I am working on an assignment for school and i seem to be having some issues. I am using OpenGl with free glut, and attempting to animate a pendulum. I can draw out the pendulum, but cannot determine how to make it swing. I have to make it swing from -45 degrees to 45 degrees, and i have the line and ball drawn. I have tried several ways to animate it and make it smooth, but i don't completely understand the process of it. I can set it up in a state where it would be at the right spot on both sides, but cannot animate it smooth. I can just make it jump from the two points. Not hitting the points in-between. I have also tried using the rotate and translate function, but it never rotates the line correctly, it always rotates at the axis, but thats not working. I could really use some help if anyone has any experience.