Added normals to Plane primitive.

src/Primitives/Plane.cpp

@@ -24,6 +24,11 @@ Plane::Plane(): MeshData(Mesh::Primitive::TriangleStrip, nullptr, {new vector<Ve
     {1.0f, 1.0f, 0.0f},
     {-1.0f, -1.0f, 0.0f},
     {-1.0f, 1.0f, 0.0f}
-}}, {}, {}) {}
+}}, {new vector<Vector3>{
+    {0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 1.0f}
+}}, {}) {}
 
 }}

src/Primitives/Plane.h

@@ -26,7 +26,7 @@ namespace Magnum { namespace Primitives {
 /**
 @brief %Plane primitive
 
-2x2 plane orthogonal to Z axis.
+2x2 plane with normals in positive Z direction.
 */
 class Plane: public Trade::MeshData {
     public: