void dskz02_c ( SpiceInt handle,
ConstSpiceDLADescr * dladsc,
SpiceInt * nv,
SpiceInt * np )
Return plate model size parameters---plate count and
vertex count---for a type 2 DSK segment.
DAS
DSK
DAS
DSK
FILES
Variable I/O Description
-------- --- --------------------------------------------------
handle I DSK file handle.
dladsc I DLA descriptor.
nv O Number of vertices.
np O Number of plates.
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 is the number of vertices belonging to
the specified plate model.
np is the number of plates belonging to the
specified plate model.
See the header file
SpiceDLA.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 enables SPICE-based user applications to
conveniently fetch the plate and vertex counts of a type 2 DSK
segment.
See the routine DSKB02 (DSK, fetch type 2 bookkeeping data)
for an interface that returns all type 2 DSK segment
bookkeeping data in a single call.
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) Look up all the vertices associated with each plate
of the model contained in a specified type 2 segment. For each
plate, display the plate's vertices and normal vector.
For this example, we'll show the context of this look-up:
opening the DSK file for read access, traversing a trivial,
one-segment list to obtain the segment of interest.
Example code begins here.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Constants
./
#define PBUFSIZ 10000
#define FILSIZ 256
/.
Local variables
./
SpiceBoolean found;
SpiceChar dsk [ FILSIZ ];
SpiceDLADescr dladsc;
SpiceDouble normal [3];
SpiceDouble verts [3][3];
SpiceInt handle;
SpiceInt i;
SpiceInt j;
SpiceInt n;
SpiceInt np;
SpiceInt nread;
SpiceInt nv;
SpiceInt nvtx;
SpiceInt plates[PBUFSIZ][3];
SpiceInt plix;
SpiceInt remain;
SpiceInt start;
/.
Prompt for name of DSK and open file for reading.
./
prompt_c ( "Enter DSK name > ", FILSIZ, dsk );
dasopr_c ( dsk, &handle );
dlabfs_c ( handle, &dladsc, &found );
if ( !found )
{
setmsg_c ( "No segment found in file #." );
errch_c ( "#", dsk );
sigerr_c ( "SPICE(NOSEGMENT)" );
}
/.
Get segment vertex and plate counts.
./
dskz02_c ( handle, &dladsc, &nv, &np );
printf ( "\n"
"Number of vertices: %d\n"
"Number of plates: %d\n",
(int)nv,
(int)np );
/.
Display the vertices of each plate.
./
remain = np;
start = 1;
while ( remain > 0 )
{
/.
`nread' is the number of plates we"ll read on this
loop pass.
./
nread = mini_c ( 2, PBUFSIZ, remain );
dskp02_c ( handle, &dladsc, start, nread, &n, plates );
for ( i = 0; i < nread; i++ )
{
plix = start + i;
/.
Read the vertices of the current plate.
./
for ( j = 0; j < 3; j++ )
{
dskv02_c ( handle, &dladsc, plates[i][j],
1, &nvtx,
( SpiceDouble(*)[3] )(verts[j]) );
}
/.
Display the vertices of the current plate:
./
printf ( "\n"
" Plate number: %d\n"
" Vertex 1: ( %16.8e %16.8e %16.8e )\n"
" Vertex 2: ( %16.8e %16.8e %16.8e )\n"
" Vertex 3: ( %16.8e %16.8e %16.8e )\n",
(int)plix,
verts[0][0], verts[0][1], verts[0][2],
verts[1][0], verts[1][1], verts[1][2],
verts[2][0], verts[2][1], verts[2][2] );
/.
Display the normal vector of the current plate:
./
dskn02_c ( handle, &dladsc, plix, normal );
printf( " Normal: ( %16.8e %16.8e %16.8e )\n",
normal[0], normal[1], normal[2] );
}
start = start + nread;
remain = remain - nread;
}
/.
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/32bit
platform, using a DSK file representing a regular icosahedron,
the output was:
Number of vertices: 12
Number of plates: 20
Plate number: 1
Vertex 1: ( 0.00000000e+00 0.00000000e+00 1.17557000e+00 )
Vertex 2: ( 1.05146000e+00 0.00000000e+00 5.25731000e-01 )
Vertex 3: ( 3.24920000e-01 1.00000000e+00 5.25731000e-01 )
Normal: ( 4.91124160e-01 3.56821347e-01 7.94654382e-01 )
Plate number: 2
Vertex 1: ( 0.00000000e+00 0.00000000e+00 1.17557000e+00 )
Vertex 2: ( 3.24920000e-01 1.00000000e+00 5.25731000e-01 )
Vertex 3: ( -8.50651000e-01 6.18034000e-01 5.25731000e-01 )
Normal: ( -1.87592328e-01 5.77350079e-01 7.94654645e-01 )
...
Plate number: 20
Vertex 1: ( 8.50651000e-01 -6.18034000e-01 -5.25731000e-01 )
Vertex 2: ( 0.00000000e+00 0.00000000e+00 -1.17557000e+00 )
Vertex 3: ( 8.50651000e-01 6.18034000e-01 -5.25731000e-01 )
Normal: ( 6.07061680e-01 0.00000000e+00 -7.94654715e-01 )
None.
None.
N.J. Bachman (JPL)
-CSPICE Version 1.1.0, 27-JAN-2016 (NJB)
Removed references to old header files. Updated
example program.
-DSKLIB_C Version 1.0.0, 03-JUN-2010 (NJB)
fetch model size parameters from a type 2 dsk segment
Link to routine dskz02_c source file dskz02_c.c
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