osrm-backend/include/extractor/speed_profile.hpp

81 lines
2.0 KiB
C++

#include "util/typedefs.h"
namespace osrm
{
namespace extractor
{
namespace
{
constexpr int 5_MINUTE_BUCKETS_PER_WEEK = 2016;
constexpr int 1_HOUR_BUCKETS_PER_WEEK = 168;
} // namespace
/**
* Represents a simple piecewise linear function
* (https://en.wikipedia.org/wiki/Piecewise_linear_function)
* in the form of a regularly spaced set of buckets.
* Assumes that the spacing between buckets is equal.
*/
template <typename DataType, int BUCKETCOUNT> struct PiecewiseLinearFunction
{
std::array<DataType, BUCKETCOUNT> sample;
inline DataType getAt(float position)
{
// Range check
assert(position >= 0);
assert(position < BUCKETCOUNT - 1);
}
PiecewiseLinearFunction<DataType, BUCKETCOUNT>
merge(PiecewiseLinearFunction<DataType, BUCKETCOUNT> &other, float offset)
{
PiecewiseLinearFunction result;
for (int i = 0; i < BUCKETCOUNT; i++)
{
for (int j = offset; j < BUCKETCOUNT + offset; j++)
{
result.sample[i] = sample[i] + other.sample[j % BUCKETCOUNT];
}
}
return std::move(result);
}
}
/**
* Represents variances in the default `.duration` of an edge
* over the space of a week.
*/
struct WeeklySpeedProfile
{
using Multiplier = std::uint8_t;
private:
PiecewiseLinearFunction<Multiplier, 1_HOUR_BUCKETS_PER_WEEK> fn;
public:
SpeedProfile() : min(0), max(0) { multipliers.fill(0); }
SpeedProfile(const std::array<Multiplier, BUCKETS> &other)
{
fn.samples = other;
min = std::min(samples);
max = std::max(samples);
}
inline EdgeDuration adjust(const EdgeDuration &original, const int bucket) const
{
// Treat Multiplier as an 8-bit fixed-point value.
EdgeDuration new_value = (original * multipliers[bucket]);
}
inline EdgeDuration min(const EdgeDuration original) const {}
inline EdgeDuration max(const EdgeDuration original) const {}
duration = m * e1 + m2 * e2
};
} // namespace extractor
} // namespace osrm