pub unsafe extern "C" fn glfwSetScrollCallback(
window: *mut GLFWwindow,
callback: Option<unsafe extern "C" fn(*mut GLFWwindow, f64, f64)>,
) -> Option<unsafe extern "C" fn(*mut GLFWwindow, f64, f64)>Expand description
@brief Sets the scroll callback.
This function sets the scroll callback of the specified window, which is called when a scrolling device is used, such as a mouse wheel or scrolling area of a touchpad.
The scroll callback receives all scrolling input, like that from a mouse wheel or a touchpad scrolling area.
@param[in] window The window whose callback to set.
@param[in] callback The new scroll 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, double xoffset, double yoffset) @endcode For more information about the callback parameters, see the [function pointer type](@ref GLFWscrollfun).
@errors Possible errors include @ref GLFW_NOT_INITIALIZED.
@thread_safety This function must only be called from the main thread.
@sa @ref scrolling
@since Added in version 3.0. Replaces glfwSetMouseWheelCallback.
@ingroup input