The breaking up of self-intersecting polygons into simple polygons (illustrated above) is also called tessellation (Woo et al. 1999).
Polygon Tessellation
See also
Polygon, Polygon Clipping, Tessellation, TriangulationExplore with Wolfram|Alpha
References
Woo, M.; Neider, J.; Davis, T.; and Shreiner, D. Ch. 11 in OpenGL 1.2 Programming Guide, 3rd ed.: The Official Guide to Learning OpenGL, Version 1.2. Reading, MA: Addison-Wesley, 1999.Referenced on Wolfram|Alpha
Polygon TessellationCite this as:
Weisstein, Eric W. "Polygon Tessellation." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PolygonTessellation.html