1MPCHLN(3NCARG) NCAR GRAPHICS MPCHLN(3NCARG)
2
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.
10
12 CALL MPCHLN (IACT,ILTY,IOAL,IOAR,NPTS,PNTS)
13
15 None.
16
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).
28 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.
37 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.
45 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.
50 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.
59
61 The C-binding argument description is the same as the FORTRAN argument
62 description.
63
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.
71
73 Use the ncargex command to see the following relevant example: mpex11.
74
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.
79
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
90
92 Copyright (C) 1987-2009
93 University Corporation for Atmospheric Research
94 The use of this Software is governed by a License Agreement.
95UNIX April 1998 MPCHLN(3NCARG)