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Breadcrumbs go here --> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <h1 class="title">trackball.cpp Example File</h1> <span class="small-subtitle">demos/boxes/trackball.cpp</span> <!-- $$$demos/boxes/trackball.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/legal ** ** This file is part of the demonstration applications of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** 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 Digia. For licensing terms and ** conditions see http://qt.digia.com/licensing. For further information ** use the contact form at http://qt.digia.com/contact-us. ** ** 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, Digia gives you certain additional ** rights. These rights are described in the Digia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "trackball.h"</span> <span class="preprocessor">#include "scene.h"</span> <span class="comment">//============================================================================//</span> <span class="comment">// TrackBall //</span> <span class="comment">//============================================================================//</span> TrackBall<span class="operator">::</span>TrackBall(TrackMode mode) : m_angularVelocity(<span class="number">0</span>) <span class="operator">,</span> m_paused(<span class="keyword">false</span>) <span class="operator">,</span> m_pressed(<span class="keyword">false</span>) <span class="operator">,</span> m_mode(mode) { m_axis <span class="operator">=</span> QVector3D(<span class="number">0</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">0</span>); m_rotation <span class="operator">=</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span>(); m_lastTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); } TrackBall<span class="operator">::</span>TrackBall(<span class="type">float</span> angularVelocity<span class="operator">,</span> <span class="keyword">const</span> QVector3D<span class="operator">&</span> axis<span class="operator">,</span> TrackMode mode) : m_axis(axis) <span class="operator">,</span> m_angularVelocity(angularVelocity) <span class="operator">,</span> m_paused(<span class="keyword">false</span>) <span class="operator">,</span> m_pressed(<span class="keyword">false</span>) <span class="operator">,</span> m_mode(mode) { m_rotation <span class="operator">=</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span>(); m_lastTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); } <span class="type">void</span> TrackBall<span class="operator">::</span>push(<span class="keyword">const</span> <span class="type"><a href="qpointf.html">QPointF</a></span><span class="operator">&</span> p<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span> <span class="operator">&</span>) { m_rotation <span class="operator">=</span> rotation(); m_pressed <span class="operator">=</span> <span class="keyword">true</span>; m_lastTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); m_lastPos <span class="operator">=</span> p; m_angularVelocity <span class="operator">=</span> <span class="number">0.0f</span>; } <span class="type">void</span> TrackBall<span class="operator">::</span>move(<span class="keyword">const</span> <span class="type"><a href="qpointf.html">QPointF</a></span><span class="operator">&</span> p<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span> <span class="operator">&</span>transformation) { <span class="keyword">if</span> (<span class="operator">!</span>m_pressed) <span class="keyword">return</span>; <span class="type"><a href="qtime.html">QTime</a></span> currentTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); <span class="type">int</span> msecs <span class="operator">=</span> m_lastTime<span class="operator">.</span>msecsTo(currentTime); <span class="keyword">if</span> (msecs <span class="operator"><</span><span class="operator">=</span> <span class="number">20</span>) <span class="keyword">return</span>; <span class="keyword">switch</span> (m_mode) { <span class="keyword">case</span> Plane: { <span class="type"><a href="qlinef.html">QLineF</a></span> delta(m_lastPos<span class="operator">,</span> p); m_angularVelocity <span class="operator">=</span> <span class="number">180</span><span class="operator">*</span>delta<span class="operator">.</span>length() <span class="operator">/</span> (PI<span class="operator">*</span>msecs); m_axis <span class="operator">=</span> QVector3D(<span class="operator">-</span>delta<span class="operator">.</span>dy()<span class="operator">,</span> delta<span class="operator">.</span>dx()<span class="operator">,</span> <span class="number">0.0f</span>)<span class="operator">.</span>normalized(); m_axis <span class="operator">=</span> transformation<span class="operator">.</span>rotatedVector(m_axis); m_rotation <span class="operator">=</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span><span class="operator">::</span>fromAxisAndAngle(m_axis<span class="operator">,</span> <span class="number">180</span> <span class="operator">/</span> PI <span class="operator">*</span> delta<span class="operator">.</span>length()) <span class="operator">*</span> m_rotation; } <span class="keyword">break</span>; <span class="keyword">case</span> Sphere: { QVector3D lastPos3D <span class="operator">=</span> QVector3D(m_lastPos<span class="operator">.</span>x()<span class="operator">,</span> m_lastPos<span class="operator">.</span>y()<span class="operator">,</span> <span class="number">0.0f</span>); <span class="type">float</span> sqrZ <span class="operator">=</span> <span class="number">1</span> <span class="operator">-</span> QVector3D<span class="operator">::</span>dotProduct(lastPos3D<span class="operator">,</span> lastPos3D); <span class="keyword">if</span> (sqrZ <span class="operator">></span> <span class="number">0</span>) lastPos3D<span class="operator">.</span>setZ(sqrt(sqrZ)); <span class="keyword">else</span> lastPos3D<span class="operator">.</span>normalize(); QVector3D currentPos3D <span class="operator">=</span> QVector3D(p<span class="operator">.</span>x()<span class="operator">,</span> p<span class="operator">.</span>y()<span class="operator">,</span> <span class="number">0.0f</span>); sqrZ <span class="operator">=</span> <span class="number">1</span> <span class="operator">-</span> QVector3D<span class="operator">::</span>dotProduct(currentPos3D<span class="operator">,</span> currentPos3D); <span class="keyword">if</span> (sqrZ <span class="operator">></span> <span class="number">0</span>) currentPos3D<span class="operator">.</span>setZ(sqrt(sqrZ)); <span class="keyword">else</span> currentPos3D<span class="operator">.</span>normalize(); m_axis <span class="operator">=</span> QVector3D<span class="operator">::</span>crossProduct(lastPos3D<span class="operator">,</span> currentPos3D); <span class="type">float</span> angle <span class="operator">=</span> <span class="number">180</span> <span class="operator">/</span> PI <span class="operator">*</span> asin(sqrt(QVector3D<span class="operator">::</span>dotProduct(m_axis<span class="operator">,</span> m_axis))); m_angularVelocity <span class="operator">=</span> angle <span class="operator">/</span> msecs; m_axis<span class="operator">.</span>normalize(); m_axis <span class="operator">=</span> transformation<span class="operator">.</span>rotatedVector(m_axis); m_rotation <span class="operator">=</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span><span class="operator">::</span>fromAxisAndAngle(m_axis<span class="operator">,</span> angle) <span class="operator">*</span> m_rotation; } <span class="keyword">break</span>; } m_lastPos <span class="operator">=</span> p; m_lastTime <span class="operator">=</span> currentTime; } <span class="type">void</span> TrackBall<span class="operator">::</span>release(<span class="keyword">const</span> <span class="type"><a href="qpointf.html">QPointF</a></span><span class="operator">&</span> p<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span> <span class="operator">&</span>transformation) { <span class="comment">// Calling move() caused the rotation to stop if the framerate was too low.</span> move(p<span class="operator">,</span> transformation); m_pressed <span class="operator">=</span> <span class="keyword">false</span>; } <span class="type">void</span> TrackBall<span class="operator">::</span>start() { m_lastTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); m_paused <span class="operator">=</span> <span class="keyword">false</span>; } <span class="type">void</span> TrackBall<span class="operator">::</span>stop() { m_rotation <span class="operator">=</span> rotation(); m_paused <span class="operator">=</span> <span class="keyword">true</span>; } <span class="type"><a href="qquaternion.html">QQuaternion</a></span> TrackBall<span class="operator">::</span>rotation() <span class="keyword">const</span> { <span class="keyword">if</span> (m_paused <span class="operator">|</span><span class="operator">|</span> m_pressed) <span class="keyword">return</span> m_rotation; <span class="type"><a href="qtime.html">QTime</a></span> currentTime <span class="operator">=</span> <span class="type"><a href="qtime.html">QTime</a></span><span class="operator">::</span>currentTime(); <span class="type">float</span> angle <span class="operator">=</span> m_angularVelocity <span class="operator">*</span> m_lastTime<span class="operator">.</span>msecsTo(currentTime); <span class="keyword">return</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span><span class="operator">::</span>fromAxisAndAngle(m_axis<span class="operator">,</span> angle) <span class="operator">*</span> m_rotation; }</pre> </div> <!-- @@@demos/boxes/trackball.cpp --> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2013 Digia Plc and/or its subsidiaries. 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