ncl_arscam(3)

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

6       ARSCAM - Scans an area map from left to right, extracting the
7       definitions of all the areas defined by the area map and delivering
8       them to a user-defined subroutine for processing.
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SYNOPSIS

11       CALL ARSCAM (MAP,XCS,YCS,MCS,IAI,IAG,MAI,APR)
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C-BINDING SYNOPSIS

14       #include <ncarg/ncargC.h>
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16       void c_arscam (int *map, float *xcs, float *ycs, int mcs, int *iai, int
17       *iag, int mai, int (*apr)(float *xcs, float *ycs, int *ncs, int *iai,
18       int *iag, int *nai))
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DESCRIPTION

21       MAP         (an input/output array of type INTEGER) - An array
22                   containing an area map that has been initialized by a call
23                   to ARINAM and to which edges have been added by calls to
24                   AREDAM.  If you did not preprocess the area map by calling
25                   ARPRAM, ARSCAM calls it before doing anything else.
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27                   Note: As part of initializing the area map, ARINAM stores
28                   the dimension of MAP in MAP(1); therefore, the dimension
29                   does not have to be given as an argument in calls to
30                   ARSCAM.)
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32       XCS,YCS     (workspace arrays, dimensioned MCS, of type REAL) - Hold
33                   the X and Y coordinates defining the edge of a given area,
34                   for use by ARSCAM in calls to the area-processing routine
35                   APR.
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37       MCS         (an input expression of type INTEGER) - Dimension of each
38                   of the arrays XCS and YCS.
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40       IAI,IAG     (workspace arrays, dimensioned MAI, of type INTEGER) - Hold
41                   MAI pairs of area identifiers and group identifiers,
42                   respectively. Used by ARSCAM in calls to the area-
43                   processing routine APR.
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45       MAI         (an input expression of type INTEGER) - Dimension of each
46                   of the arrays IAI and IAG. MAI must be greater than or
47                   equal to n, where n is the number of groups in the area
48                   map.
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50       APR         (a subroutine) - An area-processing routine that is called
51                   by ARSCAM, and must be declared EXTERNAL in the routine
52                   that calls ARSCAM. You must supply the routine APR, and it
53                   must have the following form:
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55                   SUBROUTINE APR (XCS,YCS,NCS,IAI,IAG,NAI)
56                   DIMENSION XCS(*),YCS(*),IAI(*),IAG(*)
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58                   (code to process the area defined by XCS, YCS, IAI, and
59                   IAG)
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61                   RETURN
62                   END
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65                   XCS,YCS     (input arrays, dimensioned NCS, of type REAL) -
66                               The X and Y coordinates, in NDCs, of NCS points
67                               defining a polygonal area. The last of these
68                               points is a duplicate of the first. Holes in an
69                               area are traced in a way that maximizes the
70                               probability of hardware fill working properly.
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72                   NCS         (an input expression of type INTEGER) - Number
73                               of X and Y coordinates in the arrays XCS and
74                               YCS.
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76                   IAI,IAG     (input arrays, dimensioned NAI, of type
77                               INTEGER) - Hold NAI pairs of identifiers for
78                               the area defined by XCS and YCS. For each value
79                               of I from 1 to NAI, IAI(I) is the area
80                               identifier for the area with respect to the
81                               group of edges specified by the group
82                               identifier IAG(I).
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84                   NAI         (an input expression of type INTEGER) - Number
85                               of values returned in IAI and IAG. NAI equals
86                               the number of groups of edges that you put in
87                               the area map.
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89       Before executing the first call to APR, ARSCAM calls GETSET to retrieve
90       the current user coordinates and then executes the statement:
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92       CALL SET (VPL,VPR,VPB,VPT,VPL,VPR,VPB,VPT,1)
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94       where VPL, VPR, VPB, and VPT are the viewport left, right, bottom, and
95       top coordinates in NDCs.
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97       This ensures correct results if the NDCs in XCS and YCS are used in
98       calls to such routines as GFA and GPL, and it allows clipping at the
99       edges of the viewport. APR may make its own SET call to achieve some
100       other effect. Before returning control to the calling routine, ARSCAM
101       calls SET again to restore the original mapping parameters.
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C-BINDING DESCRIPTION

104       The C-binding argument descriptions are the same as the FORTRAN
105       argument descriptions.
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EXAMPLES

108       Use the ncargex command to see the following relevant examples: cardb1,
109       carfill, ccpcldm, ccpfil, ccplbam, ccpllb, ccplll, ccpllw, ccpscam,
110       ccpvs, colcon, cmpfil, cmpgrp, cmpita, cmptit, cpex01, cpex02, cpex03,
111       cpex04, cpex05, cpex07, cpex08, eezmpa, arex01, vvex01, tareas, tconpa,
112       tezmpa, fcover, ffex00, fcirc, fsfsgfa, fsppoint.
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ACCESS

115       To use ARSCAM or c_arscam, load the NCAR Graphics libraries ncarg,
116       ncarg_gks, and ncarg_c, preferably in that order.
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MESSAGES

119       See the areas man page for a description of all Areas error messages
120       and/or informational messages.
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COPYRIGHT

129       Copyright (C) 1987-2009
130       University Corporation for Atmospheric Research
131       The use of this Software is governed by a License Agreement.
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135UNIX                              March 1993                    ARSCAM(3NCARG)