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filter: fix constant acceleration for the X230

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The x230 has a special acceleration method that relies on the touchpad magic
slowdown. This was missing from commit c8da19b50a, making two-finger
scroll motions unusably fast

https://bugs.freedesktop.org/show_bug.cgi?id=91819

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Peter Hutterer 2015-08-31 14:05:11 +10:00
parent 58f25a47ed
commit 6a0f9411f2
1 changed files with 23 additions and 10 deletions
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33
src/filter.c
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@ -114,6 +114,8 @@ filter_get_speed(struct motion_filter *filter)
#define X230_THRESHOLD v_ms2us(0.4) /* in units/us */
#define X230_ACCELERATION 2.0 /* unitless factor */
#define X230_INCLINE 1.1 /* unitless factor */
#define X230_MAGIC_SLOWDOWN 0.4 /* unitless */
#define X230_TP_MAGIC_LOW_RES_FACTOR 4.0 /* unitless */
/*
* Pointer acceleration filter constants
@ -420,6 +422,21 @@ accelerator_filter_x230(struct motion_filter *filter,
return accelerated;
}
static struct normalized_coords
accelerator_filter_constant_x230(struct motion_filter *filter,
const struct normalized_coords *unaccelerated,
void *data, uint64_t time)
{
struct normalized_coords normalized;
const double factor =
X230_MAGIC_SLOWDOWN/X230_TP_MAGIC_LOW_RES_FACTOR;
normalized.x = factor * unaccelerated->x;
normalized.y = factor * unaccelerated->y;
return normalized;
}
static struct normalized_coords
touchpad_constant_filter(struct motion_filter *filter,
const struct normalized_coords *unaccelerated,
@ -631,26 +648,22 @@ touchpad_lenovo_x230_accel_profile(struct motion_filter *filter,
double speed_in,
uint64_t time)
{
/* Keep the magic factor from touchpad_accel_profile_linear. */
const double X230_MAGIC_SLOWDOWN = 0.4; /* unitless */
/* Those touchpads presents an actual lower resolution that what is
* advertised. We see some jumps from the cursor due to the big steps
* in X and Y when we are receiving data.
* Apply a factor to minimize those jumps at low speed, and try
* keeping the same feeling as regular touchpads at high speed.
* It still feels slower but it is usable at least */
const double TP_MAGIC_LOW_RES_FACTOR = 4.0; /* unitless */
double factor; /* unitless */
struct pointer_accelerator *accel_filter =
(struct pointer_accelerator *)filter;
double f1, f2; /* unitless */
const double max_accel = accel_filter->accel *
TP_MAGIC_LOW_RES_FACTOR; /* unitless factor */
X230_TP_MAGIC_LOW_RES_FACTOR; /* unitless factor */
const double threshold = accel_filter->threshold /
TP_MAGIC_LOW_RES_FACTOR; /* units/us */
const double incline = accel_filter->incline * TP_MAGIC_LOW_RES_FACTOR;
X230_TP_MAGIC_LOW_RES_FACTOR; /* units/us */
const double incline = accel_filter->incline * X230_TP_MAGIC_LOW_RES_FACTOR;
/* Note: the magic values in this function are obtained by
* trial-and-error. No other meaning should be interpreted.
@ -658,14 +671,14 @@ touchpad_lenovo_x230_accel_profile(struct motion_filter *filter,
* pointer_accel_profile_linear(), look at the git history of that
* function for an explaination of what the min/max/etc. does.
*/
speed_in *= X230_MAGIC_SLOWDOWN / TP_MAGIC_LOW_RES_FACTOR;
speed_in *= X230_MAGIC_SLOWDOWN / X230_TP_MAGIC_LOW_RES_FACTOR;
f1 = min(1, v_us2ms(speed_in) * 5);
f2 = 1 + (v_us2ms(speed_in) - v_us2ms(threshold)) * incline;
factor = min(max_accel, f2 > 1 ? f2 : f1);
return factor * X230_MAGIC_SLOWDOWN / TP_MAGIC_LOW_RES_FACTOR;
return factor * X230_MAGIC_SLOWDOWN / X230_TP_MAGIC_LOW_RES_FACTOR;
}
double
@ -795,7 +808,7 @@ create_pointer_accelerator_filter_touchpad(int dpi)
struct motion_filter_interface accelerator_interface_x230 = {
.filter = accelerator_filter_x230,
.filter_constant = accelerator_filter_noop,
.filter_constant = accelerator_filter_constant_x230,
.restart = accelerator_restart,
.destroy = accelerator_destroy,
.set_speed = accelerator_set_speed,