// 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);
}
QDebug operator<<(QDebug dbg, const QGLCamera &cam)
{
dbg << "QGLCamera";
if (!cam.objectName().isEmpty())
dbg << cam.objectName();
dbg << "\n";
dbg << " projection:" << ( cam.projectionType() == QGLCamera::Perspective ?
"Perspective" : "Orthographic" );
dbg << "-- viewsize:" << cam.viewSize().width() << "x" << cam.viewSize().height() << "\n";
dbg << " near-plane:" << cam.nearPlane() << "-- far-plane:" << cam.farPlane();
dbg << "-- field-of-view:" << cam.fieldOfView() << "\n";
dbg << " rotation:" << cam.screenRotation() << " -- motion adjust:" <<
cam.motionAdjustment() << " -- aspect adjust:" << cam.adjustForAspectRatio() << "\n";
dbg << " eye:" << cam.eye() << "-- center:" << cam.center();
dbg << "-- up:" << cam.upVector() << "\n";
return dbg;
}
