#include "geometry.hpp" struct point { double x; double y; point(double x_, double y_) : x(x_), y(y_) { } }; drawvec clean_polygon(drawvec const &geom, int z, int detail) { double scale = 1LL << (-(32 - detail - z)); // decompose polygon rings into segments std::vector> segments; for (size_t i = 0; i < geom.size(); i++) { if (geom[i].op == VT_MOVETO) { size_t j; for (j = i + 1; j < geom.size(); j++) { if (geom[i].op != VT_LINETO) { break; } } for (size_t k = i; k + 1 < j; k++) { std::pair segment = std::make_pair( point(geom[k].x / scale, geom[k].y / scale), point(geom[k + 1].x / scale, geom[k + 1].y / scale)); segments.push_back(segment); } i = j - 1; } } // snap-round intersecting segments // remove duplicate segments with opposite windings // reassemble segments into rings // remove collinear points? // determine ring nesting return drawvec(); }