[PATCH libinput 02/13] filter: drop the dpi_factor in favor of direct calculation

[Peter Hutterer]

This was badly since the factor was the ratio of "dpi:default dpi"

Most devices don't need it, so storing it in all filters event though we only
use it for some devices is confusing. Now that we have the dpi stored
directlyconfusing. Now that we have the dpi stored directly we might as well
use that.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/filter.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/src/filter.c b/src/filter.c
index eecf4ca..06f07af 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -153,7 +153,6 @@ struct pointer_accelerator {
 	double accel;		/* unitless factor */
 	double incline;		/* incline of the function */
 
-	double dpi_factor;
 	int dpi;
 };
 
@@ -161,7 +160,6 @@ struct pointer_accelerator_flat {
 	struct motion_filter base;
 
 	double factor;
-	double dpi_factor;
 	int dpi;
 };
 
@@ -382,7 +380,7 @@ accelerator_filter_low_dpi(struct motion_filter *filter,
 	double accel_value; /* unitless factor */
 	struct normalized_coords accelerated;
 	struct normalized_coords unnormalized;
-	double dpi_factor = accel->dpi_factor;
+	double dpi_factor = accel->dpi/(double)DEFAULT_MOUSE_DPI;
 
 	/* For low-dpi mice, use device units, everything else uses
 	   1000dpi normalized */
@@ -411,7 +409,7 @@ accelerator_filter_trackpoint(struct motion_filter *filter,
 	double accel_value; /* unitless factor */
 	struct normalized_coords accelerated;
 	struct normalized_coords unnormalized;
-	double dpi_factor = accel->dpi_factor;
+	double dpi_factor = accel->dpi/(double)DEFAULT_MOUSE_DPI;
 
 	/* trackpoints with a dpi factor have a const accel set, remove that
 	 * and restore device units. The accel profile takes const accel
@@ -568,8 +566,8 @@ pointer_accel_profile_linear_low_dpi(struct motion_filter *filter,
 	double max_accel = accel_filter->accel; /* unitless factor */
 	double threshold = accel_filter->threshold; /* units/us */
 	const double incline = accel_filter->incline;
+	double dpi_factor = accel_filter->dpi/(double)DEFAULT_MOUSE_DPI;
 	double factor; /* unitless */
-	double dpi_factor = accel_filter->dpi_factor;
 
 	/* dpi_factor is always < 1.0, increase max_accel, reduce
 	   the threshold so it kicks in earlier */
@@ -727,8 +725,8 @@ trackpoint_accel_profile(struct motion_filter *filter,
 	double max_accel = accel_filter->accel; /* unitless factor */
 	double threshold = accel_filter->threshold; /* units/ms */
 	const double incline = accel_filter->incline;
+	double dpi_factor = accel_filter->dpi/(double)DEFAULT_MOUSE_DPI;
 	double factor;
-	double dpi_factor = accel_filter->dpi_factor;
 
 	/* dpi_factor is always < 1.0, increase max_accel, reduce
 	   the threshold so it kicks in earlier */
@@ -775,8 +773,6 @@ create_default_filter(int dpi)
 	filter->threshold = DEFAULT_THRESHOLD;
 	filter->accel = DEFAULT_ACCELERATION;
 	filter->incline = DEFAULT_INCLINE;
-
-	filter->dpi_factor = dpi/(double)DEFAULT_MOUSE_DPI;
 	filter->dpi = dpi;
 
 	return filter;
@@ -878,8 +874,6 @@ create_pointer_accelerator_filter_lenovo_x230(int dpi)
 	filter->threshold = X230_THRESHOLD;
 	filter->accel = X230_ACCELERATION; /* unitless factor */
 	filter->incline = X230_INCLINE; /* incline of the acceleration function */
-
-	filter->dpi_factor = 1; /* unused for this accel method */
 	filter->dpi = dpi;
 
 	return &filter->base;
@@ -923,11 +917,12 @@ accelerator_filter_flat(struct motion_filter *filter,
 	double factor; /* unitless factor */
 	struct normalized_coords accelerated;
 	struct normalized_coords unnormalized;
+	double dpi_factor = accel_filter->dpi/(double)DEFAULT_MOUSE_DPI;
 
 	/* You want flat acceleration, you get flat acceleration for the
 	 * device */
-	unnormalized.x = unaccelerated->x * accel_filter->dpi_factor;
-	unnormalized.y = unaccelerated->y * accel_filter->dpi_factor;
+	unnormalized.x = unaccelerated->x * dpi_factor;
+	unnormalized.y = unaccelerated->y * dpi_factor;
 	factor = accel_filter->factor;
 
 	accelerated.x = factor * unnormalized.x;
@@ -984,7 +979,6 @@ create_pointer_accelerator_filter_flat(int dpi)
 		return NULL;
 
 	filter->base.interface = &accelerator_interface_flat;
-	filter->dpi_factor = dpi/(double)DEFAULT_MOUSE_DPI;
 	filter->dpi = dpi;
 
 	return &filter->base;
-- 
2.9.3