[PATCH libinput 1/3] Fix scroll-threshold check for edge-scrolling to use normalized coordinates

[Hans de Goede]

The DEFAULT_SCROLL_THRESHOLD value is a TP_MM_TO_DPI_NORMALIZED value and as
such should be compared to a normalized value. But since commit 8101e43774
("touchpad: switch delta handling to typesafe coordinates"), the
initial_dx / initial_dy values initial_delta points to are no longer in
normalized coordinates, as the result of tp_normalize_delta is now stored
into the normalized value.

This commit changes the check to use the delta pointer which does point to
the normalized x/y values. While at it also use the zero variable to
set normalized to zero rather then manually setting x and y to 0.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 src/evdev-mt-touchpad-edge-scroll.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/evdev-mt-touchpad-edge-scroll.c b/src/evdev-mt-touchpad-edge-scroll.c
index 26d6bbc..d304316 100644
--- a/src/evdev-mt-touchpad-edge-scroll.c
+++ b/src/evdev-mt-touchpad-edge-scroll.c
@@ -313,7 +313,7 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
 	struct tp_touch *t;
 	enum libinput_pointer_axis axis;
 	double *delta;
-	double initial_dx, initial_dy, *initial_delta;
+	double initial_dx, initial_dy;
 	struct normalized_coords normalized;
 	const struct normalized_coords zero = { 0.0, 0.0 };
 	const struct discrete_coords zero_discrete = { 0.0, 0.0 };
@@ -340,12 +340,10 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
 			case EDGE_RIGHT:
 				axis = LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL;
 				delta = &normalized.y;
-				initial_delta = &initial_dy;
 				break;
 			case EDGE_BOTTOM:
 				axis = LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL;
 				delta = &normalized.x;
-				initial_delta = &initial_dx;
 				break;
 			default: /* EDGE_RIGHT | EDGE_BOTTOM */
 				continue; /* Don't know direction yet, skip */
@@ -369,10 +367,8 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
 					   initial_dx,
 					   initial_dy,
 					   &normalized);
-			if (fabs(*initial_delta) < DEFAULT_SCROLL_THRESHOLD) {
-				normalized.x = 0.0;
-				normalized.y = 0.0;
-			}
+			if (fabs(*delta) < DEFAULT_SCROLL_THRESHOLD)
+				normalized = zero;
 			break;
 		case EDGE_SCROLL_TOUCH_STATE_EDGE:
 			break;
-- 
2.3.3