1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QGRAPHICSSCENEBSPTREE_P_H
5#define QGRAPHICSSCENEBSPTREE_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists for the convenience
12// of other Qt classes. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include <QtWidgets/private/qtwidgetsglobal_p.h>
19#include <QtCore/qlist.h>
20#include <QtCore/qrect.h>
21#include <QtCore/qset.h>
22
23QT_REQUIRE_CONFIG(graphicsview);
24
25QT_BEGIN_NAMESPACE
26
27class QGraphicsItem;
28
29class QGraphicsSceneBspTree
30{
31public:
32 struct Node
33 {
34 enum Type { Horizontal, Vertical, Leaf };
35 union {
36 qreal offset;
37 int leafIndex;
38 };
39 Type type;
40 };
41
42 QGraphicsSceneBspTree();
43 ~QGraphicsSceneBspTree();
44
45 void initialize(const QRectF &rect, int depth);
46 void clear();
47
48 void insertItem(QGraphicsItem *item, const QRectF &rect);
49 void removeItem(QGraphicsItem *item, const QRectF &rect);
50 void removeItems(const QSet<QGraphicsItem *> &items);
51
52 QList<QGraphicsItem *> items(const QRectF &rect, bool onlyTopLevelItems = false) const;
53 int leafCount() const;
54
55 inline int firstChildIndex(int index) const
56 { return index * 2 + 1; }
57
58 inline int parentIndex(int index) const
59 { return index > 0 ? ((index & 1) ? ((index - 1) / 2) : ((index - 2) / 2)) : -1; }
60
61 QString debug(int index) const;
62
63private:
64 void initialize(const QRectF &rect, int depth, int index);
65 template<typename Visitor>
66 void climbTree(Visitor &&visitor, const QRectF &rect, int index = 0) const;
67 QRectF rectForIndex(int index) const;
68
69 QList<Node> nodes;
70 QList<QList<QGraphicsItem *>> leaves;
71 int leafCnt;
72 QRectF rect;
73};
74
75QT_END_NAMESPACE
76
77#endif // QGRAPHICSSCENEBSPTREE_P_H
78

source code of qtbase/src/widgets/graphicsview/qgraphicsscene_bsp_p.h