User input interpretation mechanisms can pass along user input without delay by initially treating it as freeform movement and passing it along unmodified, rather than waiting to receive a sufficient quantity of user input from which to derive a user's intentions. User input within a defined range from an initial point is freeform movement, passed along unmodified, while user input beyond that range can be confined to a groove if it evidences an intention to move in a precisely linear manner. Grooves can be established to aid in precise vertical movement, with no horizontal deviations, precise horizontal movement, with no vertical deviations, or any other orientation. Before being passed along, user input in groove regions can be modified to center the input within the groove region and eliminate human inaccuracies, such as slight deviations to either side. User input can escape groove regions by moving orthogonally to them.