Move code to new function `copy_shift`

Preparing for more complex association criterium.

Overlap/CMakeLists.txt

@@ -7,7 +7,8 @@ if(MPI_Fortran_HAVE_F08_MODULE)
   add_executable(eddy_graph eddy_graph.f90 get_snapshot.f90 overlap.f90
     dispatch_snapshot.f90 recv_snapshot.f90 candidate_overlap.f90
     spher_polygon_area.f90 send_snapshot.f90 unit_edge_m.f90 config_graph.F90
-    read_grid.F90 read_snapshot.f90 read_eddy.f90 inters_lines.f90)
+    read_grid.F90 read_snapshot.f90 read_eddy.f90 inters_lines.f90
+    copy_shift.f90)
   target_link_libraries(eddy_graph PRIVATE EZMPI::ezmpi Jumble::jumble
     Shapelib_03::shapelib_03 Contour_531::contour_531 gpc_f Geometry::geometry
     MPI::MPI_Fortran Numer_Rec_95::numer_rec_95)
@@ -21,7 +22,7 @@ endif()
 add_subdirectory(Tests)
 target_sources(test_overlap PRIVATE overlap.f90 spher_polygon_area.f90
   candidate_overlap.f90 unit_edge_m.f90 config_graph.F90 read_grid.F90
-  read_snapshot.f90 read_eddy.f90 inters_lines.f90)
+  read_snapshot.f90 read_eddy.f90 inters_lines.f90 copy_shift.f90)
 target_sources(test_spher_polygon_area PRIVATE spher_polygon_area.f90)
 target_sources(test_read_snapshot PRIVATE read_snapshot.f90 read_eddy.f90
   read_grid.F90 config_graph.F90)

Overlap/copy_shift.f90

+module copy_shift_m
+
+  implicit none
+
+contains
+
+  function copy_shift(p, delta_long)
+
+    ! Libraries:
+    use contour_531, only: polyline
+    use jumble, only: twopi
+
+    type(polyline), intent(in):: p
+    real, intent(in):: delta_long ! difference in longitude, in rad
+    type(polyline) copy_shift
+
+    !------------------------------------------------------------------
+
+    copy_shift%n_points = p%n_points
+    copy_shift%closed = p%closed
+    allocate(copy_shift%points(2, p%n_points))
+    copy_shift%points(2, :) = p%points(2, :)
+
+    ! Shift the longitudes of `p`:
+    copy_shift%points(1, :) = p%points(1, :) &
+         + floor(delta_long / twopi + 0.5) * twopi
+
+  end function copy_shift
+
+end module copy_shift_m

Overlap/overlap.f90

@@ -13,9 +13,9 @@ contains
 
     ! Libraries:
     use contour_531, only: polyline
-    use jumble, only: twopi
 
     use inters_lines_m, only: inters_lines
+    use copy_shift_m, only: copy_shift
     use candidate_overlap_m, only: candidate_overlap
     use config_graph_m, only: dist_lim, min_inters_speed
     use derived_types, only: snapshot
@@ -86,19 +86,14 @@ contains
               ! Assertion: {e1%delta_out >= delta .or. e2%delta_in
               ! >= delta}
 
+              delta_long = e1%extr%coord(1) - e2%extr%coord(1)
+
               if (e2%speed_cont%n_points /= 0) then
-                 polyline_2 = e2%speed_cont%polyline
+                 polyline_2 = copy_shift(e2%speed_cont%polyline, delta_long)
               else
-                 polyline_2 = e2%out_cont%polyline
+                 polyline_2 = copy_shift(e2%out_cont%polyline, delta_long)
               end if
 
-              delta_long = e1%extr%coord(1) - e2%extr%coord(1)
-
-              ! Shift the longitudes of polyline_2 to values close to the
-              ! longitude of extremum i1:
-              polyline_2%points(1, :) = polyline_2%points(1, :) &
-                   + floor(delta_long / twopi + 0.5) * twopi
-
               assoc_eddies = inters_lines(polyline_1, polyline_2, &
                    min_inters_speed)