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#include "generator/srtm_parser.hpp"
#include "coding/endianness.hpp"
#include "coding/zip_reader.hpp"
#include "base/file_name_utils.hpp"
#include "base/logging.hpp"
#include <iomanip>
#include <sstream>
namespace generator
{
namespace
{
size_t constexpr kArcSecondsInDegree = 60 * 60;
size_t constexpr kSrtmTileSize = (kArcSecondsInDegree + 1) * (kArcSecondsInDegree + 1) * 2;
struct UnzipMemDelegate : public ZipFileReader::Delegate
{
explicit UnzipMemDelegate(std::string & buffer) : m_buffer(buffer), m_completed(false) {}
// ZipFileReader::Delegate overrides:
void OnBlockUnzipped(size_t size, char const * data) override { m_buffer.append(data, size); }
void OnStarted() override
{
m_buffer.clear();
m_completed = false;
}
void OnCompleted() override { m_completed = true; }
std::string & m_buffer;
bool m_completed;
};
std::string GetSrtmContFileName(std::string const & dir, std::string const & base)
{
return base::JoinPath(dir, base + ".SRTMGL1.hgt.zip");
}
} // namespace
// SrtmTile ----------------------------------------------------------------------------------------
SrtmTile::SrtmTile()
{
Invalidate();
}
SrtmTile::SrtmTile(SrtmTile && rhs) : m_data(move(rhs.m_data)), m_valid(rhs.m_valid)
{
rhs.Invalidate();
}
void SrtmTile::Init(std::string const & dir, ms::LatLon const & coord)
{
Invalidate();
std::string const base = GetBase(coord);
std::string const cont = GetSrtmContFileName(dir, base);
std::string file = base + ".hgt";
UnzipMemDelegate delegate(m_data);
try
{
ZipFileReader::UnzipFile(cont, file, delegate);
}
catch (ZipFileReader::LocateZipException const & e)
{
// Sometimes packed file has different name. See N39E051 measure.
file = base + ".SRTMGL1.hgt";
ZipFileReader::UnzipFile(cont, file, delegate);
}
if (!delegate.m_completed)
{
LOG(LWARNING, ("Can't decompress SRTM file:", cont));
Invalidate();
return;
}
if (m_data.size() != kSrtmTileSize)
{
LOG(LWARNING, ("Bad decompressed SRTM file size:", cont, m_data.size()));
Invalidate();
return;
}
m_valid = true;
}
geometry::Altitude SrtmTile::GetHeight(ms::LatLon const & coord) const
{
if (!IsValid())
return geometry::kInvalidAltitude;
double ln = coord.m_lon - static_cast<int>(coord.m_lon);
if (ln < 0)
ln += 1;
double lt = coord.m_lat - static_cast<int>(coord.m_lat);
if (lt < 0)
lt += 1;
lt = 1 - lt; // from North to South
auto const row = static_cast<size_t>(std::round(kArcSecondsInDegree * lt));
auto const col = static_cast<size_t>(std::round(kArcSecondsInDegree * ln));
size_t const ix = row * (kArcSecondsInDegree + 1) + col;
CHECK_LESS(ix, Size(), (coord));
return ReverseByteOrder(Data()[ix]);
}
// static
std::string SrtmTile::GetPath(std::string const & dir, std::string const & base)
{
return GetSrtmContFileName(dir, base);
}
// static
ms::LatLon SrtmTile::GetCenter(ms::LatLon const & coord)
{
return {floor(coord.m_lat) + 0.5, floor(coord.m_lon) + 0.5};
}
// static
std::string SrtmTile::GetBase(ms::LatLon const & coord)
{
auto center = GetCenter(coord);
std::ostringstream ss;
if (center.m_lat < 0)
{
ss << "S";
center.m_lat *= -1;
center.m_lat += 1;
}
else
{
ss << "N";
}
ss << std::setw(2) << std::setfill('0') << static_cast<int>(center.m_lat);
if (center.m_lon < 0)
{
ss << "W";
center.m_lon *= -1;
center.m_lon += 1;
}
else
{
ss << "E";
}
ss << std::setw(3) << static_cast<int>(center.m_lon);
return ss.str();
}
void SrtmTile::Invalidate()
{
m_data.clear();
m_data.shrink_to_fit();
m_valid = false;
}
// SrtmTileManager ---------------------------------------------------------------------------------
SrtmTileManager::SrtmTileManager(std::string const & dir) : m_dir(dir) {}
geometry::Altitude SrtmTileManager::GetHeight(ms::LatLon const & coord)
{
auto const key = GetKey(coord);
auto it = m_tiles.find(key);
if (it == m_tiles.end())
{
SrtmTile tile;
try
{
tile.Init(m_dir, coord);
}
catch (RootException const & e)
{
std::string const base = SrtmTile::GetBase(coord);
LOG(LINFO, ("Can't init SRTM tile:", base, "reason:", e.Msg()));
}
// It's OK to store even invalid tiles and return invalid height
// for them later.
it = m_tiles.emplace(key, std::move(tile)).first;
}
return it->second.GetHeight(coord);
}
// static
SrtmTileManager::LatLonKey SrtmTileManager::GetKey(ms::LatLon const & coord)
{
auto const tileCenter = SrtmTile::GetCenter(coord);
return {static_cast<int32_t>(tileCenter.m_lat), static_cast<int32_t>(tileCenter.m_lon)};
}
SrtmTile const & SrtmTileManager::GetTile(ms::LatLon const & coord)
{
// Touch the tile to force its loading.
GetHeight(coord);
auto const key = GetKey(coord);
auto const it = m_tiles.find(key);
CHECK(it != m_tiles.end(), (coord));
return it->second;
}
} // namespace generator
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