Discussed here is the polyline output primitive GPL and the
functions that are used to set polyline attributes and retrieve
current attribute settings.
The polyline output primitive GPL causes a series of N-1
straight line segments to be drawn connecting successive points
specified by the coordinate pairs (X(I),Y(I)) for I=1,N.
------------------------------------------------
Argument | Type | Mode | Dimension
------------------------------------------------
CALL GPL (N, | Integer | Input |
X, | Real | Input | N
Y) | Real | Input | N
------------------------------------------------
- N
- The number of points in the line to be drawn. (N > 1)
- X
- An array of dimension N containing the X coordinates of N
points to be connected by line segments. These values are in
world coordinates.
- Y
- An array of dimension N containing the Y coordinates of
N points to be connected by line segments. These values are in
world coordinates.
- Defaults:
- none
- Errors:
- 5,
100
------------------------------------------------------------------------
C Synopsis
#include <ncarg/gks.h>
void gpolyline(
const Gpoint_list *point_list /* list of points */
);
------------------------------------------------------------------------
Figure 6
- Examples of polylines
Before generating output you can change various polyline attributes from
the default values. You can set polyline type and width
attributes using GSLN and GSLWSC, respectively.
-------------------------------------------------
Argument | Type | Mode | Dimension
-------------------------------------------------
CALL GSLN (LTYPE) | Integer | Input |
-------------------------------------------------
- LTYPE
- The type of polyline to be drawn. Options are:
-
- < 0 - implementation dependent (not used in NCAR GKS)
-
- 1 - solid line
-
- 2 - dashed line
-
- 3 - dotted line
-
- 4 - dashed dotted line
-
- >= 5 - reserved for future standardization (not used in NCAR GKS)
- Default:
- The default linetype is 1 (solid line).
- Errors:
- 8,
63
--------------------------------------------------------------
C Synopsis
#include <ncarg/gks.h>
void gset_linetype(
Gint linetype /* linetype */
);
--------------------------------------------------------------
-------------------------------------------------
Argument | Type | Mode | Dimension
-------------------------------------------------
CALL GSLWSC (LWIDTH) | Real | Input |
-------------------------------------------------
- LWIDTH
- A scale factor to control the linewidth of the
polyline to be drawn. It must be greater than or equal to 0.
LWIDTH is applied to the nominal linewidth on a given device and
the linewidths are mapped to the nearest available linewidth representable
on that device. See Figure 6
for examples of polylines drawn with
different widths. If an output device does not support differing
linewidths, then you will see no effect on that device from setting
this value.
- Default:
- The default linewidth scale factor is 1.0.
- Errors:
- 8,
65
--------------------------------------------------------------------------
C Synopsis
#include <ncarg/gks.h>
void gset_linewidth(
Gdouble linewidth /* linewidth scale factor */
);
--------------------------------------------------------------------------
----------------------------------------------------
Argument | Type | Mode | Dimension
----------------------------------------------------
CALL GQLN (ERRIND, | Integer | Output |
LTYPE) | Integer | Output |
----------------------------------------------------
- ERRIND
- Error flag. Gives an integer error number from the
Errors list
in Appendix D,
or a 0 if no error occurred.
- LTYPE
- Gives the type of polyline to be drawn as set by GSLN.
- Errors:
- 8
----------------------------------------------------------------------
C Synopsis
#include <ncarg/gks.h>
void ginq_linetype(
Gint *err_ind, /* error indicator */
Gint *linetype /* linetype */
);
----------------------------------------------------------------------
----------------------------------------------------
Argument | Type | Mode | Dimension
----------------------------------------------------
CALL GQLWSC (ERRIND, | Integer | Output |
LWIDTH) | Real | Output |
----------------------------------------------------
- ERRIND
- Error flag. Gives an integer error number from the
Errors list
in Appendix D,
or a 0 if no error occurred.
- LWIDTH
- Gives the line width scale factor as set by GSLWSC.
- Errors:
- 8
--------------------------------------------------------------------------
C Synopsis
#include <ncarg/gks.h>
void ginq_linewidth(
Gint *err_ind, /* error indicator */
Gdouble *linewidth /* linewidth scale factor */
);
--------------------------------------------------------------------------
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