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touchscreen: Add gesture recognition API

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Add a basic gesture API which can detect taps, long presses,
and dragging gestures.

Change-Id: Id10bf8d46b9195330ce951f9f108c81e87a8dad4
This commit is contained in:
Aidan MacDonald 2022-04-23 16:15:15 +01:00 • committed by Solomon Peachy
parent 0f4cc33d26
commit 7aa823215b
3 changed files with 247 additions and 0 deletions
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121
apps/gesture.c Normal file
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2022 by Aidan MacDonald
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "gesture.h"
#include "button.h"
#include "viewport.h"
#include "system.h"
/* could be a setting */
#define TOUCH_LONG_PRESS_TIME (30 * HZ / 100)
void gesture_reset(struct gesture *g)
{
g->flags = 0;
}
void gesture_process(struct gesture *g, const struct touchevent *ev)
{
/* wait for the first press if we haven't seen it */
if (!gesture_is_pressed(g) && ev->type != TOUCHEVENT_PRESS)
return;
int dx, dy, dist_sqr;
switch (ev->type)
{
case TOUCHEVENT_PRESS:
g->flags |= GESTURE_F_PRESSED | GESTURE_F_VALID;
g->id = GESTURE_NONE;
g->ox = g->x = ev->x;
g->oy = g->y = ev->y;
g->start_tick = ev->tick;
g->last_tick = ev->tick;
break;
case TOUCHEVENT_CONTACT:
g->x = ev->x;
g->y = ev->y;
g->last_tick = ev->tick;
if (g->id == GESTURE_LONG_PRESS)
g->id = GESTURE_HOLD;
else if (g->id == GESTURE_DRAGSTART)
g->id = GESTURE_DRAG;
else if (g->id != GESTURE_DRAG)
{
dx = ev->x - g->ox;
dy = ev->y - g->oy;
dist_sqr = dx*dx + dy*dy;
/* if squared distance exceeds a threshold, report as a DRAG. */
const int thresh = touchscreen_get_scroll_threshold();
if (dist_sqr > thresh*thresh)
g->id = GESTURE_DRAGSTART;
/* report a LONG_PRESS if no motion occurs within a timeout */
if (g->id == GESTURE_NONE &&
TIME_AFTER(ev->tick, g->start_tick + TOUCH_LONG_PRESS_TIME))
g->id = GESTURE_LONG_PRESS;
}
break;
case TOUCHEVENT_RELEASE:
/* report a RELEASE event after a continuous HOLD or DRAG */
if (g->id == GESTURE_HOLD ||
g->id == GESTURE_DRAGSTART ||
g->id == GESTURE_DRAG)
g->id = GESTURE_RELEASE;
/* report a TAP event if we got a press & release without
* triggering any other gestures */
else if (g->id == GESTURE_NONE)
g->id = GESTURE_TAP;
g->flags &= ~GESTURE_F_PRESSED;
g->last_tick = ev->tick;
break;
}
}
bool gesture_get_event_in_vp(struct gesture *g, struct gesture_event *gevt,
const struct viewport *vp)
{
if (!gesture_is_valid(g))
return false;
gevt->id = g->id;
gevt->x = g->x;
gevt->y = g->y;
gevt->ox = g->ox;
gevt->oy = g->oy;
gevt->start_tick = g->start_tick;
gevt->last_tick = g->last_tick;
if (vp) {
gevt->x -= vp->x;
gevt->y -= vp->y;
gevt->ox -= vp->x;
gevt->oy -= vp->y;
}
return !vp || viewport_point_within_vp(vp, g->ox, g->oy);
}