From 2cd0b55e8854c80b8836d70aa3fc5992a8f06338 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Tue, 9 Feb 2010 17:28:17 +0000
Subject: [PATCH] enforce default gamma function - improves upon #428, closes
 #512

---
 CHANGELOG            | 3 +++
 src/agg_renderer.cpp | 8 +++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG b/CHANGELOG
index c0463bc00..d76a3e5d3 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -14,6 +14,9 @@ For a complete change history, see the SVN log.
 Mapnik Trunk
 ------------
 
+- AGG Renderer - Enforced default gamma function on all symbolizers to ensure proper antialiasing
+  even when gamma is modified on the PolygonSymbolizer. (#512)
+
 - Added ability to read pre 0.8.0 stylesheets, but prints a warning for deprecated syntax (r1592, #501)
 
 - Rasterlite Plugin: Experimental support for Rasterlite, to practically use sqlite database with wavelet compressed rasters (#469)
diff --git a/src/agg_renderer.cpp b/src/agg_renderer.cpp
index f341ec41e..8fe8e9175 100644
--- a/src/agg_renderer.cpp
+++ b/src/agg_renderer.cpp
@@ -190,7 +190,6 @@ void agg_renderer<T>::process(polygon_symbolizer const& sym,
     renderer ren(renb);
 
     ras_ptr->reset();
-            
     ras_ptr->gamma(agg::gamma_linear(0.0, sym.get_gamma()));
 
     for (unsigned i=0;i<feature.num_geometries();++i)
@@ -237,6 +236,8 @@ void agg_renderer<T>::process(building_symbolizer const& sym,
     agg::scanline_u8 sl;
 
     ras_ptr->reset();
+    ras_ptr->gamma(agg::gamma_linear());
+    
     double height = 0.7071 * sym.height(); // height in meters
 
     for (unsigned i=0;i<feature.num_geometries();++i)
@@ -343,6 +344,8 @@ void agg_renderer<T>::process(line_symbolizer const& sym,
     unsigned a=col.alpha();
     renderer ren(renb);
     ras_ptr->reset();
+    ras_ptr->gamma(agg::gamma_linear());
+
     agg::scanline_p8 sl;
 
     for (unsigned i=0;i<feature.num_geometries();++i)
@@ -686,6 +689,7 @@ void agg_renderer<T>::process(polygon_pattern_symbolizer const& sym,
     
     agg::scanline_u8 sl;
     ras_ptr->reset();
+    ras_ptr->gamma(agg::gamma_linear());
 
     std::string filename = path_processor_type::evaluate( *sym.get_filename(), feature);
     boost::optional<mapnik::image_ptr> pat = mapnik::image_cache::instance()->find(filename,true);
@@ -799,6 +803,8 @@ void agg_renderer<T>::process(markers_symbolizer const& sym,
     typedef agg::renderer_scanline_aa_solid<ren_base> renderer;
     arrow arrow_;
     ras_ptr->reset();
+    ras_ptr->gamma(agg::gamma_linear());
+
 
     agg::scanline_u8 sl;
     agg::rendering_buffer buf(pixmap_.raw_data(),width_,height_, width_ * 4);