[PATCH libinput 02/19] touchpad: add a touchpad driver based on per-finger tracking
Peter Hutterer
peter.hutterer at who-t.net
Sun Feb 16 22:48:21 PST 2014
This patch is a mixture of an experimental project (libtouchpad) and
evdev-touchpad.c. It adds a new touchpad driver for multi-touch touchpads that
tracks each touchpoint separately. This makes it a lot easier to handle
multi-finger tapping, software button areas, etc.
libtouchpad used a slightly different coding style, this is the attempt to get
closer to the one used in libinput.
Currently sends motion events for single-finger motion, button events only for
physical buttons.
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
src/evdev-mt-touchpad.c | 300 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 281 insertions(+), 19 deletions(-)
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index a360651..856d54f 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -22,38 +22,300 @@
#include "config.h"
+#include <assert.h>
+#include <stdbool.h>
+
#include "evdev.h"
-struct touchpad_dispatch {
+#define TOUCHPAD_HISTORY_LENGTH 4
+
+#define tp_for_each_touch(_tp, _t) \
+ for (unsigned int _i = 0; _i < (_tp)->ntouches && (_t = &(_tp)->touches[_i]); _i++)
+
+enum touch_state {
+ TOUCH_NONE = 0,
+ TOUCH_BEGIN,
+ TOUCH_UPDATE,
+ TOUCH_END
+};
+
+struct tp_motion {
+ int32_t x;
+ int32_t y;
+};
+
+struct tp_touch {
+ enum touch_state state;
+ bool dirty;
+ int32_t x;
+ int32_t y;
+ uint32_t millis;
+
+ struct {
+ struct tp_motion samples[TOUCHPAD_HISTORY_LENGTH];
+ unsigned int index;
+ unsigned int count;
+ } history;
+};
+
+struct tp_dispatch {
struct evdev_dispatch base;
struct evdev_device *device;
+ unsigned int nfingers_down; /* number of fingers down */
+ unsigned int slot; /* current slot */
+
+ unsigned int ntouches; /* number of slots */
+ struct tp_touch *touches; /* len == ntouches */
};
+static inline struct tp_motion *
+tp_motion_history_offset(struct tp_touch *t, int offset)
+{
+ int offset_index =
+ (t->history.index - offset + TOUCHPAD_HISTORY_LENGTH) %
+ TOUCHPAD_HISTORY_LENGTH;
+
+ return &t->history.samples[offset_index];
+}
+
+static inline void
+tp_motion_history_push(struct tp_touch *t)
+{
+ int motion_index = (t->history.index + 1) % TOUCHPAD_HISTORY_LENGTH;
+
+ if (t->history.count < TOUCHPAD_HISTORY_LENGTH)
+ t->history.count++;
+
+ t->history.samples[motion_index].x = t->x;
+ t->history.samples[motion_index].y = t->y;
+ t->history.index = motion_index;
+}
+
+static inline void
+tp_motion_history_reset(struct tp_touch *t)
+{
+ t->history.count = 0;
+}
+
+static inline struct tp_touch *
+tp_current_touch(struct tp_dispatch *tp)
+{
+ return &tp->touches[min(tp->slot, tp->ntouches)];
+}
+
+static inline void
+tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t)
+{
+ if (t->state != TOUCH_UPDATE) {
+ tp_motion_history_reset(t);
+ t->dirty = true;
+ t->state = TOUCH_BEGIN;
+ tp->nfingers_down++;
+ assert(tp->nfingers_down >= 1);
+ }
+}
+
+static inline void
+tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t)
+{
+ if (t->state == TOUCH_NONE)
+ return;
+
+ t->dirty = true;
+ t->state = TOUCH_END;
+ assert(tp->nfingers_down >= 1);
+ tp->nfingers_down--;
+}
+
+static double
+tp_estimate_delta(int x0, int x1, int x2, int x3)
+{
+ return (x0 + x1 - x2 - x3) / 4;
+}
+
static void
-touchpad_process(struct evdev_dispatch *dispatch,
- struct evdev_device *device,
- struct input_event *e,
- uint32_t time)
+tp_get_delta(struct tp_touch *t, double *dx, double *dy)
{
+ if (t->history.count < 4) {
+ *dx = 0;
+ *dy = 0;
+ return;
+ }
+
+ *dx = tp_estimate_delta(tp_motion_history_offset(t, 0)->x,
+ tp_motion_history_offset(t, 1)->x,
+ tp_motion_history_offset(t, 2)->x,
+ tp_motion_history_offset(t, 3)->x);
+ *dy = tp_estimate_delta(tp_motion_history_offset(t, 0)->y,
+ tp_motion_history_offset(t, 1)->y,
+ tp_motion_history_offset(t, 2)->y,
+ tp_motion_history_offset(t, 3)->y);
+}
+
+static void
+tp_process_absolute(struct tp_dispatch *tp,
+ const struct input_event *e,
+ uint32_t time)
+{
+ struct tp_touch *t = tp_current_touch(tp);
+
+ switch(e->code) {
+ case ABS_MT_POSITION_X:
+ t->x = e->value;
+ t->millis = time;
+ t->dirty = true;
+ break;
+ case ABS_MT_POSITION_Y:
+ t->y = e->value;
+ t->millis = time;
+ t->dirty = true;
+ break;
+ case ABS_MT_SLOT:
+ tp->slot = e->value;
+ break;
+ case ABS_MT_TRACKING_ID:
+ t->millis = time;
+ if (e->value != -1)
+ tp_begin_touch(tp, t);
+ else
+ tp_end_touch(tp, t);
+ }
}
static void
-touchpad_destroy(struct evdev_dispatch *dispatch)
+tp_process_key(struct tp_dispatch *tp,
+ const struct input_event *e,
+ uint32_t time)
{
- free(dispatch);
+ switch (e->code) {
+ case BTN_LEFT:
+ case BTN_MIDDLE:
+ case BTN_RIGHT:
+ pointer_notify_button(
+ &tp->device->base,
+ time,
+ e->code,
+ e->value ? LIBINPUT_POINTER_BUTTON_STATE_PRESSED :
+ LIBINPUT_POINTER_BUTTON_STATE_RELEASED);
+ break;
+ }
+}
+
+static void
+tp_process_state(struct tp_dispatch *tp, uint32_t time)
+{
+ struct tp_touch *t;
+
+ tp_for_each_touch(tp, t) {
+ if (!t->dirty)
+ continue;
+
+ tp_motion_history_push(t);
+ }
+}
+
+static void
+tp_post_process_state(struct tp_dispatch *tp, uint32_t time)
+{
+ struct tp_touch *t;
+
+ tp_for_each_touch(tp, t) {
+ if (!t->dirty)
+ continue;
+
+ if (t->state == TOUCH_END)
+ t->state = TOUCH_NONE;
+ else if (t->state == TOUCH_BEGIN)
+ t->state = TOUCH_UPDATE;
+
+ t->dirty = false;
+ }
+}
+
+static void
+tp_post_events(struct tp_dispatch *tp, uint32_t time)
+{
+ struct tp_touch *t = tp_current_touch(tp);
+ double dx, dy;
+
+ if (tp->nfingers_down != 1)
+ return;
+
+ tp_get_delta(t, &dx, &dy);
+
+ if (dx != 0 || dy != 0)
+ pointer_notify_motion(
+ &tp->device->base,
+ time,
+ li_fixed_from_double(dx),
+ li_fixed_from_double(dy));
+}
+
+static void
+tp_process(struct evdev_dispatch *dispatch,
+ struct evdev_device *device,
+ struct input_event *e,
+ uint32_t time)
+{
+ struct tp_dispatch *tp =
+ (struct tp_dispatch *)dispatch;
+
+ switch (e->type) {
+ case EV_ABS:
+ tp_process_absolute(tp, e, time);
+ break;
+ case EV_KEY:
+ tp_process_key(tp, e, time);
+ break;
+ case EV_SYN:
+ tp_process_state(tp, time);
+ tp_post_events(tp, time);
+ tp_post_process_state(tp, time);
+ break;
+ }
+}
+
+static void
+tp_destroy(struct evdev_dispatch *dispatch)
+{
+ struct tp_dispatch *tp =
+ (struct tp_dispatch*)dispatch;
+
+ free(tp->touches);
+ free(tp);
}
-static struct evdev_dispatch_interface touchpad_interface = {
- touchpad_process,
- touchpad_destroy
+static struct evdev_dispatch_interface tp_interface = {
+ tp_process,
+ tp_destroy
};
static int
-touchpad_init(struct touchpad_dispatch *touchpad,
+tp_init_slots(struct tp_dispatch *tp,
struct evdev_device *device)
{
- touchpad->base.interface = &touchpad_interface;
- touchpad->device = device;
+ struct input_absinfo absinfo = {0};
+
+ ioctl(device->fd, EVIOCGABS(ABS_MT_SLOT), &absinfo);
+
+ tp->ntouches = absinfo.maximum + 1;
+ tp->touches = calloc(tp->ntouches,
+ sizeof(struct tp_touch));
+ tp->slot = absinfo.value;
+
+ return 0;
+}
+
+
+static int
+tp_init(struct tp_dispatch *tp,
+ struct evdev_device *device)
+{
+ tp->base.interface = &tp_interface;
+ tp->device = device;
+
+ if (tp_init_slots(tp, device) != 0)
+ return -1;
return 0;
}
@@ -61,16 +323,16 @@ touchpad_init(struct touchpad_dispatch *touchpad,
struct evdev_dispatch *
evdev_mt_touchpad_create(struct evdev_device *device)
{
- struct touchpad_dispatch *touchpad;
+ struct tp_dispatch *tp;
- touchpad = zalloc(sizeof *touchpad);
- if (!touchpad)
+ tp = zalloc(sizeof *tp);
+ if (!tp)
return NULL;
- if (touchpad_init(touchpad, device) != 0) {
- free(touchpad);
+ if (tp_init(tp, device) != 0) {
+ tp_destroy(&tp->base);
return NULL;
}
- return &touchpad->base;
+ return &tp->base;
}
--
1.8.4.2
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