Jungfraujoch/common/DetectorOrientation.cpp

// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include "DetectorOrientation.h"
#include "JFJochException.h"

DetectorOrientation::DetectorOrientation(bool mirror_y, int64_t quarter_turns) {
    MirrorY(mirror_y);
    QuarterTurns(quarter_turns);
}

DetectorOrientation &DetectorOrientation::MirrorY(bool input) {
    mirror_y = input;
    return *this;
}

DetectorOrientation &DetectorOrientation::QuarterTurns(int64_t input) {
    if ((input < 0) || (input > 3))
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                              "Quarter turns must be 0, 1, 2 or 3");
    quarter_turns = input;
    return *this;
}

bool DetectorOrientation::IsMirrorY() const {
    return mirror_y;
}

int64_t DetectorOrientation::GetQuarterTurns() const {
    return quarter_turns;
}

bool DetectorOrientation::IsIdentity() const {
    return !mirror_y && (quarter_turns == 0);
}

RotMatrix DetectorOrientation::Matrix() const {
    // Columns of Rz(k*90 deg), in the internal frame (x = column, y = row downward, z = beam). y
    // points down, so a positive right-handed turn about +z takes +x to +y - clockwise on screen.
    const float c[4] = {1, 0, -1, 0};
    const float s[4] = {0, 1, 0, -1};
    const Coord rz_x = {c[quarter_turns], s[quarter_turns], 0};
    const Coord rz_y = {-s[quarter_turns], c[quarter_turns], 0};

    // Rz * diag(1,-1,1): the mirror negates the second column.
    return {rz_x, mirror_y ? -rz_y : rz_y, {0, 0, 1}};
}

std::optional<DetectorOrientation> DetectorOrientation::Match(const Coord &fast, const Coord &slow) {
    for (int64_t quarter_turns = 0; quarter_turns < 4; quarter_turns++) {
        for (const bool mirror_y: {false, true}) {
            const DetectorOrientation orientation(mirror_y, quarter_turns);
            const RotMatrix m = orientation.Matrix();
            if (((m.Column(0) - fast).Length() < 1e-3f) && ((m.Column(1) - slow).Length() < 1e-3f))
                return orientation;
        }
    }
    return {};
}

bool DetectorOrientation::operator==(const DetectorOrientation &other) const {
    return (mirror_y == other.mirror_y) && (quarter_turns == other.quarter_turns);
}