The line is drawn using OpenGL ES 2.0 library features.
ANDROID ARTOOLKIT TUTORIAL HOW TO
ARDistanceOpenGLES20: An example on how to measure the distance and draw a line between two markers.ARMulti: An example that shows how to configure and usenmulti marker tracking.ARSimpleInteraction: An example that adds simple interaction to ARSimple.ARSimple: An example that extends the ARActivity class in ARBaseLib to create a simple augmented reality application.The examples are as follows: All Java-based These examples offer the greatest power to the AR developer and direct access to the full native ARToolKit API. AR and rendering code in native C/C++ using Android NDK: examples where most of the user-developed code is native C/C++.Code can use the provided ARBaseLib java classes while also addressing ARToolKit in C/C++ via the libARWrapper C/C++ API. Mixed Java and native C/C++ using Android NDK: examples where user-developed code is split between the Java environment and native C/C++ environment.All Java-based: examples where all user-developed code is in Java, and is based on the provided ARBaseLib classes.
Coming soon - the example apps projects are being migrated to the Android Studio integrated development environment (IDE) from the Eclipse projects. However, the example apps will likely lag behind as newer Android SDK Platforms are released. The ARToolKit SDK example apps are in the process of being upgraded to be built over the latest and greatest Android SDK Platform API level. Each app is built against a selected API level of the Android SDK Platform and does not have dependencies on Google APIs.
You can copy and build on the examples to create your own application.
ARToolKit includes a number of fully-working examples on Android that demonstrate basic and advanced techniques.