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From Lee Bulter, "I noticed that when "throwing" things the rate of motion once thrown was

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dependent on the complexity of the geometry. For complex scenes this
meant that it looked like you were "throwing" the display into molasses.
For simple geometry things get over-excited once thrown.

The fix is to factor in the frame rendering time to the caluclated
motion. I've implemented this for rotation and panning.

Now when things are thrown they maintain a rate very close to what was
happening when the mouse button was released."
This commit is contained in:
Robert Osfield
2009-06-25 18:11:29 +00:00
parent 44a8e850f4
commit b1a99ba25f
2 changed files with 42 additions and 1 deletions
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25
src/osgGA/TrackballManipulator.cpp
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@@ -12,6 +12,7 @@ TrackballManipulator::TrackballManipulator()
_minimumZoomScale = 0.05f;
_allowThrow = true;
_thrown = false;
_rate_sensitive = true;
_distance = 1.0f;
_trackballSize = 0.8f;
@@ -81,11 +82,18 @@ bool TrackballManipulator::handle(const GUIEventAdapter& ea,GUIActionAdapter& us
switch(ea.getEventType())
{
case(GUIEventAdapter::FRAME):
{
double current_frame_time = ea.getTime();
_delta_frame_time = current_frame_time - _last_frame_time;
_last_frame_time = current_frame_time;
if (_thrown && _allowThrow)
{
if (calcMovement()) us.requestRedraw();
}
return false;
}
default:
break;
}
@@ -321,7 +329,15 @@ bool TrackballManipulator::calcMovement()
trackball(axis,angle,px1,py1,px0,py0);
osg::Quat new_rotate;
new_rotate.makeRotate(angle,axis);
if (_thrown && _rate_sensitive && _ga_t0.valid() && _ga_t1.valid())
{
// frame_time / delta_event_time
double rate = _delta_frame_time / (_ga_t0->getTime() - _ga_t1->getTime());
new_rotate.makeRotate(angle * rate,axis);
} else {
new_rotate.makeRotate(angle,axis);
}
_rotation = _rotation*new_rotate;
@@ -339,6 +355,13 @@ bool TrackballManipulator::calcMovement()
osg::Matrix rotation_matrix;
rotation_matrix.makeRotate(_rotation);
if (_thrown && _rate_sensitive && _ga_t0.valid() && _ga_t1.valid())
{
// frame_time / delta_event_time
double rate = _delta_frame_time / (_ga_t0->getTime() - _ga_t1->getTime());
scale *= rate;
}
osg::Vec3 dv(dx*scale,dy*scale,0.0f);
_center += dv*rotation_matrix;