ViewOSMMap/osmquadtree.cpp at main · tigerlet/ViewOSMMap · GitHub

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#include "osmquadtree.h"
#include <QtMath>

OsmQuadTree::OsmQuadTree(const QRectF &bounds, int maxDepth, int maxElements)
    : m_maxDepth(maxDepth), m_maxElements(maxElements)
{
    m_root.bounds = bounds;
}

void OsmQuadTree::clear()
{
    m_root.elements.clear();
    m_root.elementBBoxes.clear();
    m_root.hasChildren = false;
    for (int i = 0; i < 4; i++) {
        m_root.children[i].reset();
    }
    m_pendingInsert.clear();
}

QRectF OsmQuadTree::childBounds(const Node &node, int quadrant) const
{
    double x = node.bounds.x();
    double y = node.bounds.y();
    double w = node.bounds.width() / 2.0;
    double h = node.bounds.height() / 2.0;

    switch (quadrant) {
    case 0: return QRectF(x + w, y, w, h);
    case 1: return QRectF(x, y, w, h);
    case 2: return QRectF(x, y + h, w, h);
    case 3: return QRectF(x + w, y + h, w, h);
    default: return node.bounds;
    }
}

int OsmQuadTree::getQuadrant(const Node &node, const QRectF &bbox) const
{
    QPointF center = node.bounds.center();

    bool top = bbox.bottom() < center.y();
    bool bottom = bbox.y() > center.y();
    bool left = bbox.right() < center.x();
    bool right = bbox.x() > center.x();

    if (top) {
        if (right) return 0;
        if (left) return 1;
    }
    if (bottom) {
        if (left) return 2;
        if (right) return 3;
    }
    return -1;
}

void OsmQuadTree::split(Node &node)
{
    for (int i = 0; i < 4; i++) {
        node.children[i] = std::make_unique<Node>();
        node.children[i]->bounds = childBounds(node, i);
    }
    node.hasChildren = true;
}

void OsmQuadTree::insert(int elementIndex, const QRectF &bbox)
{
    insertRecursive(m_root, 0, elementIndex, bbox);
}

void OsmQuadTree::insertRecursive(Node &node, int depth, int elementIndex, const QRectF &bbox)
{
    if (node.hasChildren) {
        int quadrant = getQuadrant(node, bbox);
        if (quadrant != -1) {
            insertRecursive(*node.children[quadrant], depth + 1, elementIndex, bbox);
            return;
        }
    }

    node.elements.append(elementIndex);
    node.elementBBoxes.append(bbox);

    if (!node.hasChildren && depth < m_maxDepth && node.elements.size() > m_maxElements) {
        split(node);
        QVector<int> oldElements = node.elements;
        QVector<QRectF> oldBBoxes = node.elementBBoxes;
        node.elements.clear();
        node.elementBBoxes.clear();

        for (int i = 0; i < oldElements.size(); i++) {
            int q = getQuadrant(node, oldBBoxes[i]);
            if (q != -1) {
                insertRecursive(*node.children[q], depth + 1, oldElements[i], oldBBoxes[i]);
            } else {
                node.elements.append(oldElements[i]);
                node.elementBBoxes.append(oldBBoxes[i]);
            }
        }
    }
}

QList<int> OsmQuadTree::query(const QRectF &bbox) const
{
    QList<int> result;
    queryRecursive(m_root, bbox, result);
    return result;
}

void OsmQuadTree::queryRecursive(const Node &node, const QRectF &bbox, QList<int> &result) const
{
    for (int i = 0; i < node.elements.size(); i++) {
        if (node.elementBBoxes[i].intersects(bbox)) {
            result.append(node.elements[i]);
        }
    }

    if (node.hasChildren) {
        for (int i = 0; i < 4; i++) {
            if (node.children[i]->bounds.intersects(bbox)) {
                queryRecursive(*node.children[i], bbox, result);
            }
        }
    }
}

QList<int> OsmQuadTree::queryPoint(const QPointF &point, double tolerance) const
{
    QRectF searchRect(point.x() - tolerance, point.y() - tolerance, tolerance * 2, tolerance * 2);
    return query(searchRect);
}

void OsmQuadTree::rebuild()
{
}