bool TerrainManipulator::performMovementMiddleMouseButton( const double eventTimeDelta, const double dx, const double dy )
{
// pan model.
double scale = -0.3f * _distance * getThrowScale( eventTimeDelta );
Matrixd rotation_matrix;
rotation_matrix.makeRotate(_rotation);
// compute look vector.
Vec3d lookVector = -getUpVector(rotation_matrix);
Vec3d sideVector = getSideVector(rotation_matrix);
Vec3d upVector = getFrontVector(rotation_matrix);
// CoordinateFrame coordinateFrame = getCoordinateFrame(_center);
// Vec3d localUp = getUpVector(coordinateFrame);
Vec3d localUp = _previousUp;
Vec3d forwardVector =localUp^sideVector;
sideVector = forwardVector^localUp;
forwardVector.normalize();
sideVector.normalize();
Vec3d dv = forwardVector * (dy*scale) + sideVector * (dx*scale);
_center += dv;
// need to recompute the intersection point along the look vector.
bool hitFound = false;
if (_node.valid())
{
// now reorientate the coordinate frame to the frame coords.
CoordinateFrame coordinateFrame = getCoordinateFrame(_center);
// need to reintersect with the terrain
double distance = _node->getBound().radius()*0.25f;
Vec3d ip1;
Vec3d ip2;
bool hit_ip1 = intersect(_center, _center + getUpVector(coordinateFrame) * distance, ip1);
bool hit_ip2 = intersect(_center, _center - getUpVector(coordinateFrame) * distance, ip2);
if (hit_ip1)
{
if (hit_ip2)
{
_center = (_center-ip1).length2() < (_center-ip2).length2() ?
ip1 :
ip2;
hitFound = true;
}
else
{
_center = ip1;
hitFound = true;
}
}
else if (hit_ip2)
{
_center = ip2;
hitFound = true;
}
if (!hitFound)
{
// ??
OSG_INFO<<"TerrainManipulator unable to intersect with terrain."<<std::endl;
}
coordinateFrame = getCoordinateFrame(_center);
Vec3d new_localUp = getUpVector(coordinateFrame);
Quat pan_rotation;
pan_rotation.makeRotate(localUp,new_localUp);
if (!pan_rotation.zeroRotation())
{
_rotation = _rotation * pan_rotation;
_previousUp = new_localUp;
//OSG_NOTICE<<"Rotating from "<<localUp<<" to "<<new_localUp<<" angle = "<<acos(localUp*new_localUp/(localUp.length()*new_localUp.length()))<<std::endl;
//clampOrientation();
}
else
{
OSG_INFO<<"New up orientation nearly inline - no need to rotate"<<std::endl;
}
}
return true;
}
