ORB-SLAM3 Android

An attempt to get ORB-SLAM3 working on Android. Please note that it builds, partially initialises, but then currently crashes (crash with SIGILL error on emulator, investigation of cause ongoing)

Steps to create project

1. Thanks to Vladimir Somers for this extremely useful setup guide for OpenCV on Android. The template project was created using this

2. Basic ORB_SLAM Android project structure taken from Lewis Baker's repository and added to OpenCV template above. Note this is ORB_SLAM2, not ORB_SLAM3. OpenCV references commented out as step 1 already brings in OpenCV.

3. ORB_SLAM2 code replaced by ORB-SLAM3 code taken from the Emscripten port here - please use the binvoc branch. Thirdparty libraries also replaced.

Problems

• Currently crashes on x64 emulator, see here for stack trace.

• Division operator (Matx,float) not recognised e.g. in LocalMapping.cc line 628 and KannalaBrandt8.cpp line 534. This didn't occur with emscripten: issue with C++ compiler used on Android? Replaced with code to divide individual values within matrix.