Issue Framstag#1045 - Update projection

- Added simple Earth object to centralize some constants
- Changed enum type of LaneTurn
- Centralized gradtorad constant

libosmscout/CMakeLists.txt

@@ -69,10 +69,11 @@ set(HEADER_FILES_NAVIGATION
         include/osmscout/navigation/LaneAgent.h)
 
 set(HEADER_FILES_OST
-    include/osmscout/ost/Parser.h
-    include/osmscout/ost/Scanner.h)
+        include/osmscout/ost/Parser.h
+        include/osmscout/ost/Scanner.h)
 
 set(HEADER_FILES_PROJECTION
+        include/osmscout/projection/Earth.h
         include/osmscout/projection/MercatorProjection.h
         include/osmscout/projection/Projection.h
         include/osmscout/projection/TileProjection.h)
@@ -150,6 +151,7 @@ set(HEADER_FILES_UTIL
 set(SOURCE_FILES
     src/osmscout/ost/Parser.cpp
     src/osmscout/ost/Scanner.cpp
+    src/osmscout/projection/Earth.cpp
     src/osmscout/projection/MercatorProjection.cpp
     src/osmscout/projection/Projection.cpp
     src/osmscout/projection/TileProjection.cpp

libosmscout/include/meson.build

@@ -4,6 +4,7 @@ osmscoutHeader = [
             'osmscout/CoreImportExport.h',
             'osmscout/ost/Parser.h',
             'osmscout/ost/Scanner.h',
+            'osmscout/projection/Earth.h',
             'osmscout/projection/MercatorProjection.h',
             'osmscout/projection/Projection.h',
             'osmscout/projection/TileProjection.h',

libosmscout/include/osmscout/projection/Earth.h

@@ -0,0 +1,44 @@
+#ifndef OSMSCOUT_PROJECTION_EARTH_H
+#define OSMSCOUT_PROJECTION_EARTH_H
+
+/*
+  This source is part of the libosmscout library
+  Copyright (C) 2023  Tim Teulings
+
+  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., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+*/
+
+#include <osmscout/CoreImportExport.h>
+
+namespace osmscout {
+
+  /**
+   * Some general information regarding the earth
+   *
+   * To make the stack support other planets, too, one would have
+   * to define a interface base class, from which Earth inherits and
+   * implements the interface.
+   */
+  class OSMSCOUT_API Earth
+  {
+  public:
+    static const double radiusMeter;
+    //< Radius of the earth in meter
+    static const double extentMeter;
+    //< Extent of the earth in meter
+  };
+}
+
+#endif

libosmscout/include/osmscout/system/Math.h

@@ -22,4 +22,8 @@
 
 #include <cmath>
 
+namespace osmscout {
+  static const double gradtorad=2*M_PI/360.0;
+}
+
 #endif

libosmscout/include/osmscout/util/LaneTurn.h

@@ -20,6 +20,7 @@
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 */
 
+#include <cstddef>
 #include <string>
 
 #include <osmscout/CoreImportExport.h>
@@ -40,8 +41,10 @@ namespace osmscout {
    * Note: Numeric values of variants are used for database serialization,
    * do not change them without increasing database format version.
    * Just append new variants to the end.
+   *
+   * Note: There is no need to export Enums
    */
-  enum class OSMSCOUT_API LaneTurn: char {
+  enum class LaneTurn: std::uint8_t {
     Null = 0,
     None = 1,
     Left = 2,

libosmscout/src/meson.build

@@ -2,6 +2,7 @@
 osmscoutSrc = [
             'src/osmscout/ost/Parser.cpp',
             'src/osmscout/ost/Scanner.cpp',
+            'src/osmscout/projection/Earth.cpp',
             'src/osmscout/projection/MercatorProjection.cpp',
             'src/osmscout/projection/Projection.cpp',
             'src/osmscout/projection/TileProjection.cpp',

libosmscout/src/osmscout/projection/Earth.cpp

@@ -0,0 +1,37 @@
+/*
+  This source is part of the libosmscout library
+  Copyright (C) 2023  Tim Teulings
+
+  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., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+*/
+
+#include <osmscout/projection/Earth.h>
+
+#include <osmscout/system/Math.h>
+
+namespace osmscout {
+
+  /*
+   * For the calculations here see:
+   * http://en.wikipedia.org/wiki/Mercator_projection
+   * http://en.wikipedia.org/wiki/Web_Mercator
+   * http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
+   */
+
+  //< Radius of the earth in meter
+  const double Earth::radiusMeter=6'378'137.0;
+  //< Extent of the earth in meter
+  const double Earth::extentMeter=2*M_PI*Earth::radiusMeter;
+}

libosmscout/src/osmscout/projection/MercatorProjection.cpp

@@ -21,6 +21,8 @@
 
 #include <algorithm>
 
+#include <osmscout/projection/Earth.h>
+
 #include <osmscout/system/Assert.h>
 #include <osmscout/system/Math.h>
 
@@ -37,12 +39,6 @@ namespace osmscout {
    * http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
    */
 
-  //< Radius of the earth in meter
-  static const double earthRadiusMeter=6'378'137.0;
-  //< Extent of the earth in meter
-  static const double earthExtentMeter=2*M_PI*earthRadiusMeter;
-  //< Width of a tile at the equator for zoom level 0 in meter (equal to extent of the earth at the equator
-  static const double tileWidthZoom0Aquator=earthExtentMeter;
   //< DPI of a classical OSM tile
   static const double tileDPI=96.0;
 
@@ -55,8 +51,6 @@ namespace osmscout {
   static const ALIGN16_BEG double sseGradtorad[] ALIGN16_END = {2*M_PI/360, 2*M_PI/360};
 #endif
 
-  static const double gradtorad=2*M_PI/360;
-
   bool MercatorProjection::Set(const GeoCoord& coord,
                                double angle,
                                const Magnification& magnification,
@@ -89,8 +83,8 @@ namespace osmscout {
     this->height=height;
 
     if (angle!=0.0) {
-      angleSin=::sin(angle);
-      angleCos=::cos(angle);
+      angleSin=std::sin(angle);
+      angleCos=std::cos(angle);
       angleNegSin=-angleSin;
       angleNegCos=angleCos;
     }
@@ -102,7 +96,7 @@ namespace osmscout {
     }
 
     // Width in meter of a tile of the given magnification at the equator
-    double equatorTileWidth=tileWidthZoom0Aquator/magnification.GetMagnification();
+    double equatorTileWidth=Earth::extentMeter/magnification.GetMagnification();
 
     // Resolution (meter/pixel) of a pixel in a classical 256 pixel tile for the given zoom level at the equator
     double equatorTileResolution=equatorTileWidth/256.0;
@@ -114,10 +108,10 @@ namespace osmscout {
     double groundWidthEquatorMeter=width*equatorCorrectedEquatorTileResolution;
 
     // Width of the visible area in meter
-    double groundWidthVisibleMeter=groundWidthEquatorMeter*::cos(lat*gradtorad);
+    double groundWidthVisibleMeter=groundWidthEquatorMeter*std::cos(lat*gradtorad);
 
     // Resulting projection scale factor
-    scale=width/(2*M_PI*groundWidthEquatorMeter/earthExtentMeter);
+    scale=width/(2*M_PI*groundWidthEquatorMeter/Earth::extentMeter);
     scaleGradtorad=scale*gradtorad;
 
     // Size of one pixel in meter
@@ -130,7 +124,7 @@ namespace osmscout {
     meterInMM=meterInPixel*25.4/dpi;
 
     // Absolute Y mercator coordinate for latitude
-    latOffset=::atanh(::sin(coord.GetLat()*gradtorad));
+    latOffset=std::atanh(std::sin(coord.GetLat()*gradtorad));
 
     GeoCoord topLeft;
 
@@ -160,7 +154,7 @@ namespace osmscout {
                                     std::max(bottomLeft.GetLon(),bottomRight.GetLon())));
 
     // derivation of "latToYPixel" function in projection center
-    double latDeriv = 1.0 / ::sin( (2 * this->lat * gradtorad + M_PI) /  2);
+    double latDeriv = 1.0 / std::sin( (2 * this->lat * gradtorad + M_PI) /  2);
     scaledLatDeriv = latDeriv * gradtorad * scale;
 
     return true;
@@ -184,7 +178,7 @@ namespace osmscout {
     }
 
     // Transform to absolute geo coordinate
-    coord.Set(::atan(::sinh(y/scale+latOffset))/gradtorad,
+    coord.Set(std::atan(std::sinh(y/scale+latOffset))/gradtorad,
               this->lon+x/scaleGradtorad);
 
     return IsValidFor(coord);
@@ -207,7 +201,7 @@ namespace osmscout {
       // For values outside this range is better to result projection border
       // than some invalid coordinate, like INFINITY
       double lat = std::min(std::max(coord.GetLat(), MinLat), MaxLat);
-      y=(::atanh(::sin(lat*gradtorad))-latOffset)*scale;
+      y=(std::atanh(std::sin(lat*gradtorad))-latOffset)*scale;
     }
 
     if (angle!=0.0) {

libosmscout/src/osmscout/projection/TileProjection.cpp

@@ -19,6 +19,8 @@
 
 #include <osmscout/projection/TileProjection.h>
 
+#include <osmscout/projection/Earth.h>
+
 #include <osmscout/system/Assert.h>
 #include <osmscout/system/Math.h>
 
@@ -34,20 +36,6 @@ namespace osmscout {
   static const ALIGN16_BEG double sseGradtorad[] ALIGN16_END = {2*M_PI/360, 2*M_PI/360};
 #endif
 
-  /*
- * For the calculations here see:
- * http://en.wikipedia.org/wiki/Mercator_projection
- * http://en.wikipedia.org/wiki/Web_Mercator
- * http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
- */
-
-  //< Radius of the earth in meter
-  static const double earthRadiusMeter=6'378'137.0;
-  //< Extent of the earth in meter
-  static const double earthExtentMeter=2*M_PI*earthRadiusMeter;
-
-  static const double gradtorad=2*M_PI/360;
-
   bool TileProjection::SetInternal(double lonMin,double latMin,
                                    double lonMax,double latMax,
                                    const Magnification& magnification,
@@ -86,14 +74,14 @@ namespace osmscout {
     scaleGradtorad = scale * gradtorad;
 
     lonOffset=lonMin*scaleGradtorad;
-    latOffset=scale*::atanh(::sin(latMin*gradtorad));
+    latOffset=scale*std::atanh(std::sin(latMin*gradtorad));
 
-    pixelSize=earthExtentMeter/magnification.GetMagnification()/width;
+    pixelSize=Earth::extentMeter/magnification.GetMagnification()/width;
     meterInPixel=1/pixelSize;
     meterInMM=meterInPixel*25.4/pixelSize;
 
     // derivation of "latToYPixel" function in projection center
-    double latDeriv = 1.0 / ::sin( (2 * this->lat * gradtorad + M_PI) /  2);
+    double latDeriv = 1.0 / std::sin( (2 * this->lat * gradtorad + M_PI) /  2);
     scaledLatDeriv = latDeriv * gradtorad * scale;
 
 #ifdef OSMSCOUT_HAVE_SSE2
@@ -142,7 +130,7 @@ namespace osmscout {
   bool TileProjection::PixelToGeo(double x, double y,
                                   GeoCoord& coord) const
   {
-    coord.Set(::atan(::sinh((height-y+latOffset)/scale))/gradtorad,
+    coord.Set(std::atan(std::sinh((height-y+latOffset)/scale))/gradtorad,
               (x+lonOffset)/(scale*gradtorad));
 
     return IsValidFor(coord);
@@ -187,7 +175,7 @@ namespace osmscout {
       y=(height/2.0)-((coord.GetLat()-this->lat)*scaledLatDeriv);
     }
     else {
-      y=height-(scale*::atanh(::sin(coord.GetLat()*gradtorad))-latOffset);
+      y=height-(scale*std::atanh(std::sin(coord.GetLat()*gradtorad))-latOffset);
     }
 
     pixel=Vertex2D(x,y);