Code re-work: HDR

src/5.advanced_lighting/4.normal_mapping/normal_mapping.cpp

@@ -145,7 +145,8 @@ int main()
     return 0;
 }
 
-// renderQuad() renders a 1x1 quad in NDC
+// renders a 1x1 quad in NDC with manually calculated tangent vectors
+// ------------------------------------------------------------------
 unsigned int quadVAO = 0;
 unsigned int quadVBO;
 void renderQuad()

src/5.advanced_lighting/5.1.parallax_mapping/parallax_mapping.cpp

@@ -155,7 +155,8 @@ int main()
     return 0;
 }
 
-// renderQuad() renders a 1x1 quad in NDC
+// renders a 1x1 quad in NDC with manually calculated tangent vectors
+// ------------------------------------------------------------------
 unsigned int quadVAO = 0;
 unsigned int quadVBO;
 void renderQuad()

src/5.advanced_lighting/5.2.steep_parallax_mapping/steep_parallax_mapping.cpp

@@ -155,7 +155,8 @@ int main()
     return 0;
 }
 
-// renderQuad() renders a 1x1 quad in NDC
+// renders a 1x1 quad in NDC with manually calculated tangent vectors
+// ------------------------------------------------------------------
 unsigned int quadVAO = 0;
 unsigned int quadVBO;
 void renderQuad()

src/5.advanced_lighting/5.3.parallax_occlusion_mapping/parallax_occlusion_mapping.cpp

@@ -155,7 +155,8 @@ int main()
     return 0;
 }
 
-// renderQuad() renders a 1x1 quad in NDC
+// renders a 1x1 quad in NDC with manually calculated tangent vectors
+// ------------------------------------------------------------------
 unsigned int quadVAO = 0;
 unsigned int quadVBO;
 void renderQuad()

src/5.advanced_lighting/6.hdr/6.hdr.fs

@@ -1,5 +1,6 @@
 #version 330 core
-out vec4 color;
+out vec4 FragColor;
+
 in vec2 TexCoords;
 
 uniform sampler2D hdrBuffer;
@@ -18,11 +19,11 @@ void main()
         vec3 result = vec3(1.0) - exp(-hdrColor * exposure);
         // also gamma correct while we're at it       
         result = pow(result, vec3(1.0 / gamma));
-        color = vec4(result, 1.0f);
+        FragColor = vec4(result, 1.0);
     }
     else
     {
         vec3 result = pow(hdrColor, vec3(1.0 / gamma));
-        color = vec4(result, 1.0);
+        FragColor = vec4(result, 1.0);
     }
 }

src/5.advanced_lighting/6.hdr/6.hdr.vs

@@ -1,11 +1,11 @@
 #version 330 core
-layout (location = 0) in vec3 position;
+layout (location = 0) in vec3 aPos;
-layout (location = 1) in vec2 texCoords;
+layout (location = 1) in vec2 aTexCoords;
 
 out vec2 TexCoords;
 
 void main()
 {
-    gl_Position = vec4(position, 1.0f);
+    TexCoords = aTexCoords;
-    TexCoords = texCoords;
+    gl_Position = vec4(aPos, 1.0);
 }

src/5.advanced_lighting/6.hdr/6.lighting.fs

@@ -20,22 +20,22 @@ void main()
 {           
     vec3 color = texture(diffuseTexture, fs_in.TexCoords).rgb;
     vec3 normal = normalize(fs_in.Normal);
-    // Ambient
+    // ambient
     vec3 ambient = 0.0 * color;
-    // Lighting
+    // lighting
-    vec3 lighting = vec3(0.0f);
+    vec3 lighting = vec3(0.0);
     for(int i = 0; i < 16; i++)
     {
-        // Diffuse
+        // diffuse
         vec3 lightDir = normalize(lights[i].Position - fs_in.FragPos);
         float diff = max(dot(lightDir, normal), 0.0);
         vec3 diffuse = lights[i].Color * diff * color;      
         vec3 result = diffuse;        
-        // Attenuation (use quadratic as we have gamma correction)
+        // attenuation (use quadratic as we have gamma correction)
         float distance = length(fs_in.FragPos - lights[i].Position);
         result *= 1.0 / (distance * distance);
         lighting += result;
                 
     }
-    FragColor = vec4(ambient + lighting, 1.0f);
+    FragColor = vec4(ambient + lighting, 1.0);
 }

src/5.advanced_lighting/6.hdr/6.lighting.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 position;
+layout (location = 0) in vec3 aPos;
-layout (location = 1) in vec3 normal;
+layout (location = 1) in vec3 aNormal;
-layout (location = 2) in vec2 texCoords;
+layout (location = 2) in vec2 aTexCoords;
 
 out VS_OUT {
     vec3 FragPos;
@@ -17,12 +17,13 @@ uniform bool inverse_normals;
 
 void main()
 {
-    gl_Position = projection * view * model * vec4(position, 1.0f);
+    vs_out.FragPos = vec3(model * vec4(aPos, 1.0));   
-    vs_out.FragPos = vec3(model * vec4(position, 1.0));   
+    vs_out.TexCoords = aTexCoords;
-    vs_out.TexCoords = texCoords;
     
-    vec3 n = inverse_normals ? -normal : normal;
+    vec3 n = inverse_normals ? -aNormal : aNormal;
     
     mat3 normalMatrix = transpose(inverse(mat3(model)));
     vs_out.Normal = normalize(normalMatrix * n);
+    
+    gl_Position = projection * view * model * vec4(aPos, 1.0);
 }

src/5.advanced_lighting/6.hdr/hdr.cpp

@@ -1,118 +1,114 @@
-// GLEW
+#include <glad/glad.h>
-#define GLEW_STATIC
-#include <GL/glew.h>
-
-// GLFW
 #include <GLFW/glfw3.h>
+#include <stb_image.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>
 #include <learnopengl/filesystem.h>
+#include <learnopengl/shader.h>
+#include <learnopengl/camera.h>
+#include <learnopengl/model.h>
 
-// Properties
+#include <iostream>
-const GLuint SCR_WIDTH = 800, SCR_HEIGHT = 600;
 
-// Function prototypes
+void framebuffer_size_callback(GLFWwindow* window, int width, int height);
-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();
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
-GLuint loadTexture(GLchar const * path);
+void processInput(GLFWwindow *window);
-void RenderScene(Shader &shader);
+unsigned int loadTexture(const char *path, bool gammaCorrection);
-void RenderCube();
+void renderQuad();
-void RenderQuad();
+void renderCube();
 
-// Camera
+// settings
+const unsigned int SCR_WIDTH = 1280;
+const unsigned int SCR_HEIGHT = 720;
+bool hdr = true;
+bool hdrKeyPressed = false;
+float exposure = 0.1;
+
+// camera
 Camera camera(glm::vec3(0.0f, 0.0f, 5.0f));
+float lastX = (float)SCR_WIDTH / 2.0;
+float lastY = (float)SCR_HEIGHT / 2.0;
+bool firstMouse = true;
 
-// Delta
+// timing
-GLfloat deltaTime = 0.0f;
+float deltaTime = 0.0f;
-GLfloat lastFrame = 0.0f;
+float lastFrame = 0.0f;
 
-// Options
-GLboolean hdr = true; // Change with 'Space'
-GLfloat exposure = 1.0f; // Change with Q and E
-
-// Global variables
-GLuint woodTexture;
-
-// The MAIN function, from here we start our application and run our Game loop
 int main()
 {
-    // Init GLFW
+    // 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_RESIZABLE, GL_FALSE);
 
-    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nullptr, nullptr); // Windowed
+    // glfw window creation
+    // --------------------
+    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
     glfwMakeContextCurrent(window);
-
+    if (window == NULL)
-    // Set the required callback functions
+    {
-    glfwSetKeyCallback(window, key_callback);
+        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);
 
-    // Options
+    // tell GLFW to capture our mouse
     glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
 
-    // Initialize GLEW to setup the OpenGL Function pointers
+    // glad: load all OpenGL function pointers
-    glewExperimental = GL_TRUE;
+    // ---------------------------------------
-    glewInit();
+    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
+    {
+        std::cout << "Failed to initialize GLAD" << std::endl;
+        return -1;
+    }
 
-    // Define the viewport dimensions
+    // configure global opengl state
-    glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
+    // -----------------------------
-
-    // Setup some OpenGL options
     glEnable(GL_DEPTH_TEST);
 
-    // Setup and compile our shaders
+    // build and compile shaders
-    Shader shader("lighting.vs", "lighting.frag");
+    // -------------------------
-    Shader hdrShader("hdr.vs", "hdr.frag");
+    Shader shader("6.lighting.vs", "6.lighting.fs");
+    Shader hdrShader("6.hdr.vs", "6.hdr.fs");
 
-    // Light sources
+    // load textures
-    // - Positions
+    // -------------
-    std::vector<glm::vec3> lightPositions;
+    unsigned int woodTexture = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str(), true); // note that we're loading the texture as an SRGB texture
-    lightPositions.push_back(glm::vec3(0.0f, 0.0f, 49.5f)); // back light
-    lightPositions.push_back(glm::vec3(-1.4f, -1.9f, 9.0f));
-    lightPositions.push_back(glm::vec3(0.0f, -1.8f, 4.0f));
-    lightPositions.push_back(glm::vec3(0.8f, -1.7f, 6.0f));
-    // - Colors
-    std::vector<glm::vec3> lightColors;
-    lightColors.push_back(glm::vec3(200.0f, 200.0f, 200.0f));
-    lightColors.push_back(glm::vec3(0.1f, 0.0f, 0.0f));
-    lightColors.push_back(glm::vec3(0.0f, 0.0f, 0.2f));
-    lightColors.push_back(glm::vec3(0.0f, 0.1f, 0.0f));
 
-    // Load textures
+    // shader configuration
-    woodTexture = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str());
+    // --------------------
+    shader.use();
+    shader.setInt("diffuseTexture", 0);
+    hdrShader.use();
+    hdrShader.setInt("hdrBuffer", 0);
 
-    // Set up floating point framebuffer to render scene to
+    // configure floating point framebuffer
-    GLuint hdrFBO;
+    // ------------------------------------
+    unsigned int hdrFBO;
     glGenFramebuffers(1, &hdrFBO);
-    // - Create floating point color buffer
+    // create floating point color buffer
-    GLuint colorBuffer;
+    unsigned int colorBuffer;
     glGenTextures(1, &colorBuffer);
     glBindTexture(GL_TEXTURE_2D, colorBuffer);
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGBA, GL_FLOAT, NULL);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    // - Create depth buffer (renderbuffer)
+    // create depth buffer (renderbuffer)
-    GLuint rboDepth;
+    unsigned int rboDepth;
     glGenRenderbuffers(1, &rboDepth);
     glBindRenderbuffer(GL_RENDERBUFFER, rboDepth);
     glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, SCR_WIDTH, SCR_HEIGHT);
-    // - Attach buffers
+    // attach buffers
     glBindFramebuffer(GL_FRAMEBUFFER, hdrFBO);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorBuffer, 0);
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboDepth);
@@ -120,246 +116,247 @@ int main()
         std::cout << "Framebuffer not complete!" << std::endl;
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
-    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+    // lighting info
+    // -------------
+    // positions
+    std::vector<glm::vec3> lightPositions;
+    lightPositions.push_back(glm::vec3( 0.0f,  0.0f, 49.5f)); // back light
+    lightPositions.push_back(glm::vec3(-1.4f, -1.9f, 9.0f));
+    lightPositions.push_back(glm::vec3( 0.0f, -1.8f, 4.0f));
+    lightPositions.push_back(glm::vec3( 0.8f, -1.7f, 6.0f));
+    // colors
+    std::vector<glm::vec3> lightColors;
+    lightColors.push_back(glm::vec3(200.0f, 200.0f, 200.0f));
+    lightColors.push_back(glm::vec3(0.1f, 0.0f, 0.0f));
+    lightColors.push_back(glm::vec3(0.0f, 0.0f, 0.2f));
+    lightColors.push_back(glm::vec3(0.0f, 0.1f, 0.0f));
 
-    // Game loop
+    // render loop
+    // -----------
     while (!glfwWindowShouldClose(window))
     {
-        // Set frame time
+        // per-frame time logic
-        GLfloat currentFrame = glfwGetTime();
+        // --------------------
+        float currentFrame = glfwGetTime();
         deltaTime = currentFrame - lastFrame;
         lastFrame = currentFrame;
 
-        // Check and call events
+        // input
-        glfwPollEvents();
+        // -----
-        Do_Movement();
+        processInput(window);
 
-        // 1. Render scene into floating point framebuffer
+        // render
+        // ------
+        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // 1. render scene into floating point framebuffer
+        // -----------------------------------------------
         glBindFramebuffer(GL_FRAMEBUFFER, hdrFBO);
             glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
             glm::mat4 projection = glm::perspective(camera.Zoom, (GLfloat)SCR_WIDTH / (GLfloat)SCR_HEIGHT, 0.1f, 100.0f);
-            glm::mat4 view       = camera.GetViewMatrix();
+            glm::mat4 view = camera.GetViewMatrix();
-            glm::mat4 model;
+            shader.use();
-            shader.Use();
+            shader.setMat4("projection", projection);
-            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
+            shader.setMat4("view", view);
-            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "view"),       1, GL_FALSE, glm::value_ptr(view));
             glActiveTexture(GL_TEXTURE0);
             glBindTexture(GL_TEXTURE_2D, woodTexture);
-            // - set lighting uniforms
+            // set lighting uniforms
-            for (GLuint i = 0; i < lightPositions.size(); i++)
+            for (unsigned int i = 0; i < lightPositions.size(); i++)
             {
-                glUniform3fv(glGetUniformLocation(shader.Program, ("lights[" + std::to_string(i) + "].Position").c_str()), 1, &lightPositions[i][0]);
+                shader.setVec3("lights[" + std::to_string(i) + "].Position", lightPositions[i]);
-                glUniform3fv(glGetUniformLocation(shader.Program, ("lights[" + std::to_string(i) + "].Color").c_str()), 1, &lightColors[i][0]);
+                shader.setVec3("lights[" + std::to_string(i) + "].Color", lightColors[i]);
             }
-            glUniform3fv(glGetUniformLocation(shader.Program, "viewPos"), 1, &camera.Position[0]);
+            shader.setVec3("viewPos", camera.Position);
-            // - render tunnel
+            // render tunnel
-            model = glm::mat4();
+            glm::mat4 model = glm::mat4();
             model = glm::translate(model, glm::vec3(0.0f, 0.0f, 25.0));
-            model = glm::scale(model, glm::vec3(5.0f, 5.0f, 55.0f));
+            model = glm::scale(model, glm::vec3(2.5f, 2.5f, 22.5f));
-            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
+            shader.setMat4("model", model);
-            glUniform1i(glGetUniformLocation(shader.Program, "inverse_normals"), GL_TRUE);
+            shader.setInt("inverse_normals", true);
-            RenderCube();
+            renderCube();
-        glBindFramebuffer(GL_FRAMEBUFFER, 0);      
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
-        // 2. Now render floating point color buffer to 2D quad and tonemap HDR colors to default framebuffer's (clamped) color range
+        // 2. now render floating point color buffer to 2D quad and tonemap HDR colors to default framebuffer's (clamped) color range
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);        
+        // --------------------------------------------------------------------------------------------------------------------------
-        hdrShader.Use();
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+        hdrShader.use();
         glActiveTexture(GL_TEXTURE0);
         glBindTexture(GL_TEXTURE_2D, colorBuffer);
-        glUniform1i(glGetUniformLocation(hdrShader.Program, "hdr"), hdr);
+        hdrShader.setInt("hdr", hdr);
-        glUniform1f(glGetUniformLocation(hdrShader.Program, "exposure"), exposure);
+        hdrShader.setFloat("exposure", exposure);
-        RenderQuad();       
+        renderQuad();
 
-        std::cout << "exposure: " << exposure << std::endl;
+        std::cout << "hdr: " << (hdr ? "on" : "off") << "| exposure: " << exposure << std::endl;
 
-        // Swap the buffers
+        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
+        // -------------------------------------------------------------------------------
         glfwSwapBuffers(window);
+        glfwPollEvents();
     }
 
     glfwTerminate();
     return 0;
 }
 
+// renderCube() renders a 1x1 3D cube in NDC.
+// -------------------------------------------------
+unsigned int cubeVAO = 0;
+unsigned int cubeVBO = 0;
+void renderCube()
+{
+    // initialize (if necessary)
+    if (cubeVAO == 0)
+    {
+        float vertices[] = {
+            // back face
+            -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
+             1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
+             1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 0.0f, // bottom-right         
+             1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
+            -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
+            -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 1.0f, // top-left
+            // front face
+            -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
+             1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 0.0f, // bottom-right
+             1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
+             1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
+            -1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 1.0f, // top-left
+            -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
+            // left face
+            -1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
+            -1.0f,  1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-left
+            -1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
+            -1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
+            -1.0f, -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-right
+            -1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
+            // right face
+             1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
+             1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
+             1.0f,  1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-right         
+             1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
+             1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
+             1.0f, -1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-left     
+            // bottom face
+            -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
+             1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 1.0f, // top-left
+             1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
+             1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
+            -1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 0.0f, // bottom-right
+            -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
+            // top face
+            -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
+             1.0f,  1.0f , 1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
+             1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 1.0f, // top-right     
+             1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
+            -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
+            -1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 0.0f  // bottom-left        
+        };
+        glGenVertexArrays(1, &cubeVAO);
+        glGenBuffers(1, &cubeVBO);
+        // fill buffer
+        glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+        // link vertex attributes
+        glBindVertexArray(cubeVAO);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
+        glEnableVertexAttribArray(1);
+        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
+        glEnableVertexAttribArray(2);
+        glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        glBindVertexArray(0);
+    }
+    // render Cube
+    glBindVertexArray(cubeVAO);
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+    glBindVertexArray(0);
+}
 
-// RenderQuad() Renders a 1x1 quad in NDC, best used for framebuffer color targets
+// renderQuad() renders a 1x1 XY quad in NDC
-// and post-processing effects.
+// -----------------------------------------
-GLuint quadVAO = 0;
+unsigned int quadVAO = 0;
-GLuint quadVBO;
+unsigned int quadVBO;
-void RenderQuad()
+void renderQuad()
 {
     if (quadVAO == 0)
     {
-        GLfloat quadVertices[] = {
+        float quadVertices[] = {
-            // Positions        // Texture Coords
+            // positions        // texture Coords
-            -1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
+            -1.0f,  1.0f, 0.0f, 0.0f, 1.0f,
             -1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
-            1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
+             1.0f,  1.0f, 0.0f, 1.0f, 1.0f,
-            1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
+             1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
         };
-        // Setup plane VAO
+        // setup plane VAO
         glGenVertexArrays(1, &quadVAO);
         glGenBuffers(1, &quadVBO);
         glBindVertexArray(quadVAO);
         glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
         glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
         glEnableVertexAttribArray(0);
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
         glEnableVertexAttribArray(1);
-        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
+        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
     }
     glBindVertexArray(quadVAO);
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
     glBindVertexArray(0);
 }
 
-// RenderCube() Renders a 1x1 3D cube in NDC.
+// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
-GLuint cubeVAO = 0;
+// ---------------------------------------------------------------------------------------------------------
-GLuint cubeVBO = 0;
+void processInput(GLFWwindow *window)
-void RenderCube()
 {
-    // Initialize (if necessary)
+    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
-    if (cubeVAO == 0)
+        glfwSetWindowShouldClose(window, true);
-    {
-        GLfloat vertices[] = {
-            // Back face
-            -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // Bottom-left
-            0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
-            0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, // bottom-right         
-            0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f,  // top-right
-            -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f,  // bottom-left
-            -0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f,// top-left
-            // Front face
-            -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
-            0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,  // bottom-right
-            0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,  // top-right
-            0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
-            -0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f,  // top-left
-            -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,  // bottom-left
-            // Left face
-            -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
-            -0.5f, 0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-left
-            -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f,  // bottom-left
-            -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
-            -0.5f, -0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f,  // bottom-right
-            -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
-            // Right face
-            0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
-            0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
-            0.5f, 0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-right         
-            0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f,  // bottom-right
-            0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,  // top-left
-            0.5f, -0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-left     
-            // Bottom face
-            -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
-            0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, // top-left
-            0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f,// bottom-left
-            0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, // bottom-left
-            -0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, // bottom-right
-            -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
-            // Top face
-            -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
-            0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
-            0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, // top-right     
-            0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
-            -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
-            -0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f // bottom-left        
-        };
-        glGenVertexArrays(1, &cubeVAO);
-        glGenBuffers(1, &cubeVBO);
-        // Fill buffer
-        glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
-        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-        // Link vertex attributes
-        glBindVertexArray(cubeVAO);
-        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)));
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
-        glBindVertexArray(0);
-    }
-    // Render Cube
-    glBindVertexArray(cubeVAO);
-    glDrawArrays(GL_TRIANGLES, 0, 36);
-    glBindVertexArray(0);
-}
 
-// This function loads a texture from file. Note: texture loading functions like these are usually 
+    float cameraSpeed = 2.5 * deltaTime;
-// managed by a 'Resource Manager' that manages all resources (like textures, models, audio). 
+    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
-// For learning purposes we'll just define it as a utility function.
-GLuint loadTexture(GLchar const * path)
-{
-    // 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, GL_SRGB, 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])
+    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
         camera.ProcessKeyboard(BACKWARD, deltaTime);
-    if (keys[GLFW_KEY_A])
+    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
         camera.ProcessKeyboard(LEFT, deltaTime);
-    if (keys[GLFW_KEY_D])
+    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
         camera.ProcessKeyboard(RIGHT, deltaTime);
 
-    if (keys[GLFW_KEY_SPACE] && !keysPressed[GLFW_KEY_SPACE])
+    if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS && !hdrKeyPressed)
     {
         hdr = !hdr;
-        keysPressed[GLFW_KEY_SPACE] = true;
+        hdrKeyPressed = true;
     }
-
+    if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_RELEASE)
-    // Change exposure of the scene's HDR camera
-    if (keys[GLFW_KEY_Q])
-        exposure -= 0.5 * deltaTime;
-    else if (keys[GLFW_KEY_E])
-        exposure += 0.5 * deltaTime;
-}
-
-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)
+        hdrKeyPressed = false;
-            keys[key] = true;
+    }
-        else if (action == GLFW_RELEASE)
+
-        {
+    if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS)
-            keys[key] = false;
+    {
-            keysPressed[key] = false;
+        if (exposure > 0.0f)
-        }
+            exposure -= 0.001f;
+        else
+            exposure = 0.0f;
+    }
+    else if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS)
+    {
+        exposure += 0.001f;
     }
 }
 
+// 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)
@@ -369,8 +366,8 @@ void mouse_callback(GLFWwindow* window, double xpos, double ypos)
         firstMouse = false;
     }
 
-    GLfloat xoffset = xpos - lastX;
+    float xoffset = xpos - lastX;
-    GLfloat yoffset = lastY - ypos;
+    float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
 
     lastX = xpos;
     lastY = ypos;
@@ -378,7 +375,57 @@ void mouse_callback(GLFWwindow* window, double xpos, double 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, bool gammaCorrection)
+{
+    unsigned int textureID;
+    glGenTextures(1, &textureID);
+
+    int width, height, nrComponents;
+    unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
+    if (data)
+    {
+        GLenum internalFormat;
+        GLenum dataFormat;
+        if (nrComponents == 1)
+        {
+            internalFormat = dataFormat = GL_RED;
+        }
+        else if (nrComponents == 3)
+        {
+            internalFormat = gammaCorrection ? GL_SRGB : GL_RGB;
+            dataFormat = GL_RGB;
+        }
+        else if (nrComponents == 4)
+        {
+            internalFormat = gammaCorrection ? GL_SRGB_ALPHA : GL_RGBA;
+            dataFormat = GL_RGBA;
+        }
+
+        glBindTexture(GL_TEXTURE_2D, textureID);
+        glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, width, height, 0, dataFormat, 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;
 }