+void
+FGViewer::dampEyeData (double &roll_deg, double &pitch_deg, double &heading_deg)
+{
+ const double interval = 0.01;
+
+ static FGViewer *last_view = 0;
+ if (last_view != this) {
+ _damp_sync = 0.0;
+ _damped_roll_deg = roll_deg;
+ _damped_pitch_deg = pitch_deg;
+ _damped_heading_deg = heading_deg;
+ last_view = this;
+ return;
+ }
+
+ if (_damp_sync < interval) {
+ if (_damp_roll > 0.0)
+ roll_deg = _damped_roll_deg;
+ if (_damp_pitch > 0.0)
+ pitch_deg = _damped_pitch_deg;
+ if (_damp_heading > 0.0)
+ heading_deg = _damped_heading_deg;
+ return;
+ }
+
+ while (_damp_sync >= interval) {
+ _damp_sync -= interval;
+
+ double d;
+ if (_damp_roll > 0.0) {
+ d = _damped_roll_deg - roll_deg;
+ if (d >= 180.0)
+ _damped_roll_deg -= 360.0;
+ else if (d < -180.0)
+ _damped_roll_deg += 360.0;
+ roll_deg = _damped_roll_deg = roll_deg * _damp_roll + _damped_roll_deg * (1 - _damp_roll);
+ }
+
+ if (_damp_pitch > 0.0) {
+ d = _damped_pitch_deg - pitch_deg;
+ if (d >= 180.0)
+ _damped_pitch_deg -= 360.0;
+ else if (d < -180.0)
+ _damped_pitch_deg += 360.0;
+ pitch_deg = _damped_pitch_deg = pitch_deg * _damp_pitch + _damped_pitch_deg * (1 - _damp_pitch);
+ }
+
+ if (_damp_heading > 0.0) {
+ d = _damped_heading_deg - heading_deg;
+ if (d >= 180.0)
+ _damped_heading_deg -= 360.0;
+ else if (d < -180.0)
+ _damped_heading_deg += 360.0;
+ heading_deg = _damped_heading_deg = heading_deg * _damp_heading + _damped_heading_deg * (1 - _damp_heading);
+ }
+ }
+}
+