sphere: add stub sphere class

Makefile.am

@@ -161,6 +161,8 @@ UTIL_FILES   =		\
     signal.hpp		\
     signal.ipp		\
     si.hpp		\
+    sphere.cpp		\
+    sphere.hpp		\
     stats.cpp		\
     stats.hpp		\
     stream.cpp		\

sphere.cpp

@@ -0,0 +1,22 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2015 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "sphere.hpp"
+
+using util::sphere;
+
+//-----------------------------------------------------------------------------
+template struct util::sphere<3,float>;

sphere.hpp

@@ -0,0 +1,32 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2015 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef __UTIL_SPHERE_HPP
+#define __UTIL_SPHERE_HPP
+
+#include "point.hpp"
+
+namespace util {
+    template <size_t S, typename T>
+    struct sphere {
+        point<S,T> c;
+        T r;
+    };
+
+    typedef sphere<3,float> sphere3f;
+}
+
+#endif