Method paintGL

example/nbody.cpp:172–191

    glViewport(0, 0, width, height);
}
void NBodyWidget::paintGL()
{
    // clear buffer
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // check if this is the first draw
    if(m_initial_draw) {
        // do not update particles
        m_initial_draw = false;
    } else {
        // update particles
        updateParticles();
    }

    // draw
    glVertexPointer(4, GL_FLOAT, 0, 0);
    glEnableClientState(GL_VERTEX_ARRAY);
    glDrawArrays(GL_POINTS, 0, m_particles);
    glFinish();
}
void NBodyWidget::updateParticles()
{
    // enqueue kernels to update particles and make sure that the command queue is finished