<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>mouse.cpp Example File | Qt Widgets 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qtwidgets-index.html">Qt Widgets</a></td><td ><a href="qtwidgets-graphicsview-collidingmice-example.html">Colliding Mice Example</a></td><td >mouse.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">mouse.cpp Example File</h1> <span class="subtitle">graphicsview/collidingmice/mouse.cpp</span> <!-- $$$graphicsview/collidingmice/mouse.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "mouse.h"</span> <span class="preprocessor">#include <QGraphicsScene></span> <span class="preprocessor">#include <QPainter></span> <span class="preprocessor">#include <QStyleOption></span> <span class="preprocessor">#include <math.h></span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">double</span> Pi <span class="operator">=</span> <span class="number">3.14159265358979323846264338327950288419717</span>; <span class="keyword">static</span> <span class="type">double</span> TwoPi <span class="operator">=</span> <span class="number">2.0</span> <span class="operator">*</span> Pi; <span class="keyword">static</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> normalizeAngle(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> angle) { <span class="keyword">while</span> (angle <span class="operator"><</span> <span class="number">0</span>) angle <span class="operator">+</span><span class="operator">=</span> TwoPi; <span class="keyword">while</span> (angle <span class="operator">></span> TwoPi) angle <span class="operator">-</span><span class="operator">=</span> TwoPi; <span class="keyword">return</span> angle; } Mouse<span class="operator">::</span>Mouse() : angle(<span class="number">0</span>)<span class="operator">,</span> speed(<span class="number">0</span>)<span class="operator">,</span> mouseEyeDirection(<span class="number">0</span>)<span class="operator">,</span> color(qrand() <span class="operator">%</span> <span class="number">256</span><span class="operator">,</span> qrand() <span class="operator">%</span> <span class="number">256</span><span class="operator">,</span> qrand() <span class="operator">%</span> <span class="number">256</span>) { setRotation(qrand() <span class="operator">%</span> (<span class="number">360</span> <span class="operator">*</span> <span class="number">16</span>)); } <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> Mouse<span class="operator">::</span>boundingRect() <span class="keyword">const</span> { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> adjust <span class="operator">=</span> <span class="number">0.5</span>; <span class="keyword">return</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(<span class="operator">-</span><span class="number">18</span> <span class="operator">-</span> adjust<span class="operator">,</span> <span class="operator">-</span><span class="number">22</span> <span class="operator">-</span> adjust<span class="operator">,</span> <span class="number">36</span> <span class="operator">+</span> adjust<span class="operator">,</span> <span class="number">60</span> <span class="operator">+</span> adjust); } <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> Mouse<span class="operator">::</span>shape() <span class="keyword">const</span> { <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> path; path<span class="operator">.</span>addRect(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">20</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">40</span>); <span class="keyword">return</span> path; } <span class="type">void</span> Mouse<span class="operator">::</span>paint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> <span class="operator">*</span>painter<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstyleoptiongraphicsitem.html">QStyleOptionGraphicsItem</a></span> <span class="operator">*</span><span class="operator">,</span> <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>) { <span class="comment">// Body</span> painter<span class="operator">-</span><span class="operator">></span>setBrush(color); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">20</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">40</span>); <span class="comment">// Eyes</span> painter<span class="operator">-</span><span class="operator">></span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>white); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">17</span><span class="operator">,</span> <span class="number">8</span><span class="operator">,</span> <span class="number">8</span>); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="number">2</span><span class="operator">,</span> <span class="operator">-</span><span class="number">17</span><span class="operator">,</span> <span class="number">8</span><span class="operator">,</span> <span class="number">8</span>); <span class="comment">// Nose</span> painter<span class="operator">-</span><span class="operator">></span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(<span class="operator">-</span><span class="number">2</span><span class="operator">,</span> <span class="operator">-</span><span class="number">22</span><span class="operator">,</span> <span class="number">4</span><span class="operator">,</span> <span class="number">4</span>)); <span class="comment">// Pupils</span> painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(<span class="operator">-</span><span class="number">8.0</span> <span class="operator">+</span> mouseEyeDirection<span class="operator">,</span> <span class="operator">-</span><span class="number">17</span><span class="operator">,</span> <span class="number">4</span><span class="operator">,</span> <span class="number">4</span>)); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(<span class="number">4.0</span> <span class="operator">+</span> mouseEyeDirection<span class="operator">,</span> <span class="operator">-</span><span class="number">17</span><span class="operator">,</span> <span class="number">4</span><span class="operator">,</span> <span class="number">4</span>)); <span class="comment">// Ears</span> painter<span class="operator">-</span><span class="operator">></span>setBrush(scene()<span class="operator">-</span><span class="operator">></span>collidingItems(<span class="keyword">this</span>)<span class="operator">.</span>isEmpty() <span class="operator">?</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkYellow : <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>red); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="operator">-</span><span class="number">17</span><span class="operator">,</span> <span class="operator">-</span><span class="number">12</span><span class="operator">,</span> <span class="number">16</span><span class="operator">,</span> <span class="number">16</span>); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">12</span><span class="operator">,</span> <span class="number">16</span><span class="operator">,</span> <span class="number">16</span>); <span class="comment">// Tail</span> <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> path(<span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">20</span>)); path<span class="operator">.</span>cubicTo(<span class="operator">-</span><span class="number">5</span><span class="operator">,</span> <span class="number">22</span><span class="operator">,</span> <span class="operator">-</span><span class="number">5</span><span class="operator">,</span> <span class="number">22</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">25</span>); path<span class="operator">.</span>cubicTo(<span class="number">5</span><span class="operator">,</span> <span class="number">27</span><span class="operator">,</span> <span class="number">5</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">30</span>); path<span class="operator">.</span>cubicTo(<span class="operator">-</span><span class="number">5</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> <span class="operator">-</span><span class="number">5</span><span class="operator">,</span> <span class="number">42</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">35</span>); painter<span class="operator">-</span><span class="operator">></span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoBrush); painter<span class="operator">-</span><span class="operator">></span>drawPath(path); } <span class="type">void</span> Mouse<span class="operator">::</span>advance(<span class="type">int</span> step) { <span class="keyword">if</span> (<span class="operator">!</span>step) <span class="keyword">return</span>; <span class="comment">// Don't move too far away</span> <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> lineToCenter(<span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> mapFromScene(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)); <span class="keyword">if</span> (lineToCenter<span class="operator">.</span>length() <span class="operator">></span> <span class="number">150</span>) { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> angleToCenter <span class="operator">=</span> <span class="operator">::</span>acos(lineToCenter<span class="operator">.</span>dx() <span class="operator">/</span> lineToCenter<span class="operator">.</span>length()); <span class="keyword">if</span> (lineToCenter<span class="operator">.</span>dy() <span class="operator"><</span> <span class="number">0</span>) angleToCenter <span class="operator">=</span> TwoPi <span class="operator">-</span> angleToCenter; angleToCenter <span class="operator">=</span> normalizeAngle((Pi <span class="operator">-</span> angleToCenter) <span class="operator">+</span> Pi <span class="operator">/</span> <span class="number">2</span>); <span class="keyword">if</span> (angleToCenter <span class="operator"><</span> Pi <span class="operator">&</span><span class="operator">&</span> angleToCenter <span class="operator">></span> Pi <span class="operator">/</span> <span class="number">4</span>) { <span class="comment">// Rotate left</span> angle <span class="operator">+</span><span class="operator">=</span> (angle <span class="operator"><</span> <span class="operator">-</span>Pi <span class="operator">/</span> <span class="number">2</span>) <span class="operator">?</span> <span class="number">0.25</span> : <span class="operator">-</span><span class="number">0.25</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (angleToCenter <span class="operator">></span><span class="operator">=</span> Pi <span class="operator">&</span><span class="operator">&</span> angleToCenter <span class="operator"><</span> (Pi <span class="operator">+</span> Pi <span class="operator">/</span> <span class="number">2</span> <span class="operator">+</span> Pi <span class="operator">/</span> <span class="number">4</span>)) { <span class="comment">// Rotate right</span> angle <span class="operator">+</span><span class="operator">=</span> (angle <span class="operator"><</span> Pi <span class="operator">/</span> <span class="number">2</span>) <span class="operator">?</span> <span class="number">0.25</span> : <span class="operator">-</span><span class="number">0.25</span>; } } <span class="keyword">else</span> <span class="keyword">if</span> (<span class="operator">::</span>sin(angle) <span class="operator"><</span> <span class="number">0</span>) { angle <span class="operator">+</span><span class="operator">=</span> <span class="number">0.25</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (<span class="operator">::</span>sin(angle) <span class="operator">></span> <span class="number">0</span>) { angle <span class="operator">-</span><span class="operator">=</span> <span class="number">0.25</span>; } <span class="comment">// Try not to crash with any other mice</span> <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span><span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span><span class="operator">></span> dangerMice <span class="operator">=</span> scene()<span class="operator">-</span><span class="operator">></span>items(<span class="type"><a href="../qtgui/qpolygonf.html">QPolygonF</a></span>() <span class="operator"><</span><span class="operator"><</span> mapToScene(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>) <span class="operator"><</span><span class="operator"><</span> mapToScene(<span class="operator">-</span><span class="number">30</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>) <span class="operator"><</span><span class="operator"><</span> mapToScene(<span class="number">30</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>)); foreach (<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>item<span class="operator">,</span> dangerMice) { <span class="keyword">if</span> (item <span class="operator">=</span><span class="operator">=</span> <span class="keyword">this</span>) <span class="keyword">continue</span>; <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> lineToMouse(<span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> mapFromItem(item<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)); <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> angleToMouse <span class="operator">=</span> <span class="operator">::</span>acos(lineToMouse<span class="operator">.</span>dx() <span class="operator">/</span> lineToMouse<span class="operator">.</span>length()); <span class="keyword">if</span> (lineToMouse<span class="operator">.</span>dy() <span class="operator"><</span> <span class="number">0</span>) angleToMouse <span class="operator">=</span> TwoPi <span class="operator">-</span> angleToMouse; angleToMouse <span class="operator">=</span> normalizeAngle((Pi <span class="operator">-</span> angleToMouse) <span class="operator">+</span> Pi <span class="operator">/</span> <span class="number">2</span>); <span class="keyword">if</span> (angleToMouse <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> angleToMouse <span class="operator"><</span> Pi <span class="operator">/</span> <span class="number">2</span>) { <span class="comment">// Rotate right</span> angle <span class="operator">+</span><span class="operator">=</span> <span class="number">0.5</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (angleToMouse <span class="operator"><</span><span class="operator">=</span> TwoPi <span class="operator">&</span><span class="operator">&</span> angleToMouse <span class="operator">></span> (TwoPi <span class="operator">-</span> Pi <span class="operator">/</span> <span class="number">2</span>)) { <span class="comment">// Rotate left</span> angle <span class="operator">-</span><span class="operator">=</span> <span class="number">0.5</span>; } } <span class="comment">// Add some random movement</span> <span class="keyword">if</span> (dangerMice<span class="operator">.</span>size() <span class="operator">></span> <span class="number">1</span> <span class="operator">&</span><span class="operator">&</span> (qrand() <span class="operator">%</span> <span class="number">10</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>) { <span class="keyword">if</span> (qrand() <span class="operator">%</span> <span class="number">1</span>) angle <span class="operator">+</span><span class="operator">=</span> (qrand() <span class="operator">%</span> <span class="number">100</span>) <span class="operator">/</span> <span class="number">500.0</span>; <span class="keyword">else</span> angle <span class="operator">-</span><span class="operator">=</span> (qrand() <span class="operator">%</span> <span class="number">100</span>) <span class="operator">/</span> <span class="number">500.0</span>; } speed <span class="operator">+</span><span class="operator">=</span> (<span class="operator">-</span><span class="number">50</span> <span class="operator">+</span> qrand() <span class="operator">%</span> <span class="number">100</span>) <span class="operator">/</span> <span class="number">100.0</span>; <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> dx <span class="operator">=</span> <span class="operator">::</span>sin(angle) <span class="operator">*</span> <span class="number">10</span>; mouseEyeDirection <span class="operator">=</span> (<a href="../qtcore/qtglobal.html#qAbs">qAbs</a>(dx <span class="operator">/</span> <span class="number">5</span>) <span class="operator"><</span> <span class="number">1</span>) <span class="operator">?</span> <span class="number">0</span> : dx <span class="operator">/</span> <span class="number">5</span>; setRotation(rotation() <span class="operator">+</span> dx); setPos(mapToParent(<span class="number">0</span><span class="operator">,</span> <span class="operator">-</span>(<span class="number">3</span> <span class="operator">+</span> sin(speed) <span class="operator">*</span> <span class="number">3</span>))); } </pre> </div> <!-- @@@graphicsview/collidingmice/mouse.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>