Jungfraujoch/image_analysis/bragg_integration/SystematicAbsence.h

// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

inline bool odd_int(int v) { return (v & 1) != 0; }

inline bool systematic_absence(int h, int k, int l, char centering) {
    if (h == 0 && k == 0 && l == 0) return true;
    switch (centering) {
        case 'I': return odd_int(h + k + l);
        case 'A': return odd_int(k + l);
        case 'B': return odd_int(h + l);
        case 'C': return odd_int(h + k);
        case 'F': return (odd_int(h + k) || odd_int(h + l) || odd_int(k + l));
        case 'R': {
            int mod = (-h + k + l) % 3;
            if (mod < 0) mod += 3;
            return mod != 0;
        }
        default:  return false; // P
    }
}