image: add area and is_packed methods

Makefile.am

@@ -96,6 +96,7 @@ UTIL_FILES   =			\
     hash/wang.ipp		\
     image.cpp			\
     image.hpp			\
+    image.ipp			\
     introspection.cpp		\
     introspection.hpp		\
     io.cpp			\

image.hpp

@@ -48,6 +48,9 @@ namespace util { namespace image {
 
         buffer<T> downsample (float factor) const;
 
+        constexpr size_t area (void) const;
+        constexpr bool is_packed (void) const;
+
         size_t w;
         size_t h;
         size_t s;
@@ -71,4 +74,6 @@ namespace util { namespace image {
     };
 } }
 
+#include "image.ipp"
+
 #endif

image.ipp

@@ -0,0 +1,38 @@
+/*
+ * 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 2011-2015 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifdef __UTIL_IMAGE_IPP
+#error
+#endif
+#define __UTIL_IMAGE_IPP
+
+namespace util { namespace image {
+    //-------------------------------------------------------------------------
+    template <typename T>
+    constexpr size_t
+    buffer<T>::area (void) const
+    {
+        return w * h;
+    }
+
+    //-------------------------------------------------------------------------
+    template <typename T>
+    constexpr bool
+    buffer<T>::is_packed (void) const
+    {
+        return s == w;
+    }
+} }