Function opencv::highgui::get_mouse_wheel_delta

pub fn get_mouse_wheel_delta(flags: i32) -> Result<i32>

Gets the mouse-wheel motion delta, when handling mouse-wheel events cv::EVENT_MOUSEWHEEL and cv::EVENT_MOUSEHWHEEL.

For regular mice with a scroll-wheel, delta will be a multiple of 120. The value 120 corresponds to a one notch rotation of the wheel or the threshold for action to be taken and one such action should occur for each delta. Some high-precision mice with higher-resolution freely-rotating wheels may generate smaller values.

For cv::EVENT_MOUSEWHEEL positive and negative values mean forward and backward scrolling, respectively. For cv::EVENT_MOUSEHWHEEL, where available, positive and negative values mean right and left scrolling, respectively.

Note:

Mouse-wheel events are currently supported only on Windows.

Parameters

• flags: The mouse callback flags parameter.