{"id":824,"date":"2018-01-15T00:25:08","date_gmt":"2018-01-14T16:25:08","guid":{"rendered":"http:\/\/www.whudj.cn\/?p=824"},"modified":"2018-01-15T00:25:08","modified_gmt":"2018-01-14T16:25:08","slug":"%e5%8f%a0%e7%bd%ae%e5%88%86%e6%9e%902%e6%95%b0%e6%8d%ae%e7%bb%93%e6%9e%84%ef%bc%9atopology%e6%a8%a1%e5%9e%8b-dcel","status":"publish","type":"post","link":"http:\/\/www.whudj.cn\/?p=824","title":{"rendered":"\u53e0\u7f6e\u5206\u6790(2):\u6570\u636e\u7ed3\u6784\uff1atopology\u6a21\u578b\/DCEL"},"content":{"rendered":"<p>\u8fd9\u4e00\u8282\u6211\u8ba1\u5212\u4ecb\u7ecd\u53e0\u7f6e\u5206\u6790\u7b97\u6cd5\u7684\u57fa\u7840-\u6570\u636e\u7ed3\u6784\uff0c\u5373\u62d3\u6251(topology)\u6570\u636e\u6a21\u578b\uff0c\u5728\u4e0d\u540c\u7684\u9886\u57df\/\u8f6f\u4ef6\u4e2d\uff0c\u5bf9\u62d3\u6251\u6570\u636e\u6a21\u578b\u7684\u5b9e\u73b0\u6709\u4e0d\u4e00\u6837\u7684\u53eb\u6cd5\uff0c\u6bd4\u5982geos\u4e2d\u79f0\u4e4b\u4e3aplanargraph(\u5e73\u9762\u56fe)\u6216\u8005geomgraph,\u8ba1\u7b97\u51e0\u4f55(Computational Geometry)\u7684\u4e66\u7c4d\u4ee5\u53caCGAL\u4e2d\u5c06\u5176\u79f0\u4e3aDCEL(Double Connected Edge List)\uff0cArcGIS\u65e9\u671f\u7684\u6570\u636e\u6a21\u578b\u79f0\u4e4b\u4e3aCoverage\u3002\u62d3\u6251\u6570\u636e\u6a21\u578b\u662f\u4e00\u79cd\u7528GeoRelational\u6a21\u578b\uff0c\u5373\u663e\u5f0f\u7684\u8868\u8fbe\u4e86\u7a7a\u95f4\u5173\u7cfb\uff0c\u53e0\u7f6e\u7b97\u6cd5\u5c31\u662f\u5efa\u7acb\u5728\u8fd9\u79cd\u6570\u636e\u6a21\u578b\u4e4b\u4e0a\u7684\u3002<!--more--><\/p>\n<p><strong>1\uff09\u53d1\u5c55\u8d8b\u52bf\u7684\u4e0d\u5b8c\u5168\u603b\u7ed3<\/strong><\/p>\n<p>\u65e9\u671f\u7684GIS\u7528\u6237\u4e00\u5b9a\u5bf9\u62d3\u6251\u6570\u636e\u6a21\u578b\u4e0d\u964c\u751f\uff0c\u56e0\u4e3a\u62d3\u6251\u6570\u636e\u6a21\u578b\u66fe\u7ecf\u662fGIS\u8f6f\u4ef6\u7cfb\u7edf\u7684\u4e3b\u6d41\u6570\u636e\u6a21\u578b\uff0c\u6bd4\u5982ArcGIS\u5c31\u66fe\u91c7\u7528\u4e86(\u73b0\u5728\u4e5f\u652f\u6301)converage\/E00\u4f5c\u4e3a\u4e3b\u8981\u7684\u6570\u636e\u6a21\u578b\u3002topo\u6a21\u578b\u5efa\u7acb\u7684\u521d\u8877\u4e3b\u8981\u6709\u4e24\u70b9\uff1a<\/p>\n<p>1.\u5f3a\u8c03\u7a7a\u95f4\u8981\u7d20\u7684\u62d3\u6251\u5173\u7cfb\uff0c\u5c06\u62d3\u6251\u5173\u7cfb(\u90bb\u63a5\u5173\u7cfb)\u8fdb\u884c\u4e86\u4fdd\u5b58\uff0c\u65b9\u4fbf\u7cfb\u7edf\u8fdb\u884c\u7a7a\u95f4\u5173\u7cfb\u5206\u6790(GIS\u8f6f\u4ef6\u7684\u57fa\u672c\u529f\u80fd)\u3002<\/p>\n<p>2.\u901a\u8fc7\u5171\u4eab\u51e0\u4f55\u8fbe\u5230\u8282\u7ea6\u7269\u7406\u5b58\u50a8\u7684\u76ee\u7684\u3002\u56e0\u6b64\u53d7\u5230\u4e0a\u53e4\u7cfb\u7edf\u7684\u504f\u7231\u3002\u6d77\u91cf\u7684\u5730\u7406\u4fe1\u606f\u6570\u636e\u7684\u5b58\u50a8\u548c\u5206\u53d1\u672c\u6765\u5c31\u662f\u65e9\u671fGIS\u7cfb\u7edf\u7684\u96be\u9898\u3002\u8fd9\u91cc\u53ef\u4ee5\u63d0\u4e00\u4e0bE00\u6587\u4ef6\u6709\u610f\u8bc6\u7684\u547d\u540d\u89c4\u5219\u3002\u4e3a\u4ec0\u4e48\u53ebE00\uff1f\u8fd9\u662f\u56e0\u4e3a\u65e9\u671f\u7684\u8f6f\u76d8\u53ea\u67091.44MB,\u56e0\u6b64ARC\/INFO\u8bbe\u8ba1\uff0c\u53ef\u4ee5\u901a\u8fc7\u591a\u5f20\u8f6f\u76d8(\u6216\u5176\u4ed6\u4ecb\u8d28)\u4fdd\u5b58\u4e00\u4e2a\u5927\u6587\u4ef6\uff0c\u540d\u5b57\u4f9d\u6b21\u662fx.e00,x.e01,x.e02&#8230;<\/p>\n<p>\u8fd9\u79cd\u6a21\u578b\u540e\u6765\u88ab\u5f3a\u5927\u7684\u7b2c\u4e09\u4ee3\u5730\u7406\u6570\u636e\u5e93\u6a21\u578b\u6240\u53d6\u4ee3\uff0c\u4eca\u5929\u6211\u4eec\u719f\u77e5\u7684ESRI FileGDB,ArcSDE,Oracle spatial,PostgreSQL(with PostGIS)\u90fd\u662f\u9762\u5411\u5bf9\u8c61\u7684\u5730\u7406\u4fe1\u606f\u6570\u636e\u5e93\u3002\u8fd9\u4e0d\u662f\u8bf4\u62d3\u6251\u6570\u636e\u6a21\u578b\u4e0d\u91cd\u8981\u4e86\uff0c\u800c\u662f\u5b58\u50a8\u6a21\u578b\u7684\u53d8\u9769\u3002\u62d3\u6251\u6570\u636e\u6a21\u578b\u7531\u6301\u4e45\u5316\u4fdd\u5b58\u8f6c\u5411\u4e86\u901a\u8fc7\u8ba1\u7b97\u751f\u6210\uff0c\u5728\u5185\u5b58\u4e2d\u8fdb\u884c\u4fdd\u5b58\uff0c\u5982geos\u4e0eCGAL\u3002\u62d3\u6251\u6570\u636e\u6a21\u578b\u4ecd\u7136\u4e3b\u5bb0\u7740\u591a\u8fb9\u5f62\u5e03\u5c14\u8fd0\u7b97\u3001\u62d3\u6251\u5173\u7cfb\u67e5\u8be2\u3001overlay\u7b49\u4e3b\u8981\u7684\u5e94\u7528\u3002<\/p>\n<p>\u76ee\u524d\uff0c\u90e8\u5206\u8f6f\u4ef6\u4ecd\u7136\u5b9a\u4e49\u4e86\u91c7\u7528\u5173\u7cfb\u578b\u6570\u636e\u5e93\u5b58\u50a8\u8868\u8fbe\u62d3\u6251\u6a21\u578b\u3002\u6bd4\u5982postGIS Topology\uff0c\u53caOracle Spatial Topology \u5c31\u5b9a\u4e49\u4e86\u4e00\u5957\u62d3\u6251\u6570\u636e\u6a21\u578b\u548c\u5bf9\u5e94\u7684\u6570\u636e\u5e93\u51fd\u6570\u3002\u8fd9\u4e9b\u8f6f\u4ef6\u63d0\u4f9b\u4e86\u4e00\u79cd\u6301\u4e45\u5316\u4fdd\u5b58\u62d3\u6251\u6a21\u578b\u4ee5\u53ca\u5728\u5176\u4e0a\u6267\u884c\u5206\u6790\u64cd\u4f5c\u7684\u65b9\u6cd5\u3002<\/p>\n<p><strong>2\uff09\u5b9a\u4e49<\/strong><\/p>\n<p>Topology \u662f\u4e00\u4e2a\u6570\u5b66\u540d\u8bcd\uff0c\u5728GIS\u9886\u57df\u4e2d\uff0c\u7528\u6765\u6307\u8282\u70b9(node)\u3001\u5f27\u6bb5(arc)\u3001\u9762(face)\u76f8\u4e92\u5173\u8054\u6784\u6210\u7684\u4e00\u79cd\u56fe\u6570\u636e\u7ed3\u6784\uff0c\u7528\u6765\u8868\u8fbe\u5730\u7406\u8981\u7d20\u7684\u8054\u901a\u4e0e\u90bb\u63a5\u5173\u7cfb\u3002\u62d3\u6251\u5173\u7cfb\u7684\u8868\u8fbe\u4e3b\u8981\u501f\u52a9\u56db\u5f20\u8868\uff1a<\/p>\n<p>1\uff09\u5f27\u6bb5-\u8282\u70b9\u5173\u7cfb\uff1a\u8868\u8fbe\u5f27\u6bb5\u7684\u8d77\u59cb\u3001\u7ed3\u675f\u8282\u70b9\u3002\u5f27\u6bb5\u7684\u51e0\u4f55\u662f\u6298\u7ebf(polyline)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-826\" src=\"http:\/\/www.whudj.cn\/wp-content\/uploads\/2018\/01\/arc-node.gif\" alt=\"\" width=\"317\" height=\"185\" \/><\/p>\n<p>2\uff09\u8282\u70b9-\u5f27\u6bb5\u5173\u7cfb<\/p>\n<p>\u8868\u8fbe\u8282\u70b9\u4e0a\u5173\u8054\u7684\u5f27\u6bb5\u7684\u5217\u8868\u3002\u5176\u4e2d\u8282\u70b9\u5173\u8054\u7684\u5f27\u6bb5\u7684\u4e2a\u6570\u6210\u4e3a\u8282\u70b9\u7684\u5ea6\u6570(degree)\u3002\u5ea6\u6570\u4e3a1\u7684\u8282\u70b9\u4e5f\u6210\u4e3a\u60ac\u6302\u8282\u70b9(dangle node)\uff0c\u5728\u4e0a\u56fe\u4e2d\uff0c\u5171\u670910,11,&#8230;,17\u51717\u4e2a\u8282\u70b9\uff0c10,12,15,16,17\u4e3a\u60ac\u6302\u8282\u70b9\u3002<\/p>\n<p>\u8282\u70b9\u4fdd\u5b58\u7684\u5f27\u6bb5\u5217\u8868\u7684\u987a\u5e8f\u4e0d\u662f\u65e0\u5e8f\u7684\uff0c\u800c\u662f\u6309\u7167\u65f6\u9488\u987a\u5e8f\u4fdd\u5b58\u7684\u3002\u5047\u8bbe\u6309\u7167\u987a\u65f6\u9488\u987a\u5e8f\u4fdd\u5b58\u6570\u636e\uff0c\u8282\u70b911\u7684\u8fb9\u8868\u4e3a1,2,3\uff0c\u8282\u70b913\u7684\u8fb9\u8868\u4e3a3,5,4\u3002&#8230; \u5728\u540e\u9762\u5177\u4f53\u5b9e\u73b0\u7684\u535a\u5ba2\u4e2d\uff0c\u6211\u4f1a\u7ed9\u5927\u5bb6\u4ecb\u7ecd\u4e00\u4e0bgeos\u5bf9\u91c7\u7528\u5f27\u6bb5\u672b\u7aef\u8c61\u9650\u4e0estd::sort\u751f\u6210\u8fb9\u8868\u7684\u7b97\u6cd5\uff0c\u975e\u5e38\u4f18\u96c5\u3002<\/p>\n<p>3\uff09\u5f27\u6bb5-\u9762\u5173\u7cfb<\/p>\n<p>\u8868\u8fbe\u5f27\u6bb5\u5de6\u53f3\u4e24\u4fa7\u7684\u9762\u7684\u4fe1\u606f\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-827\" src=\"http:\/\/www.whudj.cn\/wp-content\/uploads\/2018\/01\/arc-face.gif\" alt=\"\" width=\"366\" height=\"239\" \/><\/p>\n<p>\u7ec6\u5fc3\u7684\u4f60\u53ef\u80fd\u53d1\u73b0\u4e86\u4e00\u4e2a\u975e\u5e38\u7279\u6b8a\u7684\u9762\uff0c\u5c31\u662f\u9762A\u3002\u6211\u4eec\u5047\u8bbe\u6240\u6709\u7684\u9762\u5145\u65a5\u4e86\u6574\u4e2a\u5e73\u9762\uff0c\u56e0\u6b64\u9664\u4e86B,C,D,E,F\u4e4b\u5916\uff0c\u8fd8\u6709\u4ed6\u4eec\u7684\u8865\u96c6\u9762A,\u9762A\u6bd4\u8f83\u7279\u6b8a\uff0c\u6ca1\u6709\u5916\u8f6e\u5ed3\u3002\u5728CGAL\u4e2d\uff0c\u9762A\u88ab\u79f0\u4e3aunbounded face \uff0c\u53ef\u4ee5\u901a\u8fc7<span class=\"lang:c++ decode:true crayon-inline\">ArrangementDcelFace::is_unbounded()<\/span>\u65b9\u6cd5\u5224\u65ad\u9762\u662f\u5426\u4e3aunbounded face\u3002<\/p>\n<p>4\uff09\u9762-\u5f27\u6bb5\u5173\u7cfb<\/p>\n<p>\u8868\u8fbe\u9762\u7531\u54ea\u4e9b\u5f27\u6bb5\u6784\u6210\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-830\" src=\"http:\/\/www.whudj.cn\/wp-content\/uploads\/2018\/01\/face-arc-1.gif\" alt=\"\" width=\"384\" height=\"161\" \/><\/p>\n<p>\u9762\u7684\u8fb9\u8868\u4e5f\u8981\u6309\u7167\u4e00\u5b9a\u7684\u987a\u5e8f\uff0c\u9996\u5148\u8981\u6309\u7167\u90bb\u63a5\u8fb9\u7684\u987a\u5e8f\u8bb0\u5f55\u3002\u5176\u6b21\uff0c\u8981\u786e\u5b9a\u8fb9\u7684\u987a\u5e8f\u4e3a\u4f60\u662f\u9006\u65f6\u9488(CCW)\u8fd8\u662f\u987a\u65f6\u9488(CW)\u3002\u9006\u65f6\u9488\u987a\u5e8f\u8868\u793a\u8fb9\u7684\u5de6\u4fa7\u4e3a\u9762\u7684\u5185\u90e8\u3002\u987a\u65f6\u9488\u5219\u76f8\u53cd\u3002\u4e00\u822c\u7684\u60ef\u4f8b\u4e3aCCW,\u5982CGAL,geos\u7684\u8bbe\u5b9a\u3002\u4e0a\u56fe\u662fArcGIS\u7684\u8bbe\u5b9a\uff0c\u4e3aCW\u987a\u65f6\u9488\u987a\u5e8f\u3002ArcGIS\u5728\u5176\u8f6f\u4ef6\u4e2d\u4e00\u8d2f\u6309\u7167\u8fb9\u7684\u53f3\u4fa7\u4e3a\u591a\u8fb9\u5f62\u7684\u5185\u90e8\u8ba1\u7b97\uff0c\u8fd9\u70b9\u4e0e\u5f00\u6e90\u8f6f\u4ef6\u4e0d\u540c\u3002<\/p>\n<p>\u53e6\u5916\uff0cF\u542b\u6709\u4e00\u4e2a\u5c9b\uff0c\u4e00\u4e2a\u9762\u53ef\u80fd\u542b\u67090\u4e2a\u6216\u82e5\u5e72\u5c9b\u5c7f\uff0c\u9700\u8981\u5728\u8bb0\u5f55\u65f6\u52a0\u4ee5\u533a\u522b\u3002\u5982\u4e0a\u56fe\uff0c\u5728\u5c9b\u5c7f\u548c\u5916\u73af\u4e4b\u95f4\u52a0\u5165\u4e86\u201c0\u201d\u4f5c\u4e3a\u95f4\u9694\u7b26\uff0c\u8fd9\u6837\u505a\u4e5f\u662f\u4e3a\u4e86\u4fdd\u8bc1\u6bcf\u4e2a\u9762\u7684\u8fb9\u8868\u53ea\u542b\u6709\u4e00\u4e2aList\u3002<\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u770b\u5230\uff0c\u5728\u5f27\u6bb5-\u9762\u5173\u7cfb\u8868\u4e2d\uff0c\u5f27\u6bb5\u662f\u6709\u65b9\u5411\u7684\uff0c\u4f46\u662f\u5728\u9762-\u5f27\u6bb5\u5173\u7cfb\u793a\u610f\u56fe\u4e2d\uff0c\u5f27\u6bb5\u7684\u65b9\u5411\u88ab\u523b\u610f\u9690\u53bb\u4e0d\u8868\u8fbe\u3002\u5176\u5b9e\uff0c\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ef\u4ee5\u5728\u8fb9\u7684\u5e8f\u53f7\u4e0a\u52a0\u4e0a\u6b63\u8d1f\u53f7\u8868\u8fbe\u65b9\u5411\u3002\u6b63\u53f7\u8868\u793a\u540c\u5411\uff0c\u8d1f\u53f7\u8868\u793a\u53cd\u65b9\u5411\u3002\u8fd9\u79cd\u8868\u8fbe\u65b9\u5f0f\u89c1\u4e8eESRI E00\u4e0eOracle spatial Topology\u3002\u5b9e\u9645\u4e0a\uff0c\u5728\u903b\u8f91\u4e0a\u4ea7\u751f\u4e86\u6709\u5411\u8fb9\u7684\u6982\u5ff5\u3002\u5bf9\u4e8e\u6bcf\u4e00\u6761\u8fb9\uff0c\u5176\u90fd\u542b\u6709\u4e24\u4e2a\u65b9\u5411\u4e0d\u540c\u7684\u6709\u5411\u8fb9\u3002goes\u4e2d\u7684\u7c7b\u578b\u4e3aDirected Edge\uff0cCGAL\u4e2d\u7684\u6982\u5ff5\u4e3aHalfEdge(\u534a\u8fb9)\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-832\" src=\"http:\/\/www.whudj.cn\/wp-content\/uploads\/2018\/01\/dcel-1.png\" alt=\"\" width=\"500\" height=\"348\" \/><\/p>\n<p>3\uff09\u5b9e\u73b0<\/p>\n<p>\u6839\u636e\u5b9a\u4e49\uff0c\u4e00\u5171\u6709\u8282\u70b9\uff08Node\uff09,\u5f27\u6bb5\uff08Edge\uff09,\u6709\u5411\u5f27\u6bb5\uff08DirectedEdge\uff09,\u9762(Face)\u56db\u79cd\u5b9e\u4f53\u3002\u5f53\u7136\uff0c\u53ef\u4ee5\u76f4\u63a5\u6309\u7167\u5b9a\u4e49\u7684\u65b9\u5f0f\u5b9a\u4e49\u4e0a\u8ff0\u51e0\u79cd\u6570\u636e\u7ed3\u6784\uff0c\u5b9e\u73b0\u62d3\u6251\u6a21\u578b\u3002\u6bd4\u5982geos\u7684\u5b9e\u73b0\u5c31\u4e0e\u4e0a\u8ff0\u5b9a\u4e49\u7684\u65b9\u5f0f\u76f8\u540c\u3002\u4f46\u662f\uff0c\u4ece\u62d3\u6251\u6a21\u578b\u7684\u6784\u5efa\u4e0e\u67e5\u8be2\u7b97\u6cd5\u4e0a\u8003\u8651\uff0cCGAL, PostGIS,Oracle Spatial\u7b49\u8f6f\u4ef6\u63d0\u51fa\u4e86\u4e00\u79cd\u66f4\u5408\u7406\u7684\u53d8\u4f53\uff0c\u5c06\u8fb9\u8868\u8f6c\u6362\u4e3a\u8fb9\u7684\u90bb\u63a5\u5173\u7cfb\u8868\uff0c\u4e0d\u4ec5\u8282\u7ea6\u4e86\u5185\u5b58\u7a7a\u95f4\uff0c\u4f7f\u7528\u8d77\u6765\u8fd8\u975e\u5e38\u65b9\u4fbf\u3002<\/p>\n<p>\u4ee5ORACLE\u7684\u5b9e\u73b0\u4e3a\u4f8b\uff1a<\/p>\n<p>1.\u8fb9\u7ed3\u6784<\/p>\n<ul>\n<li>START_NODE_ID,END_NODE_ID:\u8d77\u6b62node\uff0c\u4e0e\u5b9a\u4e49\u76f8\u540c\u3002<\/li>\n<li>LEFT_FACE_ID,RIGHT_FACE_ID:\u5de6\u53f3\u591a\u8fb9\u5f62\uff0c\u4e0e\u5b9a\u4e49\u76f8\u540c\u3002<\/li>\n<li>NEXT_LEFT_EDGE_ID:\u6309\u6b63\u65b9\u5411\u9006\u65f6\u9488\u8f6c\u52a8\u7684\u4e0b\u4e00\u6761EDGE\u3002<\/li>\n<li>NEXT_RIGHT_EDGE_ID:\u6309\u53cd\u65b9\u5411\u9006\u65f6\u9488\u8f6c\u52a8\u7684\u4e0b\u4e00\u6761EDGE\u3002<\/li>\n<li>PREV_LEFT_EDGE_ID:\u6309\u6b63\u65b9\u5411\u4e0a\u4e00\u6761EDGE\u3002<\/li>\n<li>PREV_RIGHT_EDGE_ID:\u6309\u53cd\u65b9\u5411\u4e0a\u4e00\u6761EDGE\u3002<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-834\" src=\"http:\/\/www.whudj.cn\/wp-content\/uploads\/2018\/01\/edge_table_oracle.gif\" alt=\"\" width=\"293\" height=\"191\" \/><\/p>\n<p>\u770b\u4e0a\u56fe\uff0c\u8fb9E4\u6b63\u65b9\u5411\u9006\u65f6\u9488\u8f6c\u52a8\u7684\u4e0b\u4e00\u6761Edge\u4e3a-E5\uff0c\u56e0\u6b64\u5176NEXT_LEFT_EDGE_ID\u4e3a-E5\u3002\u540c\u7406\uff0c\u5176PREV_LEFT_EDGE_ID\u4e3aE3\u3002NEXT_RIGHT_EDGE_ID\u4e3aE2,NEXT_PREV_EDGE_ID\u4e3a-E6\u3002<\/p>\n<p>2.\u8282\u70b9\u7ed3\u6784<\/p>\n<ul>\n<li>EDGE_ID:\u8868\u793a\u8282\u70b9\u6240\u5173\u8054\u7684\u4efb\u610f\u4e00\u4e2a\u8fb9\u7684ID\u3002<\/li>\n<\/ul>\n<p>\u6309\u7167\u5b9a\u4e49\uff0c\u8282\u70b9\u8bb0\u5f55\u7684\u662f\u8fb9\u8868\uff0c\u4f46\u662f\u8fd9\u91cc\u4e3a\u5565\u4e00\u4e2a\u8fb9\u5c31\u591f\u4e86\uff1f\u8fd9\u6b63\u662f\u8fd9\u4e2a\u8bbe\u8ba1\u7684\u7cbe\u5999\u4e4b\u5904\u3002\u5982\u679c\u5df2\u77e5\u4e00\u4e2a\u8fb9\uff0c\u6c42\u5728\u4ee5\u76f8\u540c\u7684START_NODE\u4e0a\u7684\u5176\u4ed6\u8fb9\uff0c\u53ea\u9700\u8981\u8c03\u7528<span class=\"lang:c++ decode:true crayon-inline\">this-&gt;opposite()-&gt;next_left_edge()<\/span>\u65b9\u6cd5\u5c31OK\u4e86\u3002\u5176\u4e2dopposite()\u91c7\u7528\u7684\u662fCGAL\u7684\u53eb\u6cd5\uff0c\u6307\u7684\u662f\u6709\u5411\u8fb9\u7684\u5bf9\u5411\u8fb9(twin)\u3002<\/p>\n<p>3.\u9762\u7ed3\u6784<\/p>\n<ul>\n<li>BOUNDARY_EDGE_ID: \u540c\u7406\uff0c\u9762\u7684\u5916\u73af\u4e0d\u9700\u8981\u4e00\u4e2a\u8fb9\u8868\uff0c\u53ea\u9700\u8981\u4efb\u610f\u4e00\u4e2aEDGE\u7684ID\u5c31\u597d\u4e86\uff0c\u53ef\u4ee5\u901a\u8fc7\u5faa\u73af\u8c03\u7528<span class=\"lang:c++ decode:true  crayon-inline \">next_left_edge()<\/span>\u00a0\u5b9e\u73b0\u5bf9\u6240\u6709\u8fb9\u7684\u904d\u5386\u3002<\/li>\n<li>ISLAND_EDGE_ID_LIST:\u56e0\u4e3a\u9762\u6709\u53ef\u80fd\u67090\u5230\u591a\u4e2a\u5c9b\u5c7f\uff0c\u56e0\u6b64\u91c7\u53d6\u6bcf\u4e2a\u5c9b\u5c7f\u8bb0\u5f55\u4e00\u4e2aEDGE\u7684\u65b9\u5f0f\u6784\u6210\u4e00\u4e2aID_LIST\u3002<\/li>\n<\/ul>\n<p>\u8fd9\u79cd\u6539\u826f\u7684\u62d3\u6251\u6a21\u578b\u8868\u8fbe\u65b9\u5f0f\u786e\u5b9e\u5177\u6709\u7b80\u6d01\u3001\u5e94\u7528\u65b9\u4fbf\u7684\u4f18\u70b9\u3002<\/p>\n<hr \/>\n<p>\u9700\u8981\u8bf4\u660e\u7684\u662f\uff0cPostGIS,Oracle,CGAL\u5747\u5bf9\u62d3\u6251\u6a21\u578b\u8fdb\u884c\u4e86\u6269\u5c55\uff0c\u652f\u6301\u9762\u4e2d\u5305\u542b\u5b64\u7acb\u70b9(isolated node)\uff0c\u56e0\u6b64\uff0c\u4f1a\u51fa\u73b0\u6709\u7684node\u7684EDGE_ID\u4e3a\u7a7a\uff0c\u5e76\u4e14\u589e\u52a0FACE_ID\u8868\u8fbe\u5b64\u7acb\u70b9\u7684\u60c5\u51b5\u3002\u56e0\u4e3a\u6ca1\u6709\u5728\u5b9a\u4e49\u4e2d\u6d89\u53ca\u5230\uff0c\u6211\u8fd9\u91cc\u6682\u65f6\u4e0d\u505a\u8868\u8ff0\u3002<\/p>\n<hr \/>\n<p>\u53c2\u8003\u6587\u732e<\/p>\n<p><a href=\"https:\/\/trac.osgeo.org\/postgis\/wiki\/UsersWikiPostgisTopology\">PostGIS Topology<\/a><\/p>\n<p><a href=\"https:\/\/trac.osgeo.org\/postgis\/wiki\/UsersWikiPostgisTopology\">Oracle Spatial : Spatial Topology and Network Data Models<\/a><\/p>\n<p><a href=\"http:\/\/webhelp.esri.com\/arcgisdesktop\/9.2\/index.cfm?TopicName=Coverage_topology\">ArcGIS Desktop Help: Coverage Topology<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8fd9\u4e00\u8282\u6211\u8ba1\u5212\u4ecb\u7ecd\u53e0\u7f6e\u5206\u6790\u7b97\u6cd5\u7684\u57fa\u7840-\u6570\u636e\u7ed3\u6784\uff0c\u5373\u62d3\u6251(topology)\u6570\u636e\u6a21\u578b &hellip; <a href=\"http:\/\/www.whudj.cn\/?p=824\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[],"_links":{"self":[{"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/posts\/824"}],"collection":[{"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=824"}],"version-history":[{"count":6,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/posts\/824\/revisions"}],"predecessor-version":[{"id":837,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=\/wp\/v2\/posts\/824\/revisions\/837"}],"wp:attachment":[{"href":"http:\/\/www.whudj.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=824"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=824"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.whudj.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=824"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}