CGAL has a general voronoi diagram module that's quite customizable. While I've never used it to build power diagrams, it should not be hard to add in the right kind of distance function to generate the diagrams you need:

http://www.cgal.org/Manual/3.5/doc_html/cgal_manual/Voronoi_diagram_2/Chapter_main.html

CGAL has a general Voronoi diagram module that's quite customizable. While I've never used it to build power diagrams, it should not be hard to add in the right kind of distance function to generate the diagrams you need:

https://doc.cgal.org/Manual/3.5/doc_html/cgal_manual/Voronoi_diagram_2/Chapter_main.html