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 demonstration applications 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 **

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    34 **

    35 **

    36 **

    37 **

    38 ** $QT_END_LICENSE$

    39 **

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

    41 

    42 //#include <GL/glew.h>

    43 #include "glextensions.h"

    44 

    45 #include "scene.h"

    46 

    47 #include <QtGui>

    48 #include <QGLWidget>

    49 

    50 class GraphicsView : public QGraphicsView

    51 {

    52 public:

    53     GraphicsView()

    54     {

    55         setWindowTitle(tr("Boxes"));

    56         setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);

    57         //setRenderHints(QPainter::SmoothPixmapTransform);

    58     }

    59 

    60 protected:

    61     void resizeEvent(QResizeEvent *event) {

    62         if (scene())

    63             scene()->setSceneRect(QRect(QPoint(0, 0), event->size()));

    64         QGraphicsView::resizeEvent(event);

    65     }

    66 };

    67 

    68 inline bool matchString(const char *extensionString, const char *subString)

    69 {

    70     int subStringLength = strlen(subString);

    71     return (strncmp(extensionString, subString, subStringLength) == 0)

    72         && ((extensionString[subStringLength] == ' ') || (extensionString[subStringLength] == '\0'));

    73 }

    74 

    75 bool necessaryExtensionsSupported()

    76 {

    77     const char *extensionString = reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));

    78     const char *p = extensionString;

    79 

    80     const int GL_EXT_FBO = 1;

    81     const int GL_ARB_VS = 2;

    82     const int GL_ARB_FS = 4;

    83     const int GL_ARB_SO = 8;

    84     int extensions = 0;

    85 

    86     while (*p) {

    87         if (matchString(p, "GL_EXT_framebuffer_object"))

    88             extensions |= GL_EXT_FBO;

    89         else if (matchString(p, "GL_ARB_vertex_shader"))

    90             extensions |= GL_ARB_VS;

    91         else if (matchString(p, "GL_ARB_fragment_shader"))

    92             extensions |= GL_ARB_FS;

    93         else if (matchString(p, "GL_ARB_shader_objects"))

    94             extensions |= GL_ARB_SO;

    95         while ((*p != ' ') && (*p != '\0'))

    96             ++p;

    97         if (*p == ' ')

    98             ++p;

    99     }

   100     return (extensions == 15);

   101 }

   102 

   103 int main(int argc, char **argv)

   104 {

   105     QApplication app(argc, argv);

   106 

   107     if ((QGLFormat::openGLVersionFlags() & QGLFormat::OpenGL_Version_1_5) == 0) {

   108         QMessageBox::critical(0, "OpenGL features missing",

   109             "OpenGL version 1.5 or higher is required to run this demo.\n"

   110             "The program will now exit.");

   111         return -1;

   112     }

   113 

   114     int maxTextureSize = 1024;

   115     QGLWidget *widget = new QGLWidget(QGLFormat(QGL::SampleBuffers));

   116     widget->makeCurrent();

   117 

   118     if (!necessaryExtensionsSupported()) {

   119         QMessageBox::critical(0, "OpenGL features missing",

   120             "The OpenGL extensions required to run this demo are missing.\n"

   121             "The program will now exit.");

   122         delete widget;

   123         return -2;

   124     }

   125 

   126     // Check if all the necessary functions are resolved.

   127     if (!getGLExtensionFunctions().resolve(widget->context())) {

   128         QMessageBox::critical(0, "OpenGL features missing",

   129             "Failed to resolve OpenGL functions required to run this demo.\n"

   130             "The program will now exit.");

   131         delete widget;

   132         return -3;

   133     }

   134 

   135     // TODO: Make conditional for final release

   136     QMessageBox::information(0, "For your information",

   137         "This demo can be GPU and CPU intensive and may\n"

   138         "work poorly or not at all on your system.");

   139 

   140     widget->makeCurrent(); // The current context must be set before calling Scene's constructor

   141     Scene scene(1024, 768, maxTextureSize);

   142     GraphicsView view;

   143     view.setViewport(widget);

   144     view.setViewportUpdateMode(QGraphicsView::FullViewportUpdate);

   145     view.setScene(&scene);

   146     view.show();

   147 

   148     return app.exec();

   149 }

   150