fix.

Former-commit-id: 56c2aed231319267331ee1f04c921ace1f247290

include/igl/fast_winding_number.cpp

@@ -2,6 +2,7 @@
 #include "octree.h"
 #include "knn.h"
 #include "parallel_for.h"
+#include "PI.h"
 #include <vector>
 
 namespace igl {

include/igl/flip_avoiding_line_search.cpp

@@ -7,6 +7,7 @@
 // obtain one at http://mozilla.org/MPL/2.0/.
 #include "flip_avoiding_line_search.h"
 #include "line_search.h"
+#include "PI.h"
 
 #include <Eigen/Dense>
 #include <vector>

include/igl/line_field_missmatch.cpp

@@ -20,6 +20,7 @@
 #include <igl/triangle_triangle_adjacency.h>
 #include <igl/rotation_matrix_from_directions.h>
 #include <igl/local_basis.h>
+#include <igl/PI.h>
 
 namespace igl {
 template <typename DerivedV, typename DerivedF, typename DerivedO>

include/igl/map_vertices_to_circle.cpp

@@ -7,6 +7,7 @@
 // obtain one at http://mozilla.org/MPL/2.0/.
 
 #include "map_vertices_to_circle.h"
+#include "PI.h"
 
 IGL_INLINE void igl::map_vertices_to_circle(
   const Eigen::MatrixXd& V,

include/igl/piecewise_constant_winding_number.cpp

@@ -7,6 +7,7 @@
 // obtain one at http://mozilla.org/MPL/2.0/.
 #include "piecewise_constant_winding_number.h"
 #include "unique_edge_map.h"
+#include "PI.h"
 
 template <
   typename DerivedF,

include/igl/random_quaternion.cpp

@@ -6,6 +6,7 @@
 // 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 "random_quaternion.h"
+#include "PI.h"
 
 template <typename Scalar>
 IGL_INLINE Eigen::Quaternion<Scalar> igl::random_quaternion()

include/igl/shapeup.cpp

@@ -11,6 +11,7 @@
 #include <igl/igl_inline.h>
 #include <igl/setdiff.h>
 #include <igl/cat.h>
+#include <igl/PI.h>
 #include <Eigen/Core>
 #include <vector>