53 lines
1.6 KiB
Diff
53 lines
1.6 KiB
Diff
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From f6313a9d010f03a66fd1f68e0bbd5e073101f342 Mon Sep 17 00:00:00 2001
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From: Peter Hutterer <peter.hutterer@who-t.net>
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Date: Thu, 4 Jun 2015 11:40:15 +1000
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Subject: [PATCH libinput] filter: require minimum acceleration factor of 0.3
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For really slow motions, the previous acceleration factor would go down to
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effectively zero. So the slower the mouse motion was, the more it would be
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slowed down which made the mouse at low speeds almost unusable.
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Cap the minimum acceleration at 0.3 which provides a predictable slow motion
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for the cursor when high precision is required.
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New/old acceleration functions comparison:
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^
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| /
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ty| _________/
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| / /
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| / /
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| / /
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|/ / <----- new minimum accel factor
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| /
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|/___________________>
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tx
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i.e. the general shape is maintained, but it doesn't go to zero anymore. The
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functions aren't parallel, the new shape is slightly flatter than the previous
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one and they meet at the point where the functions flatten for the threshold
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(tx/ty). ascii art has its limits...
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Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
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---
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src/filter.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/filter.c b/src/filter.c
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index c54d866..ed5a184 100644
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--- a/src/filter.c
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+++ b/src/filter.c
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@@ -354,7 +354,7 @@ pointer_accel_profile_linear(struct motion_filter *filter,
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const double threshold = accel_filter->threshold; /* units/ms */
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const double incline = accel_filter->incline;
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- s1 = min(1, speed_in * 5);
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+ s1 = min(1, 0.3 + speed_in * 4);
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s2 = 1 + (speed_in - threshold) * incline;
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return min(max_accel, s2 > 1 ? s2 : s1);
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--
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2.4.1
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