src/marnav/seatalk/message_50.cpp

   1 #include <marnav/seatalk/message_50.hpp>
   2
   3 namespace marnav
   4 {
   5 namespace seatalk
   6 {
   7
   8 message_50::message_50()
   9         : message(ID)
  10 {
  11 }
  12
  13 std::unique_ptr<message> message_50::parse(const raw & data)
  14 {
  15         check_size(data, SIZE);
  16
  17         std::unique_ptr<message> result = utils::make_unique<message_50>();
  18         message_50 & msg = static_cast<message_50 &>(*result);
  19
  20         // 50  Z2  XX  YY  YY
  21         // raw  1   2   3   4
  22
  23         const uint32_t degrees = data[2];
  24         uint32_t m = 0;
  25         m += data[3];
  26         m <<= 8;
  27         m += data[4];
  28
  29         const uint32_t minutes = (m & 0x7fff) / 100;
  30         const uint32_t seconds = (((m & 0x7fff) % 100) * 60) / 100;
  31         const geo::latitude::hemisphere hemisphere
  32                 = (m & 0x8000) ? geo::latitude::hemisphere::south : geo::latitude::hemisphere::north;
  33
  34         msg.lat_ = geo::latitude{degrees, minutes, seconds, hemisphere};
  35
  36         // deliberately ignored 'Z'
  37
  38         return result;
  39 }
  40
  41 raw message_50::get_data() const
  42 {
  43         uint16_t m = 0;
  44         m += lat_.minutes() * 100;
  45         m += (lat_.seconds() * 100) / 60;
  46         if (lat_.hem() == geo::latitude::hemisphere::south)
  47                 m |= 0x8000;
  48
  49         return raw{static_cast<uint8_t>(ID), 0x02, static_cast<uint8_t>(lat_.degrees() & 0xff),
  50                 static_cast<uint8_t>((m >> 8) & 0xff), static_cast<uint8_t>((m >> 0) & 0xff)};
  51 }
  52 }
  53 }