Freeform Gesture Detector
Multi-touch transform gestures for Android.
FreeformGestureDetector (2018) is an Android library that converts multi-touch gestures into incremental Matrix transformations.
It processes any kind of touch gesture, from single-finger dragging to multitouch skew and scale, and spits out the corresponding Matrix transforms needed to render that manipulation.
This library arose from the development of Hypertangram. I wanted free manipulation of puzzle pieces because I wanted intuitive game controls.
Matrix.setPolyToPoly for making this easy.
It’s open-source and available on GitHub.