The window whose framebuffer to query.
Where to store the width, in pixels, of the framebuffer, or null.
Where to store the height, in pixels, of the framebuffer, or null.
Errors: Possible errors include @ref GLFW_NOT_INITIALIZED and @ref GLFW_PLATFORM_ERROR.
This function must only be called from the main thread.
@sa @ref window_fbsize @sa @ref glfwSetFramebufferSizeCallback
Added in version 3.0.
Ingroup: window
Retrieves the size of the framebuffer of the specified window.
This function retrieves the size, in pixels, of the framebuffer of the specified window. If you wish to retrieve the size of the window in screen coordinates, see @ref glfwGetWindowSize.
Any or all of the size arguments may be null. If an error occurs, all non-null size arguments will be set to zero.