The scroll and zoom gestures use of how far the fingers have travelled
as a way to determine how many times to send the scroll/zoom event.
When a gesture first starts, however, the fingers have already moved a
large distance simply to have the gesture be recognized. This may cause
a rapid and undesired "catch up" effect due to the large built-up delta.
To work around this, when a gesture starts, we reset the wcmGestureState
so that the functions are working with a clean slate and do not see the
large delta.
Signed-off-by: Jason Gerecke <killert...@gmail.com>
---
src/wcmTouchFilter.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/src/wcmTouchFilter.c b/src/wcmTouchFilter.c
index 3062cde..e945a9d 100644
--- a/src/wcmTouchFilter.c
+++ b/src/wcmTouchFilter.c
@@ -616,6 +616,7 @@ static void wcmFingerScroll(WacomDevicePtr priv)
int i = 0, dist = 0;
WacomFilterState filterd; /* borrow this struct */
int max_spread = common->wcmGestureParameters.wcmMaxScrollFingerSpread;
+ int gestureStart = 0;
if (!common->wcmGesture)
return;
@@ -640,6 +641,7 @@ static void wcmFingerScroll(WacomDevicePtr priv)
/* left button might be down. Send it up first
*/
wcmSendButtonClick(priv, 1, 0);
common->wcmGestureMode = GESTURE_SCROLL_MODE;
+ gestureStart = 1;
}
}
}
@@ -648,6 +650,13 @@ static void wcmFingerScroll(WacomDevicePtr priv)
if (common->wcmGestureMode != GESTURE_SCROLL_MODE)
return;
+ /* forget history leading up to the beginning of the gesture */
+ if (gestureStart)
+ {
+ common->wcmGestureState[0] = ds[0];
+ common->wcmGestureState[1] = ds[1];
+ }
+
/* initialize the points so we can rotate them */
filterd.x[0] = ds[0].x;
filterd.y[0] = ds[0].y;
@@ -713,9 +722,9 @@ static void wcmFingerZoom(WacomDevicePtr priv)
WacomCommonPtr common = priv->common;
WacomDeviceState ds[2] = {};
int count, button;
- int dist = touchDistance(common->wcmGestureState[0],
- common->wcmGestureState[1]);
+ int dist;
int max_spread = common->wcmGestureParameters.wcmMaxScrollFingerSpread;
+ int gestureStart = 0;
if (!common->wcmGesture)
return;
@@ -738,13 +747,21 @@ static void wcmFingerZoom(WacomDevicePtr priv)
/* fingers moved apart more than 3 times
* wcmMaxScrollFingerSpread, zoom mode is entered */
common->wcmGestureMode = GESTURE_ZOOM_MODE;
+ gestureStart = 1;
}
}
if (common->wcmGestureMode != GESTURE_ZOOM_MODE)
return;
- dist = touchDistance(ds[0], ds[1]) - dist;
+ /* forget history leading up to the beginning of the gesture */
+ if (gestureStart)
+ {
+ common->wcmGestureState[0] = ds[0];
+ common->wcmGestureState[1] = ds[1];
+ }
+
+ dist = touchDistance(ds[0], ds[1]) -
touchDistance(common->wcmGestureState[0], common->wcmGestureState[1]);
count = (int)((1.0 *
abs(dist)/common->wcmGestureParameters.wcmZoomDistance) + 0.5);
/* user might have changed from left to right or vice versa */
--
2.1.0
------------------------------------------------------------------------------
Slashdot TV. Video for Nerds. Stuff that Matters.
http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk
_______________________________________________
Linuxwacom-devel mailing list
Linuxwacom-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
