Jungfraujoch/common/DiffractionSpot.h

// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include "Coord.h"
#include "DiffractionExperiment.h"
#include "DiffractionGeometry.h"
#include "SpotToSave.h"

// Definition of Bragg spot
class DiffractionSpot {
    // Photon-weighted position sums, sum(col * photons) and sum(line * photons). Integers, not a
    // centroid: column, line and the per-pixel count are all integral, so the sums are exact and
    // every implementation that builds them - host, GPU, whatever the build lets the compiler
    // contract - arrives at the same bits. In float they did not: gcc fuses the multiply-add under
    // -march=x86-64-v3 and not at the baseline, which left the last bit of the centroid a property
    // of the build flags rather than of the data.
    int64_t x = 0;
    int64_t y = 0;
    int64_t pixel_count = 0;
    int64_t photons = 0;     // total photon count
    int64_t max_photons = INT64_MIN; // maximum number of counts per pixel in the spot
    int64_t panel = -1;      // the panel (DetectorModules index) the spot was found on; -1 = no panel table
public:
    DiffractionSpot() = default;
    DiffractionSpot(uint32_t col, uint32_t line, int64_t photons);
    // From already-summed quantities, i.e. the members as AddPixel leaves them, NOT a centroid.
    // Used by the GPU spot extractor, which computes those sums on the device.
    DiffractionSpot(int64_t x_sum, int64_t y_sum, int64_t pixel_count, int64_t photons, int64_t max_photons,
                    int64_t panel = -1);
    DiffractionSpot& operator+=(const DiffractionSpot& spot);
    int64_t PixelCount() const;
    int64_t Count() const;
    int64_t MaxCount() const;
    Coord RawCoord() const;
    int64_t Panel() const;
    void Panel(int64_t panel);
    void ConvertToImageCoordinates(const DiffractionExperiment& experiment, uint16_t module_number);
    std::optional<SpotToSave> Export(const DiffractionGeometry &geometry, int64_t image_num = 0) const;
    void AddPixel(uint32_t col, uint32_t line, int64_t photons);
};