File SpatialGrid.hpp¶

File List > QAccelPlot > src > QAccelPlot > series > SpatialGrid.hpp
//
// SPDX-FileCopyrightText: 2026 Michal Grabarczyk
// SPDX-License-Identifier: GPL-3.0-only WITH Universal-FOSS-exception-1.0
//
// This file is also available under a separate commercial license.
// See COMMERCIAL-LICENSING.md for contact information.
//
#pragma once

#include <functional>
#include <vector>

namespace QAccelPlot {

class SpatialGrid {
public:
    void build(const double* data, int itemCount, int valuesPerItem = 4);
    void buildF(const float* data, int itemCount, int valuesPerItem = 4);
    int query(double x, double y) const;
    int queryTopmost(double minX, double minY, double maxX, double maxY, const std::function<bool(int)>& accept) const;

    static int scanTopmost(
        const double* data, int itemCount, double minX, double minY, double maxX, double maxY, const std::function<bool(int)>& accept, int valuesPerItem = 4);
    static int scanTopmostF(
        const float* data, int itemCount, double minX, double minY, double maxX, double maxY, const std::function<bool(int)>& accept, int valuesPerItem = 4);

private:
    struct ItemBounds {
        double minX;
        double minY;
        double maxX;
        double maxY;

        bool contains(double x, double y) const;
        bool overlaps(double boxMinX, double boxMinY, double boxMaxX, double boxMaxY) const;
        bool isValid() const;
    };

    // Cell coordinate of \a value, clamped to [0, count - 1] so infinite values map to the edge cells.
    static int cellIndex(double value, double min, double cellSize, int count);

    template <typename T>
    static int scanTopmostFrom(const T* data, int itemCount, int valuesPerItem, const ItemBounds& box, const std::function<bool(int)>& accept);
    template <typename T> void buildFrom(const T* data, int itemCount, int valuesPerItem);
    template <typename T> void computeDataBounds(const T* data, int itemCount, int valuesPerItem);
    void computeGridDimensions(int itemCount);
    void fillSpatialGrid(int itemCount);

    // The grid covers the finite extent of all edges. An axis without finite edges gets a single cell.
    double minX_{0.0};
    double minY_{0.0};
    double maxX_{1.0};
    double maxY_{1.0};
    bool boundedX_{false};
    bool boundedY_{false};
    int cols_{0};
    int rows_{0};
    double cellW_{1.0};
    double cellH_{1.0};
    std::vector<ItemBounds> itemBounds_;
    std::vector<std::vector<int>> cells_;
    std::vector<int> largeItems_;
};

} // namespace QAccelPlot