From 3ed68b80ae7b5badbafe540ece9cccb0a74bf9a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Bartoletti?= <loic.bartoletti@oslandia.com>
Date: Tue, 10 Oct 2023 10:13:08 +0200
Subject: [PATCH] refacto: query visibility parts was almost the same. refactor
 this and fix test accordingly

---
 src/algorithm/visibility.cpp              | 71 +++++++++++------------
 test/unit/SFCGAL/algorithm/Visibility.cpp |  6 +-
 2 files changed, 37 insertions(+), 40 deletions(-)

diff --git a/src/algorithm/visibility.cpp b/src/algorithm/visibility.cpp
index 352c1dc3..db12901b 100644
--- a/src/algorithm/visibility.cpp
+++ b/src/algorithm/visibility.cpp
@@ -27,6 +27,38 @@ using Halfedge_const_handle = Arrangement_2::Halfedge_const_handle;
 using TEV =
     CGAL::Triangular_expansion_visibility_2<Arrangement_2, CGAL::Tag_true>;
 using PolygonWithHoles = CGAL::Polygon_with_holes_2<Kernel>;
+
+static auto
+query_visibility(Face_handle fh, Halfedge_const_handle he)
+    -> std::unique_ptr<Polygon>
+{
+
+  std::unique_ptr<LineString> extRing{new LineString()};
+  // Make sure the visibility polygon we find has an outer boundary
+  if (fh->has_outer_ccb()) {
+    Arrangement_2::Ccb_halfedge_circulator curr = fh->outer_ccb();
+
+    // find the right halfedge first
+    if (he != Halfedge_const_handle())
+      while (++curr != fh->outer_ccb())
+        if (curr->source()->point() == he->source()->point())
+          break;
+
+    Arrangement_2::Ccb_halfedge_circulator first = curr;
+    extRing->addPoint(Point(curr->source()->point()));
+
+    // Save the points from the visibility polygon
+    while (++curr != first) {
+      extRing->addPoint(Point(curr->source()->point()));
+    }
+  }
+
+  extRing->closes();
+  std::unique_ptr<Polygon> result{new Polygon(extRing.release())};
+
+  return result;
+}
+
 ///
 ///
 ///
@@ -103,29 +135,8 @@ visibility(const Geometry &polygon, const Geometry &point, NoValidityCheck)
     // Use the half edge to compute the visibility
     fh = tev.compute_visibility(queryPoint, he, output_arr);
   }
-  // Make sure the visibility polygon we find has an outer boundary
-  if (fh->has_outer_ccb()) {
-    Arrangement_2::Ccb_halfedge_circulator curr = fh->outer_ccb();
-
-    // find the right halfedge first
-    if (he != Halfedge_const_handle())
-      while (++curr != fh->outer_ccb())
-        if (curr->source()->point() == he->source()->point())
-          break;
-
-    Arrangement_2::Ccb_halfedge_circulator first = curr;
-    extRing->addPoint(Point(curr->source()->point()));
-
-    // Save the points from the visibility polygon
-    while (++curr != first) {
-      extRing->addPoint(Point(curr->source()->point()));
-    }
-  }
-
-  extRing->closes();
-  std::unique_ptr<Polygon> result{new Polygon(extRing.release())};
 
-  return result;
+  return query_visibility(fh, he);
 }
 ///
 ///
@@ -176,21 +187,7 @@ visibility(const Geometry &polygon, const Geometry &pointA,
   TEV           tev(arr);
   Face_handle   fh = tev.compute_visibility(endPoint, he, output_arr);
 
-  // export the visibility region.
-  Arrangement_2::Ccb_halfedge_circulator curr = fh->outer_ccb();
-  std::unique_ptr<LineString>            extRing{new LineString()};
-
-  // Make sure the visibility polygon we find has an outer boundary
-  if (fh->has_outer_ccb()) {
-    extRing->addPoint(Point(curr->target()->point()));
-    while (++curr != fh->outer_ccb()) {
-      extRing->addPoint(Point(curr->target()->point()));
-    }
-  }
-  extRing->closes();
-  std::unique_ptr<Polygon> result{new Polygon(extRing.release())};
-
-  return result;
+  return query_visibility(fh, he);
 }
 
 } // namespace algorithm
diff --git a/test/unit/SFCGAL/algorithm/Visibility.cpp b/test/unit/SFCGAL/algorithm/Visibility.cpp
index fcd8a2dc..28351616 100644
--- a/test/unit/SFCGAL/algorithm/Visibility.cpp
+++ b/test/unit/SFCGAL/algorithm/Visibility.cpp
@@ -147,9 +147,9 @@ BOOST_AUTO_TEST_CASE(testVisibility_SegmentInPolygonHole)
   std::unique_ptr<Polygon> result(
       algorithm::visibility(poly, startPoint, endPoint));
   std::string expectedWkt =
-      "POLYGON((12.0 6.0,14.0 14.0,10.4 7.6,11.0 "
-      "7.0,11.0 6.0,10.0 6.0,9.6 6.0,9.0 5.0,1.0 2.0,4.7 "
-      "2.3,8.0 4.0,10.0 3.0,9.9 2.8,12.0 3.0,19.0 -2.0,12.0 6.0))";
+      "POLYGON((19.0 -2.0,12.0 6.0,14.0 14.0,10.4 7.6,11.0 7.0,11.0 6.0,10.0 "
+      "6.0,9.6 6.0,9.0 5.0,1.0 2.0,4.7 2.3,8.0 4.0,10.0 3.0,9.9 2.8,12.0 "
+      "3.0,19.0 -2.0))";
   BOOST_CHECK_EQUAL(result->asText(1), expectedWkt);
 }
 BOOST_AUTO_TEST_SUITE_END()