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/point_in_circle.cpp

@@ -0,0 +1,18 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// 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 "point_in_circle.h"
+
+IGL_INLINE bool igl::point_in_circle(
+  const double qx, 
+  const double qy,
+  const double cx, 
+  const double cy,
+  const double r)
+{
+  return (qx-cx)*(qx-cx) + (qy-cy)*(qy-cy) - r*r < 0;
+}