// Zoom in and out according to the change in wheel delta.
void QGLGraphicsNavigationItemPrivate::wheel(qreal delta)
{
QGLCamera *camera = viewportItem->camera();
qreal scale = qAbs(viewDelta(delta, delta).x());
if (delta < 0)
scale = -scale;
if (scale >= 0.0f)
scale += 1.0f;
else
scale = 1.0f / (1.0f - scale);
qreal fov = camera->fieldOfView();
if (fov != 0.0f)
camera->setFieldOfView(camera->fieldOfView() / scale);
else
camera->setViewSize(camera->viewSize() / scale);
}
void ViewportWidget::initializeGL(QGLPainter *painter) {
QGLCamera *camera = new QGLCamera();
camera->setNearPlane(5.0f);
camera->setFarPlane(1000.0f);
camera->setFieldOfView(34.0f);
setCamera(camera);
_lp.setPosition(QVector3D(-1.0, -2.0, 1.0));
_lp.setSpotAngle(180);
_lp.setSpotExponent(24);
_lp.setSpotDirection(QVector3D(1.0, 4.0, 4.0));
_lm.setAmbientSceneColor(QColor(200, 200, 200));
painter->setLightModel(&_lm);
painter->setMainLight(&_lp);
painter->setClearColor(Qt::black);
}
