pub unsafe extern "C" fn glfwSetWindowRefreshCallback(
window: *mut GLFWwindow,
callback: Option<unsafe extern "C" fn(*mut GLFWwindow)>,
) -> Option<unsafe extern "C" fn(*mut GLFWwindow)>Expand description
@brief Sets the refresh callback for the specified window.
This function sets the refresh callback of the specified window, which is called when the content area of the window needs to be redrawn, for example if the window has been exposed after having been covered by another window.
On compositing window systems such as Aero, Compiz, Aqua or Wayland, where the window contents are saved off-screen, this callback may be called only very infrequently or never at all.
@param[in] window The window whose callback to set.
@param[in] callback The new callback, or NULL to remove the currently set
callback.
@return The previously set callback, or NULL if no callback was set or the
library had not been [initialized](@ref intro_init).
@callback_signature @code void function_name(GLFWwindow* window); @endcode For more information about the callback parameters, see the [function pointer type](@ref GLFWwindowrefreshfun).
@errors Possible errors include @ref GLFW_NOT_INITIALIZED.
@thread_safety This function must only be called from the main thread.
@sa @ref window_refresh
@since Added in version 2.5. @glfw3 Added window handle parameter and return value.
@ingroup window