[PATCH libinput 1/2] Replace output screen size callback with transform helpers
Peter Hutterer
peter.hutterer at who-t.net
Wed Jan 29 19:02:15 PST 2014
On Wed, Jan 29, 2014 at 09:33:11PM +0100, Jonas Ådahl wrote:
> Instead of automatically transforming absolute coordinates of touch and
> pointer events to screen coordinates, the user now uses the corresponding
> transform helper function. This means the coordinates returned by
> libinput_event_pointer_get_absolute_x(),
> libinput_event_pointer_get_absolute_y(), libinput_touch_get_x() and
> libinput_touch_get_y() has changed from being in output screen coordinate
> space to being in device specific coordinate space.
>
> For example, where one before would call libinput_event_touch_get_x(event),
> one now calls libinput_event_touch_get_x_transformed(event, output_width).
>
> Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
> ---
> src/evdev.c | 54 ++++++++++--------------
> src/evdev.h | 10 +++++
> src/libinput.c | 44 ++++++++++++++++++++
> src/libinput.h | 128 +++++++++++++++++++++++++++++++++++++++++++++++++--------
> test/litest.c | 11 -----
> 5 files changed, 186 insertions(+), 61 deletions(-)
>
> diff --git a/src/evdev.c b/src/evdev.c
> index 46bd35a..cb83a1f 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -86,6 +86,24 @@ transform_absolute(struct evdev_device *device, int32_t *x, int32_t *y)
> }
> }
>
> +li_fixed_t
> +evdev_device_transform_x(struct evdev_device *device,
> + li_fixed_t x,
> + uint32_t width)
> +{
> + return (x - device->abs.min_x) * width /
> + (device->abs.max_x - device->abs.min_x);
> +}
> +
> +li_fixed_t
> +evdev_device_transform_y(struct evdev_device *device,
> + li_fixed_t y,
> + uint32_t height)
> +{
> + return (y - device->abs.min_y) * height /
> + (device->abs.max_y - device->abs.min_y);
you're mixing coordinate systems here, x and y are in fixed_t but
abs.min/max is in normal integers. that breaks if you have a non-zero min.
You'll need to convert the rest to li_fixed_t too if you want to keep the
integer division.
also, should we add a non-zero min for width and height to scale to a screen
not the top/left-most? The compositor can just add it afterwards, but
it would have to convert to fixed_t as well:
x = libinput_event_touch_get_x_transformed(event, screen_width);
x += li_fixed_from_int(screen_offset);
which is more error prone than something like:
x = libinput_event_touch_get_x_transformed(event, screen_offset_x, screen_width);
also, is it likely that the caller always has the screen dimensions handy
when it comes to processing events? or would an config-style approach work
better:
libinput_device_set_output_dimensions(device, xoff, yoff, width, height);
...
x = libinput_event_touch_get_x_transformed(event);
y = libinput_event_touch_get_y_transformed(event);
I also suspect that the device-specific dimensions will be rather useless if
we don't have a call to get the min/max from each device. which I should be
focusing on real soon :)
Cheers,
Peter
> +}
> +
> static void
> evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
> {
> @@ -242,16 +260,6 @@ evdev_process_touch(struct evdev_device *device,
> struct input_event *e,
> uint32_t time)
> {
> - struct libinput *libinput = device->base.seat->libinput;
> - int screen_width;
> - int screen_height;
> -
> - libinput->interface->get_current_screen_dimensions(
> - &device->base,
> - &screen_width,
> - &screen_height,
> - libinput->user_data);
> -
> switch (e->code) {
> case ABS_MT_SLOT:
> evdev_flush_pending_event(device, time);
> @@ -267,16 +275,12 @@ evdev_process_touch(struct evdev_device *device,
> device->pending_event = EVDEV_ABSOLUTE_MT_UP;
> break;
> case ABS_MT_POSITION_X:
> - device->mt.slots[device->mt.slot].x =
> - (e->value - device->abs.min_x) * screen_width /
> - (device->abs.max_x - device->abs.min_x);
> + device->mt.slots[device->mt.slot].x = e->value;
> if (device->pending_event == EVDEV_NONE)
> device->pending_event = EVDEV_ABSOLUTE_MT_MOTION;
> break;
> case ABS_MT_POSITION_Y:
> - device->mt.slots[device->mt.slot].y =
> - (e->value - device->abs.min_y) * screen_height /
> - (device->abs.max_y - device->abs.min_y);
> + device->mt.slots[device->mt.slot].y = e->value;
> if (device->pending_event == EVDEV_NONE)
> device->pending_event = EVDEV_ABSOLUTE_MT_MOTION;
> break;
> @@ -287,28 +291,14 @@ static inline void
> evdev_process_absolute_motion(struct evdev_device *device,
> struct input_event *e)
> {
> - struct libinput *libinput = device->base.seat->libinput;
> - int screen_width;
> - int screen_height;
> -
> - libinput->interface->get_current_screen_dimensions(
> - &device->base,
> - &screen_width,
> - &screen_height,
> - libinput->user_data);
> -
> switch (e->code) {
> case ABS_X:
> - device->abs.x =
> - (e->value - device->abs.min_x) * screen_width /
> - (device->abs.max_x - device->abs.min_x);
> + device->abs.x = e->value;
> if (device->pending_event == EVDEV_NONE)
> device->pending_event = EVDEV_ABSOLUTE_MOTION;
> break;
> case ABS_Y:
> - device->abs.y =
> - (e->value - device->abs.min_y) * screen_height /
> - (device->abs.max_y - device->abs.min_y);
> + device->abs.y = e->value;
> if (device->pending_event == EVDEV_NONE)
> device->pending_event = EVDEV_ABSOLUTE_MOTION;
> break;
> diff --git a/src/evdev.h b/src/evdev.h
> index 58ae552..37c32e5 100644
> --- a/src/evdev.h
> +++ b/src/evdev.h
> @@ -146,6 +146,16 @@ int
> evdev_device_has_capability(struct evdev_device *device,
> enum libinput_device_capability capability);
>
> +li_fixed_t
> +evdev_device_transform_x(struct evdev_device *device,
> + li_fixed_t x,
> + uint32_t width);
> +
> +li_fixed_t
> +evdev_device_transform_y(struct evdev_device *device,
> + li_fixed_t y,
> + uint32_t height);
> +
> void
> evdev_device_remove(struct evdev_device *device);
>
> diff --git a/src/libinput.c b/src/libinput.c
> index a77f165..cfce2c5 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -245,6 +245,28 @@ libinput_event_pointer_get_absolute_y(
> return event->y;
> }
>
> +LIBINPUT_EXPORT li_fixed_t
> +libinput_event_pointer_get_absolute_x_transformed(
> + struct libinput_event_pointer *event,
> + uint32_t width)
> +{
> + struct evdev_device *device =
> + (struct evdev_device *) event->base.device;
> +
> + return evdev_device_transform_x(device, event->x, width);
> +}
> +
> +LIBINPUT_EXPORT li_fixed_t
> +libinput_event_pointer_get_absolute_y_transformed(
> + struct libinput_event_pointer *event,
> + uint32_t height)
> +{
> + struct evdev_device *device =
> + (struct evdev_device *) event->base.device;
> +
> + return evdev_device_transform_y(device, event->y, height);
> +}
> +
> LIBINPUT_EXPORT uint32_t
> libinput_event_pointer_get_button(
> struct libinput_event_pointer *event)
> @@ -295,6 +317,28 @@ libinput_event_touch_get_x(
> }
>
> LIBINPUT_EXPORT li_fixed_t
> +libinput_event_touch_get_x_transformed(
> + struct libinput_event_touch *event,
> + uint32_t width)
> +{
> + struct evdev_device *device =
> + (struct evdev_device *) event->base.device;
> +
> + return evdev_device_transform_x(device, event->x, width);
> +}
> +
> +LIBINPUT_EXPORT li_fixed_t
> +libinput_event_touch_get_y_transformed(
> + struct libinput_event_touch *event,
> + uint32_t height)
> +{
> + struct evdev_device *device =
> + (struct evdev_device *) event->base.device;
> +
> + return evdev_device_transform_y(device, event->y, height);
> +}
> +
> +LIBINPUT_EXPORT li_fixed_t
> libinput_event_touch_get_y(
> struct libinput_event_touch *event)
> {
> diff --git a/src/libinput.h b/src/libinput.h
> index ddaeb73..8d347b9 100644
> --- a/src/libinput.h
> +++ b/src/libinput.h
> @@ -395,16 +395,19 @@ libinput_event_pointer_get_dy(
> /**
> * @ingroup event_pointer
> *
> - * Return the absolute x coordinate of the device, scaled to screen
> - * coordinates.
> - * The axes' positive direction is device-specific. For pointer events that
> - * are not of type LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function
> - * returns 0.
> + * Return the current absolute x coordinate of the pointer event.
> + *
> + * The coordinate is in a device specific coordinate space; to get the
> + * corresponding output screen coordinate, use
> + * libinput_event_pointer_get_x_transformed().
> + *
> + * For pointer events that are not of type
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function returns 0.
> *
> * @note It is an application bug to call this function for events other than
> * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE.
> *
> - * @return the current absolute x coordinate scaled to screen coordinates.
> + * @return the current absolute x coordinate
> */
> li_fixed_t
> libinput_event_pointer_get_absolute_x(
> @@ -413,15 +416,19 @@ libinput_event_pointer_get_absolute_x(
> /**
> * @ingroup event_pointer
> *
> - * Return the absolute y coordinate of the device, scaled to screen coordinates.
> - * The axes' positive direction is device-specific. For pointer events that
> - * are not of type LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function
> - * returns 0.
> + * Return the current absolute y coordinate of the pointer event.
> + *
> + * The coordinate is in a device specific coordinate space; to get the
> + * corresponding output screen coordinate, use
> + * libinput_event_pointer_get_y_transformed().
> + *
> + * For pointer events that are not of type
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, this function returns 0.
> *
> * @note It is an application bug to call this function for events other than
> * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE.
> *
> - * @return the current absolute y coordinate scaled to screen coordinates.
> + * @return the current absolute y coordinate
> */
> li_fixed_t
> libinput_event_pointer_get_absolute_y(
> @@ -430,6 +437,50 @@ libinput_event_pointer_get_absolute_y(
> /**
> * @ingroup event_pointer
> *
> + * Return the current absolute x coordinate of the pointer event, transformed to
> + * screen coordinates.
> + *
> + * For pointer events that are not of type
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, the return value of this function is
> + * undefined.
> + *
> + * @note It is an application bug to call this function for events other than
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE.
> + *
> + * @param event The libinput pointer event
> + * @param width The current output screen width
> + * @return the current absolute x coordinate transformed to a screen coordinate
> + */
> +li_fixed_t
> +libinput_event_pointer_get_absolute_x_transformed(
> + struct libinput_event_pointer *event,
> + uint32_t width);
> +
> +/**
> + * @ingroup event_pointer
> + *
> + * Return the current absolute y coordinate of the pointer event, transformed to
> + * screen coordinates.
> + *
> + * For pointer events that are not of type
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE, the return value of this function is
> + * undefined.
> + *
> + * @note It is an application bug to call this function for events other than
> + * LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE.
> + *
> + * @param event The libinput pointer event
> + * @param height The current output screen height
> + * @return the current absolute y coordinate transformed to a screen coordinate
> + */
> +li_fixed_t
> +libinput_event_pointer_get_absolute_y_transformed(
> + struct libinput_event_pointer *event,
> + uint32_t height);
> +
> +/**
> + * @ingroup event_pointer
> + *
> * Return the button that triggered this event.
> * For pointer events that are not of type LIBINPUT_EVENT_POINTER_BUTTON,
> * this function returns 0.
> @@ -531,9 +582,16 @@ libinput_event_touch_get_slot(
> /**
> * @ingroup event_touch
> *
> + * Return the current absolute x coordinate of the touch event.
> + *
> + * The coordinate is in a device specific coordinate space; to get the
> + * corresponding output screen coordinate, use
> + * libinput_event_touch_get_x_transformed().
> + *
> * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
> *
> - * @return the absolute X coordinate on this touch device, scaled to screen coordinates.
> + * @param event The libinput touch event
> + * @return the current absolute x coordinate
> */
> li_fixed_t
> libinput_event_touch_get_x(
> @@ -542,9 +600,16 @@ libinput_event_touch_get_x(
> /**
> * @ingroup event_touch
> *
> + * Return the current absolute y coordinate of the touch event.
> + *
> + * The coordinate is in a device specific coordinate space; to get the
> + * corresponding output screen coordinate, use
> + * libinput_event_touch_get_y_transformed().
> + *
> * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
> *
> - * @return the absolute X coordinate on this touch device, scaled to screen coordinates.
> + * @param event The libinput touch event
> + * @return the current absolute y coordinate
> */
> li_fixed_t
> libinput_event_touch_get_y(
> @@ -553,6 +618,38 @@ libinput_event_touch_get_y(
> /**
> * @ingroup event_touch
> *
> + * Return the current absolute x coordinate of the touch event, transformed to
> + * screen coordinates.
> + *
> + * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
> + *
> + * @param event The libinput touch event
> + * @param width The current output screen width
> + * @return the current absolute x coordinate transformed to a screen coordinate
> + */
> +li_fixed_t
> +libinput_event_touch_get_x_transformed(struct libinput_event_touch *event,
> + uint32_t width);
> +
> +/**
> + * @ingroup event_touch
> + *
> + * Return the current absolute y coordinate of the touch event, transformed to
> + * screen coordinates.
> + *
> + * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
> + *
> + * @param event The libinput touch event
> + * @param height The current output screen height
> + * @return the current absolute y coordinate transformed to a screen coordinate
> + */
> +li_fixed_t
> +libinput_event_touch_get_y_transformed(struct libinput_event_touch *event,
> + uint32_t height);
> +
> +/**
> + * @ingroup event_touch
> + *
> * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
> *
> * @return the type of touch that occured on the device
> @@ -586,11 +683,6 @@ struct libinput_interface {
> * libinput_create_from_udev()
> */
> void (*close_restricted)(int fd, void *user_data);
> -
> - void (*get_current_screen_dimensions)(struct libinput_device *device,
> - int *width,
> - int *height,
> - void *user_data);
> };
>
> /**
> diff --git a/test/litest.c b/test/litest.c
> index 5235e3c..216e1a0 100644
> --- a/test/litest.c
> +++ b/test/litest.c
> @@ -318,20 +318,9 @@ close_restricted(int fd, void *userdata)
> close(fd);
> }
>
> -static void
> -get_current_screen_dimensions(struct libinput_device *device,
> - int *width,
> - int *height,
> - void *user_data)
> -{
> - *width = 1024;
> - *height = 768;
> -}
> -
> const struct libinput_interface interface = {
> .open_restricted = open_restricted,
> .close_restricted = close_restricted,
> - .get_current_screen_dimensions = get_current_screen_dimensions,
> };
>
> struct litest_device *
> --
> 1.8.3.2
>
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