봄날은 갔다. 이제 그 정신으로 공부하자

GPS 관련 처리를 하다보면 사용자가 선택한 포인트가 영역내에 포함되어 있는지 체크해 별도의 처리를 해주어야 하는 경우가 있는데 이를 지원해주는 함수는 아래와 같습니다. function ptInPolygon($polygon, $point) { $p0 = end($polygon); $ctr = 0; foreach ( $polygon as $p1 ) { // there is a bug with this algorithm, when a point in "on" a vertex // in that case just add an epsilon if ($point[1] == $p0[1]) $point[1]+=0.0000000001; #epsilon ..