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//
// GENERATED FILE
//
use super::*;
use crate::SpiceContext;
use f2rust_std::*;
pub const UBEL: i32 = 9;
const CTRPOS: i32 = 1;
const MAJPOS: i32 = 4;
const MINPOS: i32 = 7;
/// Center and generating vectors to ellipse
///
/// Form a SPICE ellipse from a center vector and two generating
/// vectors.
///
/// # Required Reading
///
/// * [ELLIPSES](crate::required_reading::ellipses)
///
/// # Brief I/O
///
/// ```text
/// VARIABLE I/O DESCRIPTION
/// -------- --- --------------------------------------------------
/// CENTER,
/// VEC1,
/// VEC2 I Center and two generating vectors for an ellipse.
/// ELLIPS O The SPICE ellipse defined by the input vectors.
/// ```
///
/// # Detailed Input
///
/// ```text
/// CENTER,
/// VEC1,
/// VEC2 are a center and two generating vectors defining
/// an ellipse in three-dimensional space. The
/// ellipse is the set of points
///
/// CENTER + cos(theta) VEC1 + sin(theta) VEC2
///
/// where theta ranges over the interval (-pi, pi].
/// VEC1 and VEC2 need not be linearly independent.
/// ```
///
/// # Detailed Output
///
/// ```text
/// ELLIPS is the SPICE ellipse defined by the input
/// vectors.
/// ```
///
/// # Exceptions
///
/// ```text
/// 1) If VEC1 and VEC2 are linearly dependent, ELLIPS will be
/// degenerate. SPICE ellipses are allowed to represent
/// degenerate geometric ellipses.
/// ```
///
/// # Particulars
///
/// ```text
/// SPICE ellipses serve to simplify calling sequences and reduce
/// the chance for error in declaring and describing argument lists
/// involving ellipses.
///
/// The set of ellipse conversion routines is
///
/// CGV2EL ( Center and generating vectors to ellipse )
/// EL2CGV ( Ellipse to center and generating vectors )
/// ```
///
/// # Examples
///
/// ```text
/// The numerical results shown for these examples may differ across
/// platforms. The results depend on the SPICE kernels used as
/// input, the compiler and supporting libraries, and the machine
/// specific arithmetic implementation.
///
/// 1) Create a SPICE ellipse given its center and two linearly
/// independent generating vectors of the ellipse.
///
///
/// Example code begins here.
///
///
/// PROGRAM CGV2EL_EX1
/// IMPLICIT NONE
///
/// C
/// C Local constants.
/// C
/// INTEGER UBEL
/// PARAMETER ( UBEL = 9 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION CENTER ( 3 )
/// DOUBLE PRECISION ECENTR ( 3 )
/// DOUBLE PRECISION ELLIPS ( UBEL )
/// DOUBLE PRECISION SMAJOR ( 3 )
/// DOUBLE PRECISION SMINOR ( 3 )
/// DOUBLE PRECISION VEC1 ( 3 )
/// DOUBLE PRECISION VEC2 ( 3 )
///
/// INTEGER I
///
/// C
/// C Define the center and two linearly independent
/// C generating vectors of an ellipse (the vectors need not
/// C be linearly independent).
/// C
/// DATA CENTER / -1.D0, 1.D0, -1.D0 /
///
/// DATA VEC1 / 1.D0, 1.D0, 1.D0 /
///
/// DATA VEC2 / 1.D0, -1.D0, 1.D0 /
///
/// C
/// C Create the ELLIPS.
/// C
/// CALL CGV2EL ( CENTER, VEC1, VEC2, ELLIPS )
///
/// C
/// C In a real application, please use SPICELIB API EL2CGV
/// C to retrieve the center and generating vectors from the
/// C ellipse structure (see next block).
/// C
/// WRITE(*,'(A)') 'SPICE ellipse:'
/// WRITE(*,'(A,3F10.6)') ' Semi-minor axis:',
/// . ( ELLIPS(I), I=7,9 )
/// WRITE(*,'(A,3F10.6)') ' Semi-major axis:',
/// . ( ELLIPS(I), I=4,6 )
/// WRITE(*,'(A,3F10.6)') ' Center :',
/// . ( ELLIPS(I), I=1,3 )
/// WRITE(*,*) ' '
///
/// C
/// C Obtain the center and generating vectors from the
/// C ELLIPS.
/// C
/// CALL EL2CGV ( ELLIPS, ECENTR, SMAJOR, SMINOR )
///
/// WRITE(*,'(A)') 'SPICE ellipse (using EL2CGV):'
/// WRITE(*,'(A,3F10.6)') ' Semi-minor axis:', SMINOR
/// WRITE(*,'(A,3F10.6)') ' Semi-major axis:', SMAJOR
/// WRITE(*,'(A,3F10.6)') ' Center :', ECENTR
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// SPICE ellipse:
/// Semi-minor axis: 0.000000 1.414214 0.000000
/// Semi-major axis: 1.414214 -0.000000 1.414214
/// Center : -1.000000 1.000000 -1.000000
///
/// SPICE ellipse (using EL2CGV):
/// Semi-minor axis: 0.000000 1.414214 0.000000
/// Semi-major axis: 1.414214 -0.000000 1.414214
/// Center : -1.000000 1.000000 -1.000000
///
///
/// 2) Find the intersection of an ellipse with a plane.
///
///
/// Example code begins here.
///
///
/// PROGRAM CGV2EL_EX2
/// IMPLICIT NONE
///
/// C
/// C Local constants.
/// C
/// INTEGER UBEL
/// PARAMETER ( UBEL = 9 )
///
/// INTEGER UBPL
/// PARAMETER ( UBPL = 4 )
///
/// C
/// C Local variables.
/// C
/// DOUBLE PRECISION CENTER ( 3 )
/// DOUBLE PRECISION ELLIPS ( UBEL )
/// DOUBLE PRECISION NORMAL ( 3 )
/// DOUBLE PRECISION PLANE ( UBPL )
/// DOUBLE PRECISION VEC1 ( 3 )
/// DOUBLE PRECISION VEC2 ( 3 )
/// DOUBLE PRECISION XPTS ( 3, 2 )
///
/// INTEGER I
/// INTEGER NXPTS
///
/// C
/// C The ellipse is defined by the vectors CENTER, VEC1, and
/// C VEC2. The plane is defined by the normal vector NORMAL
/// C and the CENTER.
/// C
/// DATA CENTER / 0.D0, 0.D0, 0.D0 /
/// DATA VEC1 / 1.D0, 7.D0, 2.D0 /
/// DATA VEC2 / -1.D0, 1.D0, 3.D0 /
///
/// DATA NORMAL / 0.D0, 1.D0, 0.D0 /
///
/// C
/// C Make a SPICE ellipse and a plane.
/// C
/// CALL CGV2EL ( CENTER, VEC1, VEC2, ELLIPS )
/// CALL NVP2PL ( NORMAL, CENTER, PLANE )
///
/// C
/// C Find the intersection of the ellipse and plane.
/// C NXPTS is the number of intersection points; XPTS
/// C are the points themselves.
/// C
/// CALL INELPL ( ELLIPS, PLANE, NXPTS,
/// . XPTS(1,1), XPTS(1,2) )
///
/// WRITE(*,'(A,I2)') 'Number of intercept points: ', NXPTS
///
/// DO I = 1, NXPTS
///
/// WRITE(*,'(A,I2,A,3F10.6)') ' Point', I, ':',
/// . XPTS(1,I), XPTS(2,I), XPTS(3,I)
///
/// END DO
///
/// END
///
///
/// When this program was executed on a Mac/Intel/gfortran/64-bit
/// platform, the output was:
///
///
/// Number of intercept points: 2
/// Point 1: 1.131371 0.000000 -2.687006
/// Point 2: -1.131371 -0.000000 2.687006
/// ```
///
/// # Author and Institution
///
/// ```text
/// N.J. Bachman (JPL)
/// J. Diaz del Rio (ODC Space)
/// W.L. Taber (JPL)
/// ```
///
/// # Version
///
/// ```text
/// - SPICELIB Version 1.1.0, 24-AUG-2021 (JDR)
///
/// Added IMPLICIT NONE statement.
///
/// Edited the header to comply with NAIF standard.
/// Added complete code example.
///
/// - SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)
///
/// Comment section for permuted index source lines was added
/// following the header.
///
/// - SPICELIB Version 1.0.0, 02-NOV-1990 (NJB)
/// ```
pub fn cgv2el(
ctx: &mut SpiceContext,
center: &[f64; 3],
vec1: &[f64; 3],
vec2: &[f64; 3],
ellips: &mut [f64; 9],
) -> crate::Result<()> {
CGV2EL(center, vec1, vec2, ellips, ctx.raw_context())?;
ctx.handle_errors()?;
Ok(())
}
//$Procedure CGV2EL ( Center and generating vectors to ellipse )
pub fn CGV2EL(
CENTER: &[f64],
VEC1: &[f64],
VEC2: &[f64],
ELLIPS: &mut [f64],
ctx: &mut Context,
) -> f2rust_std::Result<()> {
let CENTER = DummyArray::new(CENTER, 1..=3);
let VEC1 = DummyArray::new(VEC1, 1..=3);
let VEC2 = DummyArray::new(VEC2, 1..=3);
let mut ELLIPS = DummyArrayMut::new(ELLIPS, 1..=UBEL);
//
// SPICELIB functions
//
//
// Local parameters
//
//
// SPICE ellipses contain a center vector, a semi-major
// axis vector, and a semi-minor axis vector. These are
// located, respectively, in elements
//
// CTRPOS through CTRPOS + 1
//
// MAJPOS through MAJPOS + 1
//
// MINPOS through MINPOS + 1
//
//
//
// Standard SPICE error handling.
//
if RETURN(ctx) {
return Ok(());
} else {
CHKIN(b"CGV2EL", ctx)?;
}
//
// The center of the ellipse is held in the first three elements.
//
VEQU(CENTER.as_slice(), ELLIPS.subarray_mut(CTRPOS));
//
// Find the semi-axes of the ellipse. These may be degenerate.
//
let [arg2, arg3] = ELLIPS.get_disjoint_slices_mut([MAJPOS, MINPOS]).unwrap();
SAELGV(VEC1.as_slice(), VEC2.as_slice(), arg2, arg3, ctx)?;
CHKOUT(b"CGV2EL", ctx)?;
Ok(())
}