diff --git a/doc/normalization-of-relative-motion.dox b/doc/normalization-of-relative-motion.dox index d0a42e03..d0ab5603 100644 --- a/doc/normalization-of-relative-motion.dox +++ b/doc/normalization-of-relative-motion.dox @@ -38,6 +38,10 @@ libinput scales unaccelerated touchpad motion to the resolution of the touchpad's x axis, i.e. the unaccelerated value for the y axis is: y = (x / resolution_x) * resolution_y +@section motion_normalization_tablet Normalization of tablet coordinates + +See @ref tablet-relative-motion + @section motion_normalization_customization Setting custom DPI settings Devices usually do not advertise their resolution and libinput relies on diff --git a/doc/tablet-support.dox b/doc/tablet-support.dox index 7207a473..cc5d4091 100644 --- a/doc/tablet-support.dox +++ b/doc/tablet-support.dox @@ -52,6 +52,28 @@ Note that the pressure threshold to trigger a logical tip event may be zero on some devices. On tools without pressure sensitivity, determining when a tip is down is device-specific. +@section tablet-relative-motion Relative motion for tablet tools + +libinput calculates the relative motion vector for each event and converts +it to the same coordinate space that a normal mouse device would use. For +the caller, this means that the delta coordinates returned by +libinput_event_tablet_tool_get_dx() and +libinput_event_tablet_tool_get_dy() can be used identical to the delta +coordinates from any other pointer event. Any resolution differences between +the x and y axes are accommodated for, a delta of N/N represents a 45 degree +diagonal move on the tablet. + +The delta coordinates are available for all tablet events, it is up to the +caller to decide when a tool should be used in relative mode. It is +recommended that mouse and lens cursor tool default to relative mode and +all pen-like tools to absolute mode. + +If a tool in relative mode must not use pointer acceleration, callers +should use the absolute coordinates returned by +libinput_event_tablet_tool_get_x() and libinput_event_tablet_tool_get_y() +and calculate the delta themselves. Callers that require exact physical +distance should also use these functions to calculate delta movements. + @section tablet-axes Special axes on tablet tools A tablet tool usually provides additional information beyond x/y positional diff --git a/src/libinput-private.h b/src/libinput-private.h index ff43d007..d78be646 100644 --- a/src/libinput-private.h +++ b/src/libinput-private.h @@ -71,6 +71,7 @@ struct threshold { struct tablet_axes { struct device_coords point; + struct normalized_coords delta; double distance; double pressure; struct normalized_range_coords tilt; diff --git a/src/libinput.c b/src/libinput.c index 2f80f039..a0dc6d68 100644 --- a/src/libinput.c +++ b/src/libinput.c @@ -1089,6 +1089,32 @@ libinput_event_tablet_tool_get_y(struct libinput_event_tablet_tool *event) event->axes.point.y); } +LIBINPUT_EXPORT double +libinput_event_tablet_tool_get_dx(struct libinput_event_tablet_tool *event) +{ + require_event_type(libinput_event_get_context(&event->base), + event->base.type, + 0, + LIBINPUT_EVENT_TABLET_TOOL_AXIS, + LIBINPUT_EVENT_TABLET_TOOL_TIP, + LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY); + + return event->axes.delta.x; +} + +LIBINPUT_EXPORT double +libinput_event_tablet_tool_get_dy(struct libinput_event_tablet_tool *event) +{ + require_event_type(libinput_event_get_context(&event->base), + event->base.type, + 0, + LIBINPUT_EVENT_TABLET_TOOL_AXIS, + LIBINPUT_EVENT_TABLET_TOOL_TIP, + LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY); + + return event->axes.delta.y; +} + LIBINPUT_EXPORT double libinput_event_tablet_tool_get_pressure(struct libinput_event_tablet_tool *event) { diff --git a/src/libinput.h b/src/libinput.h index 1cf690b9..500224df 100644 --- a/src/libinput.h +++ b/src/libinput.h @@ -1580,6 +1580,40 @@ libinput_event_tablet_tool_get_x(struct libinput_event_tablet_tool *event); double libinput_event_tablet_tool_get_y(struct libinput_event_tablet_tool *event); +/** + * @ingroup event_tablet + * + * Return the delta between the last event and the current event. + * If the tool employs pointer acceleration, the delta returned by this + * function is the accelerated delta. + * + * This value is in screen coordinate space, the delta is to be interpreted + * like the return value of libinput_event_pointer_get_dx(). + * See @ref tablet-relative-motion for more details. + * + * @param event The libinput tablet event + * @return The relative x movement since the last event + */ +double +libinput_event_tablet_tool_get_dx(struct libinput_event_tablet_tool *event); + +/** + * @ingroup event_tablet + * + * Return the delta between the last event and the current event. + * If the tool employs pointer acceleration, the delta returned by this + * function is the accelerated delta. + * + * This value is in screen coordinate space, the delta is to be interpreted + * like the return value of libinput_event_pointer_get_dx(). + * See @ref tablet-relative-motion for more details. + * + * @param event The libinput tablet event + * @return The relative y movement since the last event + */ +double +libinput_event_tablet_tool_get_dy(struct libinput_event_tablet_tool *event); + /** * @ingroup event_tablet * diff --git a/src/libinput.sym b/src/libinput.sym index 22a8dd82..666f3668 100644 --- a/src/libinput.sym +++ b/src/libinput.sym @@ -194,6 +194,8 @@ LIBINPUT_TABLET_SUPPORT { libinput_event_tablet_tool_tilt_y_has_changed; libinput_event_tablet_tool_wheel_has_changed; libinput_event_tablet_tool_slider_has_changed; + libinput_event_tablet_tool_get_dx; + libinput_event_tablet_tool_get_dy; libinput_event_tablet_tool_get_x; libinput_event_tablet_tool_get_y; libinput_event_tablet_tool_get_pressure;