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

6       TDDTRI - Draw the triangles defined by a triangle list.
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SYNOPSIS

9       CALL TDDTRI (RTRI, MTRI, NTRI, ITWK)
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C-BINDING SYNOPSIS

12       #include <ncarg/ncargC.h>
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14       void c_tddtri(float *rtri, int mtri, int *ntri, int *itwk)
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DESCRIPTION

17       This routine draws the triangles defined by a triangle list.  The
18       triangles are drawn in the order specified by the contents of the
19       permutation array ITWK.
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21       The exact manner in which each triangle is drawn depends on the
22       rendering style selected for it.  Generally, it is first filled with a
23       user-selected color; if a wire-frame image is desired and no lines are
24       to be considered hidden, this step may be skipped.  The fill color can
25       be a specific one chosen by the user (sometimes, it is useful to pick
26       the background color) or one selected from a range of user-specified
27       colors according to the angle between a line from the light source to
28       the center of the triangle and the normal to the plane of the triangle
29       (which results in a shading of the surface).  After the triangle is
30       filled, line segments representing its boundary and/or its intersection
31       with planes of constant U, V, and/or W may be drawn in a user-specified
32       contrasting color.
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34       The arguments of TDDTRI are as follows:
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36       RTRI    (an input array, of type REAL, dimensioned 10 x MTRI) - a list
37               of triangles, probably created by means of calls to TDSTRI,
38               TDITRI, and/or TDMTRI, and sorted, probably by means of a call
39               to TDOTRI.
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41               If you put triangles in the triangle list directly, keep in
42               mind the following: For each value of i from 1 to NTRI,
43               RTRI(1,i), RTRI(2,i), and RTRI(3,i) are the U, V, and W
44               coordinates of the first vertex of the triangle, RTRI(4,i),
45               RTRI(5,i), and RTRI(6,i) are the U, V, and W coordinates of the
46               second vertex of the triangle, RTRI(7,i), RTRI(8,i), and
47               RTRI(9,i) are the U, V, and W coordinates of the third vertex
48               of the triangle, and RTRI(10,i)=REAL(irst), where irst is the
49               index of the desired rendering style array for the triangle.
50               The order of the vertices is meaningful: they must be given in
51               counter-clockwise order as viewed from the "top". It is better
52               if all of the triangles in a triangle list are about the same
53               size.
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55       MTRI    (an input expression of type INTEGER) - the second dimension of
56               RTRI and thus the maximum number of triangles the triangle list
57               will hold.
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59       NTRI    (an input expression of type INTEGER) - specifies the number of
60               triangles currently in the list.
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62       ITWK    (an input array, of type INTEGER, dimensioned at least NTRI) -
63               contains a permutation of the integers from 1 to NTRI (probably
64               generated by calling the routine TDOTRI).
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C-BINDING DESCRIPTION

67       The C-binding argument descriptions are the same as the FORTRAN
68       argument descriptions.
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ACCESS

71       To use TDDTRI or c_tddtri, load the NCAR Graphics libraries ncarg,
72       ncarg_gks, and ncarg_c, preferably in that order.
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SEE ALSO

75       Online: tdclrs, tdctri, tdgeti, tdgetr, tdgrds, tdgrid, tdgtrs, tdinit,
76       tditri, tdlbla, tdlbls, tdline, tdlnpa, tdmtri, tdotri, tdpack,
77       tdpack_params, tdpara, tdplch, tdprpa, tdprpi, tdprpt, tdseti, tdsetr,
78       tdsort, tdstri, tdstrs
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81       Copyright (C) 1987-2009
82       University Corporation for Atmospheric Research
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84       The use of this Software is governed by a License Agreement.
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88UNIX                               July 1997                    TDDTRI(3NCARG)
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