From e8637dbee32253c05e99b4298f068604a5f1a618 Mon Sep 17 00:00:00 2001
From: George Gayno <George.Gayno@noaa.gov>
Date: Mon, 2 Dec 2024 20:56:40 +0000
Subject: [PATCH] Finish unit test for inside_a_polygon.

Fixes #1000.
---
 tests/orog/ftst_inside_polygon.F90 | 42 +++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/tests/orog/ftst_inside_polygon.F90 b/tests/orog/ftst_inside_polygon.F90
index 94c2d850e..b71e57c38 100644
--- a/tests/orog/ftst_inside_polygon.F90
+++ b/tests/orog/ftst_inside_polygon.F90
@@ -1,5 +1,11 @@
  program inside_polygon
 
+! Unit test for function inside_a_polygon, which determines
+! whether a test point is located within an area specified
+! by a polygon.
+!
+! Author George Gayno NCEP/EMC
+
  use orog_utils, only    : inside_a_polygon
 
  implicit none
@@ -13,13 +19,15 @@ program inside_polygon
  real                 :: lon1, lat1
  real                 :: lon2(npts), lat2(npts)
 
-! The first part of the function checks if the test point is outside
+ print*,"Starting test of inside_a_polygon."
+
+! The first part of the function checks if the test point is well outside
 ! the neighborhood of the polygon - i.e., a gross check. There 
 ! are six separate checks. The first six tests are designed
 ! so that the polygon is far enough from the test point that
 ! each check is tripped.
 
-! Test to trip the first 'if' gross check. Is point outside the
+! Test to trip the first 'if' gross check. Is point well outside the
 ! neighborhood in the plus 'x' direction?
 
  print*, "Test point 1"
@@ -40,7 +48,7 @@ program inside_polygon
 
  if (inside) stop 2  ! Test point should be outside polygon.
 
-! Test to trip the second 'if' gross check. Is point outside the
+! Test to trip the second 'if' gross check. Is point well outside the
 ! neighborhood in the minus 'x' direction?
 
  print*, "Test point 2"
@@ -61,7 +69,7 @@ program inside_polygon
 
  if (inside) stop 4 ! Test point should be outside polygon.
 
-! Test to trip the third 'if' gross check. Is point outside the
+! Test to trip the third 'if' gross check. Is point well outside the
 ! neighborhood in the plus 'y' direction?
 
  print*, "Test point 3"
@@ -82,7 +90,7 @@ program inside_polygon
 
  if (inside) stop 6 ! Test point should be outside polygon.
 
-! Test to trip the fourth 'if' gross check. Is point outside the
+! Test to trip the fourth 'if' gross check. Is point well outside the
 ! neighborhood in the minus 'y' direction?
 
  print*, "Test point 4"
@@ -103,7 +111,7 @@ program inside_polygon
 
  if (inside) stop 8 ! Test point should be outside polygon.
 
-! Test to trip the fifth 'if' gross check. Is point outside the
+! Test to trip the fifth 'if' gross check. Is point well outside the
 ! neighborhood in the plus 'z' direction?
 
  print*, "Test point 5"
@@ -124,7 +132,7 @@ program inside_polygon
 
  if (inside) stop 10 ! Test point should be outside polygon.
 
-! Test to trip the sixth 'if' gross check. Is point outside the
+! Test to trip the sixth 'if' gross check. Is point well outside the
 ! neighborhood in the minus 'z' direction?
 
  print*, "Test point 6"
@@ -189,6 +197,26 @@ program inside_polygon
 
  if (.not.inside) stop 16  ! Test point should be inside polygon.
 
+! Test the case when the test point just outside the polygon.
+
+ print*, "Test point 9"
+
+ lon1 = 89.5 * D2R      ! Test point.
+ lat1 = 0.5 * D2R
+
+ lon2(1) = 90.0 * D2R   ! Polygon.
+ lat2(1) =  0.0 * D2R
+ lon2(2) = 90.0 * D2R
+ lat2(2) =  1.0 * D2R
+ lon2(3) = 91.0 * D2R
+ lat2(3) =  1.0 * D2R
+ lon2(4) = 91.0 * D2R
+ lat2(4) =  0.0 * D2R
+
+ inside=inside_a_polygon(lon1, lat1, npts, lon2, lat2)
+
+ if (inside) stop 18 ! Test point should be outside polygon.
+
  print*,"OK"
  print*,"SUCCSSS"