diff options
| author | Peter Hutterer <peter.hutterer@who-t.net> | 2014-07-08 11:45:36 +1000 |
|---|---|---|
| committer | Peter Hutterer <peter.hutterer@who-t.net> | 2014-07-09 12:48:44 +1000 |
| commit | 066092a04fd2a9419c392575cd1675d91c550d8c (patch) | |
| tree | 6f2795a2e81972517fedc58b57367e78f6fa48fa | |
| parent | 289949d0c43e4753ecc77ee05ee2092c893f7941 (diff) | |
| download | libinput-066092a04fd2a9419c392575cd1675d91c550d8c.tar.gz | |
filter: annotate the various variables we have with units
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
| -rw-r--r-- | src/filter.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/src/filter.c b/src/filter.c index 6fbd4d91..7db78bae 100644 --- a/src/filter.c +++ b/src/filter.c @@ -51,22 +51,22 @@ filter_destroy(struct motion_filter *filter) * Default parameters for pointer acceleration profiles. */ -#define DEFAULT_CONSTANT_ACCELERATION 10.0 -#define DEFAULT_THRESHOLD 4.0 -#define DEFAULT_ACCELERATION 2.0 +#define DEFAULT_CONSTANT_ACCELERATION 10.0 /* unitless factor */ +#define DEFAULT_THRESHOLD 4.0 /* in units/ms */ +#define DEFAULT_ACCELERATION 2.0 /* unitless factor */ /* * Pointer acceleration filter constants */ -#define MAX_VELOCITY_DIFF 1.0 +#define MAX_VELOCITY_DIFF 1.0 /* units/ms */ #define MOTION_TIMEOUT 300 /* (ms) */ #define NUM_POINTER_TRACKERS 16 struct pointer_tracker { - double dx; - double dy; - uint64_t time; + double dx; /* delta to most recent event, in device units */ + double dy; /* delta to most recent event, in device units */ + uint64_t time; /* ms */ int dir; }; @@ -76,10 +76,10 @@ struct pointer_accelerator { accel_profile_func_t profile; - double velocity; - double last_velocity; - int last_dx; - int last_dy; + double velocity; /* units/ms */ + double last_velocity; /* units/ms */ + int last_dx; /* device units */ + int last_dy; /* device units */ struct pointer_tracker *trackers; int cur_tracker; @@ -183,7 +183,7 @@ calculate_tracker_velocity(struct pointer_tracker *tracker, uint64_t time) dx = tracker->dx; dy = tracker->dy; distance = sqrt(dx*dx + dy*dy); - return distance / (double)(time - tracker->time); + return distance / (double)(time - tracker->time); /* units/ms */ } static double @@ -227,7 +227,7 @@ calculate_velocity(struct pointer_accelerator *accel, uint64_t time) } } - return result; + return result; /* units/ms */ } static double @@ -254,7 +254,7 @@ calculate_acceleration(struct pointer_accelerator *accel, factor = factor / 6.0; - return factor; + return factor; /* unitless factor */ } static void @@ -264,8 +264,8 @@ accelerator_filter(struct motion_filter *filter, { struct pointer_accelerator *accel = (struct pointer_accelerator *) filter; - double velocity; - double accel_value; + double velocity; /* units/ms */ + double accel_value; /* unitless factor */ feed_trackers(accel, motion->dx, motion->dy, time); velocity = calculate_velocity(accel, time); @@ -329,12 +329,12 @@ calc_penumbral_gradient(double x) double pointer_accel_profile_smooth_simple(struct motion_filter *filter, void *data, - double velocity, + double velocity, /* units/ms */ uint64_t time) { - double threshold = DEFAULT_THRESHOLD; - double accel = DEFAULT_ACCELERATION; - double smooth_accel_coefficient; + double threshold = DEFAULT_THRESHOLD; /* units/ms */ + double accel = DEFAULT_ACCELERATION; /* unitless factor */ + double smooth_accel_coefficient; /* unitless factor */ if (threshold < 1.0) threshold = 1.0; |