From 12b7069cf7ec065983a26aa2b5d5a60eb33e11f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20M=C3=B6ller?= <matthias.moeller@rwth-aachen.de>
Date: Tue, 24 Mar 2015 10:36:41 +0000
Subject: [PATCH] - fix warning with vector_cast - add compile error, if
 vector_cast cannot be performed - adds some color cast specializations - add
 simple vector_cast unittest

closes #2409

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1249 fdac6126-5c0c-442c-9429-916003d36597
---
 src/OpenMesh/Core/Utils/color_cast.hh  | 28 ++++++++++++-
 src/OpenMesh/Core/Utils/vector_cast.hh | 58 ++++++++------------------
 src/Unittests/unittests_vector_type.cc | 18 ++++++++
 3 files changed, 62 insertions(+), 42 deletions(-)

diff --git a/src/OpenMesh/Core/Utils/color_cast.hh b/src/OpenMesh/Core/Utils/color_cast.hh
index 3a65fad2..ddee57f3 100644
--- a/src/OpenMesh/Core/Utils/color_cast.hh
+++ b/src/OpenMesh/Core/Utils/color_cast.hh
@@ -82,7 +82,7 @@ struct color_caster
   inline static return_type cast(const src_t& _src)
   {
     dst_t dst;
-    vector_copy(_src, dst, GenProg::Int2Type<vector_traits<dst_t>::size_>());
+    vector_cast(_src, dst, GenProg::Int2Type<vector_traits<dst_t>::size_>());
     return dst;
   }
 };
@@ -222,6 +222,32 @@ struct color_caster<Vec4f,Vec3f>
   }
 };
 
+template <>
+struct color_caster<Vec4ui,Vec3uc>
+{
+  typedef Vec4ui return_type;
+
+  inline static return_type cast(const Vec3uc& _src)
+  {
+    return Vec4ui(_src[0],
+                  _src[1],
+                  _src[2],
+                  255 );
+  }
+};
+
+template <>
+struct color_caster<Vec4f,Vec3i>
+{
+  typedef Vec4f return_type;
+
+  inline static return_type cast(const Vec3i& _src)
+  {
+    const float f = 1.0f / 255.0f;
+    return Vec4f(_src[0]*f, _src[1]*f, _src[2]*f, 1.0f );
+  }
+};
+
 template <>
 struct color_caster<Vec4uc,Vec4f>
 {
diff --git a/src/OpenMesh/Core/Utils/vector_cast.hh b/src/OpenMesh/Core/Utils/vector_cast.hh
index 845d2338..0b723b5c 100644
--- a/src/OpenMesh/Core/Utils/vector_cast.hh
+++ b/src/OpenMesh/Core/Utils/vector_cast.hh
@@ -77,57 +77,33 @@ namespace OpenMesh {
 
 //-----------------------------------------------------------------------------
 
-
-template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<1> )
+template <typename src_t, typename dst_t, int n>
+inline void vector_cast( const src_t &_src, dst_t &_dst, GenProg::Int2Type<n> )
 {
-  _dst[0] = _src[0];
+  GenProg::AssertCompile< (vector_traits<dst_t>::size_ <= vector_traits<src_t>::size_) > vectorCastingToHigherDimension;
+  vector_cast(_src,_dst, GenProg::Int2Type<n-1>());
+  _dst[n-1] = static_cast<typename vector_traits<dst_t>::value_type >(_src[n-1]);
 }
 
 template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<2> )
+inline void vector_cast( const src_t &_src, dst_t &_dst, GenProg::Int2Type<0> )
 {
-  _dst[0] = _src[0];
-  _dst[1] = _src[1];
+}
+
+
+template <typename src_t, typename dst_t, int n>
+inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<n> )
+{
+  GenProg::AssertCompile< (vector_traits<dst_t>::size_ <= vector_traits<src_t>::size_) > vectorCopyToHigherDimension;
+  vector_copy(_src,_dst, GenProg::Int2Type<n-1>());
+  _dst[n-1] = _src[n-1];
 }
 
 template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<3> )
+inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<0> )
 {
-  _dst[0] = _src[0];
-  _dst[1] = _src[1];
-  _dst[2] = _src[2];
 }
 
-template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<4> )
-{
-  _dst[0] = _src[0];
-  _dst[1] = _src[1];
-  _dst[2] = _src[2];
-  _dst[3] = _src[3];
-}
-
-template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<5> )
-{
-  _dst[0] = _src[0];
-  _dst[1] = _src[1];
-  _dst[2] = _src[2];
-  _dst[3] = _src[3];
-  _dst[4] = _src[4];
-}
-
-template <typename src_t, typename dst_t>
-inline void vector_copy( const src_t &_src, dst_t &_dst, GenProg::Int2Type<6> )
-{
-  _dst[0] = _src[0];
-  _dst[1] = _src[1];
-  _dst[2] = _src[2];
-  _dst[3] = _src[3];
-  _dst[4] = _src[4];
-  _dst[5] = _src[5];
-}
 
 
 //-----------------------------------------------------------------------------
@@ -141,7 +117,7 @@ struct vector_caster
   inline static return_type cast(const src_t& _src)
   {
     dst_t dst;
-    vector_copy(_src, dst, GenProg::Int2Type<vector_traits<dst_t>::size_>());
+    vector_cast(_src, dst, GenProg::Int2Type<vector_traits<dst_t>::size_>());
     return dst;
   }
 };
diff --git a/src/Unittests/unittests_vector_type.cc b/src/Unittests/unittests_vector_type.cc
index afb7b29e..240eab07 100644
--- a/src/Unittests/unittests_vector_type.cc
+++ b/src/Unittests/unittests_vector_type.cc
@@ -65,6 +65,24 @@ TEST_F(OpenMeshVectorTest, AbsTest) {
 
 }
 
+/* Compute surface area via cross product
+ */
+TEST_F(OpenMeshVectorTest, VectorCasting) {
+
+  OpenMesh::Vec3d vecd(1.0,2.0,3.0);
+  OpenMesh::Vec3f vecf = OpenMesh::vector_cast<OpenMesh::Vec3f>(vecd);
+  EXPECT_EQ(1.f, vecf[0]) << "vector type cast failed on component 0";
+  EXPECT_EQ(2.f, vecf[1]) << "vector type cast failed on component 1";
+  EXPECT_EQ(3.f, vecf[2]) << "vector type cast failed on component 2";
+
+  OpenMesh::Vec4d vecd4(40.0,30.0,20.0,10.0);
+  vecd = OpenMesh::vector_cast<OpenMesh::Vec3d>(vecd4);
+  EXPECT_EQ(40.0, vecd[0]) << "vector dimension cast failed on component 0";
+  EXPECT_EQ(30.0, vecd[1]) << "vector dimension cast failed on component 1";
+  EXPECT_EQ(20.0, vecd[2]) << "vector dimension cast failed on component 2";
+
+}
+
 
 
 }