Merge pull request #1567 from anne-glerum/distance_to_polygon

Add non-convex polygons to test and remove statement

include/aspect/utilities.h

@@ -143,8 +143,7 @@ namespace aspect
     /**
      * Given a 2d point and a list of points which form a polygon, compute the smallest
      * distance of the point to the polygon. The sign is negative for points outside of
-     * the polygon and positive for points inside the polygon. Note that the polygon
-     * is required to be convex for this function.
+     * the polygon and positive for points inside the polygon.
      */
     template <int dim>
     double

tests/prm_distance_polygon.cc

@@ -18,17 +18,37 @@ int f()
   polygon[2] = Point<2>(1.0,1.0);
   polygon[3] = Point<2>(0.0,1.0);
 
+  // A concave polygon
+  std::vector< Point<2> > concave_polygon(5);
+  concave_polygon[0] = Point<2>(0.0,0.0);
+  concave_polygon[1] = Point<2>(1.0,0.0);
+  concave_polygon[2] = Point<2>(1.0,1.0);
+  concave_polygon[3] = Point<2>(0.5,0.5);
+  concave_polygon[4] = Point<2>(0.0,1.0);
+
+  // A selfcrossing polygon
+  std::vector< Point<2> > crossing_polygon(4);
+  crossing_polygon[0] = Point<2>(0.0,0.0);
+  crossing_polygon[1] = Point<2>(1.0,0.0);
+  crossing_polygon[2] = Point<2>(1.0,-1.0);
+  crossing_polygon[3] = Point<2>(0.0,1.0);
+
+
   // Some points inside and outside the polygon
-  Point<2> points[] = {Point<2>(0.5,-1), Point<2>(0.5,0.5), Point<2>(0.001,0.2), Point<2>(2.0,2.0), Point<2>(0.001,0.75)};
+  Point<2> points[] = {Point<2>(0.5,-1), Point<2>(0.5,0.5), Point<2>(0.001,0.2), Point<2>(2.0,2.0), Point<2>(0.25,0.70)};
 
-  std::cout << "Testing distance to polygon function with the following parameters: (polygon) " << polygon[0] << ", " << polygon[1] << ", " << polygon[2] << ", " << polygon[3]
+  std::cout << "Testing distance to polygon function with the following parameters: (polygon 1) "
+            << polygon[0] << ", " << polygon[1] << ", " << polygon[2] << ", " << polygon[3] << ", "
+            << "(polygon 2) " << concave_polygon[0] << ", " << concave_polygon[1] << ", " << concave_polygon[2] << ", " << concave_polygon[3] << ", " << concave_polygon[4] << ", "
+            << "(polygon 3) " << crossing_polygon[0] << ", " << crossing_polygon[1] << ", " << crossing_polygon[2] << ", " << crossing_polygon[3]
             << ", (points) "
-            << points[0] << ", " << points[1] << ", " << points[2] << ", " << points[3] << ", "
-            << points[4] << std::endl;
+            << points[0] << ", " << points[1] << ", " << points[2] << ", " << points[3] << ", " << points[4] << std::endl;
 
   for (unsigned int i = 0; i < 5; i++)
     {
-      std::cout << "Minimal distance of point " << points[i] << " to polygon = " << signed_distance_to_polygon<dim>(polygon,points[i]) << std::endl;
+      std::cout << "Minimal distance of point " << points[i] << " to polygon 1 = " << signed_distance_to_polygon<dim>(polygon,points[i]) << std::endl;
+      std::cout << "Minimal distance of point " << points[i] << " to polygon 2 = " << signed_distance_to_polygon<dim>(concave_polygon,points[i]) << std::endl;
+      std::cout << "Minimal distance of point " << points[i] << " to polygon 3 = " << signed_distance_to_polygon<dim>(crossing_polygon,points[i]) << std::endl;
     }
 
   exit(0);

tests/prm_distance_polygon/screen-output

@@ -2,9 +2,19 @@
 -----------------------------------------------------------------------------
 
 Loading shared library <./libprm_distance_polygon.so>
-Testing distance to polygon function with the following parameters: (polygon) 0 0, 1 0, 1 1, 0 1, (points) 0.5 -1, 0.5 0.5, 0.001 0.2, 2 2, 0.001 0.75
-Minimal distance of point 0.5 -1 to polygon = -1
-Minimal distance of point 0.5 0.5 to polygon = 0.5
-Minimal distance of point 0.001 0.2 to polygon = 0.001
-Minimal distance of point 2 2 to polygon = -1.41421
-Minimal distance of point 0.001 0.75 to polygon = 0.001
+Testing distance to polygon function with the following parameters: (polygon 1) 0 0, 1 0, 1 1, 0 1, (polygon 2) 0 0, 1 0, 1 1, 0.5 0.5, 0 1, (polygon 3) 0 0, 1 0, 1 -1, 0 1, (points) 0.5 -1, 0.5 0.5, 0.001 0.2, 2 2, 0.25 0.7
+Minimal distance of point 0.5 -1 to polygon 1 = -1
+Minimal distance of point 0.5 -1 to polygon 2 = -1
+Minimal distance of point 0.5 -1 to polygon 3 = -0.447214
+Minimal distance of point 0.5 0.5 to polygon 1 = 0.5
+Minimal distance of point 0.5 0.5 to polygon 2 = 0
+Minimal distance of point 0.5 0.5 to polygon 3 = -0.223607
+Minimal distance of point 0.001 0.2 to polygon 1 = 0.001
+Minimal distance of point 0.001 0.2 to polygon 2 = 0.001
+Minimal distance of point 0.001 0.2 to polygon 3 = 0.001
+Minimal distance of point 2 2 to polygon 1 = -1.41421
+Minimal distance of point 2 2 to polygon 2 = -1.41421
+Minimal distance of point 2 2 to polygon 3 = -2.23607
+Minimal distance of point 0.25 0.7 to polygon 1 = 0.25
+Minimal distance of point 0.25 0.7 to polygon 2 = 0.0353553
+Minimal distance of point 0.25 0.7 to polygon 3 = -0.0894427