PWRZT - Draws the projections of character strings that are
positioned in a plane parallel to one of the three coordinate planes.
NOTE: At one time, a Threed routine called PSYM3 was supported. It
has long been considered obsolete. If you call PSYM3, you will get an error
message telling you to use PWRZT instead and execution will be
terminated.
As nearly as we can determine, the statement
-
- CALL PSYM3 (U,V,W,ICHAR,ISIZE,IDIR,ITOP,IUP)
may be replaced by the statements
-
- IF (IUP.EQ.2) CALL VECT3 (U,V,W)
CALL PWRZT (U,V,W,ICHAR,1,ISIZE,IDIR,ITOP,0)
(Old manuals seem to indicate that the fifth argument in the call
to PSYM3 may have been a real called SIZE, rather than an integer called
ISIZE; it is not clear whether this was a misprint or not.)
The function of PSYM3 was to plot a symbol at the projection of a
particular point; this can now be done with PWRZT. If the eighth argument in
the second and following of a series of calls to PSYM3 had the value 2,
straight-line segments were drawn connecting the projections of the points;
this is better done with a single call to CURVE3, or by calling FRST3 for
the first point and VECT3 for each of the other points.
CALL PWRZT (U,V,W,CHRS,LCHRS,ISIZE,IDIR,ITOP,ICEN)
#include <ncarg/ncargC.h>
void c_pwrzt (float u, float v, float w, char *chrs, int lchrs,
int isize, int idir, int itop, int icen)
- U,V,W
- (input expressions of type REAL) are the U, V, and W coordinates of a
point, in the user's 3-space, relative to which the character string is to
be positioned.
- CHRS
- (an input constant or variable of type CHARACTER) is the character string
to be drawn. It may contain uppercase alphabetic characters, the digits 0
through 9, and a small set of "special" characters (plus, minus,
asterisk, slash, left and right parentheses, equals sign, blank, comma,
and period). Other characters are treated as blanks. (Note especially that
lowercase alphabetic characters are not available.)
- LCHRS
- (an input expression of type INTEGER) is the number of characters in
CHRS.
- ISIZE
- (an input expression of type INTEGER) specifies the character width to be
used, defined in terms of the width of the plotter frame. Because
projected characters vary in width depending on just where they are placed
within the box being viewed and the position from which that box is
viewed, ISIZE is interpreted as specifying the width of a character when
that character is positioned and viewed in such a way as to make it as
large as it could possibly be - when the character is on the near side of
the box and in a plane perpendicular to the line of sight.
Specifically,
-
- If between 0 and 3, ISIZE is 1., 1.5, 2., or 3. times a standard width
equal to 1/128th of the screen width.
-
- If greater than 3, ISIZE is the character width in units of 1/1024th of
the plotter frame.
-
- One third of the "width" referred to here is white space. What
ISIZE really specifies is the distance between the centers of adjacent
characters in a string. Characters are digitized to be 7/6 * ISIZE units
high and 4/6 * ISIZE units wide, excluding white space.
- IDIR
- (an input expression of type INTEGER) is the direction in which the
character string is to be written, as follows:
-
- 1 = +U -1 = -U
-
- 2 = +V -2 = -V
-
- 3 = +W -3 = -W
- ITOP
- (an input expression of type INTEGER) is the direction from the center of
the first character to the top of the first character; possible values of
ITOP are the same as those of IDIR, above. ABS(ITOP) must not be equal to
ABS(IDIR).
- ICEN
- (an input expression of type INTEGER) is the centering option, specifying
where (U,V,W) is relative to the string written, as follows:
- -1
- (U,V,W) is the center of the left edge of the first character.
- 0
- (U,V,W) is the center of the entire string.
- 1
- (U,V,W) is the center of the right edge of the last character.
Because characters drawn by PWRZT are stroked using the GKS
polyline primitive (so that they can be projected from 3-D to 2-D), they are
drawn in the current polyline color, as determined by the last call to the
GKS routine GSPLCI; by default, color index 1 is used. Line width is
determined by the last call to the GKS routine GSLWSC; by default, the line
width scale factor is 1.
The C-binding argument descriptions are the same as the FORTRAN
argument descriptions.
Use the ncargex command to see the following relevant example:
tpwrzt.
To use PWRZT or c_pwrzt, load the NCAR Graphics libraries ncarg,
ncarg_gks, and ncarg_c, preferably in that order.
Online: threed, curve3, fence3, frst3, line3, perim3, point3,
psym3, pwrz, set3, threed, tick3, tick43, vect3, ncarg_cbind.
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.