add CMake dependency handling for portability

code/src/main.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <CGAL/Simple_cartesian.h>
+ 
+typedef CGAL::Simple_cartesian<double> Kernel;
+typedef Kernel::Point_2 Point_2;
+typedef Kernel::Segment_2 Segment_2;
+ 
+int main()
+{
+  Point_2 p(1,1), q(10,10);
+ 
+  std::cout << "p = " << p << std::endl;
+  std::cout << "q = " << q.x() << " " << q.y() << std::endl;
+ 
+  std::cout << "sqdist(p,q) = "
+            << CGAL::squared_distance(p,q) << std::endl;
+ 
+  Segment_2 s(p,q);
+  Point_2 m(5, 9);
+ 
+  std::cout << "m = " << m << std::endl;
+  std::cout << "sqdist(Segment_2(p,q), m) = "
+            << CGAL::squared_distance(s,m) << std::endl;
+ 
+  std::cout << "p, q, and m ";
+  switch (CGAL::orientation(p,q,m)){
+  case CGAL::COLLINEAR:
+    std::cout << "are collinear\n";
+    break;
+  case CGAL::LEFT_TURN:
+    std::cout << "make a left turn\n";
+    break;
+  case CGAL::RIGHT_TURN:
+    std::cout << "make a right turn\n";
+    break;
+  }
+ 
+  std::cout << " midpoint(p,q) = " << CGAL::midpoint(p,q) << std::endl;
+  return 0;
+}