// Pan left/right/up/down without rotating about the object.
void QGLGraphicsNavigationItemPrivate::pan(qreal deltax, qreal deltay)
{
QGLCamera *camera = viewportItem->camera();
QPointF delta = viewDelta(deltax, deltay);
QVector3D t = camera->translation(delta.x(), -delta.y(), 0.0f);
// Technically panning the eye left should make the object appear to
// move off to the right, but this looks weird on-screen where the user
// actually thinks they are picking up the object and dragging it rather
// than moving the eye. We therefore apply the inverse of the translation
// to make it "look right".
camera->setEye(camera->eye() - t);
camera->setCenter(camera->center() - t);
}
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;
}
