Plotting intersection curves for implicit surfaces

Implicit surfaces can be plotted with the isosurface function, but to my knowledge there is no function for plotting the intersection curve between two implicit surfaces. The isocurve3 function provided here does the job, with input parameters similar to those of isosurface. The implementation uses a crossing detection method which I found on Mike Garrity's blog http://blogs.mathworks.com/graphics/2015/07/22/implicit-surface-intersections/. His method is combined with some combinatorial algorithms to identify and sort the isocurve components. Examples are provided in the enclosed file test_isocurve.m, among the examples is the problem considered in Mike Garrity's blog post mentioned above.