Lab 01 - Window and Context

Task 1 - Initialise GLFW and Set Version Hints

Open src/main.cpp and add the following at the top of main().

1. Call glfwInit() and check its return value. Print an error message and return -1 if it fails.
2. Call glfwWindowHint three times to target OpenGL 4.3 Core Profile:
   • GLFW_CONTEXT_VERSION_MAJOR set to 4
   • GLFW_CONTEXT_VERSION_MINOR set to 3
   • GLFW_OPENGL_PROFILE set to GLFW_OPENGL_CORE_PROFILE

// file: src/main.cpp
int main() {
    // TODO: Call glfwInit() and return -1 with an error message if it fails.

    // TODO: Set GLFW_CONTEXT_VERSION_MAJOR to 4.
    // TODO: Set GLFW_CONTEXT_VERSION_MINOR to 3.
    // TODO: Set GLFW_OPENGL_PROFILE to GLFW_OPENGL_CORE_PROFILE.
}

Task 2 - Create the Window and Make the Context Current

Immediately after the hints, create the window and bind its context.

1. Call glfwCreateWindow(800, 600, "OpenGL Window", NULL, NULL) and store the result in a GLFWwindow* named window.
2. Check that window is not nullptr. If it is, call glfwTerminate() and return -1.
3. Call glfwMakeContextCurrent(window) to bind the context to this thread.

// file: src/main.cpp  (after the window hints)

    // TODO: Create an 800x600 window titled "OpenGL Window".
    //       Store the result in GLFWwindow* window.

    // TODO: If window is nullptr, terminate GLFW and return -1.

    // TODO: Make the window's context current on this thread.

Task 3 - Initialise GLEW

After the context is current, load OpenGL function pointers.

1. Set glewExperimental = GL_TRUE before calling glewInit.
2. Call glewInit(). If it does not return GLEW_OK, print an error, call glfwTerminate(), and return -1.
3. Print the loaded OpenGL version to confirm everything is working:
   std::cout << "OpenGL version: " << glGetString(GL_VERSION) << std::endl;
4. Call glfwSwapInterval(1) to enable V-Sync.

// file: src/main.cpp  (after glfwMakeContextCurrent)

    // TODO: Set glewExperimental = GL_TRUE.

    // TODO: Call glewInit(). If it fails, terminate GLFW and return -1.

    // TODO: Print the OpenGL version string using glGetString(GL_VERSION).

    // TODO: Call glfwSwapInterval(1) to cap to the monitor refresh rate.

Task 4 - Write the Main Render Loop

Add the loop that runs every frame until the window is closed.

1. Write a while loop that continues as long as !glfwWindowShouldClose(window) is true.
2. Inside the loop, call glClearColor(0.1f, 0.1f, 0.15f, 1.0f) to set a dark blue-grey clear colour.
3. Call glClear(GL_COLOR_BUFFER_BIT) to clear the colour buffer.
4. Call glfwSwapBuffers(window) to present the back buffer.
5. Call glfwPollEvents() to process queued OS events.

// file: src/main.cpp  (after glfwSwapInterval)

    // TODO: Loop while the window should not close.
    while (!glfwWindowShouldClose(window)) {

        // TODO: Set the clear colour to a dark blue-grey (r=0.1, g=0.1, b=0.15, a=1.0).

        // TODO: Clear the colour buffer.

        // TODO: Swap front and back buffers.

        // TODO: Poll for OS events (keyboard, mouse, window close).
    }

Task 5 - Shutdown and Cleanup

After the loop exits, release all GLFW resources. The code below is provided as a reference - add it after the closing brace of your render loop.

// file: src/main.cpp  (after the render loop) -- provided for reference
    glfwDestroyWindow(window);
    glfwTerminate();
    return 0;

1. Build the project with Ctrl+Shift+B and check the Output window for errors.
2. Run with F5 (Debug) or Ctrl+F5 (without debugger).
3. Verify the console prints the OpenGL version string before the window opens.