pub const PARALLEL_THRESHOLD: usize = 65_536;Expand description
Element count at or above which kernels switch from a serial loop to rayon’s parallel iteration.
Type: usize, counted in array elements. For
luminosity_blend_core it is counted
in pixels (H × W) rather than elements (H × W × 3).
Provisional placeholder, not a measured value. 256 × 256 = 65,536
was picked only as a plausible order of magnitude for rayon’s
dispatch overhead to be amortized. Run cargo bench and replace it
with the crossover point benches/blend_bench.rs actually measures
on the target hardware.