Refactor folder (#10475)

Move many third-party components' source codes from the src folder to a new folder called deps_src. The goal is to make the code structure clearer and easier to navigate.

deps_src/libigl/igl/grid_search.h

@@ -0,0 +1,42 @@
+#ifndef IGL_GRID_SEARCH_H
+#define IGL_GRID_SEARCH_H
+#include "igl_inline.h"
+#include <Eigen/Core>
+#include <functional>
+namespace igl
+{
+  // Solve the problem:
+  //
+  //   minimize f(x)
+  //   subject to lb ≤ x ≤ ub 
+  // 
+  // by exhaustive grid search.
+  //
+  // Inputs:
+  //   f  function to minimize
+  //   LB  #X vector of finite lower bounds
+  //   UB  #X vector of finite upper bounds
+  //   I  #X vector of number of steps for each variable
+  // Outputs:
+  //   X  #X optimal parameter vector
+  // Returns f(X)
+  //
+  template <
+    typename Scalar, 
+    typename DerivedX, 
+    typename DerivedLB, 
+    typename DerivedUB, 
+    typename DerivedI>
+  IGL_INLINE Scalar grid_search(
+    const std::function< Scalar (DerivedX &) > f,
+    const Eigen::MatrixBase<DerivedLB> & LB,
+    const Eigen::MatrixBase<DerivedUB> & UB,
+    const Eigen::MatrixBase<DerivedI> & I,
+    DerivedX & X);
+}
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "grid_search.cpp"
+#endif
+
+#endif