kGamutMapProbes

int fl::anonymous_namespace{gamut_map.cpp.hpp}::kGamutMapProbes = 8

constexpr

Probes used to find a seed inside the feasible chroma interval when the target is brighter than the device's brightest neutral (#4245).

Above that lightness the feasible chroma is still a single interval, but it no longer contains zero – so the halving bracket [0, target], whose whole invariant is that the low end is feasible, starts infeasible and converges on zero. That is the clamp this replaces: it discards up to 29.7% of the lightness the hull can actually reach on this device.

A linear scan rather than a search because there is nothing to search on: the interval's location is what is unknown. Bounded like the halvings and for the same reason (A3/B11) – the cost of the above-cap path is kGamutMapProbes + 2 * kGamutMapHalvings feasibility tests, fixed when the firmware is built. Targets at or below the cap never run it.

Definition at line 28 of file gamut_map.cpp.hpp.

Referenced by feasibleChromaInterval().