Repo created

libs/traffic/speed_groups.hpp

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+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace traffic
+{
+enum class SpeedGroup : uint8_t
+{
+  G0 = 0,
+  G1,
+  G2,
+  G3,
+  G4,
+  G5,
+  TempBlock,
+  Unknown,
+  Count
+};
+
+static_assert(static_cast<uint8_t>(SpeedGroup::Count) <= 8, "");
+
+// Let M be the maximal speed that is possible on a free road
+// and let V be the maximal speed that is possible on this road when
+// taking the traffic data into account.
+// We group all possible ratios (V/M) into a small number of
+// buckets and only use the number of a bucket everywhere.
+// That is, we forget the specific values of V when transmitting and
+// displaying traffic information. The value M of a road is known at the
+// stage of building the mwm containing this road.
+//
+// kSpeedGroupThresholdPercentage[g] denotes the maximal value of (V/M)
+// that is possible for group |g|. Values falling on a border of two groups
+// may belong to either group.
+//
+// The threshold percentage is defined to be 100 for the
+// special groups where V is unknown or not defined.
+extern uint32_t const kSpeedGroupThresholdPercentage[static_cast<size_t>(SpeedGroup::Count)];
+
+/// \note This method is used in traffic jam generation.
+SpeedGroup GetSpeedGroupByPercentage(double p);
+
+std::string DebugPrint(SpeedGroup const & group);
+}  // namespace traffic