MeshTools: add type-erased flipNormals() and flipFaceWinding().

src/Magnum/MeshTools/FlipNormals.cpp

@@ -56,6 +56,18 @@ void flipFaceWindingInPlace(const Containers::StridedArrayView1D<UnsignedByte>&
     flipFaceWindingInPlaceImplementation(indices);
 }
 
+void flipFaceWindingInPlace(const Containers::StridedArrayView2D<char>& indices) {
+    CORRADE_ASSERT(indices.isContiguous<1>(), "MeshTools::flipFaceWindingInPlace(): second index view dimension is not contiguous", );
+    if(indices.size()[1] == 4)
+        return flipFaceWindingInPlaceImplementation(Containers::arrayCast<1, UnsignedInt>(indices));
+    else if(indices.size()[1] == 2)
+        return flipFaceWindingInPlaceImplementation(Containers::arrayCast<1, UnsignedShort>(indices));
+    else {
+        CORRADE_ASSERT(indices.size()[1] == 1, "MeshTools::flipFaceWindingInPlace(): expected index type size 1, 2 or 4 but got" << indices.size()[1], );
+        return flipFaceWindingInPlaceImplementation(Containers::arrayCast<1, UnsignedByte>(indices));
+    }
+}
+
 void flipNormalsInPlace(const Containers::StridedArrayView1D<Vector3>& normals) {
     for(Vector3& normal: normals)
         normal = -normal;

src/Magnum/MeshTools/FlipNormals.h

@@ -67,6 +67,17 @@ void flipNormalsInPlace(const Containers::StridedArrayView1D<UnsignedShort>& ind
  */
 void flipNormalsInPlace(const Containers::StridedArrayView1D<UnsignedByte>& indices, const Containers::StridedArrayView1D<Vector3>& normals);
 
+/**
+@brief Flip mesh normals and face winding in-place on a type-erased index array
+@m_since_latest
+
+Expects that the second dimension of @p indices is contiguous and represents
+the actual 1/2/4-byte index type. Based on its size then calls one of the
+@ref flipNormalsInPlace(const Containers::StridedArrayView1D<UnsignedInt>&, const Containers::StridedArrayView1D<Vector3>&)
+etc. overloads.
+*/
+void flipNormalsInPlace(const Containers::StridedArrayView2D<char>& indices, const Containers::StridedArrayView1D<Vector3>& normals);
+
 #ifdef MAGNUM_BUILD_DEPRECATED
 /**
 @brief @copybrief flipNormalsInPlace(const Containers::StridedArrayView1D<UnsignedInt>&, const Containers::StridedArrayView1D<Vector3>&)
@@ -99,6 +110,17 @@ void MAGNUM_MESHTOOLS_EXPORT flipFaceWindingInPlace(const Containers::StridedArr
  */
 void MAGNUM_MESHTOOLS_EXPORT flipFaceWindingInPlace(const Containers::StridedArrayView1D<UnsignedByte>& indices);
 
+/**
+@brief Flip face winding in-place on a type-erased index array
+@m_since_latest
+
+Expects that the second dimension of @p indices is contiguous and represents
+the actual 1/2/4-byte index type. Based on its size then calls one of the
+@ref flipFaceWindingInPlace(const Containers::StridedArrayView1D<UnsignedInt>&)
+etc. overloads.
+*/
+void MAGNUM_MESHTOOLS_EXPORT flipFaceWindingInPlace(const Containers::StridedArrayView2D<char>& indices);
+
 #ifdef MAGNUM_BUILD_DEPRECATED
 /**
 @brief @copybrief flipFaceWindingInPlace(const Containers::StridedArrayView1D<UnsignedInt>&)
@@ -141,6 +163,11 @@ inline void flipNormalsInPlace(const Containers::StridedArrayView1D<UnsignedByte
     flipNormalsInPlace(normals);
 }
 
+inline void flipNormalsInPlace(const Containers::StridedArrayView2D<char>& indices, const Containers::StridedArrayView1D<Vector3>& normals) {
+    flipFaceWindingInPlace(indices);
+    flipNormalsInPlace(normals);
+}
+
 }}
 
 #endif

src/Magnum/MeshTools/Test/FlipNormalsTest.cpp

@@ -39,9 +39,11 @@ struct FlipNormalsTest: TestSuite::Tester {
 
     void wrongIndexCount();
     template<class T> void flipFaceWinding();
+    template<class T> void flipFaceWindingErased();
     void flipNormals();
 
     template<class T> void flipNormalsFaceWinding();
+    template<class T> void flipNormalsFaceWindingErased();
 };
 
 FlipNormalsTest::FlipNormalsTest() {
@@ -49,11 +51,18 @@ FlipNormalsTest::FlipNormalsTest() {
               &FlipNormalsTest::flipFaceWinding<UnsignedByte>,
               &FlipNormalsTest::flipFaceWinding<UnsignedShort>,
               &FlipNormalsTest::flipFaceWinding<UnsignedInt>,
+              &FlipNormalsTest::flipFaceWindingErased<UnsignedByte>,
+              &FlipNormalsTest::flipFaceWindingErased<UnsignedShort>,
+              &FlipNormalsTest::flipFaceWindingErased<UnsignedInt>,
               &FlipNormalsTest::flipNormals,
 
               &FlipNormalsTest::flipNormalsFaceWinding<UnsignedByte>,
               &FlipNormalsTest::flipNormalsFaceWinding<UnsignedShort>,
-              &FlipNormalsTest::flipNormalsFaceWinding<UnsignedInt>});
+              &FlipNormalsTest::flipNormalsFaceWinding<UnsignedInt>,
+              &FlipNormalsTest::flipNormalsFaceWindingErased<UnsignedByte>,
+              &FlipNormalsTest::flipNormalsFaceWindingErased<UnsignedShort>,
+              &FlipNormalsTest::flipNormalsFaceWindingErased<UnsignedInt>,
+    });
 }
 
 void FlipNormalsTest::wrongIndexCount() {
@@ -77,6 +86,17 @@ template<class T> void FlipNormalsTest::flipFaceWinding() {
         TestSuite::Compare::Container);
 }
 
+template<class T> void FlipNormalsTest::flipFaceWindingErased() {
+    setTestCaseTemplateName(Math::TypeTraits<T>::name());
+
+    T indices[]{0, 1, 2, 3, 4, 5};
+    MeshTools::flipFaceWindingInPlace(indices);
+
+    CORRADE_COMPARE_AS(Containers::arrayView(indices),
+        Containers::arrayView<T>({0, 2, 1, 3, 5, 4}),
+        TestSuite::Compare::Container);
+}
+
 void FlipNormalsTest::flipNormals() {
     Vector3 normals[]{Vector3::xAxis(), Vector3::yAxis(), Vector3::zAxis()};
     MeshTools::flipNormalsInPlace(normals);
@@ -103,6 +123,24 @@ template<class T> void FlipNormalsTest::flipNormalsFaceWinding() {
         }), TestSuite::Compare::Container);
 }
 
+template<class T> void FlipNormalsTest::flipNormalsFaceWindingErased() {
+    setTestCaseTemplateName(Math::TypeTraits<T>::name());
+
+    T indices[]{0, 1, 2, 3, 4, 5};
+    Vector3 normals[]{Vector3::xAxis(), Vector3::yAxis(), Vector3::zAxis()};
+    MeshTools::flipNormalsInPlace(
+        Containers::arrayCast<2, char>(Containers::stridedArrayView(indices)),
+        normals);
+
+    CORRADE_COMPARE_AS(Containers::arrayView(indices),
+        Containers::arrayView<T>({0, 2, 1, 3, 5, 4}),
+        TestSuite::Compare::Container);
+    CORRADE_COMPARE_AS(Containers::arrayView(normals),
+        Containers::arrayView<Vector3>({
+            -Vector3::xAxis(), -Vector3::yAxis(), -Vector3::zAxis()
+        }), TestSuite::Compare::Container);
+}
+
 }}}}
 
 CORRADE_TEST_MAIN(Magnum::MeshTools::Test::FlipNormalsTest)