[PATCH evdev 5/5] Keep the states of multitouch events
Peter Hutterer
peter.hutterer at who-t.net
Thu Apr 8 23:19:16 PDT 2010
On Sun, Mar 28, 2010 at 01:58:13PM +0200, Benjamin Tissoires wrote:
> The idea here is to track the different touches given by the device.
>
> Currently, the driver continue to send the trackingID as the XInput
> implementation in the server does not contains the masks of the
> valuators.
>
> Note that I currently assume two things:
> - the trackingID has to be given by the device
> - the device reports all multitouch fields at each frame
>
> Signed-off-by: Benjamin Tissoires <tissoire at cena.fr>
> ---
> src/evdev.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
> src/evdev.h | 11 +++++++++
> 2 files changed, 76 insertions(+), 8 deletions(-)
>
> diff --git a/src/evdev.c b/src/evdev.c
> index 76af8dc..554e796 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -556,12 +556,10 @@ EvdevProcessAbsoluteMotionEvent(InputInfoPtr pInfo, struct input_event *ev)
>
> if (ev->code < ABS_MT_TOUCH_MAJOR)
> pEvdev->vals[pEvdev->axis_map[ev->code]] = value;
> - else if (pEvdev->current_num_multitouch < EVDEV_MAX_TOUCHPOINTS) {
> - /* MT value -> store it at the first available place */
> - pEvdev->vals[pEvdev->axis_map[ev->code] +
> - pEvdev->current_num_multitouch * pEvdev->mt_num_valuators] = value;
> - } else
> - return; /* mt-event, but not enough place to store it */
> + else
> + /* multitouch event */
> + pEvdev->mt_current_vals[pEvdev->axis_map[ev->code] -
> + pEvdev->mt_first_axis] = value;
that took me a bit to understand so I think a comment (and exhaustive commit
message) would definitely be in order here. If I understand this correctly,
mt_current_vals only constains the values of the _current_ touchpoint. these
values are copied out at MT_SYNC and they are then overwritten at the next
touchpoint. correct?
> if (ev->code == ABS_X)
> pEvdev->abs |= ABS_X_VALUE;
> @@ -692,6 +690,7 @@ EvdevProcessSyncEvent(InputInfoPtr pInfo, struct input_event *ev)
> int num_v = 0, first_v = 0;
> int v[MAX_VALUATORS];
> EvdevPtr pEvdev = pInfo->private;
> + int i;
>
> EvdevProcessValuators(pInfo, v, &num_v, &first_v);
>
> @@ -704,7 +703,17 @@ EvdevProcessSyncEvent(InputInfoPtr pInfo, struct input_event *ev)
> pEvdev->num_queue = 0;
> pEvdev->abs = 0;
> pEvdev->rel = 0;
> - pEvdev->current_num_multitouch = 0;
> +
> + if (pEvdev->flags & EVDEV_MULTITOUCH) {
> + pEvdev->current_num_multitouch = 0;
> +
> + /* clean up known multitouch */
> + for (i = 0; i < EVDEV_MAX_TOUCHPOINTS; i++) {
> + if (!pEvdev->known_touches[i].used)
> + pEvdev->known_touches[i].id = -1;
> + pEvdev->known_touches[i].used = FALSE;
> + }
> + }
> }
>
> /**
> @@ -714,7 +723,48 @@ static void
> EvdevProcessMTSyncReport(InputInfoPtr pInfo, struct input_event *ev)
> {
> EvdevPtr pEvdev = pInfo->private;
> - pEvdev->current_num_multitouch++;
> + EvdevTouchPtr pTouch = NULL;
> +
> + /* find the previously associated MT */
> + if (pEvdev->axis_map[ABS_MT_TRACKING_ID] > -1) {
> + /* the tracking ID is given by the device */
> + int i;
> + int id = pEvdev->mt_current_vals[
> + pEvdev->axis_map[ABS_MT_TRACKING_ID] - pEvdev->mt_first_axis];
something strikes me as odd here. Long term I don't think we should be
assigning ABS_MT_TRACKING_ID an axis mapping and maybe special treat it.
because if I read this correctly, you're relying on the mapping as an
indicator of whether it's there.
Instead, I'd rather you detect it separately and then claim in the log that
"no tracking ID, can't do multitouch" or so.
> +
> + /* Get a TouchDataRec to keep the state of the MT-event */
> + /* first, find if the id was previously assigned */
> + for (i = 0; i < EVDEV_MAX_TOUCHPOINTS; i++) {
> + if (pEvdev->known_touches[i].id == id) {
> + pTouch = &pEvdev->known_touches[i];
> + break;
> + }
> + }
> +
> + if (!pTouch) {
> + /* the TouchDataRec was not found, look at an unassigned one */
> + for (i = 0; i < EVDEV_MAX_TOUCHPOINTS; i++) {
> + if (pEvdev->known_touches[i].id <= 0) {
> + pTouch = &pEvdev->known_touches[i];
> + pTouch->id = id;
> + break;
> + }
> + }
> + }
> +
> + if (pTouch) {
> + pTouch->used = TRUE;
> + pTouch->position = pEvdev->current_num_multitouch; /* currently as mask for valuators is non available */
> + }
> + }
> +
> + if (pTouch) {
> + memcpy(pEvdev->vals + pEvdev->mt_first_axis +
> + pTouch->position * pEvdev->mt_num_valuators,
> + pEvdev->mt_current_vals,
> + sizeof(int) * pEvdev->mt_num_valuators);
> + pEvdev->current_num_multitouch++;
> + }
this one can move inside the if. or we just return early if
[ABS_MT_TRACKING_ID] > -1.
> }
>
> /**
> @@ -2091,6 +2141,7 @@ EvdevPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
> const char *device, *str;
> int num_calibration = 0, calibration[4] = { 0, 0, 0, 0 };
> EvdevPtr pEvdev;
> + int i;
>
> if (!(pInfo = xf86AllocateInput(drv, 0)))
> return NULL;
> @@ -2188,6 +2239,12 @@ EvdevPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
> return NULL;
> }
>
> + /* mt-related */
you can just skip this comment.
> + for (i = 0; i < EVDEV_MAX_TOUCHPOINTS; i++) {
> + pEvdev->known_touches[i].id = 0;
> + pEvdev->known_touches[i].used = FALSE;
> + }
> +
> EvdevAddDevice(pInfo);
>
> if (pEvdev->flags & EVDEV_BUTTON_EVENTS)
> diff --git a/src/evdev.h b/src/evdev.h
> index 0dba366..9b5c1cd 100644
> --- a/src/evdev.h
> +++ b/src/evdev.h
> @@ -116,6 +116,13 @@ typedef struct {
> int val; /* State of the key/button; pressed or released. */
> } EventQueueRec, *EventQueuePtr;
>
> +/* Touch record to store if a touch was presviously reported */
typo
> +typedef struct {
> + int id; /* the tracking ID of the touch (>0 means touch alive) */
> + BOOL used; /* true if seen in the current frame (between two SYNC_EVENT) */
maybe "is_present" instead? or "is_active"?
> + int position; /* the position in the collection of touches */
> +} EvdevTouchRec, *EvdevTouchPtr;
> +
> typedef struct {
> const char *device;
> int grabDevice; /* grab the event device? */
> @@ -199,6 +206,10 @@ typedef struct {
> unsigned int mt_first_axis;
> unsigned int mt_num_valuators;
> unsigned int current_num_multitouch;
> +
> + /* a list of the current touches */
> + EvdevTouchRec known_touches[EVDEV_MAX_TOUCHPOINTS];
please add an mt_ prefix.
> + int mt_current_vals[ABS_CNT - ABS_MT_TOUCH_MAJOR];
> } EvdevRec, *EvdevPtr;
>
> /* Event posting functions */
> --
> 1.6.6.1
Cheers,
Peter
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