Bind segment_segment_intersect (#74)

* Wrap segment_segment_intersect

Author: zfergus

python/src/ipc.cpp

@@ -93,8 +93,10 @@ void define_ipc(py::module_& m)
         },
         R"ipc_Qu8mg5v7(
         Constructs a list of unique edges represented in a given mesh F
+
         Parameters:
             F: #F by 3 list of mesh faces (must be triangles)
+
         Returns:
             #E by 2 list of edges in no particular order
         )ipc_Qu8mg5v7",

python/src/utils/intersection.cpp

@@ -2,6 +2,8 @@
 
 #include <ipc/utils/intersection.hpp>
 
+#include <igl/predicates/segment_segment_intersect.h>
+
 namespace py = pybind11;
 using namespace ipc;
 
@@ -11,4 +13,25 @@ void define_intersection(py::module_& m)
         "is_edge_intersecting_triangle", &is_edge_intersecting_triangle, "",
         py::arg("e0"), py::arg("e1"), py::arg("t0"), py::arg("t1"),
         py::arg("t2"));
+
+    m.def(
+        "segment_segment_intersect",
+        [](const Eigen::Vector2d& A, const Eigen::Vector2d& B,
+           const Eigen::Vector2d& C, const Eigen::Vector2d& D) -> bool {
+            igl::predicates::exactinit();
+            return igl::predicates::segment_segment_intersect(A, B, C, D);
+        },
+        R"ipc_Qu8mg5v7(
+        Given two segments in 2d test whether they intersect each other using predicates orient2d
+
+        Parameters:
+            A: 1st endpoint of segment 1
+            B: 2st endpoint of segment 1
+            C: 1st endpoint of segment 2
+            D: 2st endpoint of segment 2
+
+        Returns:
+            true if they intersect
+        )ipc_Qu8mg5v7",
+        py::arg("A"), py::arg("B"), py::arg("C"), py::arg("D"));
 }

python/tests/test_intersections.py

@@ -0,0 +1,7 @@
+import numpy as np
+import ipctk
+
+
+def test_segment_segment_intersect():
+    assert ipctk.segment_segment_intersect(
+        np.array([-1, 0]), np.array([1, 0]), np.array([0, -1]), np.array([0, 1]))