[PATCH] don't interpolate movement on finger-change.

[Florian Loitsch]

---
 drivers/usb/input/appletouch.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/input/appletouch.c b/drivers/usb/input/appletouch.c
index c77291d..7ffe8e7 100644
--- a/drivers/usb/input/appletouch.c
+++ b/drivers/usb/input/appletouch.c
@@ -147,6 +147,7 @@ struct atp {
 	int			valid;		/* are the sensors valid ? */
 	int			x_old;		/* last reported x/y, */
 	int			y_old;		/* used for smoothing */
+	int			fingers_old;	/* used for smoothing too */
 						/* current value of the sensors */
 	signed char		xy_cur[ATP_XSENSORS + ATP_YSENSORS];
 						/* last value of the sensors */
@@ -275,7 +276,7 @@ static inline void atp_report_fingers(struct input_dev 
*input, int fingers)
 
 static void atp_complete(struct urb* urb)
 {
-	int x, y, x_z, y_z, x_f, y_f;
+	int x, y, x_z, y_z, x_f, y_f, fingers;
 	int retval, i, j;
 	struct atp *dev = urb->context;
 
@@ -371,7 +372,7 @@ static void atp_complete(struct urb* urb)
 	if (!dev->valid) {
 		/* first sample */
 		dev->valid = 1;
-		dev->x_old = dev->y_old = -1;
+		dev->fingers_old = dev->x_old = dev->y_old = -1;
 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
 
 		if (atp_is_geyser_3(dev)) /* No 17" Macbooks (yet) */
@@ -418,12 +419,13 @@ static void atp_complete(struct urb* urb)
 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
 			      ATP_YFACT, &y_z, &y_f);
 
+	fingers = max(x_f, y_f);
 	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 (fingers == dev->fingers_old) {
+				x = (dev->x_old * 3 + x) >> 2;
+				y = (dev->y_old * 3 + y) >> 2;
+			}
 
 			if (debug > 1)
 				printk("appletouch: X: %3d Y: %3d "
@@ -435,8 +437,9 @@ static void atp_complete(struct urb* urb)
 			input_report_abs(dev->input, ABS_Y, y);
 			input_report_abs(dev->input, ABS_PRESSURE,
 					 min(ATP_PRESSURE, x_z + y_z));
-			atp_report_fingers(dev->input, max(x_f, y_f));
+			atp_report_fingers(dev->input, fingers);
 		}
+		dev->fingers_old = fingers;
 		dev->x_old = x;
 		dev->y_old = y;
 	}
-- 
1.5.1