Class Sample

tests/fl/gfx/rgbw_colorimetric.cpp:1031–1035

7^3 - 1 = 342 in-gamut samples. Skips (0,0,0) since both paths short-circuit to (0,0,0,0) without touching the solver.

// 7^3 - 1 = 342 in-gamut samples. Skips (0,0,0) since both paths short-circuit
// to (0,0,0,0) without touching the solver.
struct Sample {
    u8 r, g, b;
    u8 closed_form[4];
    u8 lut_path[4];
};

inline int sample_sweep(Sample* out) {
    // Map step v in [0,6] to a u8 in [15, 255] without overflow.