/*
 * ODE::Mass::CappedCylinder#initialize( density, direction, radius, length[, totalmass] )
 * --
 * Create and return a capped cylinder Mass object of the given <tt>radius</tt>
 * and <tt>length</tt> with the specified density, with the center of mass at
 * (0,0,0) relative to the body. The cylinder's long axis is oriented along the
 * body's x, y or z axis according to the value of <tt>direction</tt> (1=x, 2=y,
 * 3=z). If the optional <tt>totalmass</tt> parameter is given, adjust the
 * values so the total mass is <tt>totalmass</tt> before returning.
 */
static VALUE
ode_mass_ccyl_init( argc, argv, self )
	 int	argc;
	 VALUE	*argv, self;
{
	ode_MASS	*ptr;
	VALUE		density, direction, radius, length, totalmass;

	rb_scan_args( argc, argv, "41", &density, &direction, &radius, &length, &totalmass );

	if ( NUM2INT(direction) < 1 || NUM2INT(direction) > 3 )
		rb_raise( rb_eArgError,
				  "Direction argument '%d' out of bounds. Must be between 1 and 3.",
				  NUM2INT(direction) );

	CheckPositiveNonZeroNumber( NUM2DBL(density), "density" );
	CheckPositiveNonZeroNumber( NUM2DBL(radius), "radius" );
	CheckPositiveNonZeroNumber( NUM2DBL(length), "length" );

	rb_call_super( 0, 0 );
	ptr = get_mass( self );

	dMassSetCappedCylinder( ptr->massptr,
							(dReal)NUM2DBL(density),
							NUM2INT(direction),
							(dReal)NUM2DBL(radius),
							(dReal)NUM2DBL(length) );

	/* If a totalmass argument was given, check and set it */
	if ( RTEST(totalmass) ) {
		CheckPositiveNonZeroNumber( NUM2DBL(totalmass), "totalmass" );
		dMassAdjust( ptr->massptr, (dReal)NUM2DBL(totalmass) );
	}

	return self;
}