winding_numbers_algorithm: changed interface.

src/Samplegridicon.cc

@@ -316,9 +316,9 @@ compute_child_from_bounds(CellIndex *cellindex2, long ncells2, double *grid_cent
   size_t *nbr_addr = &knnWeights.m_addr[0];
 
   int ncorner = 3;
-  double center_point_xyz[3];
   double cell_corners_xyz[12];
   double cell_corners_plane_projection[8];
+  double center_point_xyz[3];
   double center_point_plane_projection[2];
 
   long *child2 = (long *) Malloc(MAX_CHILDS * ncells2 * sizeof(long));

src/Verifygrid.cc

@@ -170,24 +170,25 @@ find_coordinate_to_ignore(const double *cell_corners_xyz)
   return coordinate_to_ignore;
 }
 
-static double
-is_point_left_of_edge(const double (&point_on_line_1)[2], const double (&point_on_line_2)[2], const double *point)
+static inline double
+is_point_left_of_edge(const double (&point1)[2], const double (&point2)[2], const double (&point)[2])
 {
   /*
-     Computes whether a point is left of the line through point_on_line_1 and point_on_line_2. This is part of the
-     solution to the point in polygon problem. Returns 0 if the point is on the line, > 0 if the point is left of the
-     line, and < 0 if the point is right of the line. This algorithm is by Dan Sunday (geomalgorithms.com) and is
-     completely free for use and modification.
-  */
+     Computes whether a point is left of the line through point1 and point2.
+     This is part of the solution to the point in polygon problem.
 
-  auto answer = ((point_on_line_2[0] - point_on_line_1[0]) * (point[1] - point_on_line_1[1])
-                   - (point[0] - point_on_line_1[0]) * (point_on_line_2[1] - point_on_line_1[1]));
+     Returns:  0 if the point is on the line through point1 and point2
+             > 0 if the point is left of the line
+             < 0 if the point is right of the line
+
+     This algorithm is by Dan Sunday (geomalgorithms.com) and is completely free for use and modification.
+  */
 
-  return answer;
+  return ((point2[0] - point1[0]) * (point[1] - point1[1]) - (point[0] - point1[0]) * (point2[1] - point1[1]));
 }
 
 int
-winding_numbers_algorithm(const double *cell_corners, int number_corners, const double *point)
+winding_numbers_algorithm(const double *cell_corners, int number_corners, const double (&point)[2])
 {
   /*
      Computes whether a point is inside the bounds of a cell. This is the solution to the point in polygon problem.
@@ -203,20 +204,20 @@ winding_numbers_algorithm(const double *cell_corners, int number_corners, const
         {
           if (cell_corners[(i + 1) * 2 + 1] > point[1])
             {
-              const double point_on_edge_1[2] = { cell_corners[i * 2 + 0], cell_corners[i * 2 + 1] };
-              const double point_on_edge_2[2] = { cell_corners[(i + 1) * 2 + 0], cell_corners[(i + 1) * 2 + 1] };
+              const double point1[2] = { cell_corners[i * 2 + 0], cell_corners[i * 2 + 1] };
+              const double point2[2] = { cell_corners[(i + 1) * 2 + 0], cell_corners[(i + 1) * 2 + 1] };
 
-              if (is_point_left_of_edge(point_on_edge_1, point_on_edge_2, point) > 0) winding_number++;
+              if (is_point_left_of_edge(point1, point2, point) > 0) winding_number++;
             }
         }
       else
         {
           if (cell_corners[(i + 1) * 2 + 1] <= point[1])
             {
-              const double point_on_edge_1[2] = { cell_corners[i * 2 + 0], cell_corners[i * 2 + 1] };
-              const double point_on_edge_2[2] = { cell_corners[(i + 1) * 2 + 0], cell_corners[(i + 1) * 2 + 1] };
+              const double point1[2] = { cell_corners[i * 2 + 0], cell_corners[i * 2 + 1] };
+              const double point2[2] = { cell_corners[(i + 1) * 2 + 0], cell_corners[(i + 1) * 2 + 1] };
 
-              if (is_point_left_of_edge(point_on_edge_1, point_on_edge_2, point) < 0) winding_number--;
+              if (is_point_left_of_edge(point1, point2, point) < 0) winding_number--;
             }
         }
     }

src/verifygrid.h

@@ -23,6 +23,6 @@ void set_cell_corners_plane_projection(int coordinate_to_ignore, int ncorner, co
 int find_coordinate_to_ignore(const double *cell_corners_xyz);
 double calculate_the_polygon_area(const double *cell_corners, int number_corners);
 bool are_polygon_vertices_arranged_in_clockwise_order(double cell_area);
-int winding_numbers_algorithm(const double *cell_corners, int number_corners, const double *point);
+int winding_numbers_algorithm(const double *cell_corners, int number_corners, const double (&point)[2]);
 
 #endif /* VERIFYGRID_H */