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#include "qbsptree_p.h"

QT_BEGIN_NAMESPACE

QBspTree::QBspTree() : depth(6), visited(0) {}

void QBspTree::create(int n, int d)

{

    // simple heuristics to find the best tree depth

    if (d == -1) {

        int c;

        for (c = 0; n; ++c)

            n = n / 10;

        depth = c << 1;

    } else {

        depth = d;

    }

    depth = qMax(depth, uint(1));

    nodes.resize((1 << depth) - 1); // resize to number of nodes

    leaves.resize(1 << depth); // resize to number of leaves

}

void QBspTree::destroy()

{

    leaves.clear();

    nodes.clear();

}

void QBspTree::climbTree(const QRect &rect, callback *function, QBspTreeData data)

{

    if (nodes.isEmpty())

        return;

    ++visited;

    climbTree(rect, function, data, 0);

}

void QBspTree::climbTree(const QRect &area, callback *function, QBspTreeData data, int index)

{

    if (index >= nodes.count()) { // the index points to a leaf

        Q_ASSERT(!nodes.isEmpty());

        function(leaf(index - nodes.count()), area, visited, data);

        return;

    }

    Node::Type t = (Node::Type) nodes.at(index).type;

    int pos = nodes.at(index).pos;

    int idx = firstChildIndex(index);

    if (t == Node::VerticalPlane) {

        if (area.left() < pos)

            climbTree(area, function, data, idx); // back

        if (area.right() >= pos)

            climbTree(area, function, data, idx + 1); // front

    } else {

        if (area.top() < pos)

            climbTree(area, function, data, idx); // back

        if (area.bottom() >= pos)

            climbTree(area, function, data, idx + 1); // front

    }

}

void QBspTree::init(const QRect &area, int depth, NodeType type, int index)

{

    Node::Type t = Node::None; // t should never have this value

    if (type == Node::Both) // if both planes are specified, use 2d bsp

        t = (depth & 1) ? Node::HorizontalPlane : Node::VerticalPlane;

    else

        t = type;

    QPoint center = area.center();

    nodes[index].pos = (t == Node::VerticalPlane ? center.x() : center.y());

    nodes[index].type = t;

    QRect front = area;

    QRect back = area;

    if (t == Node::VerticalPlane) {

        front.setLeft(center.x());

        back.setRight(center.x() - 1); // front includes the center

    } else { // t == Node::HorizontalPlane

        front.setTop(center.y());

        back.setBottom(center.y() - 1);

    }

    int idx = firstChildIndex(index);

    if (--depth) {

        init(back, depth, type, idx);

        init(front, depth, type, idx + 1);

    }

}

void QBspTree::insert(QVector<int> &leaf, const QRect &, uint, QBspTreeData data)

{

    leaf.append(data.i);

}

void QBspTree::remove(QVector<int> &leaf, const QRect &, uint, QBspTreeData data)

{

    int i = leaf.indexOf(data.i);

    if (i != -1)

        leaf.remove(i);

}

QT_END_NAMESPACE