src/gui/graphicsview/qgraphicsscene_bsp.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/gui/graphicsview/qgraphicsscene_bsp.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,296 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgraphicsscene_bsp_p.h"
+
+#ifndef QT_NO_GRAPHICSVIEW
+
+#include <QtCore/qstring.h>
+#include <private/qgraphicsitem_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QGraphicsSceneInsertItemBspTreeVisitor : public QGraphicsSceneBspTreeVisitor
+{
+public:
+    QGraphicsItem *item;
+
+    void visit(QList<QGraphicsItem *> *items)
+    { items->prepend(item); }
+};
+
+class QGraphicsSceneRemoveItemBspTreeVisitor : public QGraphicsSceneBspTreeVisitor
+{
+public:
+    QGraphicsItem *item;
+
+    void visit(QList<QGraphicsItem *> *items)
+    { items->removeAll(item); }
+};
+
+class QGraphicsSceneFindItemBspTreeVisitor : public QGraphicsSceneBspTreeVisitor
+{
+public:
+    QList<QGraphicsItem *> *foundItems;
+    bool onlyTopLevelItems;
+
+    void visit(QList<QGraphicsItem *> *items)
+    {
+        for (int i = 0; i < items->size(); ++i) {
+            QGraphicsItem *item = items->at(i);
+            if (onlyTopLevelItems && item->d_ptr->parent)
+                item = item->topLevelItem();
+            if (!item->d_func()->itemDiscovered && item->d_ptr->visible) {
+                item->d_func()->itemDiscovered = 1;
+                foundItems->prepend(item);
+            }
+        }
+    }
+};
+
+QGraphicsSceneBspTree::QGraphicsSceneBspTree()
+    : leafCnt(0)
+{
+    insertVisitor = new QGraphicsSceneInsertItemBspTreeVisitor;
+    removeVisitor = new QGraphicsSceneRemoveItemBspTreeVisitor;
+    findVisitor = new QGraphicsSceneFindItemBspTreeVisitor;
+}
+
+QGraphicsSceneBspTree::~QGraphicsSceneBspTree()
+{
+    delete insertVisitor;
+    delete removeVisitor;
+    delete findVisitor;
+}
+
+void QGraphicsSceneBspTree::initialize(const QRectF &rect, int depth)
+{
+    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);
+}
+
+void QGraphicsSceneBspTree::clear()
+{
+    leafCnt = 0;
+    nodes.clear();
+    leaves.clear();
+}
+
+void QGraphicsSceneBspTree::insertItem(QGraphicsItem *item, const QRectF &rect)
+{
+    insertVisitor->item = item;
+    climbTree(insertVisitor, rect);
+}
+
+void QGraphicsSceneBspTree::removeItem(QGraphicsItem *item, const QRectF &rect)
+{
+    removeVisitor->item = item;
+    climbTree(removeVisitor, rect);
+}
+
+void QGraphicsSceneBspTree::removeItems(const QSet<QGraphicsItem *> &items)
+{
+    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;
+    }
+}
+
+QList<QGraphicsItem *> QGraphicsSceneBspTree::items(const QRectF &rect, bool onlyTopLevelItems) const
+{
+    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;
+}
+
+int QGraphicsSceneBspTree::leafCount() const
+{
+    return leafCnt;
+}
+
+QString QGraphicsSceneBspTree::debug(int index) const
+{
+    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;
+}
+
+void QGraphicsSceneBspTree::initialize(const QRectF &rect, int depth, int index)
+{
+    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++;
+    }
+}
+
+void QGraphicsSceneBspTree::climbTree(QGraphicsSceneBspTreeVisitor *visitor, const QRectF &rect, int index) const
+{
+    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);
+        }
+    }
+}
+
+QRectF QGraphicsSceneBspTree::rectForIndex(int index) const
+{
+    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;
+}
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_GRAPHICSVIEW