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Improve internal algorithm for RotateGesture

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This commit is contained in:
Pavel fljot 2012-07-10 17:11:30 +03:00
parent 0555813e25
commit fd55468579
1 changed files with 34 additions and 25 deletions
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59
src/org/gestouch/gestures/RotateGesture.as
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@ -21,11 +21,12 @@ package org.gestouch.gestures
*/
public class RotateGesture extends Gesture
{
public var slop:Number = Gesture.DEFAULT_SLOP >> 1;
public var slop:Number = Gesture.DEFAULT_SLOP;
protected var _touch1:Touch;
protected var _touch2:Touch;
protected var _transformVector:Point;
protected var _thresholdAngle:Number;
public function RotateGesture(target:Object = null)
@ -73,6 +74,9 @@ package org.gestouch.gestures
_touch2 = touch;
_transformVector = _touch2.location.subtract(_touch1.location);
// @see chord length formula
_thresholdAngle = Math.asin(slop / (2 * _transformVector.length)) * 2;
}
}
@ -82,38 +86,43 @@ package org.gestouch.gestures
if (touchesCount < 2)
return;
var recognized:Boolean = true;
var currTransformVector:Point = _touch2.location.subtract(_touch1.location);
var rotation:Number = Math.atan2(currTransformVector.y, currTransformVector.x) - Math.atan2(_transformVector.y, _transformVector.x);
if (state == GestureState.POSSIBLE && slop > 0 && touch.locationOffset.length < slop)
if (state == GestureState.POSSIBLE)
{
recognized = false;
const absRotation:Number = rotation >= 0 ? rotation : -rotation;
if (absRotation < _thresholdAngle)
{
// not recognized yet
return;
}
// adjust angle to avoid initial "jump"
rotation = rotation > 0 ? rotation - _thresholdAngle : rotation + _thresholdAngle;
}
if (recognized)
// TODO: switch to radians everywhere
rotation *= GestureUtils.RADIANS_TO_DEGREES;
_transformVector.x = currTransformVector.x;
_transformVector.y = currTransformVector.y;
updateLocation();
if (state == GestureState.POSSIBLE)
{
var currTransformVector:Point = _touch2.location.subtract(_touch1.location);
var rotation:Number = Math.atan2(currTransformVector.y, currTransformVector.x) - Math.atan2(_transformVector.y, _transformVector.x);
rotation *= GestureUtils.RADIANS_TO_DEGREES;
_transformVector.x = currTransformVector.x;
_transformVector.y = currTransformVector.y;
updateLocation();
if (state == GestureState.POSSIBLE)
if (setState(GestureState.BEGAN) && hasEventListener(RotateGestureEvent.GESTURE_ROTATE))
{
if (setState(GestureState.BEGAN) && hasEventListener(RotateGestureEvent.GESTURE_ROTATE))
{
dispatchEvent(new RotateGestureEvent(RotateGestureEvent.GESTURE_ROTATE, false, false, GestureState.BEGAN,
_location.x, _location.y, _localLocation.x, _localLocation.y, rotation));
}
dispatchEvent(new RotateGestureEvent(RotateGestureEvent.GESTURE_ROTATE, false, false, GestureState.BEGAN,
_location.x, _location.y, _localLocation.x, _localLocation.y, rotation));
}
else
}
else
{
if (setState(GestureState.CHANGED) && hasEventListener(RotateGestureEvent.GESTURE_ROTATE))
{
if (setState(GestureState.CHANGED) && hasEventListener(RotateGestureEvent.GESTURE_ROTATE))
{
dispatchEvent(new RotateGestureEvent(RotateGestureEvent.GESTURE_ROTATE, false, false, GestureState.CHANGED,
_location.x, _location.y, _localLocation.x, _localLocation.y, rotation));
}
dispatchEvent(new RotateGestureEvent(RotateGestureEvent.GESTURE_ROTATE, false, false, GestureState.CHANGED,
_location.x, _location.y, _localLocation.x, _localLocation.y, rotation));
}
}
}