Engine Class (C++)

void Engine::initializeGL( void )
    {
        glEnable( GL_DEPTH_TEST );
        glEnable( GL_BLEND );
        glEnable( GL_POLYGON_SMOOTH );

        glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
        glClearColor( 0, 0, 0, 0 );

        glm::mat4 projection = glm::perspective( 45.0f, (float)( width() / height() ), 0.1f, 100.0f );

        glm::mat4 view = glm::mat4( 1 );
        view = glm::translate( view, glm::vec3( 1, 1, 1 ) );

        glm::mat4 model = glm::mat4( 1 );
        model = glm::translate( model, glm::vec3( 0.5f ) );

        glm::mat4 mvp = projection  * view * model;

        glLoadMatrixf( glm::value_ptr( mvp ) );

        mShapes = new QVector< Shape* >;

        QVector< Shader > shaders;

        Shader tVert = mShaderHandler->getShader( "Triangle Vertex Shader", "Shaders/Position.vert", GL_VERTEX_SHADER );
        Shader tFrag = mShaderHandler->getShader( "Triangle Fragment Shader", "Shaders/GenericColor.frag", GL_FRAGMENT_SHADER );

        shaders.push_back( tVert );
        shaders.push_back( tFrag );

        mShaderHandler->createShaders(shaders);
        mShaderHandler->compileAndLink();

        mProgram = mShaderHandler->getProgram( 0 );

        mShapes->push_back( new Circle( glm::vec4( 1 ), 5 ) );

        glUseProgram( mProgram );
    }

//---------------------------

void Engine::paintGL( void )
    {
        QVectorIterator< Shape* > iShapes( *mShapes );

        glVertexAttribPointer( 0, 4, GL_FLOAT, GL_FALSE, 0, 0 );

        while( iShapes.hasNext() )
        {
            iShapes.next()->draw( mProgram );
        }
    }