Three static circles with dynamic radius are drawn, with three dynamic lights into a scene. Circles are created using GL_POLYGON with an increment of each vertex of 2 x PI x INDEX / SIZE, where INDEX is the current iteration from 0 to reach SIZE.
Lights should be enable/disable using keys F1, F2, and F3 for red, green and blue respectively. Lights affect a pixel's color (distance and position), because a Lambert's cosine law is applied. A normal vector of an internal 2D circle position is obtained as pos - center, where center is the center of the circle.
Lights bounce over the external window, and their colors are mixed into the final result.
The last time, this code was tested on Visual Studio 2017. You need to use CMake to be more easy the dependencies (at least for me :-) due that I have several times the GLUT library on my repositories!)