Start code re-work Advanced OpenGL chapter.

src/4.advanced_opengl/11.anti_aliasing_offscreen/11.anti_aliasing.fs

@@ -0,0 +1,7 @@
+#version 330 core
+out vec4 color;
+
+void main()
+{
+    color = vec4(0.0, 1.0, 0.0, 1.0);
+} 

src/4.advanced_opengl/11.anti_aliasing_offscreen/11.anti_aliasing.vs

@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec3 position;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    gl_Position = projection * view * model * vec4(position, 1.0f);
+}

src/4.advanced_opengl/11.anti_aliasing_offscreen/anti_aliasing_offscreen.cpp

@@ -0,0 +1,255 @@
+// 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>
+
+// Properties
+GLuint screenWidth = 800, screenHeight = 600;
+
+// Function prototypes
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
+void mouse_callback(GLFWwindow* window, double xpos, double ypos);
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
+void Do_Movement();
+GLuint generateMultiSampleTexture(GLuint samples);
+
+// Camera
+Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
+bool keys[1024];
+GLfloat lastX = 400, lastY = 300;
+bool firstMouse = true;
+
+GLfloat deltaTime = 0.0f;
+GLfloat lastFrame = 0.0f;
+
+// 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(screenWidth, screenHeight, "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, screenWidth, screenHeight);
+
+    // Setup OpenGL options
+    glEnable(GL_MULTISAMPLE); // Enabled by default on some drivers, but not all so always enable to make sure
+    glEnable(GL_DEPTH_TEST);
+
+    // Setup and compile our shaders
+    Shader shader("anti_aliasing.vs", "anti_aliasing.frag");
+
+    #pragma region "object_initialization"
+    // Set the object data (buffers, vertex attributes)
+    GLfloat cubeVertices[] = {
+        // Positions       
+        -0.5f, -0.5f, -0.5f, 
+         0.5f, -0.5f, -0.5f, 
+         0.5f,  0.5f, -0.5f, 
+         0.5f,  0.5f, -0.5f,  
+        -0.5f,  0.5f, -0.5f,  
+        -0.5f, -0.5f, -0.5f, 
+
+        -0.5f, -0.5f,  0.5f, 
+         0.5f, -0.5f,  0.5f, 
+         0.5f,  0.5f,  0.5f, 
+         0.5f,  0.5f,  0.5f,  
+        -0.5f,  0.5f,  0.5f, 
+        -0.5f, -0.5f,  0.5f, 
+
+        -0.5f,  0.5f,  0.5f, 
+        -0.5f,  0.5f, -0.5f,  
+        -0.5f, -0.5f, -0.5f,  
+        -0.5f, -0.5f, -0.5f, 
+        -0.5f, -0.5f,  0.5f, 
+        -0.5f,  0.5f,  0.5f, 
+
+         0.5f,  0.5f,  0.5f,  
+         0.5f,  0.5f, -0.5f, 
+         0.5f, -0.5f, -0.5f, 
+         0.5f, -0.5f, -0.5f, 
+         0.5f, -0.5f,  0.5f,  
+         0.5f,  0.5f,  0.5f,  
+
+        -0.5f, -0.5f, -0.5f, 
+         0.5f, -0.5f, -0.5f,  
+         0.5f, -0.5f,  0.5f, 
+         0.5f, -0.5f,  0.5f, 
+        -0.5f, -0.5f,  0.5f,  
+        -0.5f, -0.5f, -0.5f,  
+
+        -0.5f,  0.5f, -0.5f,  
+         0.5f,  0.5f, -0.5f,
+         0.5f,  0.5f,  0.5f,  
+         0.5f,  0.5f,  0.5f,  
+        -0.5f,  0.5f,  0.5f,  
+        -0.5f,  0.5f, -0.5f
+    };
+    // Setup cube VAO
+    GLuint cubeVAO, cubeVBO;
+    glGenVertexArrays(1, &cubeVAO);
+    glGenBuffers(1, &cubeVBO);
+    glBindVertexArray(cubeVAO);
+    glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), &cubeVertices, GL_STATIC_DRAW);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
+    glBindVertexArray(0);
+    #pragma endregion
+
+
+    // Framebuffers
+    GLuint framebuffer;
+    glGenFramebuffers(1, &framebuffer);
+    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);  
+    // Create a multisampled color attachment texture
+    GLuint textureColorBufferMultiSampled = generateMultiSampleTexture(4);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, textureColorBufferMultiSampled, 0);
+    // Create a renderbuffer object for depth and stencil attachments
+    GLuint rbo;
+    glGenRenderbuffers(1, &rbo);
+    glBindRenderbuffer(GL_RENDERBUFFER, rbo); 
+    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, screenWidth, screenHeight); 
+    glBindRenderbuffer(GL_RENDERBUFFER, 0);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo); 
+
+    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+        std::cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!" << std::endl;
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    
+
+    // Game loop
+    while(!glfwWindowShouldClose(window))
+    {
+        // Set frame time
+        GLfloat currentFrame = glfwGetTime();
+        deltaTime = currentFrame - lastFrame;
+        lastFrame = currentFrame;
+
+        // Check and call events
+        glfwPollEvents();
+        Do_Movement();      
+        
+        // 1. Draw scene as normal in multisampled buffers
+        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);   
+        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        // Set transformation matrices		
+        shader.Use();
+        glm::mat4 projection = glm::perspective(camera.Zoom, (GLfloat)screenWidth/(GLfloat)screenHeight, 0.1f, 1000.0f);
+        glUniformMatrix4fv(glGetUniformLocation(shader.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
+        glUniformMatrix4fv(glGetUniformLocation(shader.Program, "view"), 1, GL_FALSE, glm::value_ptr(camera.GetViewMatrix()));	
+        glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(glm::mat4()));
+        
+        glBindVertexArray(cubeVAO);
+        glDrawArrays(GL_TRIANGLES, 0, 36);
+        glBindVertexArray(0);
+
+        // 2. Now blit multisampled buffer(s) to default framebuffers
+        glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer);
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);				
+        glBlitFramebuffer(0, 0, screenWidth, screenHeight, 0, 0, screenWidth, screenHeight, GL_COLOR_BUFFER_BIT, GL_NEAREST);     
+        
+        // Swap the buffers
+        glfwSwapBuffers(window);
+    }
+
+
+    glfwTerminate();
+    return 0;
+}
+
+GLuint generateMultiSampleTexture(GLuint samples)
+{
+    GLuint texture;
+    glGenTextures(1, &texture);
+
+    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, texture);
+    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGB, screenWidth, screenHeight, GL_TRUE);
+    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
+
+    return texture;
+}
+
+#pragma region "User input"
+
+// 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);
+}
+
+// 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(action == GLFW_PRESS)
+        keys[key] = true;
+    else if(action == GLFW_RELEASE)
+        keys[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);
+}
+
+#pragma endregion