I see many mobile apps having a feature that user can draw a square to indicate something to tag on the image.
I\'m building Face Tagging
app and basical
You can use React Native ART library to draw shapes on top of image. It is a standard library that ships with React Native (although not linked to the binary by default).
Regarding the algorithm:
ART.Surface
onPressOut
event)Where to go from here: