02b7ec05d5
Use M_PI (and friends), where possible, in favor of hand-coded approximations of various (in)accuracies. Where that's not available (e.g. fragment shaders), use the same value that qmath.h uses for M_PI, for consistency. Replaced math.h with qmath.h in places that defined a fall-back in case math.h omits it (it's not in the C++ standard, although M_PI is in POSIX); or removed this entirely where it wasn't used. Reworked some code to reduce the amount of arithmetic needed, in the process; e.g. pulling common factors out of loops. Revised an example's doc to not waste time talking about using a six-sig-fig value for pi (which we no longer do) - it really wasn't relevant, or anything to be proud of; nor did the doc mention its later use. Task-number: QTBUG-58083 Change-Id: I5a31e3a2b6a823b97a43209bed61a37b9aa6c05f Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
154 lines
5.0 KiB
C++
154 lines
5.0 KiB
C++
/****************************************************************************
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**
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** Copyright (C) 2016 The Qt Company Ltd.
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** Contact: https://www.qt.io/licensing/
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** Commercial License Usage
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** Licensees holding valid commercial Qt licenses may use this file in
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** accordance with the commercial license agreement provided with the
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** Software or, alternatively, in accordance with the terms contained in
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** a written agreement between you and The Qt Company. For licensing terms
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** and conditions see https://www.qt.io/terms-conditions. For further
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** information use the contact form at https://www.qt.io/contact-us.
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**
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** BSD License Usage
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** Alternatively, you may use this file under the terms of the BSD license
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** as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of The Qt Company Ltd nor the names of its
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** contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "edge.h"
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#include "node.h"
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#include <qmath.h>
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#include <QPainter>
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//! [0]
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Edge::Edge(Node *sourceNode, Node *destNode)
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: arrowSize(10)
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{
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setAcceptedMouseButtons(0);
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source = sourceNode;
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dest = destNode;
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source->addEdge(this);
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dest->addEdge(this);
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adjust();
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}
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//! [0]
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//! [1]
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Node *Edge::sourceNode() const
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{
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return source;
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}
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Node *Edge::destNode() const
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{
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return dest;
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}
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//! [1]
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//! [2]
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void Edge::adjust()
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{
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if (!source || !dest)
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return;
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QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0));
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qreal length = line.length();
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prepareGeometryChange();
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if (length > qreal(20.)) {
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QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length);
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sourcePoint = line.p1() + edgeOffset;
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destPoint = line.p2() - edgeOffset;
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} else {
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sourcePoint = destPoint = line.p1();
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}
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}
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//! [2]
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//! [3]
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QRectF Edge::boundingRect() const
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{
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if (!source || !dest)
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return QRectF();
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qreal penWidth = 1;
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qreal extra = (penWidth + arrowSize) / 2.0;
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return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(),
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destPoint.y() - sourcePoint.y()))
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.normalized()
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.adjusted(-extra, -extra, extra, extra);
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}
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//! [3]
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//! [4]
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void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
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{
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if (!source || !dest)
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return;
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QLineF line(sourcePoint, destPoint);
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if (qFuzzyCompare(line.length(), qreal(0.)))
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return;
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//! [4]
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//! [5]
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// Draw the line itself
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painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
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painter->drawLine(line);
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//! [5]
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//! [6]
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// Draw the arrows
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double angle = std::atan2(-line.dy(), line.dx());
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QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + M_PI / 3) * arrowSize,
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cos(angle + M_PI / 3) * arrowSize);
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QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + M_PI - M_PI / 3) * arrowSize,
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cos(angle + M_PI - M_PI / 3) * arrowSize);
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QPointF destArrowP1 = destPoint + QPointF(sin(angle - M_PI / 3) * arrowSize,
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cos(angle - M_PI / 3) * arrowSize);
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QPointF destArrowP2 = destPoint + QPointF(sin(angle - M_PI + M_PI / 3) * arrowSize,
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cos(angle - M_PI + M_PI / 3) * arrowSize);
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painter->setBrush(Qt::black);
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painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
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painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
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}
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//! [6]
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