| startdistance | The pixel distance when multi-touch was started. |
| currentdistance | The pixel distance of the touch when the event occurred. |
| cx | The x-coordinate of the center position (in client coordinates). |
| cy | The y-coordinate of the center position (in client coordinates). |
| flag | Multi-touch state flag. 0x01 : Set for the first event when multi-touch starts. |