diff --git a/noise.cpp b/noise.cpp
index 1df999fd..2260dcf7 100644
--- a/noise.cpp
+++ b/noise.cpp
@@ -11,7 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
- * Copyright 2011 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
  */
 
 
@@ -22,6 +22,22 @@
 #include <iostream>
 #include <limits>
 
+
+//-----------------------------------------------------------------------------
+void
+util::noise::fill (image::buffer<float> &pixels,
+                   const util::noise::fractal &gen)
+{
+    size_t h = pixels.h, s = pixels.s, w = pixels.w;
+    float *data = pixels.data ();
+
+    for (size_t y = 0; y < h; ++y)
+        for (size_t x = 0; x < w; ++x)
+            data[y * s + x] = gen (double(x), double(y));
+}
+
+
+//-----------------------------------------------------------------------------
 void
 util::noise::image2d (uint8_t *restrict pixels,
                       size_t            width,
diff --git a/noise.hpp b/noise.hpp
index f7ee9586..d74e2c51 100644
--- a/noise.hpp
+++ b/noise.hpp
@@ -11,7 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
- * Copyright 2011 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
  */
 
 #ifndef __UTIL_PERLIN_HPP
@@ -23,8 +23,12 @@
 #include "noise/basis.hpp"
 #include "noise/fractal.hpp"
 
+#include "image.hpp"
+
 namespace util {
     namespace noise {
+        void fill (image::buffer<float>&, const util::noise::fractal&);
+
         void image2d (uint8_t *restrict pixels, size_t width, size_t height, const util::noise::fractal&);
     }
 }
diff --git a/noise/fractal.hpp b/noise/fractal.hpp
index 2117412d..0fa72cb5 100644
--- a/noise/fractal.hpp
+++ b/noise/fractal.hpp
@@ -32,6 +32,7 @@ namespace util {
             double   frequency;
             double   lacunarity;
 
+            virtual double operator() (double x, double y) const { return eval (x, y); };
             virtual double eval (double x, double y) const = 0;
         };