Added new project/code files

src/5.advanced_lighting/2.gamma_correction/gamma_correction.cpp

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+// GLEW
+#define GLEW_STATIC
+#include <GL/glew.h>
+
+// GLFW
+#include <GLFW/glfw3.h>
+
+// GL includes
+#include <learnopengl/shader.h>
+#include <learnopengl/camera.h>
+
+// GLM Mathemtics
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+
+// Other Libs
+#include <SOIL.h>
+
+// Properties
+const GLuint SCR_WIDTH = 800, SCR_HEIGHT = 600;
+
+// Function prototypes
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
+void mouse_callback(GLFWwindow* window, double xpos, double ypos);
+void Do_Movement();
+GLuint loadTexture(GLchar* path, bool gammaCorrection);
+
+// Camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+
+// Delta
+GLfloat deltaTime = 0.0f;
+GLfloat lastFrame = 0.0f;
+
+// Options
+GLboolean gamma = false;
+
+// The MAIN function, from here we start our application and run our Game loop
+int main()
+{
+    // Init GLFW
+    glfwInit();
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
+
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nullptr, nullptr); // Windowed
+    glfwMakeContextCurrent(window);
+
+    // Set the required callback functions
+    glfwSetKeyCallback(window, key_callback);
+    glfwSetCursorPosCallback(window, mouse_callback);
+    glfwSetScrollCallback(window, scroll_callback);
+
+    // Options
+    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+    // Initialize GLEW to setup the OpenGL Function pointers
+    glewExperimental = GL_TRUE;
+    glewInit();
+
+    // Define the viewport dimensions
+    glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
+
+    // Setup some OpenGL options
+    glEnable(GL_DEPTH_TEST);
+    //glEnable(GL_FRAMEBUFFER_SRGB); // This enables OpenGL's built-in sRGB support. Once enabled, all subsequent fragment outputs (into framebuffer's color buffer(s)) are first gamma corrected.
+
+    // Setup and compile our shaders
+    Shader shader("gamma_correction.vs", "gamma_correction.frag");
+
+    GLfloat planeVertices[] = {
+        // Positions          // Normals         // Texture Coords
+         5.0f, -0.5f,  5.0f,  0.0f, 1.0f, 0.0f,  5.0f, 0.0f,
+        -5.0f, -0.5f,  5.0f,  0.0f, 1.0f, 0.0f,  0.0f, 0.0f,
+        -5.0f, -0.5f, -5.0f,  0.0f, 1.0f, 0.0f,  0.0f, 5.0f,
+ 
+         5.0f, -0.5f,  5.0f,  0.0f, 1.0f, 0.0f,  5.0f, 0.0f,
+        -5.0f, -0.5f, -5.0f,  0.0f, 1.0f, 0.0f,  0.0f, 5.0f,
+         5.0f, -0.5f, -5.0f,  0.0f, 1.0f, 0.0f,  5.0f, 5.0f
+    };
+    // Setup plane VAO
+    GLuint planeVAO, planeVBO;
+    glGenVertexArrays(1, &planeVAO);
+    glGenBuffers(1, &planeVBO);
+    glBindVertexArray(planeVAO);
+    glBindBuffer(GL_ARRAY_BUFFER, planeVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(planeVertices), &planeVertices, GL_STATIC_DRAW);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)0);
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
+    glEnableVertexAttribArray(2);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(6 * sizeof(GLfloat)));
+    glBindVertexArray(0);
+
+    // Light sources
+    glm::vec3 lightPositions[] = {
+        glm::vec3(-3.0f, 0.0f, 0.0f),
+        glm::vec3(-1.0f, 0.0f, 0.0f),
+        glm::vec3( 1.0f, 0.0f, 0.0f),
+        glm::vec3( 3.0f, 0.0f, 0.0f)
+    };
+    glm::vec3 lightColors[] = {
+        glm::vec3(0.25),
+        glm::vec3(0.50),
+        glm::vec3(0.75),
+        glm::vec3(1.00)
+    };
+
+    // Load textures
+    GLuint floorTexture = loadTexture("../../../resources/textures/wood.png", false);
+    GLuint floorTextureGammaCorrected = loadTexture("../../../resources/textures/wood.png", true);
+
+    // Game loop
+    while (!glfwWindowShouldClose(window))
+    {
+        // Set frame time
+        GLfloat currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // Check and call events
+        glfwPollEvents();
+        Do_Movement();
+
+        // Clear the colorbuffer
+        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // Draw objects
+        shader.Use();
+        glm::mat4 view = camera.GetViewMatrix();
+        glm::mat4 projection = glm::perspective(camera.Zoom, (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
+        glUniformMatrix4fv(glGetUniformLocation(shader.Program, "view"), 1, GL_FALSE, glm::value_ptr(view));
+        glUniformMatrix4fv(glGetUniformLocation(shader.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
+        // Set light uniforms
+        glUniform3fv(glGetUniformLocation(shader.Program, "lightPositions"), 4, &lightPositions[0][0]);
+        glUniform3fv(glGetUniformLocation(shader.Program, "lightColors"), 4, &lightColors[0][0]);
+        glUniform3fv(glGetUniformLocation(shader.Program, "viewPos"), 1, &camera.Position[0]);
+        glUniform1i(glGetUniformLocation(shader.Program, "gamma"), gamma);
+        // Floor
+        glBindVertexArray(planeVAO);
+        glBindTexture(GL_TEXTURE_2D, gamma ? floorTextureGammaCorrected : floorTexture);
+        glDrawArrays(GL_TRIANGLES, 0, 6);
+        glBindVertexArray(0);
+
+        std::cout << (gamma ? "Gamma enabled" : "Gamma disabled") << std::endl;
+
+        // Swap the buffers
+        glfwSwapBuffers(window);
+    }
+
+    glfwTerminate();
+    return 0;
+}
+
+// This function loads a texture from file. Note: texture loading functions like these are usually 
+// managed by a 'Resource Manager' that manages all resources (like textures, models, audio). 
+// For learning purposes we'll just define it as a utility function.
+GLuint loadTexture(GLchar* path, bool gammaCorrection)
+{
+    // Generate texture ID and load texture data 
+    GLuint textureID;
+    glGenTextures(1, &textureID);
+    int width, height;
+    unsigned char* image = SOIL_load_image(path, &width, &height, 0, SOIL_LOAD_RGB);
+    // Assign texture to ID
+    glBindTexture(GL_TEXTURE_2D, textureID);
+    glTexImage2D(GL_TEXTURE_2D, 0, gammaCorrection ? GL_SRGB : GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
+    glGenerateMipmap(GL_TEXTURE_2D);
+
+    // Parameters
+    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);
+    glBindTexture(GL_TEXTURE_2D, 0);
+    SOIL_free_image_data(image);
+    return textureID;
+
+}
+
+bool keys[1024];
+bool keysPressed[1024];
+// Moves/alters the camera positions based on user input
+void Do_Movement()
+{
+    // Camera controls
+    if (keys[GLFW_KEY_W])
+        camera.ProcessKeyboard(FORWARD, deltaTime);
+    if (keys[GLFW_KEY_S])
+        camera.ProcessKeyboard(BACKWARD, deltaTime);
+    if (keys[GLFW_KEY_A])
+        camera.ProcessKeyboard(LEFT, deltaTime);
+    if (keys[GLFW_KEY_D])
+        camera.ProcessKeyboard(RIGHT, deltaTime);
+
+    if (keys[GLFW_KEY_SPACE] && !keysPressed[GLFW_KEY_SPACE])
+    {
+        gamma = !gamma;
+        keysPressed[GLFW_KEY_SPACE] = true;
+    }
+}
+
+GLfloat lastX = 400, lastY = 300;
+bool firstMouse = true;
+// Is called whenever a key is pressed/released via GLFW
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
+{
+    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
+        glfwSetWindowShouldClose(window, GL_TRUE);
+
+    if (key >= 0 && key <= 1024)
+    {
+        if (action == GLFW_PRESS)
+            keys[key] = true;
+        else if (action == GLFW_RELEASE)
+        {
+            keys[key] = false;
+            keysPressed[key] = false;
+        }
+    }
+}
+
+void mouse_callback(GLFWwindow* window, double xpos, double ypos)
+{
+    if (firstMouse)
+    {
+        lastX = xpos;
+        lastY = ypos;
+        firstMouse = false;
+    }
+
+    GLfloat xoffset = xpos - lastX;
+    GLfloat yoffset = lastY - ypos;
+
+    lastX = xpos;
+    lastY = ypos;
+
+    camera.ProcessMouseMovement(xoffset, yoffset);
+}
+
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
+{
+    camera.ProcessMouseScroll(yoffset);
+}

src/5.advanced_lighting/2.gamma_correction/gamma_correction.frag

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+#version 330 core
+out vec4 FragColor;
+
+in VS_OUT {
+    vec3 FragPos;
+    vec3 Normal;
+    vec2 TexCoords;
+} fs_in;
+
+uniform sampler2D floorTexture;
+
+uniform vec3 lightPositions[4];
+uniform vec3 lightColors[4];
+uniform vec3 viewPos;
+uniform bool gamma;
+
+vec3 BlinnPhong(vec3 normal, vec3 fragPos, vec3 lightPos, vec3 lightColor)
+{
+    // Diffuse
+    vec3 lightDir = normalize(lightPos - fragPos);
+    float diff = max(dot(lightDir, normal), 0.0);
+    vec3 diffuse = diff * lightColor;
+    // Specular
+    vec3 viewDir = normalize(viewPos - fragPos);
+    vec3 reflectDir = reflect(-lightDir, normal);
+    float spec = 0.0;
+    vec3 halfwayDir = normalize(lightDir + viewDir);  
+    spec = pow(max(dot(normal, halfwayDir), 0.0), 64.0);
+    vec3 specular = spec * lightColor;    
+    // Simple attenuation
+    float max_distance = 1.5;
+    float distance = length(lightPos - fragPos);
+    float attenuation = 1.0 / (gamma ? distance * distance : distance);
+    
+    diffuse *= attenuation;
+    specular *= attenuation;
+    
+    return diffuse + specular;
+}
+
+void main()
+{           
+    vec3 color = texture(floorTexture, fs_in.TexCoords).rgb;
+    vec3 lighting = vec3(0.0);
+    for(int i = 0; i < 4; ++i)
+        lighting += BlinnPhong(normalize(fs_in.Normal), fs_in.FragPos, lightPositions[i], lightColors[i]);
+    color *= lighting;
+    if(gamma)
+        color = pow(color, vec3(1.0/2.2));
+    FragColor = vec4(color, 1.0f);
+}

src/5.advanced_lighting/2.gamma_correction/gamma_correction.vs

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+#version 330 core
+layout (location = 0) in vec3 position;
+layout (location = 1) in vec3 normal;
+layout (location = 2) in vec2 texCoords;
+
+out VS_OUT {
+    vec3 FragPos;
+    vec3 Normal;
+    vec2 TexCoords;
+} vs_out;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+void main()
+{
+    gl_Position = projection * view * vec4(position, 1.0f);
+    vs_out.FragPos = position;
+    vs_out.Normal = normal;
+    vs_out.TexCoords = texCoords;
+}