At times, it is necessary to embed additional information into maps. Such information can, for example, be icons or small charts. SurgeryCuts by Angelini et al. (2019) is a technique to cut the map and distort it around the cut in order to free space for additional information. Their approach uses a sophisticated mathematical model to generate cuts similar to what doctors do during surgeries.
The CutLens shown below is inspired by SurgeryCuts. Yet, the CutLens uses classic fisheye distortion to create free space of circular shape. The involved math is quite simple, which makes it possible to adjust the CutLens in real-time. In the demonstration below, the CutLens can be moved around freely on the map. The red and blue rings can be used to adjust the fisheye distortion. Press 's' to toggle smoothing of the result.