From c0673214359cd11bf9177f6e57135eaa0de13557 Mon Sep 17 00:00:00 2001
From: Luigi Malomo <malomo.luigi@gmail.com>
Date: Mon, 28 May 2018 14:58:38 +0200
Subject: [PATCH] added compute area function for polygonal meshes

---
 vcg/complex/algorithms/stat.h | 12 ++++++++++++
 vcg/space/polygon3.h          |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/vcg/complex/algorithms/stat.h b/vcg/complex/algorithms/stat.h
index 64b9a2aa..676314a0 100644
--- a/vcg/complex/algorithms/stat.h
+++ b/vcg/complex/algorithms/stat.h
@@ -31,6 +31,7 @@
 #include <vcg/complex/algorithms/closest.h>
 #include <vcg/space/index/grid_static_ptr.h>
 #include <vcg/complex/algorithms/inertia.h>
+#include <vcg/space/polygon3.h>
 
 
 namespace vcg {
@@ -264,6 +265,17 @@ public:
     return area/ScalarType(2.0);
   }
 
+  static ScalarType ComputePolyMeshArea(MeshType & m)
+  {
+    ScalarType area=0;
+
+    for(FaceIterator fi = m.face.begin(); fi != m.face.end(); ++fi)
+      if(!(*fi).IsD())
+        area += PolyArea(*fi);
+
+    return area;
+  }
+
 	static ScalarType ComputeBorderLength(MeshType & m)
 	{
 		RequireFFAdjacency(m);
diff --git a/vcg/space/polygon3.h b/vcg/space/polygon3.h
index 2e02e6fc..031523df 100644
--- a/vcg/space/polygon3.h
+++ b/vcg/space/polygon3.h
@@ -126,6 +126,9 @@ typename PolygonType::ScalarType PolyArea(const PolygonType &F)
     typedef typename PolygonType::CoordType CoordType;
     typedef typename PolygonType::ScalarType ScalarType;
 
+	if (F.VN() == 3)
+		return vcg::DoubleArea(F) / 2;
+
     CoordType bary=PolyBarycenter(F);
     ScalarType Area=0;
     for (size_t i=0;i<(size_t)F.VN();i++)