The angles that the swipe will accept, between 0° and ±180°. The angles start from the right side (0°) and end at the left side (±180°). With the positive angles passing through down (+90°) and the negative angles passing through up (-90°). The following ASCII art shows the directions of the angles,

-90° (up)
                  |
                  |
(left) ± 180° --------- 0° (right)
                  |
                  |
         (down) +90°

To make this easier, there are several predefined angles arrays that you can use, SC.SWIPE_HORIZONTAL ([180, 0]), i.e. left or right SC.SWIPE_VERTICAL ([-90, 90]), i.e. up or down SC.SWIPE_ANY (null), i.e. 0° to up, down, left or right SC.SWIPE_LEFT ([180]), i.e. left only SC.SWIPE_RIGHT ([0]), i.e. right only SC.SWIPE_UP ([-90]), i.e. up only SC.SWIPE_DOWN ([90]), down only

However, you can provide any combination of angles that you want. For example, to support 45° angled swipes to the right and straight swipes to the left, we would use,

angles: [180, -45, 45] // 180° straight left, -45° up & right, 45° down & right

How to use the angles.

When the swipe event fires, the angle of the swipe is passed to your view allowing you to recognize which of the supported angles matched the swipe.

Note, there is one special case, as defined by SC.SWIPE_ANY, which is to set angles to null in order to support swipes in any direction. The code will look for a swipe (unidirectional fast motion) in any direction and pass the observed angle to the swipe handler.

The swipe gesture is always interested in a touch session, because it is only concerned in how the session ends. If it ends with a fast unidirectional sliding movement, then it is a swipe.

Note, that for multiple touches, touches are expected to start while other touches are already moving. When touches are added we update the swipe start position. This means that inadvertent taps that occur while swiping could break a swipe recognition by making the swipe too short to register.

The swipe gesture is always interested in a touch session, because it is only concerned in how the session ends. If it ends with a fast unidirectional sliding movement, then it is a swipe.

Note, that a touch may cancel while swiping (went off screen inadvertently). Because of this we don't immediately reduce the number of touches in the swipe, because if the rest of the touches end right away in a swipe, it's best to consider the cancelled touch as part of the group.

The swipe gesture is always interested in a touch session, because it is only concerned in how the session ends. If it ends with a fast unidirectional sliding movement, then it is a swipe.

Note, that touches are expected to end while swiping. Because of this we don't immediately reduce the number of touches in the swipe, because if the rest of the touches also end right away in a swiping motion, it's best to consider this ended touch as part of the group.

The swipe gesture is always interested in a touch session, because it is only concerned in how the session ends. If it ends with a fast unidirectional sliding movement, then it is a swipe.