glbox.cpp Example File
^{activeqt/opengl/glbox.cpp}

    /****************************************************************************
    **
    ** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
    **
    ** This file is part of the documentation of the Qt Toolkit.
    **
    ** This file may be used under the terms of the GNU General Public
    ** License version 2.0 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 GNU
    ** General Public Licensing requirements will be met:
    ** http://www.trolltech.com/products/qt/opensource.html
    **
    ** If you are unsure which license is appropriate for your use, please
    ** review the following information:
    ** http://www.trolltech.com/products/qt/licensing.html or contact the
    ** sales department at sales@trolltech.com.
    **
    ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
    ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
    **
    ****************************************************************************/

    /****************************************************************************
    **
    ** 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();
    }