From 8d60a553361b3a1219311f021da81d67752d256e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Bartoletti?= <loic.bartoletti@oslandia.com>
Date: Fri, 12 Jul 2024 16:05:57 +0200
Subject: [PATCH] ForceOrderPoints: also allow for 3D geometries

Follow-up https://gitlab.com/sfcgal/SFCGAL/-/merge_requests/324
Fix https://gitlab.com/sfcgal/SFCGAL/-/issues/268
---
 src/detail/transform/ForceOrderPoints.cpp | 59 +++++++++++------------
 test/unit/SFCGAL/capi/sfcgal_cTest.cpp    | 23 +++++++++
 2 files changed, 50 insertions(+), 32 deletions(-)

diff --git a/src/detail/transform/ForceOrderPoints.cpp b/src/detail/transform/ForceOrderPoints.cpp
index 1317c08b..af2020ed 100644
--- a/src/detail/transform/ForceOrderPoints.cpp
+++ b/src/detail/transform/ForceOrderPoints.cpp
@@ -29,50 +29,45 @@ ForceOrderPoints::transform(Point & /*p*/)
 void
 ForceOrderPoints::visit(Triangle &t)
 {
-  if (!t.is3D()) {
-    if (!algorithm::isCounterClockWiseOriented(t)) {
-      // not pointing up, reverse
-      if (_orientCCW) {
-        t.reverse();
-      }
-    } else {
-      if (!_orientCCW) {
-        t.reverse();
-      }
+  if (!algorithm::isCounterClockWiseOriented(t)) {
+    // not pointing up, reverse
+    if (_orientCCW) {
+      t.reverse();
+    }
+  } else {
+    if (!_orientCCW) {
+      t.reverse();
     }
-
-    Transform::visit(t);
   }
+
+  Transform::visit(t);
 }
 
 void
 ForceOrderPoints::visit(Polygon &p)
 {
-  if (!p.is3D()) {
-    LineString &ext = p.exteriorRing();
+  LineString &ext = p.exteriorRing();
 
-    if (!algorithm::isCounterClockWiseOriented(p.exteriorRing())) {
-      // exterior ring not pointing up, reverse
-      if (_orientCCW) {
-        ext.reverse();
-      }
-    } else {
-      if (!_orientCCW) {
-        ext.reverse();
-      }
+  if (!algorithm::isCounterClockWiseOriented(p.exteriorRing())) {
+    // exterior ring not pointing up, reverse
+    if (_orientCCW) {
+      ext.reverse();
     }
-
-    const bool isCCWO{algorithm::isCounterClockWiseOriented(ext)};
-    for (size_t i = 0; i < p.numInteriorRings(); ++i) {
-      LineString &inter = p.interiorRingN(i);
-
-      if (algorithm::isCounterClockWiseOriented(inter) == isCCWO) {
-        inter.reverse();
-      }
+  } else {
+    if (!_orientCCW) {
+      ext.reverse();
     }
+  }
+  const bool isCCWO{algorithm::isCounterClockWiseOriented(ext)};
+  for (size_t i = 0; i < p.numInteriorRings(); ++i) {
+    LineString &inter = p.interiorRingN(i);
 
-    Transform::visit(p);
+    if (algorithm::isCounterClockWiseOriented(inter) == isCCWO) {
+      inter.reverse();
+    }
   }
+
+  Transform::visit(p);
 }
 
 } // namespace SFCGAL::transform
diff --git a/test/unit/SFCGAL/capi/sfcgal_cTest.cpp b/test/unit/SFCGAL/capi/sfcgal_cTest.cpp
index 82faaac3..43c37e2b 100644
--- a/test/unit/SFCGAL/capi/sfcgal_cTest.cpp
+++ b/test/unit/SFCGAL/capi/sfcgal_cTest.cpp
@@ -214,4 +214,27 @@ BOOST_AUTO_TEST_CASE(testForceLHR)
   delete[] wkbApi;
 }
 
+BOOST_AUTO_TEST_CASE(testForceRHR_3D)
+{
+  sfcgal_set_error_handlers(printf, on_error);
+
+  std::string strGeom{"POLYGON((0 5 1,0 0 2,5 0 3,5 5 4,0 5 1),(2 1 1,1 1 2,1 "
+                      "2 3,2 2 4,2 1 1),(4 3 1,3 3 2,3 4 3,4 4 4,4 3 1))"};
+  std::string expectedGeom{
+      "POLYGON Z((0 5 1,5 5 4,5 0 3,0 0 2,0 5 1),(2 1 1,2 2 4,1 2 3,1 1 2,2 1 "
+      "1),(4 3 1,4 4 4,3 4 3,3 3 2,4 3 1))"};
+
+  std::unique_ptr<Geometry> const geom(io::readWkt(strGeom));
+
+  sfcgal_geometry_t *rhr = sfcgal_geometry_force_rhr(geom.get());
+  // retrieve wkb from C api
+  char  *wkbApi;
+  size_t wkbLen;
+  sfcgal_geometry_as_text_decim(rhr, 0, &wkbApi, &wkbLen);
+  std::string strApi(wkbApi, wkbLen);
+
+  // check
+  BOOST_CHECK_EQUAL(expectedGeom, strApi);
+  delete[] wkbApi;
+}
 BOOST_AUTO_TEST_SUITE_END()