knock out some msvc compiler warnings

include/mapnik/image_filter.hpp

@@ -114,7 +114,7 @@
 
 namespace mapnik {  namespace filter { namespace detail {
 
-static const float blur_matrix[] = {0.1111,0.1111,0.1111,0.1111,0.1111,0.1111,0.1111,0.1111,0.1111};
+static const float blur_matrix[] = {0.1111f,0.1111f,0.1111f,0.1111f,0.1111f,0.1111f,0.1111f,0.1111f,0.1111f};
 static const float emboss_matrix[] = {-2,-1,0,-1,1,1,0,1,2};
 static const float sharpen_matrix[] = {0,-1,0,-1,5,-1,0,-1,0 };
 static const float edge_detect_matrix[] = {0,1,0,1,-4,1,0,1,0 };

include/mapnik/markers_placement.hpp

@@ -293,7 +293,7 @@ private:
                 last_y = next_y;
             }
         }
-        unsigned points = round(length / s);
+        unsigned points = static_cast<unsigned>(round(length / s));
         if (points == 0) return 0.0; //Path to short
         return length / points;
     }

include/mapnik/octree.hpp

@@ -250,7 +250,7 @@ public:
 
             // select best of all reducible:
             unsigned red_idx = leaf_level_-1;
-            unsigned bestv = (*reducible_[red_idx].begin())->reduce_cost;
+            unsigned bestv = static_cast<unsigned>((*reducible_[red_idx].begin())->reduce_cost);
             for(unsigned i=red_idx; i>=InsertPolicy::MIN_LEVELS; i--)
             {
                 if (!reducible_[i].empty())

plugins/input/gdal/gdal_featureset.cpp

@@ -200,8 +200,8 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
         // if layer-level filter_factor is set, apply it
         if (filter_factor_)
         {
-            im_width *= filter_factor_;
+            im_width = int(im_width * filter_factor_ + 0.5);
-            im_height *= filter_factor_;
+            im_height = int(im_height * filter_factor_ + 0.5);
 
             MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Applying layer filter_factor=" << filter_factor_;
         }
@@ -209,8 +209,8 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
         else
         {
             double sym_downsample_factor = q.get_filter_factor();
-            im_width *= sym_downsample_factor;
+            im_width = int(im_width * sym_downsample_factor + 0.5);
-            im_height *= sym_downsample_factor;
+            im_height = int(im_height * sym_downsample_factor + 0.5);
         }
 
         // case where we need to avoid upsampling so that the

src/agg/process_line_pattern_symbolizer.cpp

@@ -132,7 +132,7 @@ void  agg_renderer<T>::process(line_pattern_symbolizer const& sym,
     if (sym.clip())
     {
         double padding = (double)(query_extent_.width()/pixmap_.width());
-        float half_stroke = (*mark)->width()/2.0;
+        double half_stroke = (*mark)->width()/2.0;
         if (half_stroke > 1)
             padding *= half_stroke;
         clipping_extent.pad(padding);

src/agg/process_line_symbolizer.cpp

@@ -89,7 +89,7 @@ void agg_renderer<T>::process(line_symbolizer const& sym,
     if (sym.clip())
     {
         double padding = (double)(query_extent_.width()/pixmap_.width());
-        float half_stroke = stroke_.get_width()/2.0;
+        double half_stroke = stroke_.get_width()/2.0;
         if (half_stroke > 1)
             padding *= half_stroke;
         if (fabs(sym.offset()) > 0)

src/cairo_renderer.cpp

@@ -1052,7 +1052,7 @@ void cairo_renderer_base::process(line_symbolizer const& sym,
     if (sym.clip())
     {
         double padding = (double)(query_extent_.width()/width_);
-        float half_stroke = stroke_.get_width()/2.0;
+        double half_stroke = stroke_.get_width()/2.0;
         if (half_stroke > 1)
             padding *= half_stroke;
         if (fabs(sym.offset()) > 0)

src/grid/process_line_symbolizer.cpp

@@ -74,7 +74,7 @@ void grid_renderer<T>::process(line_symbolizer const& sym,
     if (sym.clip())
     {
         double padding = (double)(query_extent_.width()/pixmap_.width());
-        float half_stroke = stroke_.get_width()/2.0;
+        double half_stroke = stroke_.get_width()/2.0;
         if (half_stroke > 1)
             padding *= half_stroke;
         if (fabs(sym.offset()) > 0)

src/load_map.cpp

@@ -1125,7 +1125,7 @@ void map_parser::parse_polygon_pattern_symbolizer(rule & rule,
         symbol.set_alignment(p_alignment);
 
         // opacity
-        optional<double> opacity = sym.get_opt_attr<double>("opacity");
+        optional<float> opacity = sym.get_opt_attr<float>("opacity");
         if (opacity) symbol.set_opacity(*opacity);
 
         // gamma
@@ -1212,7 +1212,7 @@ void map_parser::parse_shield_symbolizer(rule & rule, xml_node const& sym)
         shield_symbol.set_shield_displacement(shield_dx,shield_dy);
 
         // opacity
-        optional<double> opacity = sym.get_opt_attr<double>("opacity");
+        optional<float> opacity = sym.get_opt_attr<float>("opacity");
         if (opacity)
         {
             shield_symbol.set_opacity(*opacity);
@@ -1484,7 +1484,7 @@ void map_parser::parse_raster_symbolizer(rule & rule, xml_node const & sym)
         }
 
         // opacity
-        optional<double> opacity = sym.get_opt_attr<double>("opacity");
+        optional<float> opacity = sym.get_opt_attr<float>("opacity");
         if (opacity) raster_sym.set_opacity(*opacity);
 
         // filter factor