I asked this same question on StackOverflow but didn’t get any answeres there, so I figured this place would be more suitable.
When looking through the GLFW reference I came accross the
glfwGetWindowUserPointer function (and the
glfwSetWindowUserPointer function). In the reference it says the following about the user-pointer:
Each window has a user pointer that can be set with glfwSetWindowUserPointer and fetched with glfwGetWindowUserPointer. This can be used for any purpose you need and will not be modified by GLFW throughout the life-time of the window.
Now I wonder for what purpose one could use this?