Jungfraujoch/common/PanelRows.h

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

#pragma once

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <vector>

#include "DetectorModules.h"

// DetectorModules::ForEachPixel cut to the image rows [row0, row1), so that a dense map can be built a band
// of rows per thread. Calls f(panel, index, px, py) for every pixel of those rows that is on a panel, in
// index order: row by row, and within a row panel by panel from left to right. Pixels on no panel are not
// visited. Empty table: every pixel of the rows, panel -1, plane == image.
template<class F>
void ForEachPixelInRows(const DetectorModules &modules, int64_t width, int64_t row0, int64_t row1, F &&f) {
    if (modules.empty()) {
        for (int64_t y = row0; y < row1; y++)
            for (int64_t x = 0; x < width; x++)
                f(int64_t(-1), static_cast<size_t>(y * width + x), static_cast<double>(x), static_cast<double>(y));
        return;
    }
    const auto &m = modules.Get();
    std::vector<int64_t> on_row;
    for (int64_t y = row0; y < row1; y++) {
        on_row.clear();
        for (size_t p = 0; p < m.size(); p++)
            if (y >= m[p].y0 && y < m[p].y0 + m[p].height)
                on_row.push_back(static_cast<int64_t>(p));
        std::sort(on_row.begin(), on_row.end(), [&](int64_t a, int64_t b) { return m[a].x0 < m[b].x0; });
        for (const int64_t p: on_row)
            for (int64_t x = m[p].x0; x < m[p].x0 + m[p].width; x++) {
                const auto [px, py] = m[p].ImageToPlane(static_cast<double>(x), static_cast<double>(y));
                f(p, static_cast<size_t>(y * width + x), px, py);
            }
    }
}