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#pragma once
#include "coding/bit_streams.hpp"
#include "coding/elias_coder.hpp"
#include "coding/reader.hpp"
#include "coding/varint.hpp"
#include "coding/write_to_sink.hpp"
#include "base/assert.hpp"
#include "base/bits.hpp"
#include "std/cstdint.hpp"
#include "std/limits.hpp"
#include "std/vector.hpp"
namespace feature
{
using TAltitude = int16_t;
using TAltitudes = vector<feature::TAltitude>;
TAltitude constexpr kInvalidAltitude = numeric_limits<TAltitude>::min();
feature::TAltitude constexpr kDefaultAltitudeMeters = 0;
struct AltitudeHeader
{
using TAltitudeSectionVersion = uint16_t;
AltitudeHeader() { Reset(); }
template <class TSink>
void Serialize(TSink & sink) const
{
WriteToSink(sink, m_version);
WriteToSink(sink, m_minAltitude);
WriteToSink(sink, m_featureTableOffset);
WriteToSink(sink, m_altitudesOffset);
WriteToSink(sink, m_endOffset);
}
template <class TSource>
void Deserialize(TSource & src)
{
m_version = ReadPrimitiveFromSource<TAltitudeSectionVersion>(src);
m_minAltitude = ReadPrimitiveFromSource<TAltitude>(src);
m_featureTableOffset = ReadPrimitiveFromSource<uint32_t>(src);
m_altitudesOffset = ReadPrimitiveFromSource<uint32_t>(src);
m_endOffset = ReadPrimitiveFromSource<uint32_t>(src);
}
// Methods below return sizes of parts of altitude section in bytes.
size_t GetAltitudeAvailabilitySize() const
{
return m_featureTableOffset - sizeof(AltitudeHeader);
}
size_t GetFeatureTableSize() const { return m_altitudesOffset - m_featureTableOffset; }
size_t GetAltitudeInfoSize() const { return m_endOffset - m_altitudesOffset; }
void Reset()
{
m_version = 0;
m_minAltitude = kDefaultAltitudeMeters;
m_featureTableOffset = 0;
m_altitudesOffset = 0;
m_endOffset = 0;
}
TAltitudeSectionVersion m_version;
TAltitude m_minAltitude;
uint32_t m_featureTableOffset;
uint32_t m_altitudesOffset;
uint32_t m_endOffset;
};
static_assert(sizeof(AltitudeHeader) == 16, "Wrong header size of altitude section.");
class Altitudes
{
public:
Altitudes() = default;
explicit Altitudes(TAltitudes const & altitudes) : m_altitudes(altitudes) {}
template <class TSink>
void Serialize(TAltitude minAltitude, TSink & sink) const
{
CHECK(!m_altitudes.empty(), ());
BitWriter<TSink> bits(sink);
TAltitude prevAltitude = minAltitude;
for (auto const altitude : m_altitudes)
{
CHECK_LESS_OR_EQUAL(minAltitude, altitude, ("A point altitude is less than min mwm altitude"));
uint32_t const delta = bits::ZigZagEncode(static_cast<int32_t>(altitude) -
static_cast<int32_t>(prevAltitude));
coding::DeltaCoder::Encode(bits, delta + 1 /* making it greater than zero */);
prevAltitude = altitude;
}
}
template <class TSource>
bool Deserialize(TAltitude minAltitude, size_t pointCount, string const & countryFileName,
uint32_t featureId, TSource & src)
{
ASSERT_NOT_EQUAL(pointCount, 0, ());
BitReader<TSource> bits(src);
TAltitude prevAltitude = minAltitude;
m_altitudes.resize(pointCount);
for (size_t i = 0; i < pointCount; ++i)
{
uint64_t const biasedDelta = coding::DeltaCoder::Decode(bits);
if (biasedDelta == 0)
{
LOG(LERROR, ("Decoded altitude delta is zero. File", countryFileName,
". Feature Id", featureId, ". Point number in the feature", i, "."));
m_altitudes.clear();
return false;
}
uint64_t const delta = biasedDelta - 1;
m_altitudes[i] = static_cast<TAltitude>(bits::ZigZagDecode(delta) + prevAltitude);
if (m_altitudes[i] < minAltitude)
{
LOG(LERROR, ("A point altitude read from file(", m_altitudes[i],
") is less than min mwm altitude(", minAltitude, "). File ",
countryFileName, ". Feature Id", featureId, ". Point number in the feature", i, "."));
m_altitudes.clear();
return false;
}
prevAltitude = m_altitudes[i];
}
return true;
}
/// \note |m_altitudes| is a vector of feature point altitudes. There's two possibilities:
/// * |m_altitudes| is empty. It means there is no altitude information for this feature.
/// * size of |m_pointAlt| is equal to the number of this feature's points. If so
/// all items of |m_altitudes| have valid value.
TAltitudes m_altitudes;
};
} // namespace feature
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