1 /****************************************************************************

     2 **

     3 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

     6 **

     7 ** This file is part of the documentation of the Qt Toolkit.

     8 **

     9 ** $QT_BEGIN_LICENSE:LGPL$

    10 ** No Commercial Usage

    11 ** This file contains pre-release code and may not be distributed.

    12 ** You may use this file in accordance with the terms and conditions

    13 ** contained in the Technology Preview License Agreement accompanying

    14 ** this package.

    15 **

    16 ** GNU Lesser General Public License Usage

    17 ** Alternatively, this file may be used under the terms of the GNU Lesser

    18 ** General Public License version 2.1 as published by the Free Software

    19 ** Foundation and appearing in the file LICENSE.LGPL included in the

    20 ** packaging of this file.  Please review the following information to

    21 ** ensure the GNU Lesser General Public License version 2.1 requirements

    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    23 **

    24 ** In addition, as a special exception, Nokia gives you certain additional

    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception

    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    27 **

    28 ** If you have questions regarding the use of this file, please contact

    29 ** Nokia at qt-info@nokia.com.

    30 **

    31 **

    32 **

    33 **

    34 **

    35 **

    36 **

    37 **

    38 ** $QT_END_LICENSE$

    39 **

    40 ****************************************************************************/

    41 

    42 //! [0]

    43 QGLFormat fmt;

    44 fmt.setAlpha(true);

    45 fmt.setStereo(true);

    46 QGLFormat::setDefaultFormat(fmt);

    47 //! [0]

    48 

    49 

    50 //! [1]

    51 QGLFormat fmt;

    52 fmt.setDoubleBuffer(false);                 // single buffer

    53 fmt.setDirectRendering(false);              // software rendering

    54 MyGLWidget* myWidget = new MyGLWidget(fmt, ...);

    55 //! [1]

    56 

    57 

    58 //! [2]

    59 QGLFormat fmt;

    60 fmt.setOverlay(true);

    61 fmt.setStereo(true);

    62 MyGLWidget* myWidget = new MyGLWidget(fmt, ...);

    63 if (!myWidget->format().stereo()) {

    64     // ok, goggles off

    65     if (!myWidget->format().hasOverlay()) {

    66         qFatal("Cool hardware required");

    67     }

    68 }

    69 //! [2]

    70 

    71 

    72 //! [3]

    73 // The rendering in MyGLWidget depends on using

    74 // stencil buffer and alpha channel

    75 MyGLWidget::MyGLWidget(QWidget* parent)

    76     : QGLWidget(QGLFormat(QGL::StencilBuffer | QGL::AlphaChannel), parent)

    77 {

    78     if (!format().stencil())

    79         qWarning("Could not get stencil buffer; results will be suboptimal");

    80     if (!format().alpha())

    81         qWarning("Could not get alpha channel; results will be suboptimal");

    82     ...

    83 }

    84 //! [3]

    85 

    86 

    87 //! [4]

    88 QApplication a(argc, argv);

    89 QGLFormat f;

    90 f.setDoubleBuffer(false);

    91 QGLFormat::setDefaultFormat(f);

    92 //! [4]

    93 

    94 

    95 //! [5]

    96 QGLFormat f = QGLFormat::defaultOverlayFormat();

    97 f.setDoubleBuffer(true);

    98 QGLFormat::setDefaultOverlayFormat(f);

    99 //! [5]

   100 

   101 

   102 //! [6]

   103 // ...continued from above

   104 MyGLWidget* myWidget = new MyGLWidget(QGLFormat(QGL::HasOverlay), ...);

   105 if (myWidget->format().hasOverlay()) {

   106     // Yes, we got an overlay, let's check _its_ format:

   107     QGLContext* olContext = myWidget->overlayContext();

   108     if (olContext->format().doubleBuffer())

   109         ; // yes, we got a double buffered overlay

   110     else

   111         ; // no, only single buffered overlays are available

   112 }

   113 //! [6]

   114 

   115 

   116 //! [7]

   117 QGLContext *cx;

   118 //  ...

   119 QGLFormat f;

   120 f.setStereo(true);

   121 cx->setFormat(f);

   122 if (!cx->create())

   123     exit(); // no OpenGL support, or cannot render on the specified paintdevice

   124 if (!cx->format().stereo())

   125     exit(); // could not create stereo context

   126 //! [7]

   127 

   128 

   129 //! [8]

   130 class MyGLDrawer : public QGLWidget

   131 {

   132     Q_OBJECT        // must include this if you use Qt signals/slots

   133 

   134 public:

   135     MyGLDrawer(QWidget *parent)

   136         : QGLWidget(parent) {}

   137 

   138 protected:

   139 

   140     void initializeGL()

   141     {

   142         // Set up the rendering context, define display lists etc.:

   143         ...

   144         glClearColor(0.0, 0.0, 0.0, 0.0);

   145         glEnable(GL_DEPTH_TEST);

   146         ...

   147     }

   148 

   149     void resizeGL(int w, int h)

   150     {

   151         // setup viewport, projection etc.:

   152         glViewport(0, 0, (GLint)w, (GLint)h);

   153         ...

   154         glFrustum(...);

   155         ...

   156     }

   157 

   158     void paintGL()

   159     {

   160         // draw the scene:

   161         ...

   162         glRotatef(...);

   163         glMaterialfv(...);

   164         glBegin(GL_QUADS);

   165         glVertex3f(...);

   166         glVertex3f(...);

   167         ...

   168         glEnd();

   169         ...

   170     }

   171 

   172 };

   173 //! [8]