polygon corners test

tests/include/igl/polygon_corners.cpp

@@ -0,0 +1,28 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2020 Alec Jacobson <[email protected]>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include <test_common.h>
+#include <igl/polygon_corners.h>
+#include <igl/matrix_to_list.h>
+#include <igl/matlab_format.h>
+#include <iostream>
+
+TEST_CASE("polygon_corners: quads", "[igl]")
+{
+  const Eigen::MatrixXi Q = (Eigen::MatrixXi(2,4)<< 0,1,2,3, 1,4,5,2).finished();
+  std::vector<std::vector<int>> vQ;
+  igl::matrix_to_list(Q,vQ);
+  const Eigen::VectorXi Iexact = (Eigen::VectorXi(8)<<0,1,2,3,1,4,5,2).finished();
+  const Eigen::VectorXi Cexact = (Eigen::VectorXi(3)<<0,4,8).finished();
+  Eigen::VectorXi I,C;
+  igl::polygon_corners(vQ,I,C);
+  test_common::assert_eq(I,Iexact);
+  test_common::assert_eq(C,Cexact);
+  igl::polygon_corners( Q,I,C);
+  test_common::assert_eq(I,Iexact);
+  test_common::assert_eq(C,Cexact);
+}