/*===========================================================================*/
bool StreamlineBase::integrate_by_runge_kutta_2nd(
const kvs::Vec3& current_vertex,
const kvs::Vec3& current_direction,
kvs::Vec3* next_vertex )
{
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( current_vertex ) ) return false;
}
const float integration_direction = static_cast<float>( m_integration_direction );
const kvs::Vec3 k1 = current_direction.normalized() * integration_direction;
// Interpolate vector from vertex of cell.
const kvs::Vec3 vertex = current_vertex + 0.5f * m_integration_interval * k1;
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( vertex ) ) return false;
}
const kvs::Vec3 direction = this->interpolate_vector( vertex, current_direction );
const kvs::Vec3 k2 = direction.normalized() * integration_direction;
*next_vertex = vertex + m_integration_interval * k2;
return true;
}
/*===========================================================================*/
bool StreamlineBase::integrate_by_runge_kutta_4th(
const kvs::Vec3& current_vertex,
const kvs::Vec3& current_direction,
kvs::Vec3* next_vertex )
{
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( current_vertex ) ) return false;
}
// Calculate integration interval.
const float integration_direction = static_cast<float>( m_integration_direction );
const kvs::Vec3 k1 = current_direction.normalized() * integration_direction;
// Interpolate vector from vertex of cell.
const kvs::Vec3 vertex2 = current_vertex + 0.5f * m_integration_interval * k1;
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( vertex2 ) ) return false;
}
const kvs::Vec3 direction2 = this->interpolate_vector( vertex2, current_direction );
const kvs::Vec3 k2 = direction2.normalized() * integration_direction;
// Interpolate vector from vertex of cell.
const kvs::Vec3 vertex3 = current_vertex + 0.5f * m_integration_interval * k2;
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( vertex3 ) ) return false;
}
const kvs::Vec3 direction3 = this->interpolate_vector( vertex3, current_direction );
const kvs::Vec3 k3 = direction3.normalized() * integration_direction;
// Interpolate vector from vertex of cell.
const kvs::Vec3 vertex4 = current_vertex + m_integration_interval * k3;
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( vertex4 ) ) return false;
}
const kvs::Vec3 direction4 = this->interpolate_vector( vertex4, current_direction );
const kvs::Vec3 k4 = direction4.normalized() * integration_direction;
*next_vertex = current_vertex + integration_direction * ( k1 + 2.0f * ( k2 + k3 ) + k4 ) / 6.0f;
return true;
}
/*===========================================================================*/
bool StreamlineBase::integrate_by_euler(
const kvs::Vec3& current_vertex,
const kvs::Vec3& current_direction,
kvs::Vec3* next_vertex )
{
if ( m_enable_boundary_condition )
{
if ( !this->check_for_inside_volume( current_vertex ) ) return false;
}
const float integration_direction = static_cast<float>( m_integration_direction );
const kvs::Vec3 k1 = current_direction.normalized() * integration_direction;
*next_vertex = current_vertex + m_integration_interval * k1;
return true;
}