Remove the strong hysteresis filter.

It seems that the filter is obsolete, the default method is sufficient.
Simplify and clean up some related code in wsmouse.

ok mpi@

4 files changed, 36 insertions, 86 deletions

diff --git a/sys/dev/wscons/wsconsio.h b/sys/dev/wscons/wsconsio.h
index 64478d4efd9..97803143bc3 100644
--- a/sys/dev/wscons/wsconsio.h
+++ b/sys/dev/wscons/wsconsio.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsconsio.h,v 1.89 2018/07/30 15:56:30 jcs Exp $ */
+/* $OpenBSD: wsconsio.h,v 1.90 2018/11/10 14:27:51 bru Exp $ */
 /* $NetBSD: wsconsio.h,v 1.74 2005/04/28 07:15:44 martin Exp $ */
 
 /*
@@ -295,7 +295,8 @@ enum wsmousecfg {
 	WSMOUSECFG_X_HYSTERESIS,/* retard value for X coordinates */
 	WSMOUSECFG_Y_HYSTERESIS,/* retard value for Y coordinates */
 	WSMOUSECFG_DECELERATION,/* threshold (distance) for deceleration */
-	WSMOUSECFG_STRONG_HYSTERESIS,	/* apply the filter continuously */
+	WSMOUSECFG_STRONG_HYSTERESIS,	/* FALSE and read-only, the fea-
+					   ture is not supported anymore. */
 	WSMOUSECFG_SMOOTHING,	/* smoothing factor (0-7) */
 
 	/*
diff --git a/sys/dev/wscons/wsmouse.c b/sys/dev/wscons/wsmouse.c
index be654aa7ab8..9f3a34fa93a 100644
--- a/sys/dev/wscons/wsmouse.c
+++ b/sys/dev/wscons/wsmouse.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsmouse.c,v 1.45 2018/05/07 21:58:42 bru Exp $ */
+/* $OpenBSD: wsmouse.c,v 1.46 2018/11/10 14:27:51 bru Exp $ */
 /* $NetBSD: wsmouse.c,v 1.35 2005/02/27 00:27:52 perry Exp $ */
 
 /*
@@ -625,7 +625,10 @@ set_x(struct position *pos, int x, u_int *sync, u_int mask)
 	}
 	if ((pos->dx = x - pos->x)) {
 		pos->x = x;
-		pos->acc_dx += pos->dx;
+		if (pos->dx > 0 == pos->acc_dx > 0)
+			pos->acc_dx += pos->dx;
+		else
+			pos->acc_dx = pos->dx;
 		*sync |= mask;
 	}
 }
@@ -641,7 +644,10 @@ set_y(struct position *pos, int y, u_int *sync, u_int mask)
 	}
 	if ((pos->dy = y - pos->y)) {
 		pos->y = y;
-		pos->acc_dy += pos->dy;
+		if (pos->dy > 0 == pos->acc_dy > 0)
+			pos->acc_dy += pos->dy;
+		else
+			pos->acc_dy = pos->dy;
 		*sync |= mask;
 	}
 }
@@ -704,7 +710,6 @@ wsmouse_mtstate(struct device *sc, int slot, int x, int y, int pressure)
 	struct mt_state *mt = &input->mt;
 	struct mt_slot *mts;
 	u_int bit;
-	int initial;
 
 	if (slot < 0 || slot >= mt->num_slots)
 		return;
@@ -712,24 +717,17 @@ wsmouse_mtstate(struct device *sc, int slot, int x, int y, int pressure)
 	bit = (1 << slot);
 	mt->frame |= bit;
 
-	/* Is this a new touch? */
-	initial = ((mt->touches & bit) == (mt->sync[MTS_TOUCH] & bit));
-
 	mts = &mt->slots[slot];
 
-	if (initial) {
-		mts->pos.x = x;
-		mts->pos.y = y;
+	set_x(&mts->pos, x, mt->sync + MTS_X, bit);
+	set_y(&mts->pos, y, mt->sync + MTS_Y, bit);
+
+	/* Is this a new touch? */
+	if ((mt->touches & bit) == (mt->sync[MTS_TOUCH] & bit))
 		cleardeltas(&mts->pos);
-		mt->sync[MTS_X] |= bit;
-		mt->sync[MTS_Y] |= bit;
-	} else {
-		set_x(&mts->pos, x, mt->sync + MTS_X, bit);
-		set_y(&mts->pos, y, mt->sync + MTS_Y, bit);
-	}
 
 	pressure = normalized_pressure(input, pressure);
-	if (pressure != mts->pressure || initial) {
+	if (pressure != mts->pressure) {
 		mts->pressure = pressure;
 		mt->sync[MTS_PRESSURE] |= bit;
 
@@ -738,6 +736,9 @@ wsmouse_mtstate(struct device *sc, int slot, int x, int y, int pressure)
 				mt->num_touches++;
 				mt->touches |= bit;
 				mt->sync[MTS_TOUCH] |= bit;
+
+				mt->sync[MTS_X] |= bit;
+				mt->sync[MTS_Y] |= bit;
 			}
 		} else if (mt->touches & bit) {
 			mt->num_touches--;
@@ -850,7 +851,7 @@ wsmouse_mt_update(struct wsmouseinput *input)
 	 * (pressure == 0). Clear the sync flags for touches that have
 	 * been released.
 	 */
-	if (input->mt.sync[MTS_TOUCH] & ~input->mt.touches) {
+	if (input->mt.frame & ~input->mt.touches) {
 		for (i = MTS_X; i < MTS_SIZE; i++)
 			input->mt.sync[i] &= input->mt.touches;
 	}
@@ -860,18 +861,6 @@ wsmouse_mt_update(struct wsmouseinput *input)
 int
 wsmouse_hysteresis(struct wsmouseinput *input, struct position *pos)
 {
-
-	if (!(input->filter.h.hysteresis && input->filter.v.hysteresis))
-		return (0);
-
-	if ((pos->dx > 0 && pos->dx > pos->acc_dx)
-	   || (pos->dx < 0 && pos->dx < pos->acc_dx))
-		pos->acc_dx = pos->dx;
-
-	if ((pos->dy > 0 && pos->dy > pos->acc_dy)
-	   || (pos->dy < 0 && pos->dy < pos->acc_dy))
-		pos->acc_dy = pos->dy;
-
 	return (abs(pos->acc_dx) < input->filter.h.hysteresis
 	    && abs(pos->acc_dy) < input->filter.v.hysteresis);
 }
@@ -896,6 +885,14 @@ wsmouse_ptr_ctrl(struct wsmouseinput *input)
 	u_int updates;
 	int select, slot;
 
+	mt->prev_ptr = mt->ptr;
+
+	if (mt->num_touches <= 1) {
+		mt->ptr = mt->touches;
+		mt->ptr_cycle = mt->ptr;
+		return;
+	}
+
 	updates = (mt->sync[MTS_X] | mt->sync[MTS_Y]) & ~mt->sync[MTS_TOUCH];
 	FOREACHBIT(updates, slot) {
 		/*
@@ -907,14 +904,6 @@ wsmouse_ptr_ctrl(struct wsmouseinput *input)
 			updates ^= (1 << slot);
 	}
 
-	mt->prev_ptr = mt->ptr;
-
-	if (mt->num_touches <= 1) {
-		mt->ptr = mt->touches;
-		mt->ptr_cycle = mt->ptr;
-		return;
-	}
-
 	/*
 	 * If there is no pointer-controlling slot, or if it should be
 	 * masked, select a new one.
@@ -1489,8 +1478,7 @@ wsmouse_get_params(struct device *sc,
 			params[i].value = input->filter.dclr;
 			break;
 		case WSMOUSECFG_STRONG_HYSTERESIS:
-			params[i].value =
-			    !!(input->filter.mode & STRONG_HYSTERESIS);
+			params[i].value = 0; /* The feature has been removed. */
 			break;
 		case WSMOUSECFG_SMOOTHING:
 			params[i].value =
@@ -1570,12 +1558,6 @@ wsmouse_set_params(struct device *sc,
 		case WSMOUSECFG_DY_MAX:
 			input->filter.v.dmax = val;
 			break;
-		case WSMOUSECFG_STRONG_HYSTERESIS:
-			if (val)
-				input->filter.mode |= STRONG_HYSTERESIS;
-			else
-				input->filter.mode &= ~STRONG_HYSTERESIS;
-			break;
 		case WSMOUSECFG_SMOOTHING:
 			input->filter.mode &= ~SMOOTHING_MASK;
 			input->filter.mode |= (val & SMOOTHING_MASK);
diff --git a/sys/dev/wscons/wsmouseinput.h b/sys/dev/wscons/wsmouseinput.h
index e4735fc970a..68231755012 100644
--- a/sys/dev/wscons/wsmouseinput.h
+++ b/sys/dev/wscons/wsmouseinput.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsmouseinput.h,v 1.11 2018/05/07 21:58:42 bru Exp $ */
+/* $OpenBSD: wsmouseinput.h,v 1.12 2018/11/10 14:27:51 bru Exp $ */
 
 /*
  * Copyright (c) 2015, 2016 Ulf Brosziewski
@@ -167,11 +167,9 @@ struct wsmouseinput {
 #define LOG_INPUT		(1 << 19)
 #define LOG_EVENTS		(1 << 20)
 
-/* filter.mode (bit 0-2: smoothing factor, bit 3: hysteresis type) */
-#define WEAK_HYSTERESIS		0
-#define STRONG_HYSTERESIS	(1 << 3)
+/* filter.mode (bit 0-2: smoothing factor, bit 3-n: unused) */
 #define SMOOTHING_MASK		7
-#define FILTER_MODE_DEFAULT	WEAK_HYSTERESIS
+#define FILTER_MODE_DEFAULT	0
 
 struct evq_access {
 	struct wseventvar *evar;
diff --git a/sys/dev/wscons/wstpad.c b/sys/dev/wscons/wstpad.c
index d4c9cb474d8..9ed1887b400 100644
--- a/sys/dev/wscons/wstpad.c
+++ b/sys/dev/wscons/wstpad.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wstpad.c,v 1.18 2018/11/05 23:38:04 bru Exp $ */
+/* $OpenBSD: wstpad.c,v 1.19 2018/11/10 14:27:51 bru Exp $ */
 
 /*
  * Copyright (c) 2015, 2016 Ulf Brosziewski
@@ -1219,33 +1219,6 @@ wstpad_decelerate(struct wsmouseinput *input, int *dx, int *dy)
 	return (0);
 }
 
-/*
- * The hysteresis filter may suppress noise and accidental pointer
- * movements.  The "strong" variant applies independently to the axes,
- * and it is applied continuously.  It takes effect whenever the
- * orientation on an axis changes, which makes pointer paths more stable.
- *
- * The default variant, wsmouse_hysteresis, is more precise and does not
- * affect paths, it just filters noise when a touch starts or is resting.
- */
-static inline void
-strong_hysteresis(int *delta, int *acc, int threshold)
-{
-	int d;
-
-	if (*delta > 0) {
-		if (*delta > *acc)
-			*acc = *delta;
-		if ((d = *acc - threshold) < *delta)
-			*delta = (d < 0 ? 0 : d);
-	} else if (*delta < 0) {
-		if (*delta < *acc)
-			*acc = *delta;
-		if ((d = *acc + threshold) > *delta)
-			*delta = (d > 0 ? 0 : d);
-	}
-}
-
 void
 wstpad_filter(struct wsmouseinput *input)
 {
@@ -1263,12 +1236,8 @@ wstpad_filter(struct wsmouseinput *input)
 	dx = pos->dx;
 	dy = pos->dy;
 
-	if (input->filter.mode & STRONG_HYSTERESIS) {
-		strong_hysteresis(&dx, &pos->acc_dx, h->hysteresis);
-		strong_hysteresis(&dy, &pos->acc_dy, v->hysteresis);
-	} else if (wsmouse_hysteresis(input, pos)) {
+	if (wsmouse_hysteresis(input, pos))
 		dx = dy = 0;
-	}
 
 	if (input->filter.dclr && wstpad_decelerate(input, &dx, &dy))
 		/* Strong smoothing may hamper the precision at low speeds. */