Add a normalized_length helper function and use this where applicable

Add a normalized_length helper function and use this where applicable,
just a minor cleanup.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/evdev-mt-touchpad-tap.c

@@ -530,15 +530,11 @@ static bool
 tp_tap_exceeds_motion_threshold(struct tp_dispatch *tp,
 				struct tp_touch *t)
 {
-	int threshold = DEFAULT_TAP_MOVE_THRESHOLD;
-	struct normalized_coords normalized;
+	struct normalized_coords norm =
+		tp_normalize_delta(tp, device_delta(t->point,
+						    t->tap.initial));
 
-	normalized = tp_normalize_delta(tp,
-					device_delta(t->point,
-						     t->tap.initial));
-
-	return normalized.x * normalized.x + normalized.y * normalized.y
-			> threshold * threshold;
+	return normalized_length(norm) > DEFAULT_TAP_MOVE_THRESHOLD;
 }
 
 static bool

src/filter.c

@@ -137,11 +137,9 @@ tracker_by_offset(struct pointer_accelerator *accel, unsigned int offset)
 static double
 calculate_tracker_velocity(struct pointer_tracker *tracker, uint64_t time)
 {
-	double distance;
 	double tdelta = time - tracker->time + 1;
 
-	distance = hypot(tracker->delta.x, tracker->delta.y);
-	return distance / tdelta; /* units/ms */
+	return normalized_length(tracker->delta) / tdelta; /* units/ms */
 }
 
 static double

src/libinput-private.h

@@ -24,6 +24,7 @@
 #define LIBINPUT_PRIVATE_H
 
 #include <errno.h>
+#include <math.h>
 
 #include "linux/input.h"
 
@@ -373,4 +374,10 @@ device_delta(struct device_coords a, struct device_coords b)
 	return delta;
 }
 
+static inline double
+normalized_length(struct normalized_coords norm)
+{
+	return hypot(norm.x, norm.y);
+}
+
 #endif /* LIBINPUT_PRIVATE_H */