Changeset 1686

Timestamp:

03/12/10 08:34:32 (5 months ago)

Author:

alberto

Message:

modified raster_colorizer so the color of the last band is used if the value matches its value exactly. This is to make declaring legends for rasters with discrete values easier (ie: no need to define a dummy band for N+1)

Location:

trunk

Files:

• include/mapnik/raster_colorizer.hpp (modified) (2 diffs)
• tests/python_tests/raster_colorizer_test.py (modified) (2 diffs)

trunk/include/mapnik/raster_colorizer.hpp

@@ -154 +154 @@
          *   otherwise: transparent
          *     where 0 <= pos < length(bands)-1
+         *   Last band is special, its value represents the upper bound and its
+         *   color will only be used if the value matches its value exactly.
          */
          color get_color(float value) const {
-            int pos=-1, lo=0, hi=colors_.size()-1;
+            int pos=-1, last=(int)colors_.size()-1, lo=0, hi=last;
             while (lo<=hi) {
                 pos = (lo+hi)/2;
@@ -169 +171 @@
             }
             lo--;
-            return (0 <= lo && lo < (int)colors_.size()-1)?
-                colors_[lo].color_:
-                color(0,0,0,0);
+            if ((0 <= lo && lo < last) ||
+                (lo==last && colors_[last].value_==value))
+                return colors_[lo].color_;
+            else
+                return color(0,0,0,0);
          }
 

trunk/tests/python_tests/raster_colorizer_test.py

@@ -19 +19 @@
         ( 80, "#990099"),
         ( 90, "#660066"),
-        ( 200, "#00000"), # last band denotes upper limit, values above it will
-                          # not return the color
+        ( 200, "#ffffff"),
         ]]
     for value, color in bands:
@@ -29 +28 @@
     eq_(colorizer.get_color(5), bands[0][1])
     eq_(colorizer.get_color(10), bands[1][1])
-    eq_(colorizer.get_color(200), mapnik2.Color("transparent"))
+    # last value is used if it matches exactly
+    eq_(colorizer.get_color(200), bands[-1][1])
+    #  values greater than the last value are mapped to "transparent"
     eq_(colorizer.get_color(201), mapnik2.Color("transparent"))