diff --git a/include/mapnik/grid/grid.hpp b/include/mapnik/grid/grid.hpp
index c940cf8e6..9e7fd897e 100644
--- a/include/mapnik/grid/grid.hpp
+++ b/include/mapnik/grid/grid.hpp
@@ -262,6 +262,30 @@ public:
         return height_;
     }
 
+    inline void blendPixel(value_type feature_id,int x,int y,unsigned int rgba1,int t)
+    {
+        blendPixel2(x,y,rgba1,t,1.0);  // do not change opacity
+    }
+
+    inline void blendPixel2(value_type feature_id,int x,int y,unsigned int rgba1,int t,double opacity)
+    {
+        if (checkBounds(x,y))
+        {
+
+#ifdef MAPNIK_BIG_ENDIAN
+            unsigned a1 = (int)((rgba1 & 0xff) * opacity) & 0xff; // adjust for desired opacity
+#else
+            unsigned a = (int)(((rgba1 >> 24) & 0xff) * opacity) & 0xff; // adjust for desired opacity
+#endif                    
+            // if the pixel is more than a tenth
+            // opaque then burn in the feature id
+            if (a >= 25)
+            {
+                data_(x,y) = feature_id;
+            }
+        }
+    }
+    
     inline void set_rectangle(value_type id,image_data_32 const& data,int x0,int y0)
     {
         box2d<int> ext0(0,0,width_,height_);