tl;dr: Earstrip is a new C++/WebAssembly polygon triangulation library (ISC-licensed, earcut-compatible API) that triangulates 3.7M map polygons in 489ms—14% faster than earcut.hpp natively and 1.4-2.1x faster than earcut.js in browsers. Key optimizations include only testing reflex ("dent") vertices for ear-blocking, shortcutting convex polygons, emitting triangle strips instead of individual triangles, bucketing dents spatially, and using branchless counting passes. It falls back to constrained Delaunay triangulation for pathological cases like polygons with many holes or no valid ears after grid rounding.