diff --git a/include/mapnik/well_known_srs.hpp b/include/mapnik/well_known_srs.hpp index dd3d48e36..9225a0859 100644 --- a/include/mapnik/well_known_srs.hpp +++ b/include/mapnik/well_known_srs.hpp @@ -24,9 +24,9 @@ #define MAPNIK_WELL_KNOWN_SRS_HPP // mapnik -#include // for M_PI on windows #include #include +#include #pragma GCC diagnostic push #include @@ -34,7 +34,6 @@ #pragma GCC diagnostic pop // stl -#include #include namespace mapnik { @@ -47,81 +46,27 @@ enum well_known_srs_enum : std::uint8_t { 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 / 180.0; -static const double R2D = 180.0 / M_PI; -static const double M_PIby360 = M_PI / 360.0; -static const double MAXEXTENTby180 = MAXEXTENT / 180.0; -static const double MAX_LATITUDE = R2D * (2 * std::atan(std::exp(180.0 * D2R)) - M_PI_by2); -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"; +constexpr double EARTH_RADIUS = 6378137.0; +constexpr double EARTH_CIRCUMFERENCE = EARTH_RADIUS * util::tau; +constexpr double MERC_MAX_EXTENT = EARTH_RADIUS * util::pi; +constexpr double MERC_MAX_LATITUDE = 85.0511287798065923778; + // MERC_MAX_LATITUDE = degrees(2 * atan(exp(pi)) - pi / 2) -boost::optional is_well_known_srs(std::string const& srs); +extern MAPNIK_DECL std::string const MAPNIK_LONGLAT_PROJ; +extern MAPNIK_DECL std::string const MAPNIK_GMERC_PROJ; -boost::optional is_known_geographic(std::string const& srs); +MAPNIK_DECL boost::optional is_known_geographic(std::string const& srs); +MAPNIK_DECL boost::optional is_well_known_srs(std::string const& srs); -static inline bool lonlat2merc(double * x, double * y, std::size_t point_count) -{ - for (std::size_t i = 0; i < point_count; ++i) - { - if (x[i] > 180) x[i] = 180; - else if (x[i] < -180) x[i] = -180; - if (y[i] > MAX_LATITUDE) y[i] = MAX_LATITUDE; - else if (y[i] < -MAX_LATITUDE) y[i] = -MAX_LATITUDE; - x[i] = x[i] * MAXEXTENTby180; - y[i] = std::log(std::tan((90.0 + y[i]) * M_PIby360)) * R2D * MAXEXTENTby180; - } - return true; -} +MAPNIK_DECL bool lonlat2merc(double & x, double & y); +MAPNIK_DECL bool lonlat2merc(double * x, double * y, std::size_t point_count, + std::size_t stride = 1); +MAPNIK_DECL bool lonlat2merc(std::vector> & ls); -static inline bool merc2lonlat(double * x, double * y, std::size_t point_count) -{ - for(std::size_t i = 0; i < point_count; ++i) - { - if (x[i] > MAXEXTENT) x[i] = MAXEXTENT; - else if (x[i] < -MAXEXTENT) x[i] = -MAXEXTENT; - if (y[i] > MAXEXTENT) y[i] = MAXEXTENT; - else if (y[i] < -MAXEXTENT) y[i] = -MAXEXTENT; - 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); - } - return true; -} - -static inline bool lonlat2merc(std::vector> & ls) -{ - for (auto& p : ls) - { - if (p.x > 180) p.x = 180; - else if (p.x < -180) p.x = -180; - if (p.y > MAX_LATITUDE) p.y = MAX_LATITUDE; - else if (p.y < -MAX_LATITUDE) p.y = -MAX_LATITUDE; - p.x = p.x * MAXEXTENTby180; - p.y = std::log(std::tan((90 + p.y) * M_PIby360)) * R2D; - p.y = p.y * MAXEXTENTby180; - } - return true; -} - -static inline bool merc2lonlat(std::vector> & ls) -{ - for (auto & p : ls) - { - if (p.x > MAXEXTENT) p.x = MAXEXTENT; - else if (p.x < -MAXEXTENT) p.x = -MAXEXTENT; - if (p.y > MAXEXTENT) p.y = MAXEXTENT; - else if (p.y < -MAXEXTENT) p.y = -MAXEXTENT; - p.x = (p.x / MAXEXTENT) * 180; - p.y = (p.y / MAXEXTENT) * 180; - p.y = R2D * (2 * std::atan(std::exp(p.y * D2R)) - M_PI_by2); - } - return true; -} +MAPNIK_DECL bool merc2lonlat(double & x, double & y); +MAPNIK_DECL bool merc2lonlat(double * x, double * y, std::size_t point_count, + std::size_t stride = 1); +MAPNIK_DECL bool merc2lonlat(std::vector> & ls); } diff --git a/src/well_known_srs.cpp b/src/well_known_srs.cpp index c7ec4c5ba..df3b2fe0a 100644 --- a/src/well_known_srs.cpp +++ b/src/well_known_srs.cpp @@ -30,8 +30,18 @@ #include #pragma GCC diagnostic pop +// stl +#include + namespace mapnik { +extern std::string const MAPNIK_LONGLAT_PROJ = + "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"; + +extern std::string const 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"; + static const char * well_known_srs_strings[] = { "mapnik-longlat", "mapnik-gmerc", @@ -82,4 +92,60 @@ boost::optional is_known_geographic(std::string const& srs) IMPLEMENT_ENUM( well_known_srs_e, well_known_srs_strings ) +bool lonlat2merc(double & x, double & y) +{ + using namespace util; + auto dx = clamp(x, -180.0, 180.0); + auto dy = clamp(y, -MERC_MAX_LATITUDE, MERC_MAX_LATITUDE); + x = EARTH_RADIUS * radians(dx); + y = EARTH_RADIUS * std::log(std::tan(radians(90 + dy) / 2)); + return true; +} + +bool lonlat2merc(double * x, double * y, std::size_t point_count, std::size_t stride) +{ + for (std::size_t i = 0; i < point_count; ++i) + { + lonlat2merc(x[i * stride], y[i * stride]); + } + return true; +} + +bool lonlat2merc(std::vector> & ls) +{ + for (auto & p : ls) + { + lonlat2merc(p.x, p.y); + } + return true; +} + +bool merc2lonlat(double & x, double & y) +{ + using namespace util; + auto rx = clamp(x / EARTH_RADIUS, -pi, pi); + auto ry = clamp(y / EARTH_RADIUS, -pi, pi); + x = degrees(rx); + y = degrees(2 * std::atan(std::exp(ry)) - pi / 2); + return true; +} + +bool merc2lonlat(double * x, double * y, std::size_t point_count, std::size_t stride) +{ + for(std::size_t i = 0; i < point_count; ++i) + { + merc2lonlat(x[i * stride], y[i * stride]); + } + return true; +} + +bool merc2lonlat(std::vector> & ls) +{ + for (auto & p : ls) + { + merc2lonlat(p.x, p.y); + } + return true; +} + }