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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
