NhlDataPolygon
The Fortran name of this function is NhlFDataPolygon.
Given arrays containing the X and Y coordinates of points in data
coordinate space, this function outputs an immediate-mode polygon
connecting each of the points.
C Synopsis
#include <ncarg/hlu/hlu.h>
#include <hfile for Transform class object>
NhlErrorTypes NhlDataPolygon(
int pid,
int gsid,
float *x,
float *y,
int n,
)
Fortran Synopsis
subroutine NhlFDataPolygon(pid, gsid, x, y, n, ierr)
integer pid, gsid, n, ierr
real x(n), y(n)
Arguments
- pid (input)
- Id of a Transform or Workstation object.
- gsid (input)
- Id of a GraphicStyle object.
- x (input)
- Array of X-Axis coordinate values in data coordinate space.
- y (input)
- Array of Y-Axis coordinate values in data coordinate space.
- n (input)
- Number of elements in the coordinate arrays x and y.
- ierr (output, Fortran only)
- Error code.
Types
Type name: NhlTErrorTypes
Definition:
typedef enum _NhlErrType{
NhlFATAL = -4, /* "FATAL" */
NhlWARNING = -3, /* "WARNING" */
NhlINFO = -2, /* "INFO" */
NhlNOERROR = -1 /* "NOERROR" */
} NhlErrorTypes;
Description
If the parameter pid specifies a transform
(a plot object), this function draws an immediate-mode polygon in the
object's current data coordinate space. The polygon is clipped to the
object's viewport. If the parameter pid specifies a
workstation, the polygon is drawn in a data
coordinate space that is identical to NDC space with boundaries of (0.0,0.0)
at the lower left and (1.0,1.0) at the upper right. Clipping occurs
only at the viewspace boundaries. An immediate-mode polygon
appears as soon as the low-level point buffer is flushed after the
function is called. It is not drawn when the object's
Draw method is invoked.
You specify the polygon's attributes by passing in a
GraphicStyle object using the parameter
gsid. If gsid is set to NhlNULLOBJID
(0) then the polygon attributes are determined by the current settings
of the Workstation default
GraphicStyle object. Retrieve the id of the default
GraphicStyle object using the read-only
Workstation resource wkDefGraphicStyleId.
Return Values
The NhlDataPolygon C function returns a value of
type NhlErrorTypes, and the
NhlFDataPolygon Fortran subroutine returns the error
in ierr. The following table indicates what the various
return Error Values mean:
Value | Meaning
--------+-------------------------------------------------
NOERROR | function successful
--------+-------------------------------------------------
INFO | minor recoverable error
--------+-------------------------------------------------
WARNING | recoverable error
--------+-------------------------------------------------
FATAL | function failed; continuing the program
| may result in core dump
See Also
Copyright
Copyright 1987-1999 University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.
NCAR Graphics is a registered trademark of the University
Corporation for Atmospheric Research.
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$Revision: 1.8 $ $Date: 1998/08/19 03:11:39 $