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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">mainwidget.cpp Example File</h1> <span class="small-subtitle">opengl/cube/mainwidget.cpp</span> <!-- $$$opengl/cube/mainwidget.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 QtCore module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Digia Plc and its Subsidiary(-ies) 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 "mainwidget.h"</span> <span class="preprocessor">#include "geometryengine.h"</span> <span class="preprocessor">#include <QtOpenGL/QGLShaderProgram></span> <span class="preprocessor">#include <QBasicTimer></span> <span class="preprocessor">#include <QMouseEvent></span> <span class="preprocessor">#include <QDebug></span> <span class="preprocessor">#include <math.h></span> <span class="preprocessor">#include <locale.h></span> MainWidget<span class="operator">::</span>MainWidget(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qglwidget.html">QGLWidget</a></span>(parent)<span class="operator">,</span> timer(<span class="keyword">new</span> <span class="type"><a href="qbasictimer.html">QBasicTimer</a></span>)<span class="operator">,</span> program(<span class="keyword">new</span> <span class="type"><a href="qglshaderprogram.html">QGLShaderProgram</a></span>)<span class="operator">,</span> geometries(<span class="keyword">new</span> GeometryEngine) { } MainWidget<span class="operator">::</span><span class="operator">~</span>MainWidget() { <span class="keyword">delete</span> timer; timer <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">delete</span> program; program <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">delete</span> geometries; geometries <span class="operator">=</span> <span class="number">0</span>; deleteTexture(texture); } <span class="type">void</span> MainWidget<span class="operator">::</span>mousePressEvent(<span class="type"><a href="qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>e) { <span class="comment">// Saving mouse press position</span> mousePressPosition <span class="operator">=</span> QVector2D(e<span class="operator">-</span><span class="operator">></span>posF()); } <span class="type">void</span> MainWidget<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>e) { <span class="comment">// Mouse release position - mouse press position</span> QVector2D diff <span class="operator">=</span> QVector2D(e<span class="operator">-</span><span class="operator">></span>posF()) <span class="operator">-</span> mousePressPosition; <span class="comment">// Rotation axis is perpendicular to the mouse position difference</span> <span class="comment">// vector</span> QVector3D n <span class="operator">=</span> QVector3D(diff<span class="operator">.</span>y()<span class="operator">,</span> diff<span class="operator">.</span>x()<span class="operator">,</span> <span class="number">0.0</span>)<span class="operator">.</span>normalized(); <span class="comment">// Accelerate angular speed relative to the length of the mouse sweep</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> acc <span class="operator">=</span> diff<span class="operator">.</span>length() <span class="operator">/</span> <span class="number">100.0</span>; <span class="comment">// Calculate new rotation axis as weighted sum</span> rotationAxis <span class="operator">=</span> (rotationAxis <span class="operator">*</span> angularSpeed <span class="operator">+</span> n <span class="operator">*</span> acc)<span class="operator">.</span>normalized(); <span class="comment">// Increase angular speed</span> angularSpeed <span class="operator">+</span><span class="operator">=</span> acc; } <span class="type">void</span> MainWidget<span class="operator">::</span>timerEvent(<span class="type"><a href="qtimerevent.html">QTimerEvent</a></span> <span class="operator">*</span>e) { Q_UNUSED(e); <span class="comment">// Decrease angular speed (friction)</span> angularSpeed <span class="operator">*</span><span class="operator">=</span> <span class="number">0.99</span>; <span class="comment">// Stop rotation when speed goes below threshold</span> <span class="keyword">if</span> (angularSpeed <span class="operator"><</span> <span class="number">0.01</span>) angularSpeed <span class="operator">=</span> <span class="number">0.0</span>; <span class="keyword">else</span> { <span class="comment">// Update rotation</span> rotation <span class="operator">=</span> <span class="type"><a href="qquaternion.html">QQuaternion</a></span><span class="operator">::</span>fromAxisAndAngle(rotationAxis<span class="operator">,</span> angularSpeed) <span class="operator">*</span> rotation; <span class="comment">// Update scene</span> updateGL(); } } <span class="type">void</span> MainWidget<span class="operator">::</span>initializeGL() { initializeGLFunctions(); qglClearColor(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>black); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Initializing shaders..."</span>; initShaders(); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Initializing textures..."</span>; initTextures(); <span class="comment">// Enable depth buffer</span> glEnable(GL_DEPTH_TEST); <span class="comment">// Enable back face culling</span> glEnable(GL_CULL_FACE); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Initializing geometries..."</span>; geometries<span class="operator">-</span><span class="operator">></span>init(); <span class="comment">// using QBasicTimer because its faster that QTimer</span> timer<span class="operator">-</span><span class="operator">></span>start(<span class="number">12</span><span class="operator">,</span> <span class="keyword">this</span>); } <span class="type">void</span> MainWidget<span class="operator">::</span>initShaders() { <span class="comment">// Overriding system locale until shaders are compiled</span> setlocale(LC_NUMERIC<span class="operator">,</span> <span class="string">"C"</span>); <span class="comment">// Compiling vertex shader</span> <span class="keyword">if</span> (<span class="operator">!</span>program<span class="operator">-</span><span class="operator">></span>addShaderFromSourceFile(<span class="type"><a href="qglshader.html">QGLShader</a></span><span class="operator">::</span>Vertex<span class="operator">,</span> <span class="string">":/vshader.glsl"</span>)) close(); <span class="comment">// Compiling fragment shader</span> <span class="keyword">if</span> (<span class="operator">!</span>program<span class="operator">-</span><span class="operator">></span>addShaderFromSourceFile(<span class="type"><a href="qglshader.html">QGLShader</a></span><span class="operator">::</span>Fragment<span class="operator">,</span> <span class="string">":/fshader.glsl"</span>)) close(); <span class="comment">// Linking shader pipeline</span> <span class="keyword">if</span> (<span class="operator">!</span>program<span class="operator">-</span><span class="operator">></span>link()) close(); <span class="comment">// Binding shader pipeline for use</span> <span class="keyword">if</span> (<span class="operator">!</span>program<span class="operator">-</span><span class="operator">></span>bind()) close(); <span class="comment">// Restore system locale</span> setlocale(LC_ALL<span class="operator">,</span> <span class="string">""</span>); } <span class="type">void</span> MainWidget<span class="operator">::</span>initTextures() { <span class="comment">// Loading cube.png to texture unit 0</span> glActiveTexture(GL_TEXTURE0); glEnable(GL_TEXTURE_2D); texture <span class="operator">=</span> bindTexture(<span class="type"><a href="qimage.html">QImage</a></span>(<span class="string">":/cube.png"</span>)); <span class="comment">// Set nearest filtering mode for texture minification</span> glTexParameterf(GL_TEXTURE_2D<span class="operator">,</span> GL_TEXTURE_MIN_FILTER<span class="operator">,</span> GL_NEAREST); <span class="comment">// Set bilinear filtering mode for texture magnification</span> glTexParameterf(GL_TEXTURE_2D<span class="operator">,</span> GL_TEXTURE_MAG_FILTER<span class="operator">,</span> GL_LINEAR); <span class="comment">// Wrap texture coordinates by repeating</span> <span class="comment">// f.ex. texture coordinate (1.1, 1.2) is same as (0.1, 0.2)</span> glTexParameterf(GL_TEXTURE_2D<span class="operator">,</span> GL_TEXTURE_WRAP_S<span class="operator">,</span> GL_REPEAT); glTexParameterf(GL_TEXTURE_2D<span class="operator">,</span> GL_TEXTURE_WRAP_T<span class="operator">,</span> GL_REPEAT); } <span class="type">void</span> MainWidget<span class="operator">::</span>resizeGL(<span class="type">int</span> w<span class="operator">,</span> <span class="type">int</span> h) { <span class="comment">// Set OpenGL viewport to cover whole widget</span> glViewport(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> w<span class="operator">,</span> h); <span class="comment">// Calculate aspect ratio</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> aspect <span class="operator">=</span> (<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>)w <span class="operator">/</span> ((<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>)h<span class="operator">?</span>h:<span class="number">1</span>); <span class="comment">// Set near plane to 3.0, far plane to 7.0, field of view 45 degrees</span> <span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> zNear <span class="operator">=</span> <span class="number">3.0</span><span class="operator">,</span> zFar <span class="operator">=</span> <span class="number">7.0</span><span class="operator">,</span> fov <span class="operator">=</span> <span class="number">45.0</span>; <span class="comment">// Reset projection</span> projection<span class="operator">.</span>setToIdentity(); <span class="comment">// Set perspective projection</span> projection<span class="operator">.</span>perspective(fov<span class="operator">,</span> aspect<span class="operator">,</span> zNear<span class="operator">,</span> zFar); } <span class="type">void</span> MainWidget<span class="operator">::</span>paintGL() { <span class="comment">// Clear color and depth buffer</span> glClear(GL_COLOR_BUFFER_BIT <span class="operator">|</span> GL_DEPTH_BUFFER_BIT); <span class="comment">// Calculate model view transformation</span> QMatrix4x4 matrix; matrix<span class="operator">.</span>translate(<span class="number">0.0</span><span class="operator">,</span> <span class="number">0.0</span><span class="operator">,</span> <span class="operator">-</span><span class="number">5.0</span>); matrix<span class="operator">.</span>rotate(rotation); <span class="comment">// Set modelview-projection matrix</span> program<span class="operator">-</span><span class="operator">></span>setUniformValue(<span class="string">"mvp_matrix"</span><span class="operator">,</span> projection <span class="operator">*</span> matrix); <span class="comment">// Using texture unit 0 which contains cube.png</span> program<span class="operator">-</span><span class="operator">></span>setUniformValue(<span class="string">"texture"</span><span class="operator">,</span> <span class="number">0</span>); <span class="comment">// Draw cube geometry</span> geometries<span class="operator">-</span><span class="operator">></span>drawCubeGeometry(program); }</pre> </div> <!-- @@@opengl/cube/mainwidget.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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