Rockbox open source high quality audio player as a Music Player Daemon
mpris
rockbox
mpd
libadwaita
audio
rust
zig
deno
touchscreen: Add gesture velocity helper
Add a helper for computing the motion velocity during a touchscreen press.
Change-Id: I1ef7452ba9815897fd3ec01f8980c89aeef5418f
authored by
Aidan MacDonald
and committed by
Solomon Peachy
bb1e0b48
7aa82321
+76
+62
apps/gesture.c
+62
apps/gesture.c
···
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return !vp || viewport_point_within_vp(vp, g->ox, g->oy);
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}
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/*
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* gesture velocity helper
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*/
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void gesture_vel_reset(struct gesture_vel *gv)
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{
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gv->idx = 0;
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gv->cnt = 0;
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}
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void gesture_vel_process(struct gesture_vel *gv, const struct touchevent *ev)
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{
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if (ev->type != TOUCHEVENT_PRESS &&
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ev->type != TOUCHEVENT_CONTACT)
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return;
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gv->xsamp[gv->idx] = ev->x;
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gv->ysamp[gv->idx] = ev->y;
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gv->tsamp[gv->idx] = ev->tick;
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gv->idx++;
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gv->cnt++;
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if (gv->idx >= ARRAYLEN(gv->xsamp))
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gv->idx = 0;
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}
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bool gesture_vel_get(struct gesture_vel *gv, int *xvel, int *yvel)
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{
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if (gv->cnt <= 1) {
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*xvel = 0;
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*yvel = 0;
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return false;
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}
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int dx = 0, dy = 0, dt = 0;
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size_t n = MIN(gv->cnt, ARRAYLEN(gv->xsamp)) - 1;
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size_t i = gv->cnt < ARRAYLEN(gv->xsamp) ? 0 : gv->idx;
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size_t ip = i + 1;
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while (n-- > 0) {
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if (ip >= ARRAYLEN(gv->xsamp))
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ip = 0;
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dx += gv->xsamp[ip] - gv->xsamp[i];
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dy += gv->ysamp[ip] - gv->ysamp[i];
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dt += gv->tsamp[ip] - gv->tsamp[i];
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i = ip;
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ip++;
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}
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if (dt == 0) {
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*xvel = 0;
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*yvel = 0;
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} else {
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*xvel = dx * HZ / dt;
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*yvel = dy * HZ / dt;
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}
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return gv->cnt >= ARRAYLEN(gv->xsamp);
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}
+14
apps/gesture.h
+14
apps/gesture.h
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return !!(g->flags & GESTURE_F_PRESSED);
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}
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/* Helper for computing velocity vectors */
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struct gesture_vel
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{
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size_t idx;
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size_t cnt;
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short xsamp[4];
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short ysamp[4];
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long tsamp[4];
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};
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void gesture_vel_reset(struct gesture_vel *gv);
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void gesture_vel_process(struct gesture_vel *gv, const struct touchevent *ev);
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bool gesture_vel_get(struct gesture_vel *gv, int *xvel, int *yvel);
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#endif /* _GESTURE_H_ */