image: add indexing operator for ints and points

image.cpp

@@ -268,8 +268,44 @@ util::image::buffer<T>::downsample (float factor) const
 }
 
 
+///////////////////////////////////////////////////////////////////////////////
+template <typename T>
+T
+buffer<T>::operator[] (point<2,size_t> p) const
+{
+    return begin ()[p.y * s + p.x];
+}
+
+
 //-----------------------------------------------------------------------------
 template <typename T>
+T&
+buffer<T>::operator[] (point<2,size_t> p)
+{
+    return begin ()[p.y * s + p.x];
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+T
+buffer<T>::operator[] (size_t idx) const
+{
+    return begin ()[idx];
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+T&
+buffer<T>::operator[] (size_t idx)
+{
+    return begin ()[idx];
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+template <typename T>
 T*
 buffer<T>::data (void)
 {

image.hpp

@@ -18,6 +18,7 @@
 #define __UTIL_IMAGE_HPP
 
 #include "extent.hpp"
+#include "point.hpp"
 
 #include <cstdint>
 #include <cstdlib>
@@ -53,6 +54,12 @@ namespace util {
             size_t h;
             size_t s;
 
+            T  operator[] (point<2,size_t>) const;
+            T& operator[] (point<2,size_t>);
+
+            T  operator[] (size_t) const;
+            T& operator[] (size_t);
+
             T* begin (void);
             T* end   (void);
             T* data  (void);