diff --git a/include/mapnik/global.hpp b/include/mapnik/global.hpp
index 6802c94fa..63b7262b3 100644
--- a/include/mapnik/global.hpp
+++ b/include/mapnik/global.hpp
@@ -159,6 +159,15 @@ namespace mapnik
 #endif
         return val;
     }
+
+#ifdef _WINDOWS
+// msvc doesn't have rint in <cmath>
+inline int rint( double val)
+{
+    return int(floor(val + 0.5));
+}
+#endif
+
 }
 
 #endif //GLOBAL_HPP
diff --git a/include/mapnik/graphics.hpp b/include/mapnik/graphics.hpp
index c3b093dcb..5b86c5d7a 100644
--- a/include/mapnik/graphics.hpp
+++ b/include/mapnik/graphics.hpp
@@ -369,10 +369,10 @@ public:
 		    unsigned g0 = (rgba0 >> 16 ) & 0xff;
 		    unsigned b0 = (rgba0 >> 8) & 0xff;
 
-		    r0 = uint8_t(((r1 - r0) * a1 + (r0 << 8)) >> 8);
-		    g0 = uint8_t(((g1 - g0) * a1 + (g0 << 8)) >> 8);
-		    b0 = uint8_t(((b1 - b0) * a1 + (b0 << 8)) >> 8);
-		    a0 = uint8_t((a1 + a0) - ((a1 * a0 + 255) >> 8));
+		    r0 = byte(((r1 - r0) * a1 + (r0 << 8)) >> 8);
+		    g0 = byte(((g1 - g0) * a1 + (g0 << 8)) >> 8);
+		    b0 = byte(((b1 - b0) * a1 + (b0 << 8)) >> 8);
+		    a0 = byte((a1 + a0) - ((a1 * a0 + 255) >> 8));
 
 		    row_to[x] = (a0)| (b0 << 8) |  (g0 << 16) | (r0 << 24) ;
 #else
@@ -387,10 +387,10 @@ public:
 		    unsigned g0 = (rgba0 >> 8 ) & 0xff;
 		    unsigned b0 = (rgba0 >> 16) & 0xff;
 
-		    r0 = uint8_t(((r1 - r0) * a1 + (r0 << 8)) >> 8);
-		    g0 = uint8_t(((g1 - g0) * a1 + (g0 << 8)) >> 8);
-		    b0 = uint8_t(((b1 - b0) * a1 + (b0 << 8)) >> 8);
-		    a0 = uint8_t((a1 + a0) - ((a1 * a0 + 255) >> 8));
+		    r0 = byte(((r1 - r0) * a1 + (r0 << 8)) >> 8);
+		    g0 = byte(((g1 - g0) * a1 + (g0 << 8)) >> 8);
+		    b0 = byte(((b1 - b0) * a1 + (b0 << 8)) >> 8);
+		    a0 = byte((a1 + a0) - ((a1 * a0 + 255) >> 8));
 		    
 		    row_to[x] = (a0 << 24)| (b0 << 16) |  (g0 << 8) | (r0) ;
 #endif
diff --git a/include/mapnik/image_util.hpp b/include/mapnik/image_util.hpp
index 83f09ba23..247683b86 100644
--- a/include/mapnik/image_util.hpp
+++ b/include/mapnik/image_util.hpp
@@ -232,8 +232,8 @@ inline void scale_image_bilinear (Image& target,const Image& source, double x_of
     int x=0,y=0,xs=0,ys=0;
     int tw2 = target_width/2;
     int th2 = target_height/2;
-    int offs_x = int(round((source_width-target_width-x_off_f*2*source_width)/2));
-    int offs_y = int(round((source_height-target_height-y_off_f*2*source_height)/2));
+    int offs_x = rint((source_width-target_width-x_off_f*2*source_width)/2);
+    int offs_y = rint((source_height-target_height-y_off_f*2*source_height)/2);
     unsigned yprt, yprt1, xprt, xprt1;
 
     //no scaling or subpixel offset
@@ -319,8 +319,8 @@ inline void scale_image_bilinear8 (Image& target,const Image& source, double x_o
     int x=0,y=0,xs=0,ys=0;
     int tw2 = target_width/2;
     int th2 = target_height/2;
-    int offs_x = int(round((source_width-target_width-x_off_f*2*source_width)/2));
-    int offs_y = int(round((source_height-target_height-y_off_f*2*source_height)/2));
+    int offs_x = rint((source_width-target_width-x_off_f*2*source_width)/2);
+    int offs_y = rint((source_height-target_height-y_off_f*2*source_height)/2);
     unsigned yprt, yprt1, xprt, xprt1;
 
     //no scaling or subpixel offset
diff --git a/src/agg_renderer.cpp b/src/agg_renderer.cpp
index 4c3c8d55e..3f443e915 100644
--- a/src/agg_renderer.cpp
+++ b/src/agg_renderer.cpp
@@ -76,6 +76,8 @@
 #include <iostream>
 #endif
 
+#include <cmath>
+
 namespace mapnik
 {
 class pattern_source : private boost::noncopyable
@@ -595,7 +597,7 @@ void  agg_renderer<T>::process(shield_symbolizer const& sym,
 				if ( sym.get_allow_overlap() || detector_.has_placement(label_ext) )
 				{
 				    //pixmap_.set_rectangle_alpha(px,py,*data);
-				    pixmap_.set_rectangle_alpha2(*(*data),px,py,sym.get_opacity());
+				    pixmap_.set_rectangle_alpha2(*(*data),px,py,float(sym.get_opacity()));
 				    box2d<double> dim = ren.prepare_glyphs(&text_placement.placements[0]);
 				    ren.render(x,y);
 				    detector_.insert(label_ext);
@@ -749,10 +751,10 @@ void agg_renderer<T>::process(raster_symbolizer const& sym,
 	
 	box2d<double> ext=t_.forward(raster->ext_);
 	
-	int start_x = int(round(ext.minx()));
-	int start_y = int(round(ext.miny()));
-	int raster_width = int(round(ext.width()));
-	int raster_height = int(round(ext.height()));
+	int start_x = rint(ext.minx());
+	int start_y = rint(ext.miny());
+	int raster_width = rint(ext.width());
+	int raster_height = rint(ext.height());
 	int end_x = start_x + raster_width;
 	int end_y = start_y + raster_height;
 	double err_offs_x = (ext.minx()-start_x + ext.maxx()-end_x)/2;