osmscout-move-test.cpp

#include <osmscout/util/Geometry.h>
#include <osmscout/util/Projection.h>
#include <osmscout/system/Math.h>

#define CATCH_CONFIG_MAIN
#include <catch.hpp>

#include <chrono>
#include <iostream>

TEST_CASE("Move") {
  osmscout::GeoCoord position(51.57251,7.46506);
  double speedKmH = 42;
  // radians, 0 is north, M_PI_2 is east, M_PI is south, -M_PI_2 is west
  double bearing = M_PI_2; 
  auto time = std::chrono::duration<double>(0.250);

  double speed = speedKmH / 3.6; // meters/s
  auto distance = osmscout::Distance::Of<osmscout::Meter>(speed * time.count());

  // compute position2 with given distance and bearing from position
  double lat,lon;
  osmscout::GetEllipsoidalDistance(position.GetLat(), position.GetLon(),
      bearing, distance, lat, lon);
  osmscout::GeoCoord position2(lat, lon);

  // compute map coordinates for both positions
  osmscout::MercatorProjection projection;
  projection.Set(position,
      osmscout::Magnification(osmscout::Magnification::magBlock),
      /*dpi*/ 300, /*width*/ 1200, /*height*/ 1200);

  double x1,y1,x2,y2;
  projection.GeoToPixel(position,x1,y1);
  projection.GeoToPixel(position2,x2,y2);

  // mapMove [pixels] = sqrt(dx^2 * dy^2)
  double mapMove = std::hypot(x1-x2, y1-y2);
  std::cout << mapMove << std::endl;
}