1TDDTRI(3NCARG) NCAR GRAPHICS TDDTRI(3NCARG)
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6 TDDTRI - Draw the triangles defined by a triangle list.
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9 CALL TDDTRI (RTRI, MTRI, NTRI, ITWK)
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12 #include <ncarg/ncargC.h>
13 void c_tddtri(float *rtri, int mtri, int *ntri, int *itwk)
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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.
20 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.
33 The arguments of TDDTRI are as follows:
35 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.
40 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.
54 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.
58 NTRI (an input expression of type INTEGER) - specifies the number of
60 triangles currently in the list.
61 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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67 The C-binding argument descriptions are the same as the FORTRAN
68 argument descriptions.
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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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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) 1987-2007
82 University Corporation for Atmospheric Research
83 This documentation is free software; you can redistribute it and/or
85 modify it under the terms of the GNU General Public License as
86 published by the Free Software Foundation; either version 2 of the
87 License, or (at your option) any later version.
88 This software is distributed in the hope that it will be useful, but
90 WITHOUT ANY WARRANTY; without even the implied warranty of
91 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
92 General Public License for more details.
93 You should have received a copy of the GNU General Public License along
95 with this software; if not, write to the Free Software Foundation,
96 Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
97UNIX July 1997 TDDTRI(3NCARG)