Scissors congruence between two triangles of equal area.
This scissors module makes use of Mapbox’s Earcut to triangulate polygons before carrying out an equidecomposition algorithm.
Equidecomposition involves clipping polygons against one another using Sutherland-Hodgeman clipping after collections of polygons taken from a source and subject have been cut and aligned to form squares of equal area.
Done naively, it is this clipping stage which gives rise to numerical instability as degeneracies and floating point arithmetic plague efforts to make the equidecomposition algorithm robust.