static void redraw(void) {
    static float t=0;
    int a,b;
    unsigned int currentVer;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glClearColor(0.2f, 0.1f, 0.0f, 0.0f);

    if (wireframe)
        glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );

    glShadeModel(GL_SMOOTH);

    glUseProgram(theProgram);

    glBindBuffer(GL_ARRAY_BUFFER, cubeVertBuffer);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);

    glBindBuffer(GL_ARRAY_BUFFER, cubeNormalBuffer);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, 0);

    setUniforms(t);

    glBindBuffer( GL_ARRAY_BUFFER, tfvbo );

    glBeginQuery( GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN_EXT, query );

    // start transform feedback so that vertices get targetted to 'tfvbo'
    glBeginTransformFeedbackNV( GL_TRIANGLES );



    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cubeIndexBO);
    glDrawElements(GL_TRIANGLES, sCube.ids.size(), GL_UNSIGNED_INT, NULL);

    glEndTransformFeedbackNV();
    glEndQuery( GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN_EXT );

    GLuint primitives_written;
    // read back query results
    glGetQueryObjectuiv( query, GL_QUERY_RESULT, &primitives_written );
    if ( primitives_written == 0 )
        fprintf( stderr, "Primitives written to TFB: %d !\n", primitives_written );

    // retrieve the data stored in the TFB
    checkGlErrors();
    glBindBuffer( GL_ARRAY_BUFFER, tfvbo );
    float * TFBdata = static_cast<float*>( glMapBuffer(GL_ARRAY_BUFFER, GL_READ_ONLY) );
    if ( TFBdata == NULL ) {
        cout << "TFBdata == NULL\n";
        checkGlErrors();
    }
    else
    {
        // fputs("TFB contents: ", stdout);
        // for ( int i = 0; i < 2*3*4; i ++ )
        //  printf( "% 10f  ", TFBdata[i] );
        // putchar('\n');
    }
    bool success = glUnmapBuffer( GL_ARRAY_BUFFER );
    if ( ! success ) {
        cout << "glUnmapBuffer failed";
        checkGlErrors();
        cout << endl << endl;
    }

    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
    glUseProgram(0);

    glutSwapBuffers();
    glutPostRedisplay();

    t+=rSpeed;
}