Implements a new algorithm used to smooth cursor
movement, using a sampling of the cursor's last three
positions to modulate the next cursor movement. This
further mitigates the 'stepping' users see when moving
the cursor diagonally. A 'legacy' module parameter has
been added in case the older devices do not like the
new algorithm.
Signed-off-by: Clinton Sprain <clintonsprain@xxxxxxxxx>
---
drivers/input/mouse/appletouch.c | 99 ++++++++++++++++++++++++++++++++------
1 file changed, 83 insertions(+), 16 deletions(-)
diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c
index f5a16ee..4a3bbcd 100644
--- a/drivers/input/mouse/appletouch.c
+++ b/drivers/input/mouse/appletouch.c
@@ -209,13 +209,16 @@ struct atp {
bool overflow_warned;
int x_old; /* last reported x/y, */
int y_old; /* used for smoothing */
+ int x_older; /* 2nd to last reported x/y,*/
+ int y_older; /* used for smoothing */
+ int x_oldest; /* 3rd to last reported x/y,*/
+ int y_oldest; /* used for smoothing */
signed char xy_cur[ATP_XSENSORS + ATP_YSENSORS];
signed char xy_old[ATP_XSENSORS + ATP_YSENSORS];
int xy_acc[ATP_XSENSORS + ATP_YSENSORS];
int idlecount; /* number of empty packets */
struct work_struct work;
};
-
#define dbg_dump(msg, tab) \
{ \
if (debug > 1) { \
@@ -260,6 +263,13 @@ static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Activate debugging output");
+static int legacy;
+module_param(legacy, int, 0644);
+MODULE_PARM_DESC(legacy, "1 = Use old cursor movement smoothing."
+ " Older behavior averages current with"
+ " last cursor position. New behavior"
+ " uses cursor movement inertia.");
+
/*
* By default newer Geyser devices send standard USB HID mouse
* packets (Report ID 2). This code changes device mode, so it
@@ -338,6 +348,49 @@ static void atp_reinit(struct work_struct *work)
retval);
}
+static int atp_smooth_legacy(int curr, int old)
+{
+ return (old * 3 + curr) >> 2;
+}
+
+static int atp_smooth(int curr, int old, int older, int oldest)
+{
+ return (oldest + older * 2 + old * 4 + curr) >> 3;
+}
+
+static void atp_refresh_old_xy(int x, int y, struct atp *dev)
+{
+ if (legacy != true) {
+ dev->x_oldest = dev->x_older;
+ dev->y_oldest = dev->y_older;
+ dev->x_older = dev->x_old;
+ dev->y_older = dev->y_old;
+ }
+ dev->x_old = x;
+ dev->y_old = y;
+}
+
+static void atp_reset_old_xy(struct atp *dev)
+{
+ if (legacy != true) {
+ dev->x_oldest = dev->y_oldest = -1;
+ dev->x_older = dev->y_older = -1;
+ }
+ dev->x_old = dev->y_old = -1;
+}
+
+static void atp_default_old_xy(struct atp *dev)
+{
+ if (dev->x_older == -1)
+ dev->x_older = dev->x_old;
+ if (dev->y_older == -1)
+ dev->y_older = dev->y_old;
+ if (dev->x_oldest == -1)
+ dev->x_oldest = dev->x_older;
+ if (dev->y_oldest == -1)
+ dev->y_oldest = dev->y_older;
+}
+
static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
int *z, int *fingers)
{
@@ -570,10 +623,18 @@ static void atp_complete_geyser_1_2(struct urb *urb)
if (x && y) {
if (dev->x_old != -1) {
- x = (dev->x_old * 3 + x) >> 2;
- y = (dev->y_old * 3 + y) >> 2;
- dev->x_old = x;
- dev->y_old = y;
+ if (legacy == true) {
+ x = atp_smooth_legacy(x, dev->x_old);
+ y = atp_smooth_legacy(y, dev->y_old);
+ } else {
+
+ atp_default_old_xy(dev);
+
+ x = atp_smooth(x, dev->x_old,
+ dev->x_older, dev->x_oldest);
+ y = atp_smooth(y, dev->y_old,
+ dev->y_older, dev->y_oldest);
+ }
if (debug > 1)
printk(KERN_DEBUG "appletouch: "
@@ -587,12 +648,11 @@ static void atp_complete_geyser_1_2(struct urb *urb)
min(ATP_PRESSURE, x_z + y_z));
atp_report_fingers(dev->input, max(x_f, y_f));
}
- dev->x_old = x;
- dev->y_old = y;
+ atp_refresh_old_xy(x, y, dev);
} else if (!x && !y) {
- dev->x_old = dev->y_old = -1;
+ atp_reset_old_xy(dev);
input_report_key(dev->input, BTN_TOUCH, 0);
input_report_abs(dev->input, ABS_PRESSURE, 0);
atp_report_fingers(dev->input, 0);
@@ -682,10 +742,18 @@ static void atp_complete_geyser_3_4(struct urb *urb)
if (x && y) {
if (dev->x_old != -1) {
- x = (dev->x_old * 3 + x) >> 2;
- y = (dev->y_old * 3 + y) >> 2;
- dev->x_old = x;
- dev->y_old = y;
+ if (legacy == true) {
+ x = atp_smooth_legacy(x, dev->x_old);
+ y = atp_smooth_legacy(y, dev->y_old);
+ } else {
+
+ atp_default_old_xy(dev);
+
+ x = atp_smooth(x, dev->x_old,
+ dev->x_older, dev->x_oldest);
+ y = atp_smooth(y, dev->y_old,
+ dev->y_older, dev->y_oldest);
+ }
if (debug > 1)
printk(KERN_DEBUG "appletouch: X: %3d Y: %3d "
@@ -699,12 +767,11 @@ static void atp_complete_geyser_3_4(struct urb *urb)
min(ATP_PRESSURE, x_z + y_z));
atp_report_fingers(dev->input, max(x_f, y_f));
}
- dev->x_old = x;
- dev->y_old = y;
+ atp_refresh_old_xy(x, y, dev);
} else if (!x && !y) {
- dev->x_old = dev->y_old = -1;
+ atp_reset_old_xy(dev);
input_report_key(dev->input, BTN_TOUCH, 0);
input_report_abs(dev->input, ABS_PRESSURE, 0);
atp_report_fingers(dev->input, 0);
@@ -730,7 +797,7 @@ static void atp_complete_geyser_3_4(struct urb *urb)
if (!x && !y && !key) {
dev->idlecount++;
if (dev->idlecount == 10) {
- dev->x_old = dev->y_old = -1;
+ atp_reset_old_xy(dev);
dev->idlecount = 0;
schedule_work(&dev->work);
/* Don't resubmit urb here, wait for reinit */
--
1.7.9.5
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