void gfxpolywriter_init(polywriter_t*w);
gfxpoly_t* gfxpoly_from_gfxline(gfxline_t*line, double gridsize);
gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize);
void gfxpolywriter_init(polywriter_t*w);
gfxpoly_t* gfxpoly_from_gfxline(gfxline_t*line, double gridsize);
gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize);