refactor projection interface: 1. cleanup custom lonlat<->merc code. …

…2. centralize proj4 strings into constants, 3. tweak projection benchmarking to allocate objects in loop so we can test that specifically - refs #1703

benchmark/run.cpp

@@ -40,7 +40,7 @@ void benchmark(T test, std::string const& name)
     if (!test_set.empty()) {
         should_run_test = test_set.find(test_num) != test_set.end();
     }
-    if (should_run_test) {
+    if (should_run_test || dry_run) {
         if (!test.validate()) {
             std::clog << "test did not validate: " << name << "\n";
             //throw std::runtime_error(std::string("test did not validate: ") + name);
@@ -282,23 +282,26 @@ struct test6
     std::string dest_;
     mapnik::box2d<double> from_;
     mapnik::box2d<double> to_;
+    bool defer_proj4_init_;
     explicit test6(unsigned iterations,
                    unsigned threads,
                    std::string const& src,
                    std::string const& dest,
                    mapnik::box2d<double> from,
-                   mapnik::box2d<double> to) :
+                   mapnik::box2d<double> to,
+                   bool defer_proj) :
       iter_(iterations),
       threads_(threads),
       src_(src),
       dest_(dest),
       from_(from),
-      to_(to) {}
+      to_(to),
+      defer_proj4_init_(defer_proj) {}
 
     bool validate()
     {
-        mapnik::projection src(src_);
-        mapnik::projection dest(dest_);
+        mapnik::projection src(src_,defer_proj4_init_);
+        mapnik::projection dest(dest_,defer_proj4_init_);
         mapnik::proj_transform tr(src,dest);
         mapnik::box2d<double> bbox = from_;
         if (!tr.forward(bbox)) return false;
@@ -310,17 +313,17 @@ struct test6
     }
     void operator()()
     {
-        mapnik::projection src(src_);
-        mapnik::projection dest(dest_);
-        mapnik::proj_transform tr(src,dest);
         unsigned count=0;
         for (int i=-180;i<180;i=++i)
         {
             for (int j=-85;j<85;++j)
             {
-                 mapnik::box2d<double> box(i,j,i,j);
-                 if (!tr.forward(box)) throw std::runtime_error("could not transform coords");
-                 ++count;
+                mapnik::projection src(src_,defer_proj4_init_);
+                mapnik::projection dest(dest_,defer_proj4_init_);
+                mapnik::proj_transform tr(src,dest);
+                mapnik::box2d<double> box(i,j,i,j);
+                if (!tr.forward(box)) throw std::runtime_error("could not transform coords");
+                ++count;
             }
         }
     }
@@ -398,38 +401,47 @@ int main( int argc, char** argv)
 
         mapnik::box2d<double> from(-180,-80,180,80);
         mapnik::box2d<double> to(-20037508.3427892476,-15538711.0963092316,20037508.3427892476,15538711.0963092316);
+
         {
+            test6 runner(1,5,
+                         "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs",
+                         "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+                         from,to,false);
+            benchmark(runner,"lonlat -> merc coord transformation with proj4 init (literal)");
+        }
+
+        {
+            test6 runner(1,5,
+                         "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs",
+                         "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+                         from,to,true);
+            benchmark(runner,"lonlat -> merc coord transformation with lazy proj4 init (literal)");
+        }
+
+        /*{
             // echo -180 -60 | cs2cs -f "%.10f" +init=epsg:4326 +to +init=epsg:3857
             test6 runner(100000000,100,
                          "+init=epsg:4326",
                          "+init=epsg:3857",
-                         from,to);
+                         from,to,false);
             benchmark(runner,"lonlat -> merc coord transformation (epsg)");
         }
 
         {
             test6 runner(100000000,100,
                          "+init=epsg:3857",
                          "+init=epsg:4326",
-                         to,from);
+                         to,from,false);
             benchmark(runner,"merc -> lonlat coord transformation (epsg)");
-        }
-
-        {
-            test6 runner(100000000,100,
-                         "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs",
-                         "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
-                         from,to);
-            benchmark(runner,"lonlat -> merc coord transformation (literal)");
-        }
+        }*/
 
-        {
-            test6 runner(100000000,100,
+        /*{
+            test6 runner(10,2,
                          "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
                          "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs",
-                         to,from);
+                         to,from,false);
             benchmark(runner,"merc -> lonlat coord transformation (literal)");
-        }
+        }*/
 
         std::cout << "...benchmark done\n";
         return 0;

include/mapnik/layer.hpp

@@ -26,6 +26,7 @@
 // mapnik
 #include <mapnik/feature.hpp>
 #include <mapnik/datasource.hpp>
+#include <mapnik/well_known_srs.hpp>
 
 // stl
 #include <vector>
@@ -44,7 +45,7 @@ class MAPNIK_DECL layer
 {
 public:
     layer(std::string const& name,
-          std::string const& srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs");
+          std::string const& srs=MAPNIK_LONGLAT_PROJ);
 
     layer(layer const& l);
     layer& operator=(layer const& rhs);

include/mapnik/map.hpp

@@ -30,6 +30,7 @@
 #include <mapnik/datasource.hpp>  // for featureset_ptr
 #include <mapnik/layer.hpp>
 #include <mapnik/params.hpp>
+#include <mapnik/well_known_srs.hpp>
 
 // boost
 #include <boost/optional/optional.hpp>
@@ -105,7 +106,7 @@ class MAPNIK_DECL Map
      *  @param height Initial map height.
      *  @param srs Initial map projection.
      */
-    Map(int width, int height, std::string const& srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs");
+    Map(int width, int height, std::string const& srs=MAPNIK_LONGLAT_PROJ);
 
     /*! \brief Copy Constructur.
      *

include/mapnik/proj_transform.hpp

@@ -49,12 +49,13 @@ class MAPNIK_DECL proj_transform : private mapnik::noncopyable
     mapnik::projection const& dest() const;
 
 private:
-    projection const source_;
-    projection const dest_;
+    projection const& source_;
+    projection const& dest_;
     bool is_source_longlat_;
     bool is_dest_longlat_;
     bool is_source_equal_dest_;
     bool wgs84_to_merc_;
+    bool merc_to_wgs84_;
 };
 }
 

include/mapnik/projection.hpp

@@ -24,16 +24,14 @@
 #define MAPNIK_PROJECTION_HPP
 
 // mapnik
-#include <mapnik/box2d.hpp>
-
-// proj4
-#include <proj_api.h>
+#include <mapnik/config.hpp>
+#include <mapnik/well_known_srs.hpp>
 
 // boost
 #if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
 #include <boost/thread/mutex.hpp>
 #endif
-#include <boost/utility.hpp>
+#include <boost/optional.hpp>
 
 // stl
 #include <string>
@@ -52,7 +50,9 @@ class MAPNIK_DECL projection
 {
     friend class proj_transform;
 public:
-    explicit projection(std::string const& params = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs");
+
+    explicit projection(std::string const& params = MAPNIK_LONGLAT_PROJ,
+                        bool defer_proj_init = false);
     projection(projection const& rhs);
     ~projection();
 
@@ -61,24 +61,25 @@ class MAPNIK_DECL projection
     bool operator!=(const projection& other) const;
     bool is_initialized() const;
     bool is_geographic() const;
+    boost::optional<well_known_srs_e> well_known() const;
     std::string const& params() const;
 
-    void forward(double & x, double &y ) const;
+    void forward(double & x, double & y) const;
     void inverse(double & x,double & y) const;
 
     std::string expanded() const;
+    void init_proj4() const;
 
 private:
-    void init();
     void swap (projection& rhs);
 
 private:
     std::string params_;
-    projPJ proj_;
-    bool is_geographic_;
-#if PJ_VERSION >= 480
-    projCtx proj_ctx_;
-#elif defined(MAPNIK_THREADSAFE)
+    bool defer_proj_init_;
+    mutable bool is_geographic_;
+    mutable void * proj_;
+    mutable void * proj_ctx_;
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     static boost::mutex mutex_;
 #endif
 };

include/mapnik/well_known_srs.hpp

@@ -0,0 +1,94 @@
+/*****************************************************************************
+ *
+ * This file is part of Mapnik (c++ mapping toolkit)
+ *
+ * Copyright (C) 2013 Artem Pavlenko
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *****************************************************************************/
+
+#ifndef MAPNIK_WELL_KNOWN_SRS_HPP
+#define MAPNIK_WELL_KNOWN_SRS_HPP
+
+// mapnik
+#include <mapnik/enumeration.hpp>
+
+// boost
+#include <boost/optional.hpp>
+
+// stl
+#include <cmath>
+
+namespace mapnik {
+
+enum well_known_srs_enum {
+    WGS_84,
+    G_MERC,
+    well_known_srs_enum_MAX
+};
+
+DEFINE_ENUM( well_known_srs_e, well_known_srs_enum );
+
+static const double EARTH_RADIUS = 6378137.0;
+static const double EARTH_DIAMETER = EARTH_RADIUS * 2.0;
+static const double EARTH_CIRCUMFERENCE = EARTH_DIAMETER * M_PI;
+static const double MAXEXTENT = EARTH_CIRCUMFERENCE / 2.0;
+static const double M_PI_by2 = M_PI / 2;
+static const double D2R = M_PI / 180;
+static const double R2D = 180 / M_PI;
+static const double M_PIby360 = M_PI / 360;
+static const double MAXEXTENTby180 = MAXEXTENT / 180;
+static const std::string MAPNIK_LONGLAT_PROJ = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs";
+static const std::string MAPNIK_GMERC_PROJ = "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over";
+
+boost::optional<well_known_srs_e> is_well_known_srs(std::string const& srs);
+
+boost::optional<bool> is_known_geographic(std::string const& srs);
+
+static inline bool lonlat2merc(double * x, double * y , int point_count)
+{
+    int i;
+    for(i=0; i<point_count; i++) {
+        x[i] = x[i] * MAXEXTENTby180;
+        y[i] = std::log(std::tan((90 + y[i]) * M_PIby360)) * R2D;
+        y[i] = y[i] * MAXEXTENTby180;
+        if (x[i] > MAXEXTENT) x[i] = MAXEXTENT;
+        if (x[i] < -MAXEXTENT) x[i] = -MAXEXTENT;
+        if (y[i] > MAXEXTENT) y[i] = MAXEXTENT;
+        if (y[i] < -MAXEXTENT) y[i] = -MAXEXTENT;
+    }
+    return true;
+}
+
+static inline bool merc2lonlat(double * x, double * y , int point_count)
+{
+    int i;
+    for(i=0; i<point_count; i++)
+    {
+        x[i] = (x[i] / MAXEXTENT) * 180;
+        y[i] = (y[i] / MAXEXTENT) * 180;
+        y[i] = R2D * (2 * std::atan(std::exp(y[i] * D2R)) - M_PI_by2);
+        if (x[i] > 180) x[i] = 180;
+        if (x[i] < -180) x[i] = -180;
+        if (y[i] > 85.0511) y[i] = 85.0511;
+        if (y[i] < -85.0511) y[i] = -85.0511;
+    }
+    return true;
+}
+
+}
+
+#endif // MAPNIK_WELL_KNOWN_SRS_HPP

src/build.py

@@ -100,6 +100,7 @@ def ldconfig(*args,**kwargs):
 
 source = Split(
     """
+    well_known_srs.cpp
     params.cpp
     image_filter_types.cpp
     miniz_png.cpp

src/map.cpp

@@ -62,7 +62,7 @@ IMPLEMENT_ENUM( aspect_fix_mode_e, aspect_fix_mode_strings )
 Map::Map()
 : width_(400),
     height_(400),
-    srs_("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"),
+    srs_(MAPNIK_LONGLAT_PROJ),
     buffer_size_(0),
     aspectFixMode_(GROW_BBOX),
     base_path_("") {}