void dskb02_c ( SpiceInt handle,
ConstSpiceDLADescr * dladsc,
SpiceInt * nv,
SpiceInt * np,
SpiceInt * nvxtot,
SpiceDouble vtxbds [3][2],
SpiceDouble * voxsiz,
SpiceDouble voxori [3],
SpiceInt vgrext [3],
SpiceInt * cgscal,
SpiceInt * vtxnpl,
SpiceInt * voxnpt,
SpiceInt * voxnpl )
Return bookkeeping data from a DSK type 2 segment.
DAS
DSK
DAS
DSK
FILES
Variable I/O Description
-------- --- --------------------------------------------------
handle I DSK file handle.
dladsc I DLA descriptor.
nv O Number of vertices in model.
np O Number of plates in model.
nvxtot O Number of voxels in fine grid.
vtxbds O Vertex bounds.
voxsiz O Fine voxel edge length.
voxori O Fine voxel grid origin.
vgrext O Fine voxel grid exent.
cgscal O Coarse voxel grid scale.
vtxnpl O Size of vertex-plate correspondence list.
voxnpt O Size of voxel-plate pointer list.
voxnpl O Size of voxel-plate correspondence list.
handle is the handle of a DSK file containing a type 2
segment from which data are to be fetched.
dladsc is the DLA descriptor associated with the segment
from which data are to be fetched.
nv Number of vertices in model.
np Number of plates in model.
nvxtot Total number of voxels in fine grid.
vtxbds Vertex bounds. This is an array of six values giving
the minimum and maximum values of each component of
the vertex set. `vtxbds' has dimensions [3][2].
Units are km.
voxsiz Fine grid voxel size. DSK voxels are cubes; the edge
length of each cube is given by the voxel size. This
size applies to the fine voxel grid. Units are km.
voxori Voxel grid origin. This is the location of the voxel
grid origin in the body-fixed frame associated with
the target body. Units are km.
vgrext Voxel grid extent. This extent is an array of three
integers indicating the number of voxels in the X, Y, and
Z directions in the fine voxel grid.
cgscal Coarse voxel grid scale. The extent of the fine voxel
grid is related to the extent of the coarse voxel grid by
this scale factor.
vtxnpl Vertex-plate correspondence list size.
voxnpt Size of the voxel-to-plate pointer list.
voxnpl Voxel-plate correspondence list size.
See the header files
SpiceDLA.h
SpiceDSK.h
1) If the input handle is invalid, the error will be diagnosed by
routines in the call tree of this routine.
2) If a file read error occurs, the error will be diagnosed by
routines in the call tree of this routine.
3) If the input DLA descriptor is invalid, the effect of this
routine is undefined. The error *may* be diagnosed by routines
in the call tree of this routine, but there are no
guarantees.
See input argument `handle'.
This routine supports computations involving bookkeeping information
stored in DSK type 2 segments. User applications typically will not
need to call this routine.
DSK files are built using the DLA low-level format and the DAS
architecture; DLA files are a specialized type of DAS file in which
data are organized as a doubly linked list of segments. Each
segment's data belong to contiguous components of character, double
precision, and integer type.
The numerical results shown for this example 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) Dump several parameters from the first DLA segment of
a DSK file. The segment is assumed to be of type 2.
Example code begins here.
#include <stdio.h>
#include "SpiceUsr.h"
#include "SpiceDLA.h"
#include "SpiceDSK.h"
int main()
{
/.
Constants
./
#define FILSIZ 256
/.
Local variables
./
SpiceBoolean found;
SpiceChar dsk [ FILSIZ ];
SpiceDLADescr dladsc;
SpiceDouble voxori [3];
SpiceDouble voxsiz;
SpiceDouble vtxbds [3][2];
SpiceInt cgscal;
SpiceInt handle;
SpiceInt np;
SpiceInt nv;
SpiceInt nvxtot;
SpiceInt vgrext [3];
SpiceInt voxnpl;
SpiceInt voxnpt;
SpiceInt vtxnpl;
/.
Prompt for the name of DSK to read.
./
prompt_c ( "Enter DSK name > ", FILSIZ, dsk );
/.
Open the DSK file for read access. We use the
DAS-level interface for this function.
./
dasopr_c ( dsk, &handle );
/.
Begin a forward search through the kernel. In
this example, it's a very short search.
./
dlabfs_c ( handle, &dladsc, &found );
if ( !found )
{
setmsg_c ( "No segment found in file #." );
errch_c ( "#", dsk );
sigerr_c ( "SPICE(NOSEGMENT)" );
}
/.
If we made it this far, DLADSC is the
DLA descriptor of the first segment.
Read and display type 2 bookkeeping data.
./
dskb02_c ( handle, &dladsc, &nv, &np, &nvxtot,
vtxbds, &voxsiz, voxori, vgrext, &cgscal,
&vtxnpl, &voxnpt, &voxnpl );
printf ( "\n"
"Number of vertices: %d\n"
"Number of plates: %d\n"
"Number of voxels: %d\n"
"Vertex bounds in X direction (km): %f : %f\n"
"Vertex bounds in Y direction (km): %f : %f\n"
"Vertex bounds in Z direction (km): %f : %f\n"
"Voxel edge length (km): %f\n"
"Voxel grid origin (km): ( %f %f %f )\n"
"Voxel grid extents: %d %d %d\n"
"Coarse voxel grid scale: %d\n"
"Size of vertex-plate list: %d\n"
"Size of voxel-plate pointer array: %d\n"
"Size of voxel-plate list: %d\n",
(int)nv,
(int)np,
(int)nvxtot,
vtxbds[0][0], vtxbds[0][1],
vtxbds[1][0], vtxbds[1][1],
vtxbds[2][0], vtxbds[2][1],
voxsiz,
voxori[0], voxori[1], voxori[2],
(int)vgrext[0], (int)vgrext[1], (int)vgrext[2],
(int)cgscal,
(int)vtxnpl,
(int)voxnpt,
(int)voxnpl );
/.
Close the kernel. This isn't necessary in a stand-
alone program, but it's good practice in subroutines
because it frees program and system resources.
./
dascls_c ( handle );
return ( 0 );
}
When this program was executed on a PC/Linux/gcc/64bit
platform, using a DSK file representing a regular icosahedron,
the output was:
Number of vertices: 12
Number of plates: 20
Number of voxels: 512
Vertex bounds in X direction (km): -1.051460 : 1.051460
Vertex bounds in Y direction (km): -1.000000 : 1.000000
Vertex bounds in Z direction (km): -1.175570 : 1.175570
Voxel edge length (km): 0.901744
Voxel grid origin (km): ( -3.606976 -3.606976 -3.606976 )
Voxel grid extents: 8 8 8
Coarse voxel grid scale: 2
Size of vertex-plate list: 72
Size of voxel-plate pointer array: 64
Size of voxel-plate list: 288
1) The caller must verify that the segment associated with
the input DLA descriptor is a DSK type 2 segment.
None.
N.J. Bachman (JPL)
-CSPICE Version 2.1.0, 11-JUL-2016 (NJB)
Edit to example program to use "%d" with explicit casts
to int for printing SpiceInts with printf.
Removed unnecessary include statements. Updated
header.
-DSKLIB_C Version 2.0.1, 11-JUL-2014 (NJB)
Added example program to header.
-DSKLIB_C Version 2.0.0, 13-MAY-2010 (NJB)
Updated for compatibility with new DSK type 2 design.
Name has been changed from dskp02_c to dskb02_c.
-DSKLIB_C Version 1.0.0, 11-FEB-2010 (NJB)
fetch parameters from a type 2 dsk segment
Link to routine dskb02_c source file dskb02_c.c
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