compile tutorial with namespace

tutorial/507_PolyVectorField/main.cpp

@@ -1,14 +1,14 @@
-#include <igl/readOBJ.h>
-#include <igl/readDMAT.h>
-#include <igl/viewer/Viewer.h>
-#include <igl/barycenter.h>
 #include <igl/avg_edge_length.h>
-#include <vector>
-#include <igl/n_polyvector.h>
-#include <igl/local_basis.h>
-#include <stdlib.h>
+#include <igl/barycenter.h>
 #include <igl/jet.h>
+#include <igl/local_basis.h>
+#include <igl/n_polyvector.h>
+#include <igl/readDMAT.h>
+#include <igl/readOBJ.h>
+#include <igl/viewer/Viewer.h>
+#include <cstdlib>
 #include <iostream>
+#include <vector>
 
 // Input mesh
 Eigen::MatrixXd V;
@@ -68,7 +68,7 @@ Eigen::VectorXd random_constraints(const
   return r;
 }
 
-bool key_down(igl::Viewer& viewer, unsigned char key, int modifier)
+bool key_down(igl::viewer::Viewer& viewer, unsigned char key, int modifier)
 {
   using namespace std;
   using namespace Eigen;
@@ -142,7 +142,7 @@ int main(int argc, char *argv[])
   // Make the example deterministic
   srand(0);
 
-  igl::Viewer viewer;
+  igl::viewer::Viewer viewer;
   viewer.data.set_mesh(V, F);
   viewer.callback_key_down = &key_down;
   viewer.core.show_lines = false;