void MxCore::updateFovy( osg::Matrixd& proj ) const
{
if( _ortho )
{
osg::notify( osg::WARN ) << "MxCore::updateFovy: Ortho is not yet implemented. TBD." << std::endl;
}
else
{
double left, right, bottom, top, near, far;
proj.getFrustum( left, right, bottom, top, near, far );
const double fovBottom = atan( bottom / near );
const double fovTop = atan( top / near );
const double fovyRatio = getFovyRadians() /
( osg::absolute< double >( fovBottom ) + osg::absolute< double >( fovTop ) );
const double newBottom = tan( fovBottom * fovyRatio ) * near;
const double newTop = tan( fovTop * fovyRatio ) * near;
const double xScale = newTop / top;
left *= xScale;
right *= xScale;
proj = osg::Matrixd::frustum( left, right, newBottom, newTop, near, far );
}
}
void MxCore::setOrtho( bool ortho, const double viewDistance )
{
_ortho = ortho;
// tan (fovy/2) = a / e2c.len
_orthoTop = tan( getFovyRadians() * .5 ) * viewDistance;
_orthoBottom = -_orthoTop;
}
void ViewingCore::fitToScreen()
{
_viewCenter = _scene->getBound().center();
// tan( fovy/2. ) = bs.radius / distance
// Solve for distance:
// distance = bs.radius / tan( fovy/2. )
_fovy = 30;
float distance = _scene->getBound().radius() /
tan( osg::DegreesToRadians( _fovy/2. ) );
_viewDistance = _initialViewDistance = distance;
_orthoTop = tan( getFovyRadians() * 0.5 ) * _viewDistance;
_orthoBottom = -_orthoTop;
}
