reduce overhead of flexible agg gamma setting per symbolizer - closes #1174

src/agg/agg_renderer.cpp

@@ -79,7 +79,10 @@ agg_renderer<T>::agg_renderer(Map const& m, T & pixmap, double scale_factor, uns
       font_engine_(),
       font_manager_(font_engine_),
       detector_(boost::make_shared<label_collision_detector4>(box2d<double>(-m.buffer_size(), -m.buffer_size(), m.width() + m.buffer_size() ,m.height() + m.buffer_size()))),
-      ras_ptr(new rasterizer)
+      ras_ptr(new rasterizer),
+      query_extent_(),
+      gamma_method_(GAMMA_POWER),
+      gamma_(1.0)
 {
     setup(m);
 }
@@ -98,7 +101,10 @@ agg_renderer<T>::agg_renderer(Map const& m, request const& req, T & pixmap, doub
       font_engine_(),
       font_manager_(font_engine_),
       detector_(boost::make_shared<label_collision_detector4>(box2d<double>(-req.buffer_size(), -req.buffer_size(), req.width() + req.buffer_size() ,req.height() + req.buffer_size()))),
-      ras_ptr(new rasterizer)
+      ras_ptr(new rasterizer),
+      query_extent_(),
+      gamma_method_(GAMMA_POWER),
+      gamma_(1.0)
 {
     setup(m);
 }
@@ -118,7 +124,10 @@ agg_renderer<T>::agg_renderer(Map const& m, T & pixmap, boost::shared_ptr<label_
       font_engine_(),
       font_manager_(font_engine_),
       detector_(detector),
-      ras_ptr(new rasterizer)
+      ras_ptr(new rasterizer),
+      query_extent_(),
+      gamma_method_(GAMMA_POWER),
+      gamma_(1.0)
 {
     setup(m);
 }
@@ -297,7 +306,12 @@ void agg_renderer<T>::render_marker(pixel_position const& pos,
     typedef agg::pod_bvector<mapnik::svg::path_attributes> svg_attribute_type;
 
     ras_ptr->reset();
-    ras_ptr->gamma(agg::gamma_power());
+    if (gamma_method_ != GAMMA_POWER || gamma_ != 1.0)
+    {
+        ras_ptr->gamma(agg::gamma_power());
+        gamma_method_ = GAMMA_POWER;
+        gamma_ = 1.0;
+    }
     agg::scanline_u8 sl;
     agg::rendering_buffer buf(current_buffer_->raw_data(), width_, height_, width_ * 4);
     pixfmt_comp_type pixf(buf);

src/agg/process_building_symbolizer.cpp

@@ -70,7 +70,12 @@ void agg_renderer<T>::process(building_symbolizer const& sym,
     agg::scanline_u8 sl;
 
     ras_ptr->reset();
-    ras_ptr->gamma(agg::gamma_power());
+    if (gamma_method_ != GAMMA_POWER || gamma_ != 1.0)
+    {
+        ras_ptr->gamma(agg::gamma_power());
+        gamma_method_ = GAMMA_POWER;
+        gamma_ = 1.0;
+    }
 
     double height = 0.0;
     expression_ptr height_expr = sym.height();

src/agg/process_line_symbolizer.cpp

@@ -66,7 +66,12 @@ void agg_renderer<T>::process(line_symbolizer const& sym,
     unsigned a=col.alpha();
 
     ras_ptr->reset();
-    set_gamma_method(stroke_, ras_ptr);
+    if (stroke_.get_gamma() != gamma_ || stroke_.get_gamma_method() != gamma_method_)
+    {
+        set_gamma_method(stroke_, ras_ptr);
+        gamma_method_ = stroke_.get_gamma_method();
+        gamma_ = stroke_.get_gamma();
+    }
 
     agg::rendering_buffer buf(current_buffer_->raw_data(),width_,height_, width_ * 4);
 

src/agg/process_markers_symbolizer.cpp

@@ -83,7 +83,12 @@ void agg_renderer<T>::process(markers_symbolizer const& sym,
         if (mark && *mark)
         {
             ras_ptr->reset();
-            ras_ptr->gamma(agg::gamma_power());
+            if (gamma_method_ != GAMMA_POWER || gamma_ != 1.0)
+            {
+                ras_ptr->gamma(agg::gamma_power());
+                gamma_method_ = GAMMA_POWER;
+                gamma_ = 1.0;
+            }
             agg::trans_affine geom_tr;
             evaluate_transform(geom_tr, feature, sym.get_transform());
             agg::trans_affine tr = agg::trans_affine_scaling(scale_factor_);

src/agg/process_polygon_pattern_symbolizer.cpp

@@ -61,8 +61,12 @@ void agg_renderer<T>::process(polygon_pattern_symbolizer const& sym,
 
     agg::rendering_buffer buf(current_buffer_->raw_data(), width_, height_, width_ * 4);
     ras_ptr->reset();
-    set_gamma_method(sym,ras_ptr);
+    if (sym.get_gamma() != gamma_ || sym.get_gamma_method() != gamma_method_)
-
+    {
+        set_gamma_method(sym, ras_ptr);
+        gamma_method_ = sym.get_gamma_method();
+        gamma_ = sym.get_gamma();
+    }
     std::string filename = path_processor_type::evaluate( *sym.get_filename(), feature);
     boost::optional<mapnik::marker_ptr> marker;
     if ( !filename.empty() )

src/agg/process_polygon_symbolizer.cpp

@@ -48,8 +48,12 @@ void agg_renderer<T>::process(polygon_symbolizer const& sym,
 {
 
     ras_ptr->reset();
-    set_gamma_method(sym,ras_ptr);
+    if (sym.get_gamma() != gamma_ || sym.get_gamma_method() != gamma_method_)
-
+    {
+        set_gamma_method(sym, ras_ptr);
+        gamma_method_ = sym.get_gamma_method();
+        gamma_ = sym.get_gamma();
+    }
     agg::trans_affine tr;
     evaluate_transform(tr, feature, sym.get_transform());