/**
* \fn void read_input( const string& fn , size_t& np , size_t& nc , bool& closed , double*& lx , double*& ly , double*& ux , double*& uy ) throw( ExceptionObject )
*
* \brief Read in a file describing a polygonal channel.
*
* \param fn The name of a file describing a polygonal channel.
* \param np A reference to the number of b-spline segments.
* \param nc A reference to the number of c-segments of the channel.
* \param closed A reference to a flag to indicate whether the channel
* is closed.
* \param lx A reference to a pointer to an array with the
* x-coordinates of the lower polygonal chain of the channel.
* \param ly A reference to a pointer to an array with the
* y-coordinates of the lower polygonal chain of the channel.
* \param ux A reference to a pointer to an array with the
* x-coordinates of the upper polygonal chain of the channel.
* \param uy A reference to a pointer to an array with the
* y-coordinates of the upper polygonal chain of the channel.
*
*/
void read_input(
const string& fn ,
size_t& np ,
size_t& nc ,
bool& closed ,
double*& lx ,
double*& ly ,
double*& ux ,
double*& uy
)
throw( ExceptionObject )
{
//
// Open the input file
//
std::ifstream in( fn.c_str() ) ;
if ( in.is_open() ) {
//
// Read in the number of segments of the b-spline.
//
in >> np ;
//
// Read in the number of c-segments of the channel.
//
in >> nc ;
//
// Read in the flag indicating whether the channel is closed.
//
unsigned flag ;
in >> flag ;
if ( ( flag != 0 ) && ( flag != 1 ) ) {
std::stringstream ss( std::stringstream::in | std::stringstream::out ) ;
ss << "Flag value indicating whether the channel is closed or open is invalid" ;
in.close() ;
throw ExceptionObject( __FILE__ , __LINE__ , ss.str().c_str() ) ;
}
closed = ( flag == 1 ) ;
if ( closed ) {
if ( np < 4 ) {
std::stringstream ss( std::stringstream::in | std::stringstream::out ) ;
ss << "The number of curve segments must be at least 4 for a closed curve" ;
in.close() ;
throw ExceptionObject( __FILE__ , __LINE__ , ss.str().c_str() ) ;
}
if ( nc < 3 ) {
std::stringstream ss( std::stringstream::in | std::stringstream::out ) ;
ss << "The number of segments of a closed channel must be at least 3" ;
in.close() ;
throw ExceptionObject( __FILE__ , __LINE__ , ss.str().c_str() ) ;
}
}
else {
if ( np < 1 ) {
std::stringstream ss( std::stringstream::in | std::stringstream::out ) ;
ss << "The number of curve segments must be at least 1" ;
in.close() ;
throw ExceptionObject( __FILE__ , __LINE__ , ss.str().c_str() ) ;
}
if ( nc < 1 ) {
std::stringstream ss( std::stringstream::in | std::stringstream::out ) ;
ss << "The number of segments of an open channel must be at least 1" ;
in.close() ;
throw ExceptionObject( __FILE__ , __LINE__ , ss.str().c_str() ) ;
}
}
//
// Read in the channel vertex coordinates.
//
const size_t nn = ( closed ) ? nc : ( nc + 1 ) ;
lx = new double[ nn ] ;
ly = new double[ nn ] ;
for ( size_t i = 0 ; i < nn ; i++ ) {
//
// Read in the X and Y coordinates of the i-th vertex.
//
in >> lx[ i ] ;
in >> ly[ i ] ;
}
ux = new double[ nn ] ;
uy = new double[ nn ] ;
for ( size_t i = 0 ; i < nn ; i++ ) {
//
// Read in the X and Y coordinates of the i-th vertex.
//
in >> ux[ i ] ;
in >> uy[ i ] ;
}
//
// Close file
//
in.close() ;
}
