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Improve internal algorithm for SwipeGesture

Browse source 
but still under question
This commit is contained in:
Pavel fljot 2012-07-11 22:47:55 +03:00
parent 850ed9849f
commit 4a8e6feada
1 changed files with 21 additions and 19 deletions
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40
src/org/gestouch/gestures/SwipeGesture.as
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@ -1,5 +1,6 @@
package org.gestouch.gestures package org.gestouch.gestures
{ {
import org.gestouch.utils.GestureUtils;
import org.gestouch.core.GestureState; import org.gestouch.core.GestureState;
import org.gestouch.core.Touch; import org.gestouch.core.Touch;
import org.gestouch.events.SwipeGestureEvent; import org.gestouch.events.SwipeGestureEvent;
@ -20,12 +21,13 @@ package org.gestouch.gestures
*/ */
public class SwipeGesture extends Gesture public class SwipeGesture extends Gesture
{ {
private static const ANGLE:Number = 30 * GestureUtils.DEGREES_TO_RADIANS;
public var slop:Number = Gesture.DEFAULT_SLOP; public var slop:Number = Gesture.DEFAULT_SLOP;
public var numTouchesRequired:uint = 1; public var numTouchesRequired:uint = 1;
public var minVelocity:Number = 0.8; public var minVelocity:Number = 0.6;
public var minOffset:Number = Gesture.DEFAULT_SLOP; public var minOffset:Number = Gesture.DEFAULT_SLOP;
public var direction:uint = SwipeGestureDirection.ORTHOGONAL; public var direction:uint = SwipeGestureDirection.ORTHOGONAL;
public var maxDirectionalOffset:Number = Gesture.DEFAULT_SLOP << 1;
protected var _offset:Point = new Point(); protected var _offset:Point = new Point();
protected var _startTime:int; protected var _startTime:int;
@ -103,6 +105,10 @@ package org.gestouch.gestures
if (touchesCount < numTouchesRequired) if (touchesCount < numTouchesRequired)
return; return;
var totalTime:int = touch.time - _startTime;
if (totalTime == 0)
return;//It was somehow THAT MUCH performant on one Android tablet
var prevCentralPointX:Number = _centralPoint.x; var prevCentralPointX:Number = _centralPoint.x;
var prevCentralPointY:Number = _centralPoint.y; var prevCentralPointY:Number = _centralPoint.y;
updateCentralPoint(); updateCentralPoint();
@ -110,28 +116,27 @@ package org.gestouch.gestures
_offset.x = _centralPoint.x - _location.x; _offset.x = _centralPoint.x - _location.x;
_offset.y = _centralPoint.y - _location.y; _offset.y = _centralPoint.y - _location.y;
var offsetLength:Number = _offset.length; var offsetLength:Number = _offset.length;
if (offsetLength < slop) if (offsetLength < slop)
{ {
// no need in processing - we're in the very beginning of movement // no need in processing yet - we're in the very beginning of movement
return; return;
} }
// average velocity (total offset to total duration) // average velocity (total offset to total duration)
_prevAvrgVel.x = _avrgVel.x; _prevAvrgVel.x = _avrgVel.x;
_prevAvrgVel.y = _avrgVel.y; _prevAvrgVel.y = _avrgVel.y;
var absPrevAvrgVel:Number = _prevAvrgVel.length;
var totalTime:int = touch.time - _startTime;
_avrgVel.x = _offset.x / totalTime; _avrgVel.x = _offset.x / totalTime;
_avrgVel.y = _offset.y / totalTime; _avrgVel.y = _offset.y / totalTime;
var avrgVel:Number = _avrgVel.length; var avrgVel:Number = _avrgVel.length;
if (avrgVel * 0.95 < _prevAvrgVel.length)
if (avrgVel * 0.95 < absPrevAvrgVel)
{ {
_decelerationCounter++; _decelerationCounter++;
} }
if (_decelerationCounter > 5 || avrgVel < 0.1) // We should quickly fail if we have noticable deceleration
// or average velocity is too low
if (_decelerationCounter > 5 || avrgVel < 0.05)
{ {
setState(GestureState.FAILED); setState(GestureState.FAILED);
return; return;
@ -139,9 +144,6 @@ package org.gestouch.gestures
if (_noDirection) if (_noDirection)
{ {
// We should quickly fail if we have noticable deceleration
// or first movement happend way later after touch
if (avrgVel >= minVelocity && (minOffset != minOffset || offsetLength >= minOffset)) if (avrgVel >= minVelocity && (minOffset != minOffset || offsetLength >= minOffset))
{ {
if (setState(GestureState.RECOGNIZED) && hasEventListener(SwipeGestureEvent.GESTURE_SWIPE)) if (setState(GestureState.RECOGNIZED) && hasEventListener(SwipeGestureEvent.GESTURE_SWIPE))
@ -169,9 +171,9 @@ package org.gestouch.gestures
// horizontal velocity is greater then vertical, but we're not interested in any horizontal direction // horizontal velocity is greater then vertical, but we're not interested in any horizontal direction
setState(GestureState.FAILED); setState(GestureState.FAILED);
} }
else if (recentOffsetX < 0 && (direction & SwipeGestureDirection.LEFT) == 0 || else if ((recentOffsetX < 0 && (direction & SwipeGestureDirection.LEFT) == 0) ||
recentOffsetX > 0 && (direction & SwipeGestureDirection.RIGHT) == 0 || (recentOffsetX > 0 && (direction & SwipeGestureDirection.RIGHT) == 0) ||
Math.abs(_offset.y) > maxDirectionalOffset) Math.abs(Math.atan(_offset.y/_offset.x)) > ANGLE)
{ {
// movement in opposite direction // movement in opposite direction
// or too much diagonally // or too much diagonally
@ -197,9 +199,9 @@ package org.gestouch.gestures
// horizontal velocity is greater then vertical, but we're not interested in any horizontal direction // horizontal velocity is greater then vertical, but we're not interested in any horizontal direction
setState(GestureState.FAILED); setState(GestureState.FAILED);
} }
else if (recentOffsetY < 0 && (direction & SwipeGestureDirection.UP) == 0 || else if ((recentOffsetY < 0 && (direction & SwipeGestureDirection.UP) == 0) ||
recentOffsetY > 0 && (direction & SwipeGestureDirection.DOWN) == 0 || (recentOffsetY > 0 && (direction & SwipeGestureDirection.DOWN) == 0) ||
Math.abs(_offset.x) > maxDirectionalOffset) Math.abs(Math.atan(_offset.x/_offset.y)) > ANGLE)
{ {
// movement in opposite direction // movement in opposite direction
// or too much diagonally // or too much diagonally
@ -221,7 +223,7 @@ package org.gestouch.gestures
setState(GestureState.FAILED); setState(GestureState.FAILED);
} }
} }
} }
override protected function onTouchEnd(touch:Touch):void override protected function onTouchEnd(touch:Touch):void