OpenGl Basics

This is written for version opengl 3.3. Basic modules required are GLFW and glad.

Windowing

Note: glfw functions cannot be called with calling glfwInit Create a window and set it to be current

GLFWwindow* window = glfwCreateWindow(width, height, title, NULL, NULL);
glfwMakeContextCurrent(window);

Loading gl functions

Note: gl functions should only be loaded after creating a window Load glad and set it’s view port

gladLoadGL();
glViewport(0, 0, width, height);

Main loop

while (!glfwWindowShouldClose(window)) {
    // Code
    glfwPollEvents();
}

Rendering

// Loop Start
glClearColor(r, g, b, a);
glClear(GL_COLOR_BUFFER_BIT);
// Loop End

Here each of rgba must be between 0.0f and 0.01f.

Positioning

Opengl places (0, 0) coordinates in the middle of the screen. Therefore the leftside is (-1, 0), the rightside is (1, 0), the top is (0, -1) and the bottom is (0, 1).