1MPCHLN(3NCARG)                   NCAR GRAPHICS                  MPCHLN(3NCARG)
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NAME

6       MPCHLN - This routine is called repeatedly as boundary lines are
7       processed by MPLNAM, MPLNDM, and MPLNDR.  The default version of the
8       routine does nothing.  A user-supplied version may take action to
9       change various characteristics of the lines.
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SYNOPSIS

12       CALL MPCHLN (IACT,ILTY,IOAL,IOAR,NPTS,PNTS)
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C-BINDING SYNOPSIS

15       None.
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DESCRIPTION

18       IACT        (an input expression of type INTEGER) specifies which of
19                   the EZMAPB routines has called MPCHLN and what that routine
20                   is doing or has done with the boundary line defined by the
21                   arguments NPTS and PNTS.  IACT is positive if the line is
22                   about to be processed, negative if the line was just
23                   processed; its absolute value is 1 if the call comes from
24                   MPLNAM (which puts lines into an area map), 2 if the call
25                   comes from MPLNDM (which draws lines masked by some area
26                   map), and 3 if the call comes from MPLNDR (which just draws
27                   lines).
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29       ILTY        (an input expression of type INTEGER) specifies the type of
30                   the line: 1 => a line separating land from water, 2 => a
31                   line separating one "continent" from another (as, for
32                   example, Africa from Eurasia, North America from Central
33                   America, or Central America from South America), 3 => a
34                   line separating one country from another, 4 => a line
35                   separating one state from another, and 5 => a line
36                   separating one county from another.
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38       IOAL and IOAR
39                   (input/output variables of type INTEGER) are the
40                   identifiers of the areas to the left and right,
41                   respectively, of the line.  (Left and right are defined
42                   from the standpoint of a viewer standing at point 1 of the
43                   line and looking toward point 2.)  The values of IOAL and
44                   IOAR may be changed by a knowledgeable user.
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46       NPTS        (an input/output variable of type INTEGER), on entry, is
47                   the number of points defining the line.  NPTS may be zeroed
48                   by MPCHLN to suppress any use of the line by the calling
49                   routine.
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51       PNTS        (an input/output array, dimensioned 2*NPTS, of type REAL)
52                   is an array of point coordinates.  PNTS(1) and PNTS(2) are
53                   the latitude and longitude of the first point, PNTS(3) and
54                   PNTS(4) the latitude and longitude of the second point, ...
55                   PNTS(2*NPTS-1) and PNTS(2*NPTS) the latitude and longitude
56                   of the last point.  All values are in degrees.  Longitudes
57                   are all between -180 and +180; no segment crosses the
58                   meridian at -180 (+180) degrees.
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C-BINDING DESCRIPTION

61       The C-binding argument description is the same as the FORTRAN argument
62       description.
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USAGE

65       MPCHLN is called by each of the routines MPLNAM, MPLNDM, and MPLNDR
66       just before and just after the processing of each boundary line read
67       from a specified map database.  A user-supplied version may take action
68       to change various characteristics of the lines.  For example, the area
69       identifiers to be used for the line can be changed, the line can be
70       deleted entirely, and line styles, colors, and widths can be set.
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EXAMPLES

73       Use the ncargex command to see the following relevant example: mpex11.
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ACCESS

76       To use the default version of MPCHLN, load the NCAR Graphics libraries
77       ncarg, and ncarg_gks, preferably in that order.  To supply your own
78       version, just compile it and load it.
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SEE ALSO

81       Online: ezmap, ezmap_params, mapaci, mapbla, mapblm, mapdrw, mapeod,
82       mapfst, mapgci, mapgrd, mapgrm, mapgtc, mapgti, mapgtl, mapgtr, mapint,
83       mapiq, mapiqa, mapiqd, mapiqm, mapit, mapita, mapitd, mapitm, maplbl,
84       maplmb, maplot, mappos, maproj, maprs, maprst, mapsav, mapset, mapstc,
85       mapsti, mapstl, mapstr, maptra, maptri, maptrn, mapusr, mapvec, mpfnme,
86       mpgetc, mpgeti, mpgetl, mpgetr, mpglty, mpiaty, mpifnb, mpilnb, mpiola,
87       mpiosa, mpipai, mpipan, mpipar, mpisci, mplnam, mplndm, mplndr, mplnri,
88       mpname, mprset, mpsetc, mpseti, mpsetl, mpsetr, supmap, supcon,
89       ncarg_cbind
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92       Copyright (C) 1987-2009
93       University Corporation for Atmospheric Research
94       The use of this Software is governed by a License Agreement.
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98UNIX                              April 1998                    MPCHLN(3NCARG)
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