Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/LinSpaced.h

@@ -0,0 +1,61 @@
+#ifndef IGL_LINSPACED_H
+#define IGL_LINSPACED_H
+#include <Eigen/Core>
+// This function is not intended to be a permanent function of libigl. Rather
+// it is a "drop-in" workaround for documented bug in Eigen:
+// http://eigen.tuxfamily.org/bz/show_bug.cgi?id=1383
+//
+// Replace: 
+//
+//     Eigen::VectorXi::LinSpaced(size,low,high);
+//
+// With:
+//
+//     igl::LinSpaced<Eigen::VectorXi>(size,low,high);
+//
+// Specifcally, this version will _always_ return an empty vector if size==0,
+// regardless of the values for low and high. If size != 0, then this simply
+// returns the result of Eigen::Derived::LinSpaced.
+//
+// Until this bug is fixed, we should also avoid calls to the member function
+// `.setLinSpaced`. This means replacing:
+//
+//     a.setLinSpaced(size,low,high);
+//
+// with
+//
+//     a = igl::LinSpaced<decltype(a) >(size,low,high);
+//
+namespace igl
+{
+  template <typename Derived>
+  //inline typename Eigen::DenseBase< Derived >::RandomAccessLinSpacedReturnType 
+  inline Derived LinSpaced(
+    typename Derived::Index size,
+    const typename Derived::Scalar & low,
+    const typename Derived::Scalar & high);
+}
+
+// Implementation
+
+template <typename Derived>
+//inline typename Eigen::DenseBase< Derived >::RandomAccessLinSpacedReturnType 
+inline Derived
+igl::LinSpaced(
+  typename Derived::Index size,
+  const typename Derived::Scalar & low,
+  const typename Derived::Scalar & high)
+{
+  if(size == 0)
+  {
+    // Force empty vector with correct "RandomAccessLinSpacedReturnType" type.
+    return Derived::LinSpaced(0,0,1);
+  }else if(high < low)
+  {
+    return low-Derived::LinSpaced(size,low-low,low-high).array();
+  }else{
+    return Derived::LinSpaced(size,low,high);
+  }
+}
+
+#endif