Build for Android

• Download Android Studio for your platform
• Install with all options left as default.
  • Remember where the Android SDK gets installed (e.g. c:\Users???\AppData\Local\Android\sdk)
• Startup Android Studio and choose Import project (Eclipse ADT, Gradle, etc.)
  • Choose the build.gradle file in the folder app-Demo-Android
• The SLProject demo app targets the Android SDK 24 (= Android 6.0)
  • If not installed the IDE gives you a link for all missing SDK versions.
  • The min. SDK needed is 21 (Android 5.0)
• The SLProject uses the Android NDK (native development kit). If not installed:
  • Open the SDK manager with Tools > Android > SDK Manager
  • Select the tab SDK Tools
    • Check the NDK option and click Apply
    • Check also the Google USB Driver option and click Apply
  • If the missing NDK error is still present, restart Android Studio and install possibly new package updates.

- The current NDK release r17 doesn't work and produces various linker errors.
- The last known working NDK release is r16b.
- You have to download outside of Android Studio and put it into the ndk-bundle folder.

• The SLProject C++ library is configured with cmake in the CMakeList.txt file.
  • Install cmake if the IDE states it as missing.
• Build the project with Hammer button or with Build > Make Project (Ctrl-F9)
  • The app can only run on real but not on virtual devices because the prebuilt OpenCV libraries (_lib/prebuilt/Android) are only built for the arm architectures armeabi-v7a and arm64-v8a. To run the app in a virtual device you would have to build OpenCV also for Android on the x86 architecture.
• After successful build you can start the app on a USB-connected device by clicking the green start button.
  • If your device is not listed in the Deployment Targets dialog please check again your USB driver. In some cases, you have to download the appropriate driver from the device manufacturer.