f);
+    }
+} 

src/2.lighting/5.3.light_casters_spot/5.3.light_casters.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/5.3.light_casters_spot/light_casters_spot.cpp

@@ -0,0 +1,364 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+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);
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("5.3.light_casters.vs", "5.3.light_casters.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // positions all containers
+    glm::vec3 cubePositions[] = {
+        glm::vec3( 0.0f,  0.0f,  0.0f),
+        glm::vec3( 2.0f,  5.0f, -15.0f),
+        glm::vec3(-1.5f, -2.2f, -2.5f),
+        glm::vec3(-3.8f, -2.0f, -12.3f),
+        glm::vec3( 2.4f, -0.4f, -3.5f),
+        glm::vec3(-1.7f,  3.0f, -7.5f),
+        glm::vec3( 1.3f, -2.0f, -2.5f),
+        glm::vec3( 1.5f,  2.0f, -2.5f),
+        glm::vec3( 1.5f,  0.2f, -1.5f),
+        glm::vec3(-1.3f,  1.0f, -1.5f)
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", camera.Position);
+        lightingShader.setVec3("light.direction", camera.Front);
+        lightingShader.setFloat("light.cutOff", glm::cos(glm::radians(12.5f)));
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.1f, 0.1f, 0.1f);
+        // we configure the diffuse intensity slightly higher; the right lighting conditions differ with each lighting method and environment.
+        // each environment and lighting type requires some tweaking to get the best out of your environment.
+        lightingShader.setVec3("light.diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("light.constant", 1.0f);
+        lightingShader.setFloat("light.linear", 0.09f);
+        lightingShader.setFloat("light.quadratic", 0.032f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 32.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render containers
+        glBindVertexArray(cubeVAO);
+        for (unsigned int i = 0; i < 10; i++)
+        {
+            // calculate the model matrix for each object and pass it to shader before drawing
+            glm::mat4 model;
+            model = glm::translate(model, cubePositions[i]);
+            float angle = 20.0f * i;
+            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
+            lightingShader.setMat4("model", model);
+
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+
+
+        // again, a lamp object is weird when we only have a spot light, don't render the light object
+        // lampShader.use();
+        // lampShader.setMat4("projection", projection);
+        // lampShader.setMat4("view", view);
+        // model = glm::mat4();
+        // model = glm::translate(model, lightPos);
+        // model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        // lampShader.setMat4("model", model);
+
+        // glBindVertexArray(lightVAO);
+        // glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/5.4.light_casters_spot_soft/5.4.light_casters.fs

@@ -0,0 +1,66 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+}; 
+
+struct Light {
+    vec3 position;  
+    vec3 direction;
+    float cutOff;
+    float outerCutOff;
+  
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+	
+    float constant;
+    float linear;
+    float quadratic;
+};
+
+in vec3 FragPos;  
+in vec3 Normal;  
+in vec2 TexCoords;
+  
+uniform vec3 viewPos;
+uniform Material material;
+uniform Light light;
+
+void main()
+{
+    // ambient
+    vec3 ambient = light.ambient * texture(material.diffuse, TexCoords).rgb;
+    
+    // diffuse 
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(light.position - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = light.diffuse * diff * texture(material.diffuse, TexCoords).rgb;  
+    
+    // specular
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 specular = light.specular * spec * texture(material.specular, TexCoords).rgb;  
+    
+    // spotlight (soft edges)
+    float theta = dot(lightDir, normalize(-light.direction)); 
+    float epsilon = (light.cutOff - light.outerCutOff);
+    float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
+    diffuse  *= intensity;
+    specular *= intensity;
+    
+    // attenuation
+    float distance    = length(light.position - FragPos);
+    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
+    ambient  *= attenuation; 
+    diffuse   *= attenuation;
+    specular *= attenuation;   
+        
+    vec3 result = ambient + diffuse + specular;
+    fragColor = vec4(result, 1.0f);
+} 

src/2.lighting/5.4.light_casters_spot_soft/5.4.light_casters.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}

src/2.lighting/5.4.light_casters_spot_soft/light_casters_spot_soft.cpp

@@ -0,0 +1,365 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+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);
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("5.4.light_casters.vs", "5.4.light_casters.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // positions all containers
+    glm::vec3 cubePositions[] = {
+        glm::vec3( 0.0f,  0.0f,  0.0f),
+        glm::vec3( 2.0f,  5.0f, -15.0f),
+        glm::vec3(-1.5f, -2.2f, -2.5f),
+        glm::vec3(-3.8f, -2.0f, -12.3f),
+        glm::vec3( 2.4f, -0.4f, -3.5f),
+        glm::vec3(-1.7f,  3.0f, -7.5f),
+        glm::vec3( 1.3f, -2.0f, -2.5f),
+        glm::vec3( 1.5f,  2.0f, -2.5f),
+        glm::vec3( 1.5f,  0.2f, -1.5f),
+        glm::vec3(-1.3f,  1.0f, -1.5f)
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("light.position", camera.Position);
+        lightingShader.setVec3("light.direction", camera.Front);
+        lightingShader.setFloat("light.cutOff", glm::cos(glm::radians(12.5f)));
+        lightingShader.setFloat("light.outerCutOff", glm::cos(glm::radians(17.5f)));
+        lightingShader.setVec3("viewPos", camera.Position);
+
+        // light properties
+        lightingShader.setVec3("light.ambient", 0.1f, 0.1f, 0.1f);
+        // we configure the diffuse intensity slightly higher; the right lighting conditions differ with each lighting method and environment.
+        // each environment and lighting type requires some tweaking to get the best out of your environment.
+        lightingShader.setVec3("light.diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("light.constant", 1.0f);
+        lightingShader.setFloat("light.linear", 0.09f);
+        lightingShader.setFloat("light.quadratic", 0.032f);
+
+        // material properties
+        lightingShader.setFloat("material.shininess", 32.0f);
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render containers
+        glBindVertexArray(cubeVAO);
+        for (unsigned int i = 0; i < 10; i++)
+        {
+            // calculate the model matrix for each object and pass it to shader before drawing
+            glm::mat4 model;
+            model = glm::translate(model, cubePositions[i]);
+            float angle = 20.0f * i;
+            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
+            lightingShader.setMat4("model", model);
+
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+
+
+        // again, a lamp object is weird when we only have a spot light, don't render the light object
+        // lampShader.use();
+        // lampShader.setMat4("projection", projection);
+        // lampShader.setMat4("view", view);
+        // model = glm::mat4();
+        // model = glm::translate(model, lightPos);
+        // model = glm::scale(model, glm::vec3(0.2f)); // a smaller cube
+        // lampShader.setMat4("model", model);
+
+        // glBindVertexArray(lightVAO);
+        // glDrawArrays(GL_TRIANGLES, 0, 36);
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/6.multiple_lights/6.multiple_lights.cpp

@@ -0,0 +1,418 @@
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <stb_image.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 <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);
+unsigned int loadTexture(const char *path);
+
+// camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+float lastX = 800.0f / 2.0;
+float lastY = 600.0 / 2.0;
+bool firstMouse = true;
+
+float deltaTime = 0.0f;	// time between current frame and last frame
+float lastFrame = 0.0f;
+
+// lighting
+glm::vec3 lightPos(1.2f, 1.0f, 2.0f);
+
+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);
+
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+    glfwMakeContextCurrent(window);
+    if (window == NULL)
+    {
+        std::cout << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        return -1;
+    }
+    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;
+    }
+
+    // configure global opengl state
+    // -----------------------------
+    glEnable(GL_DEPTH_TEST);
+
+    // build and compile our shader zprogram
+    // ------------------------------------
+    Shader lightingShader("6.multiple_lights.vs", "6.multiple_lights.fs");
+    Shader lampShader("1.lamp.vs", "1.lamp.fs");
+
+    // set up vertex data (and buffer(s)) and configure vertex attributes
+    // ------------------------------------------------------------------
+    float vertices[] = {
+        // positions          // normals           // texture coords
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+         0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+    };
+    // positions all containers
+    glm::vec3 cubePositions[] = {
+        glm::vec3( 0.0f,  0.0f,  0.0f),
+        glm::vec3( 2.0f,  5.0f, -15.0f),
+        glm::vec3(-1.5f, -2.2f, -2.5f),
+        glm::vec3(-3.8f, -2.0f, -12.3f),
+        glm::vec3( 2.4f, -0.4f, -3.5f),
+        glm::vec3(-1.7f,  3.0f, -7.5f),
+        glm::vec3( 1.3f, -2.0f, -2.5f),
+        glm::vec3( 1.5f,  2.0f, -2.5f),
+        glm::vec3( 1.5f,  0.2f, -1.5f),
+        glm::vec3(-1.3f,  1.0f, -1.5f)
+    };
+    // positions of the point lights
+    glm::vec3 pointLightPositions[] = {
+        glm::vec3( 0.7f,  0.2f,  2.0f),
+        glm::vec3( 2.3f, -3.3f, -4.0f),
+        glm::vec3(-4.0f,  2.0f, -12.0f),
+        glm::vec3( 0.0f,  0.0f, -3.0f)
+    };
+    // first, configure the cube's VAO (and VBO)
+    unsigned int VBO, cubeVAO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &VBO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    glBindVertexArray(cubeVAO);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+    glEnableVertexAttribArray(2);
+
+    // second, configure the light's VAO (VBO stays the same; the vertices are the same for the light object which is also a 3D cube)
+    unsigned int lightVAO;
+    glGenVertexArrays(1, &lightVAO);
+    glBindVertexArray(lightVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // note that we update the lamp's position attribute's stride to reflect the updated buffer data
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // load textures (we now use a utility function to keep the code more organized)
+    // -----------------------------------------------------------------------------
+    unsigned int diffuseMap = loadTexture(FileSystem::getPath("resources/textures/container2.png").c_str());
+    unsigned int specularMap = loadTexture(FileSystem::getPath("resources/textures/container2_specular.png").c_str());
+
+    // shader configuration
+    // --------------------
+    lightingShader.use();
+    lightingShader.setInt("material.diffuse", 0);
+    lightingShader.setInt("material.specular", 1);
+
+
+    // render loop
+    // -----------
+    while (!glfwWindowShouldClose(window))
+    {
+        // per-frame time logic
+        // --------------------
+        float currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // input
+        // -----
+        processInput(window);
+
+        // render
+        // ------
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // be sure to activate shader when setting uniforms/drawing objects
+        lightingShader.use();
+        lightingShader.setVec3("viewPos", camera.Position);
+        lightingShader.setFloat("material.shininess", 32.0f);
+
+        /*
+           Here we set all the uniforms for the 5/6 types of lights we have. We have to set them manually and index 
+           the proper PointLight struct in the array to set each uniform variable. This can be done more code-friendly
+           by defining light types as classes and set their values in there, or by using a more efficient uniform approach
+           by using 'Uniform buffer objects', but that is something we'll discuss in the 'Advanced GLSL' tutorial.
+        */
+        // directional light
+        lightingShader.setVec3("dirLight.direction", -0.2f, -1.0f, -0.3f);
+        lightingShader.setVec3("dirLight.ambient", 0.05f, 0.05f, 0.05f);
+        lightingShader.setVec3("dirLight.diffuse", 0.4f, 0.4f, 0.4f);
+        lightingShader.setVec3("dirLight.specular", 0.5f, 0.5f, 0.5f);
+        // point light 1
+        lightingShader.setVec3("pointLights[0].position", pointLightPositions[0]);
+        lightingShader.setVec3("pointLights[0].ambient", 0.05f, 0.05f, 0.05f);
+        lightingShader.setVec3("pointLights[0].diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("pointLights[0].specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("pointLights[0].constant", 1.0f);
+        lightingShader.setFloat("pointLights[0].linear", 0.09);
+        lightingShader.setFloat("pointLights[0].quadratic", 0.032);
+        // point light 2
+        lightingShader.setVec3("pointLights[1].position", pointLightPositions[1]);
+        lightingShader.setVec3("pointLights[1].ambient", 0.05f, 0.05f, 0.05f);
+        lightingShader.setVec3("pointLights[1].diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("pointLights[1].specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("pointLights[1].constant", 1.0f);
+        lightingShader.setFloat("pointLights[1].linear", 0.09);
+        lightingShader.setFloat("pointLights[1].quadratic", 0.032);
+        // point light 3
+        lightingShader.setVec3("pointLights[2].position", pointLightPositions[2]);
+        lightingShader.setVec3("pointLights[2].ambient", 0.05f, 0.05f, 0.05f);
+        lightingShader.setVec3("pointLights[2].diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("pointLights[2].specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("pointLights[2].constant", 1.0f);
+        lightingShader.setFloat("pointLights[2].linear", 0.09);
+        lightingShader.setFloat("pointLights[2].quadratic", 0.032);
+        // point light 4
+        lightingShader.setVec3("pointLights[3].position", pointLightPositions[3]);
+        lightingShader.setVec3("pointLights[3].ambient", 0.05f, 0.05f, 0.05f);
+        lightingShader.setVec3("pointLights[3].diffuse", 0.8f, 0.8f, 0.8f);
+        lightingShader.setVec3("pointLights[3].specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("pointLights[3].constant", 1.0f);
+        lightingShader.setFloat("pointLights[3].linear", 0.09);
+        lightingShader.setFloat("pointLights[3].quadratic", 0.032);
+        // spotLight
+        lightingShader.setVec3("spotLight.position", camera.Position);
+        lightingShader.setVec3("spotLight.direction", camera.Front);
+        lightingShader.setVec3("spotLight.ambient", 0.0f, 0.0f, 0.0f);
+        lightingShader.setVec3("spotLight.diffuse", 1.0f, 1.0f, 1.0f);
+        lightingShader.setVec3("spotLight.specular", 1.0f, 1.0f, 1.0f);
+        lightingShader.setFloat("spotLight.constant", 1.0f);
+        lightingShader.setFloat("spotLight.linear", 0.09);
+        lightingShader.setFloat("spotLight.quadratic", 0.032);
+        lightingShader.setFloat("spotLight.cutOff", glm::cos(glm::radians(12.5f)));
+        lightingShader.setFloat("spotLight.outerCutOff", glm::cos(glm::radians(15.0f)));     
+
+        // view/projection transformations
+        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);
+        glm::mat4 view = camera.GetViewMatrix();
+        lightingShader.setMat4("projection", projection);
+        lightingShader.setMat4("view", view);
+
+        // world transformation
+        glm::mat4 model;
+        lightingShader.setMat4("model", model);
+
+        // bind diffuse map
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, diffuseMap);
+        // bind specular map
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, specularMap);
+
+        // render containers
+        glBindVertexArray(cubeVAO);
+        for (unsigned int i = 0; i < 10; i++)
+        {
+            // calculate the model matrix for each object and pass it to shader before drawing
+            glm::mat4 model;
+            model = glm::translate(model, cubePositions[i]);
+            float angle = 20.0f * i;
+            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
+            lightingShader.setMat4("model", model);
+
+            glDrawArrays(GL_TRIANGLES, 0, 36);
+        }
+
+
+         // also draw the lamp object(s)
+         lampShader.use();
+         lampShader.setMat4("projection", projection);
+         lampShader.setMat4("view", view);
+    
+         // we now draw as many light bulbs as we have point lights.
+         glBindVertexArray(lightVAO);
+         for (unsigned int i = 0; i < 4; i++)
+         {
+             model = glm::mat4();
+             model = glm::translate(model, pointLightPositions[i]);
+             model = glm::scale(model, glm::vec3(0.2f)); // Make it a smaller cube
+             lampShader.setMat4("model", model);
+             glDrawArrays(GL_TRIANGLES, 0, 36);
+         }
+
+
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
+        glfwSwapBuffers(window);
+        glfwPollEvents();
+    }
+
+    // optional: de-allocate all resources once they've outlived their purpose:
+    // ------------------------------------------------------------------------
+    glDeleteVertexArrays(1, &cubeVAO);
+    glDeleteVertexArrays(1, &lightVAO);
+    glDeleteBuffers(1, &VBO);
+
+    // 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);
+
+    float cameraSpeed = 2.5 * deltaTime;
+    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);
+}
+
+// utility function for loading a 2D texture from file
+// ---------------------------------------------------
+unsigned int loadTexture(char const * path)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum format;
+        if (nrComponents == 1)
+            format = GL_RED;
+        else if (nrComponents == 3)
+            format = GL_RGB;
+        else if (nrComponents == 4)
+            format = GL_RGBA;
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+        glGenerateMipmap(GL_TEXTURE_2D);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        stbi_image_free(data);
+    }
+    else
+    {
+        std::cout << "Texture failed to load at path: " << path << std::endl;
+        stbi_image_free(data);
+    }
+
+    return textureID;
+}

src/2.lighting/6.multiple_lights/6.multiple_lights.fs

@@ -0,0 +1,147 @@
+#version 330 core
+out vec4 fragColor;
+
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;
+    float shininess;
+}; 
+
+struct DirLight {
+    vec3 direction;
+	
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+struct PointLight {
+    vec3 position;
+    
+    float constant;
+    float linear;
+    float quadratic;
+	
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+struct SpotLight {
+    vec3 position;
+    vec3 direction;
+    float cutOff;
+    float outerCutOff;
+  
+    float constant;
+    float linear;
+    float quadratic;
+  
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;       
+};
+
+#define NR_POINT_LIGHTS 4
+
+in vec3 FragPos;
+in vec3 Normal;
+in vec2 TexCoords;
+
+uniform vec3 viewPos;
+uniform DirLight dirLight;
+uniform PointLight pointLights[NR_POINT_LIGHTS];
+uniform SpotLight spotLight;
+uniform Material material;
+
+// function prototypes
+vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
+vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
+vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
+
+void main()
+{    
+    // properties
+    vec3 norm = normalize(Normal);
+    vec3 viewDir = normalize(viewPos - FragPos);
+    
+    // == =====================================================
+    // Our lighting is set up in 3 phases: directional, point lights and an optional flashlight
+    // For each phase, a calculate function is defined that calculates the corresponding color
+    // per lamp. In the main() function we take all the calculated colors and sum them up for
+    // this fragment's final color.
+    // == =====================================================
+    // phase 1: directional lighting
+    vec3 result = CalcDirLight(dirLight, norm, viewDir);
+    // phase 2: point lights
+    for(int i = 0; i < NR_POINT_LIGHTS; i++)
+        result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);    
+    // phase 3: spot light
+    result += CalcSpotLight(spotLight, norm, FragPos, viewDir);    
+    
+    fragColor = vec4(result, 1.0);
+}
+
+// calculates the color when using a directional light.
+vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
+{
+    vec3 lightDir = normalize(-light.direction);
+    // diffuse shading
+    float diff = max(dot(normal, lightDir), 0.0);
+    // specular shading
+    vec3 reflectDir = reflect(-lightDir, normal);
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    // combine results
+    vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
+    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
+    vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
+    return (ambient + diffuse + specular);
+}
+
+// calculates the color when using a point light.
+vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
+{
+    vec3 lightDir = normalize(light.position - fragPos);
+    // diffuse shading
+    float diff = max(dot(normal, lightDir), 0.0);
+    // specular shading
+    vec3 reflectDir = reflect(-lightDir, normal);
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    // attenuation
+    float distance = length(light.position - fragPos);
+    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
+    // combine results
+    vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
+    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
+    vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
+    ambient *= attenuation;
+    diffuse *= attenuation;
+    specular *= attenuation;
+    return (ambient + diffuse + specular);
+}
+
+// calculates the color when using a spot light.
+vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
+{
+    vec3 lightDir = normalize(light.position - fragPos);
+    // diffuse shading
+    float diff = max(dot(normal, lightDir), 0.0);
+    // specular shading
+    vec3 reflectDir = reflect(-lightDir, normal);
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    // attenuation
+    float distance = length(light.position - fragPos);
+    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
+    // spotlight intensity
+    float theta = dot(lightDir, normalize(-light.direction)); 
+    float epsilon = light.cutOff - light.outerCutOff;
+    float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
+    // combine results
+    vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
+    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
+    vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
+    ambient *= attenuation * intensity;
+    diffuse *= attenuation * intensity;
+    specular *= attenuation * intensity;
+    return (ambient + diffuse + specular);
+}

src/2.lighting/6.multiple_lights/6.multiple_lights.vs

@@ -0,0 +1,21 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+layout (location = 2) in vec2 aTexCoords;
+
+out vec3 FragPos;
+out vec3 Normal;
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    FragPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(transpose(inverse(model))) * aNormal;  
+    TexCoords = aTexCoords;
+    
+    gl_Position = projection * view * vec4(FragPos, 1.0f);
+}