sdragonx
这个多边形有bug，原版的libtess2依然存在。
LINEARRING (12950683.477174498 4833655.12708581, 12950590.169765407 4833661.971891628, 12950546.108769631 4833665.209252961, 12950491.653217828 4833669.220052718, 12950434.612983717 4833673.424716553, 12950395.787768705 4833676.280624169, 12950341.376471192 4833680.274143135, 12950320.64067631 4833681.800466419, 12950314.531079613 4833682.251894767, 12950314.560554624 4833682.650807318, 12950320.670093225 4833682.1993832635, 12950341.405789915 4833680.6730672065, 12950395.817076804 4833676.679549021, 12950434.642359095 4833673.823636455, 12950491.682602832 4833669.618971911, 12950546.138119219 4833665.608174762, 12950590.199054403 4833662.37081788, 12950683.506438896 4833655.526013867, 12950683.477174498 4833655.12708581)
