Qt Reference Documentation

# glbox.cpp Example File

activeqt/opengl/glbox.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the examples 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 Nokia Corporation 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,
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     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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     ** 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."
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     /****************************************************************************
     **
     ** This is a simple QGLWidget displaying an openGL wireframe box
     **
     ** The OpenGL code is mostly borrowed from Brian Pauls "spin" example
     ** in the Mesa distribution
     **
     ****************************************************************************/

     #include "glbox.h"
     #include <QAxAggregated>
     #include <QUuid>
     #include <objsafe.h>

     #if defined(Q_CC_MSVC)
     #pragma warning(disable:4305) // init: truncation from const double to float
     #endif

     /*!
       Create a GLBox widget
     */

     GLBox::GLBox( QWidget* parent, const char* name )
         : QGLWidget( parent )
     {
         xRot = yRot = zRot = 0.0;           // default object rotation
         scale = 1.25;                       // default object scale
         object = 0;
     }

     /*!
       Release allocated resources
     */

     GLBox::~GLBox()
     {
         makeCurrent();
         glDeleteLists( object, 1 );
     }

     /*!
       Paint the box. The actual openGL commands for drawing the box are
       performed here.
     */

     void GLBox::paintGL()
     {
         glClear( GL_COLOR_BUFFER_BIT );

         glLoadIdentity();
         glTranslatef( 0.0, 0.0, -10.0 );
         glScalef( scale, scale, scale );

         glRotatef( xRot, 1.0, 0.0, 0.0 );
         glRotatef( yRot, 0.0, 1.0, 0.0 );
         glRotatef( zRot, 0.0, 0.0, 1.0 );

         glCallList( object );
     }

     /*!
       Set up the OpenGL rendering state, and define display list
     */

     void GLBox::initializeGL()
     {
         qglClearColor(Qt::black);           // Let OpenGL clear to black
         object = makeObject();              // Generate an OpenGL display list
         glShadeModel( GL_FLAT );
     }

     /*!
       Set up the OpenGL view port, matrix mode, etc.
     */

     void GLBox::resizeGL( int w, int h )
     {
         glViewport( 0, 0, (GLint)w, (GLint)h );
         glMatrixMode( GL_PROJECTION );
         glLoadIdentity();
         glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 15.0 );
         glMatrixMode( GL_MODELVIEW );
     }

     /*!
       Generate an OpenGL display list for the object to be shown, i.e. the box
     */

     GLuint GLBox::makeObject()
     {
         GLuint list;

         list = glGenLists( 1 );

         glNewList( list, GL_COMPILE );

         qglColor(Qt::white);                      // Shorthand for glColor3f or glIndex

         glLineWidth( 2.0 );

         glBegin( GL_LINE_LOOP );
         glVertex3f(  1.0,  0.5, -0.4 );
         glVertex3f(  1.0, -0.5, -0.4 );
         glVertex3f( -1.0, -0.5, -0.4 );
         glVertex3f( -1.0,  0.5, -0.4 );
         glEnd();

         glBegin( GL_LINE_LOOP );
         glVertex3f(  1.0,  0.5, 0.4 );
         glVertex3f(  1.0, -0.5, 0.4 );
         glVertex3f( -1.0, -0.5, 0.4 );
         glVertex3f( -1.0,  0.5, 0.4 );
         glEnd();

         glBegin( GL_LINES );
         glVertex3f(  1.0,  0.5, -0.4 );   glVertex3f(  1.0,  0.5, 0.4 );
         glVertex3f(  1.0, -0.5, -0.4 );   glVertex3f(  1.0, -0.5, 0.4 );
         glVertex3f( -1.0, -0.5, -0.4 );   glVertex3f( -1.0, -0.5, 0.4 );
         glVertex3f( -1.0,  0.5, -0.4 );   glVertex3f( -1.0,  0.5, 0.4 );
         glEnd();

         glEndList();

         return list;
     }

     /*!
       Set the rotation angle of the object to \e degrees around the X axis.
     */

     void GLBox::setXRotation( int degrees )
     {
         xRot = (GLfloat)(degrees % 360);
         updateGL();
     }

     /*!
       Set the rotation angle of the object to \e degrees around the Y axis.
     */

     void GLBox::setYRotation( int degrees )
     {
         yRot = (GLfloat)(degrees % 360);
         updateGL();
     }

     /*!
       Set the rotation angle of the object to \e degrees around the Z axis.
     */

     void GLBox::setZRotation( int degrees )
     {
         zRot = (GLfloat)(degrees % 360);
         updateGL();
     }

     class ObjectSafetyImpl : public QAxAggregated,
                              public IObjectSafety
     {
     public:
         ObjectSafetyImpl() {}

         long queryInterface( const QUuid &iid, void **iface )
         {
             *iface = 0;
             if ( iid == IID_IObjectSafety )
                 *iface = (IObjectSafety*)this;
             else
                 return E_NOINTERFACE;

             AddRef();
             return S_OK;
         }

         QAXAGG_IUNKNOWN;

         HRESULT WINAPI GetInterfaceSafetyOptions( REFIID riid, DWORD *pdwSupportedOptions, DWORD *pdwEnabledOptions )
         {
             *pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER;
             *pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER;
             return S_OK;
         }
         HRESULT WINAPI SetInterfaceSafetyOptions( REFIID riid, DWORD pdwSupportedOptions, DWORD pdwEnabledOptions )
         {
             return S_OK;
         }
     };

     QAxAggregated *GLBox::createAggregate()
     {
         return new ObjectSafetyImpl();
     }