QGraphicsSceneBspTree Class Reference

#include <qgraphicsscene_bsp_p.h>

Classes
struct	Node

Public Functions
void	clear ()
QString	debug (int index) const
int	firstChildIndex (int index) const
void	initialize (const QRectF &rect, int depth)
void	insertItem (QGraphicsItem *item, const QRectF &rect)
QList< QGraphicsItem * >	items (const QRectF &rect, bool onlyTopLevelItems=false) const
int	leafCount () const
int	parentIndex (int index) const
	QGraphicsSceneBspTree ()
void	removeItem (QGraphicsItem *item, const QRectF &rect)
void	removeItems (const QSet< QGraphicsItem *> &items)
	~QGraphicsSceneBspTree ()

Private Functions
void	climbTree (QGraphicsSceneBspTreeVisitor *visitor, const QRectF &rect, int index=0) const
void	initialize (const QRectF &rect, int depth, int index)
QRectF	rectForIndex (int index) const

Properties
QGraphicsSceneFindItemBspTreeVisitor *	findVisitor
QGraphicsSceneInsertItemBspTreeVisitor *	insertVisitor
int	leafCnt
QVector< QList< QGraphicsItem * > >	leaves
QVector< Node >	nodes
QRectF	rect
QGraphicsSceneRemoveItemBspTreeVisitor *	removeVisitor

Detailed Description

Definition at line 72 of file qgraphicsscene_bsp_p.h.

Constructors and Destructors

QGraphicsSceneBspTree()

QGraphicsSceneBspTree::QGraphicsSceneBspTree

(

)

Definition at line 89 of file qgraphicsscene_bsp.cpp.

    : leafCnt(0)
{
    insertVisitor = new QGraphicsSceneInsertItemBspTreeVisitor;
    removeVisitor = new QGraphicsSceneRemoveItemBspTreeVisitor;
    findVisitor = new QGraphicsSceneFindItemBspTreeVisitor;
}

~QGraphicsSceneBspTree()

QGraphicsSceneBspTree::~QGraphicsSceneBspTree

(

)

Definition at line 97 of file qgraphicsscene_bsp.cpp.

{
    delete insertVisitor;
    delete removeVisitor;
    delete findVisitor;
}

Functions

clear()

void QGraphicsSceneBspTree::clear

(

)

Definition at line 116 of file qgraphicsscene_bsp.cpp.

{
    leafCnt = 0;
    nodes.clear();
    leaves.clear();
}

climbTree()

void QGraphicsSceneBspTree::climbTree ( QGraphicsSceneBspTreeVisitor *  visitor, const QRectF &  rect, int  index = 0  ) const

private

Definition at line 237 of file qgraphicsscene_bsp.cpp.

Referenced by insertItem(), items(), parentIndex(), and removeItem().

{
    if (nodes.isEmpty())
        return;

    const Node &node = nodes.at(index);
    const int childIndex = firstChildIndex(index);

    switch (node.type) {
    case Node::Leaf: {
        visitor->visit(const_cast<QList<QGraphicsItem*>*>(&leaves[node.leafIndex]));
        break;
    }
    case Node::Vertical:
        if (rect.left() < node.offset) {
            climbTree(visitor, rect, childIndex);
            if (rect.right() >= node.offset)
                climbTree(visitor, rect, childIndex + 1);
        } else {
            climbTree(visitor, rect, childIndex + 1);
        }
        break;
    case Node::Horizontal:
        if (rect.top() < node.offset) {
            climbTree(visitor, rect, childIndex);
            if (rect.bottom() >= node.offset)
                climbTree(visitor, rect, childIndex + 1);
        } else {
            climbTree(visitor, rect, childIndex + 1);
        }
    }
}

debug()

QString QGraphicsSceneBspTree::debug

(

int

index

)

const

Definition at line 166 of file qgraphicsscene_bsp.cpp.

Referenced by parentIndex().

{
    const Node *node = &nodes.at(index);

    QString tmp;
    if (node->type == Node::Leaf) {
        QRectF rect = rectForIndex(index);
        if (!leaves[node->leafIndex].isEmpty()) {
            tmp += QString::fromLatin1("[%1, %2, %3, %4] contains %5 items\n")
                   .arg(rect.left()).arg(rect.top())
                   .arg(rect.width()).arg(rect.height())
                   .arg(leaves[node->leafIndex].size());
        }
    } else {
        if (node->type == Node::Horizontal) {
            tmp += debug(firstChildIndex(index));
            tmp += debug(firstChildIndex(index) + 1);
        } else {
            tmp += debug(firstChildIndex(index));
            tmp += debug(firstChildIndex(index) + 1);
        }
    }

    return tmp;
}

firstChildIndex()

int QGraphicsSceneBspTree::firstChildIndex ( int  index ) const

inline

Definition at line 98 of file qgraphicsscene_bsp_p.h.

Referenced by climbTree(), debug(), and initialize().

    { return index * 2 + 1; }

initialize() [1/2]

void QGraphicsSceneBspTree::initialize	(	const QRectF &	rect,
		int	depth
	)

Definition at line 104 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::_q_updateIndex(), initialize(), and parentIndex().

{
    this->rect = rect;
    leafCnt = 0;
    nodes.resize((1 << (depth + 1)) - 1);
    nodes.fill(Node());
    leaves.resize(1 << depth);
    leaves.fill(QList<QGraphicsItem *>());

    initialize(rect, depth, 0);
}

initialize() [2/2]

void QGraphicsSceneBspTree::initialize ( const QRectF &  rect, int  depth, int  index  )

private

Definition at line 192 of file qgraphicsscene_bsp.cpp.

{
    Node *node = &nodes[index];
    if (index == 0) {
        node->type = Node::Horizontal;
        node->offset = rect.center().x();
    }

    if (depth) {
        Node::Type type;
        QRectF rect1, rect2;
        qreal offset1, offset2;

        if (node->type == Node::Horizontal) {
            type = Node::Vertical;
            rect1.setRect(rect.left(), rect.top(), rect.width(), rect.height() / 2);
            rect2.setRect(rect1.left(), rect1.bottom(), rect1.width(), rect.height() - rect1.height());
            offset1 = rect1.center().x();
            offset2 = rect2.center().x();
        } else {
            type = Node::Horizontal;
            rect1.setRect(rect.left(), rect.top(), rect.width() / 2, rect.height());
            rect2.setRect(rect1.right(), rect1.top(), rect.width() - rect1.width(), rect1.height());
            offset1 = rect1.center().y();
            offset2 = rect2.center().y();
        }

        int childIndex = firstChildIndex(index);

        Node *child = &nodes[childIndex];
        child->offset = offset1;
        child->type = type;

        child = &nodes[childIndex + 1];
        child->offset = offset2;
        child->type = type;

        initialize(rect1, depth - 1, childIndex);
        initialize(rect2, depth - 1, childIndex + 1);
    } else {
        node->type = Node::Leaf;
        node->leafIndex = leafCnt++;
    }
}

insertItem()

void QGraphicsSceneBspTree::insertItem	(	QGraphicsItem *	item,
		const QRectF &	rect
	)

Definition at line 123 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::_q_updateIndex().

{
    insertVisitor->item = item;
    climbTree(insertVisitor, rect);
}

items()

QList< QGraphicsItem * > QGraphicsSceneBspTree::items	(	const QRectF &	rect,
		bool	onlyTopLevelItems = false
	)		const

Definition at line 149 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::estimateItems(), and QGraphicsSceneBspTreeVisitor::~QGraphicsSceneBspTreeVisitor().

{
    QList<QGraphicsItem *> tmp;
    findVisitor->foundItems = &tmp;
    findVisitor->onlyTopLevelItems = onlyTopLevelItems;
    climbTree(findVisitor, rect);
    // Reset discovery bits.
    for (int i = 0; i < tmp.size(); ++i)
        tmp.at(i)->d_ptr->itemDiscovered = 0;
    return tmp;
}

leafCount()

int QGraphicsSceneBspTree::leafCount

(

)

const

Definition at line 161 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::_q_updateIndex().

{
    return leafCnt;
}

parentIndex()

int QGraphicsSceneBspTree::parentIndex ( int  index ) const

inline

Definition at line 101 of file qgraphicsscene_bsp_p.h.

Referenced by rectForIndex().

    { return index > 0 ? ((index & 1) ? ((index - 1) / 2) : ((index - 2) / 2)) : -1; }

rectForIndex()

QRectF QGraphicsSceneBspTree::rectForIndex ( int  index ) const

private

Definition at line 270 of file qgraphicsscene_bsp.cpp.

Referenced by debug(), and parentIndex().

{
    if (index <= 0)
        return rect;

    int parentIdx = parentIndex(index);
    QRectF rect = rectForIndex(parentIdx);
    const Node *parent = &nodes.at(parentIdx);

    if (parent->type == Node::Horizontal) {
        if (index & 1)
            rect.setRight(parent->offset);
        else
            rect.setLeft(parent->offset);
    } else {
        if (index & 1)
            rect.setBottom(parent->offset);
        else
            rect.setTop(parent->offset);
    }

    return rect;
}

removeItem()

void QGraphicsSceneBspTree::removeItem	(	QGraphicsItem *	item,
		const QRectF &	rect
	)

Definition at line 129 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::removeItem().

{
    removeVisitor->item = item;
    climbTree(removeVisitor, rect);
}

removeItems()

void QGraphicsSceneBspTree::removeItems

(

const QSet< QGraphicsItem *> &

items

)

Definition at line 135 of file qgraphicsscene_bsp.cpp.

Referenced by QGraphicsSceneBspTreeIndexPrivate::purgeRemovedItems().

{
    for (int i = 0; i < leaves.size(); ++i) {
        QList<QGraphicsItem *> newItemList;
        const QList<QGraphicsItem *> &oldItemList = leaves[i];
        for (int j = 0; j < oldItemList.size(); ++j) {
            QGraphicsItem *item = oldItemList.at(j);
            if (!items.contains(item))
                newItemList << item;
        }
        leaves[i] = newItemList;
    }
}

Properties

findVisitor

QGraphicsSceneFindItemBspTreeVisitor* QGraphicsSceneBspTree::findVisitor

private

Definition at line 118 of file qgraphicsscene_bsp_p.h.

Referenced by items(), QGraphicsSceneBspTree(), and ~QGraphicsSceneBspTree().

insertVisitor

QGraphicsSceneInsertItemBspTreeVisitor* QGraphicsSceneBspTree::insertVisitor

private

Definition at line 116 of file qgraphicsscene_bsp_p.h.

Referenced by insertItem(), QGraphicsSceneBspTree(), and ~QGraphicsSceneBspTree().

leafCnt

int QGraphicsSceneBspTree::leafCnt

private

Definition at line 113 of file qgraphicsscene_bsp_p.h.

Referenced by clear(), initialize(), and leafCount().

leaves

QVector<QList<QGraphicsItem *> > QGraphicsSceneBspTree::leaves

private

Definition at line 112 of file qgraphicsscene_bsp_p.h.

Referenced by clear(), climbTree(), debug(), initialize(), and removeItems().

nodes

QVector<Node> QGraphicsSceneBspTree::nodes

private

Definition at line 111 of file qgraphicsscene_bsp_p.h.

Referenced by clear(), climbTree(), debug(), initialize(), and rectForIndex().

rect

QRectF QGraphicsSceneBspTree::rect

private

Definition at line 114 of file qgraphicsscene_bsp_p.h.

Referenced by debug(), initialize(), parentIndex(), and rectForIndex().

removeVisitor

QGraphicsSceneRemoveItemBspTreeVisitor* QGraphicsSceneBspTree::removeVisitor

private

Definition at line 117 of file qgraphicsscene_bsp_p.h.

Referenced by QGraphicsSceneBspTree(), removeItem(), and ~QGraphicsSceneBspTree().

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The documentation for this class was generated from the following files:

• /src/gui/graphicsview/qgraphicsscene_bsp_p.h
• /src/gui/graphicsview/qgraphicsscene_bsp.cpp