1 |
greg |
1.2 |
/* Copyright (c) 1989 Regents of the University of California */ |
2 |
greg |
1.1 |
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3 |
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#ifndef lint |
4 |
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static char SCCSid[] = "$SunId$ LBL"; |
5 |
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#endif |
6 |
greg |
1.2 |
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7 |
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/* |
8 |
greg |
1.1 |
* gensurf.c - program to generate functional surfaces |
9 |
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* |
10 |
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* Parametric functions x(s,t), y(s,t) and z(s,t) |
11 |
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* specify the surface, which is tesselated into an m by n |
12 |
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* array of paired triangles. |
13 |
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* The surface normal is defined by the right hand |
14 |
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* rule applied to (s,t). |
15 |
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* |
16 |
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* 4/3/87 |
17 |
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*/ |
18 |
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19 |
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#include <stdio.h> |
20 |
greg |
1.3 |
#include "fvect.h" |
21 |
greg |
1.1 |
|
22 |
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#define XNAME "X_" /* x function name */ |
23 |
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#define YNAME "Y_" /* y function name */ |
24 |
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#define ZNAME "Z_" /* z function name */ |
25 |
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26 |
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#define PI 3.14159265358979323846 |
27 |
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28 |
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#define FTINY 1e-7 |
29 |
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30 |
greg |
1.4 |
#define ABS(x) ((x)>=0 ? (x) : -(x)) |
31 |
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32 |
greg |
1.3 |
#define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2]) |
33 |
greg |
1.1 |
|
34 |
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char vformat[] = "%15.9g %15.9g %15.9g\n"; |
35 |
greg |
1.3 |
char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n"; |
36 |
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char texname[] = "Phong"; |
37 |
greg |
1.1 |
|
38 |
greg |
1.3 |
int smooth = 0; /* apply smoothing? */ |
39 |
greg |
1.1 |
|
40 |
greg |
1.3 |
char *modname, *surfname; |
41 |
greg |
1.1 |
|
42 |
greg |
1.4 |
double funvalue(), l_hermite(), argument(); |
43 |
greg |
1.3 |
|
44 |
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typedef struct { |
45 |
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FVECT p; /* vertex position */ |
46 |
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FVECT n; /* average normal */ |
47 |
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} POINT; |
48 |
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49 |
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50 |
greg |
1.1 |
main(argc, argv) |
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int argc; |
52 |
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char *argv[]; |
53 |
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{ |
54 |
greg |
1.3 |
POINT *row0, *row1, *row2, *rp; |
55 |
greg |
1.1 |
int i, j, m, n; |
56 |
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char stmp[256]; |
57 |
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58 |
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varset("PI", PI); |
59 |
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funset("hermite", 5, l_hermite); |
60 |
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61 |
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if (argc < 8) |
62 |
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goto userror; |
63 |
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64 |
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for (i = 8; i < argc; i++) |
65 |
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if (!strcmp(argv[i], "-e")) |
66 |
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scompile(NULL, argv[++i]); |
67 |
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else if (!strcmp(argv[i], "-f")) |
68 |
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fcompile(argv[++i]); |
69 |
greg |
1.3 |
else if (!strcmp(argv[i], "-s")) |
70 |
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smooth++; |
71 |
greg |
1.1 |
else |
72 |
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goto userror; |
73 |
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74 |
greg |
1.3 |
modname = argv[1]; |
75 |
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surfname = argv[2]; |
76 |
greg |
1.1 |
sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]); |
77 |
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scompile(NULL, stmp); |
78 |
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sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]); |
79 |
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scompile(NULL, stmp); |
80 |
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sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]); |
81 |
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scompile(NULL, stmp); |
82 |
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m = atoi(argv[6]); |
83 |
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n = atoi(argv[7]); |
84 |
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if (m <= 0 || n <= 0) |
85 |
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goto userror; |
86 |
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87 |
greg |
1.4 |
row0 = (POINT *)malloc((n+3)*sizeof(POINT)); |
88 |
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row1 = (POINT *)malloc((n+3)*sizeof(POINT)); |
89 |
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row2 = (POINT *)malloc((n+3)*sizeof(POINT)); |
90 |
greg |
1.3 |
if (row0 == NULL || row1 == NULL || row2 == NULL) { |
91 |
greg |
1.1 |
fprintf(stderr, "%s: out of memory\n", argv[0]); |
92 |
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quit(1); |
93 |
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} |
94 |
greg |
1.4 |
row0++; row1++; row2++; |
95 |
greg |
1.3 |
/* print header */ |
96 |
greg |
1.1 |
printhead(argc, argv); |
97 |
greg |
1.4 |
/* initialize */ |
98 |
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comprow(-1.0/m, row0, n); |
99 |
greg |
1.3 |
comprow(0.0, row1, n); |
100 |
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comprow(1.0/m, row2, n); |
101 |
greg |
1.4 |
compnorms(row0, row1, row2, n); |
102 |
greg |
1.3 |
/* for each row */ |
103 |
greg |
1.1 |
for (i = 0; i < m; i++) { |
104 |
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/* compute next row */ |
105 |
greg |
1.3 |
rp = row0; |
106 |
greg |
1.1 |
row0 = row1; |
107 |
greg |
1.3 |
row1 = row2; |
108 |
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row2 = rp; |
109 |
greg |
1.4 |
comprow((double)(i+2)/m, row2, n); |
110 |
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compnorms(row0, row1, row2, n); |
111 |
greg |
1.1 |
|
112 |
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for (j = 0; j < n; j++) { |
113 |
greg |
1.3 |
/* put polygons */ |
114 |
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if ((i+j) & 1) |
115 |
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putsquare(&row0[j], &row1[j], |
116 |
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&row0[j+1], &row1[j+1]); |
117 |
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else |
118 |
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putsquare(&row1[j], &row1[j+1], |
119 |
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&row0[j], &row0[j+1]); |
120 |
greg |
1.1 |
} |
121 |
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} |
122 |
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123 |
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quit(0); |
124 |
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125 |
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userror: |
126 |
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fprintf(stderr, "Usage: %s material name ", argv[0]); |
127 |
greg |
1.3 |
fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n"); |
128 |
greg |
1.1 |
quit(1); |
129 |
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} |
130 |
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131 |
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132 |
greg |
1.3 |
putsquare(p0, p1, p2, p3) /* put out a square */ |
133 |
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POINT *p0, *p1, *p2, *p3; |
134 |
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{ |
135 |
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static int nout = 0; |
136 |
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FVECT norm[4]; |
137 |
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int axis; |
138 |
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FVECT v1, v2, vc1, vc2; |
139 |
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int ok1, ok2; |
140 |
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/* compute exact normals */ |
141 |
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fvsum(v1, p1->p, p0->p, -1.0); |
142 |
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fvsum(v2, p2->p, p0->p, -1.0); |
143 |
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fcross(vc1, v1, v2); |
144 |
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ok1 = normalize(vc1) != 0.0; |
145 |
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fvsum(v1, p2->p, p3->p, -1.0); |
146 |
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fvsum(v2, p1->p, p3->p, -1.0); |
147 |
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fcross(vc2, v1, v2); |
148 |
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ok2 = normalize(vc2) != 0.0; |
149 |
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if (!(ok1 | ok2)) |
150 |
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return; |
151 |
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/* compute normal interpolation */ |
152 |
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axis = norminterp(norm, p0, p1, p2, p3); |
153 |
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154 |
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/* put out quadrilateral? */ |
155 |
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if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) { |
156 |
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printf("\n%s ", modname); |
157 |
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if (axis != -1) { |
158 |
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printf("texfunc %s\n", texname); |
159 |
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printf(tsargs); |
160 |
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printf("0\n13\t%d\n", axis); |
161 |
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pvect(norm[0]); |
162 |
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pvect(norm[1]); |
163 |
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pvect(norm[2]); |
164 |
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fvsum(v1, norm[3], vc1, -0.5); |
165 |
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fvsum(v1, v1, vc2, -0.5); |
166 |
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pvect(v1); |
167 |
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printf("\n%s ", texname); |
168 |
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} |
169 |
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printf("polygon %s.%d\n", surfname, ++nout); |
170 |
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printf("0\n0\n12\n"); |
171 |
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pvect(p0->p); |
172 |
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pvect(p1->p); |
173 |
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pvect(p3->p); |
174 |
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pvect(p2->p); |
175 |
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return; |
176 |
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} |
177 |
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/* put out triangles? */ |
178 |
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if (ok1) { |
179 |
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printf("\n%s ", modname); |
180 |
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if (axis != -1) { |
181 |
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printf("texfunc %s\n", texname); |
182 |
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printf(tsargs); |
183 |
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printf("0\n13\t%d\n", axis); |
184 |
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pvect(norm[0]); |
185 |
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pvect(norm[1]); |
186 |
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pvect(norm[2]); |
187 |
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fvsum(v1, norm[3], vc1, -1.0); |
188 |
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pvect(v1); |
189 |
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printf("\n%s ", texname); |
190 |
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} |
191 |
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printf("polygon %s.%d\n", surfname, ++nout); |
192 |
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printf("0\n0\n9\n"); |
193 |
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pvect(p0->p); |
194 |
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pvect(p1->p); |
195 |
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pvect(p2->p); |
196 |
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} |
197 |
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if (ok2) { |
198 |
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printf("\n%s ", modname); |
199 |
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if (axis != -1) { |
200 |
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printf("texfunc %s\n", texname); |
201 |
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printf(tsargs); |
202 |
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printf("0\n13\t%d\n", axis); |
203 |
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pvect(norm[0]); |
204 |
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pvect(norm[1]); |
205 |
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pvect(norm[2]); |
206 |
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fvsum(v2, norm[3], vc2, -1.0); |
207 |
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pvect(v2); |
208 |
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printf("\n%s ", texname); |
209 |
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} |
210 |
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printf("polygon %s.%d\n", surfname, ++nout); |
211 |
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printf("0\n0\n9\n"); |
212 |
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pvect(p2->p); |
213 |
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pvect(p1->p); |
214 |
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pvect(p3->p); |
215 |
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} |
216 |
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} |
217 |
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218 |
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219 |
greg |
1.1 |
comprow(s, row, siz) /* compute row of values */ |
220 |
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double s; |
221 |
greg |
1.3 |
register POINT *row; |
222 |
greg |
1.1 |
int siz; |
223 |
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{ |
224 |
greg |
1.4 |
double st[2]; |
225 |
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register int i; |
226 |
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/* compute one past each end */ |
227 |
greg |
1.1 |
st[0] = s; |
228 |
greg |
1.4 |
for (i = -1; i <= siz+1; i++) { |
229 |
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st[1] = (double)i/siz; |
230 |
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row[i].p[0] = funvalue(XNAME, 2, st); |
231 |
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row[i].p[1] = funvalue(YNAME, 2, st); |
232 |
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row[i].p[2] = funvalue(ZNAME, 2, st); |
233 |
greg |
1.1 |
} |
234 |
greg |
1.3 |
} |
235 |
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236 |
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237 |
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compnorms(r0, r1, r2, siz) /* compute row of averaged normals */ |
238 |
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register POINT *r0, *r1, *r2; |
239 |
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int siz; |
240 |
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{ |
241 |
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FVECT v1, v2, vc; |
242 |
greg |
1.4 |
register int i; |
243 |
greg |
1.3 |
|
244 |
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if (!smooth) /* not needed if no smoothing */ |
245 |
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return; |
246 |
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/* compute middle points */ |
247 |
greg |
1.4 |
while (siz-- >= 0) { |
248 |
greg |
1.3 |
fvsum(v1, r2[0].p, r1[0].p, -1.0); |
249 |
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fvsum(v2, r1[1].p, r1[0].p, -1.0); |
250 |
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fcross(r1[0].n, v1, v2); |
251 |
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fvsum(v1, r0[0].p, r1[0].p, -1.0); |
252 |
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fcross(vc, v2, v1); |
253 |
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fvsum(r1[0].n, r1[0].n, vc, 1.0); |
254 |
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fvsum(v2, r1[-1].p, r1[0].p, -1.0); |
255 |
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fcross(vc, v1, v2); |
256 |
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fvsum(r1[0].n, r1[0].n, vc, 1.0); |
257 |
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fvsum(v1, r2[0].p, r1[0].p, -1.0); |
258 |
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fcross(vc, v2, v1); |
259 |
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fvsum(r1[0].n, r1[0].n, vc, 1.0); |
260 |
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normalize(r1[0].n); |
261 |
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r0++; r1++; r2++; |
262 |
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} |
263 |
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} |
264 |
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265 |
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266 |
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int |
267 |
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norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */ |
268 |
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register FVECT resmat[4]; |
269 |
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POINT *p0, *p1, *p2, *p3; |
270 |
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{ |
271 |
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#define u ((ax+1)%3) |
272 |
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#define v ((ax+2)%3) |
273 |
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274 |
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register int ax; |
275 |
greg |
1.4 |
double eqnmat[4][4]; |
276 |
greg |
1.3 |
FVECT v1; |
277 |
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register int i, j; |
278 |
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279 |
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if (!smooth) /* no interpolation if no smoothing */ |
280 |
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return(-1); |
281 |
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/* find dominant axis */ |
282 |
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VCOPY(v1, p0->n); |
283 |
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fvsum(v1, v1, p1->n, 1.0); |
284 |
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fvsum(v1, v1, p2->n, 1.0); |
285 |
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fvsum(v1, v1, p3->n, 1.0); |
286 |
greg |
1.4 |
ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1; |
287 |
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ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2; |
288 |
greg |
1.3 |
/* assign equation matrix */ |
289 |
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eqnmat[0][0] = p0->p[u]*p0->p[v]; |
290 |
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eqnmat[0][1] = p0->p[u]; |
291 |
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eqnmat[0][2] = p0->p[v]; |
292 |
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eqnmat[0][3] = 1.0; |
293 |
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eqnmat[1][0] = p1->p[u]*p1->p[v]; |
294 |
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eqnmat[1][1] = p1->p[u]; |
295 |
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eqnmat[1][2] = p1->p[v]; |
296 |
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eqnmat[1][3] = 1.0; |
297 |
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eqnmat[2][0] = p2->p[u]*p2->p[v]; |
298 |
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eqnmat[2][1] = p2->p[u]; |
299 |
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eqnmat[2][2] = p2->p[v]; |
300 |
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eqnmat[2][3] = 1.0; |
301 |
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eqnmat[3][0] = p3->p[u]*p3->p[v]; |
302 |
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eqnmat[3][1] = p3->p[u]; |
303 |
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eqnmat[3][2] = p3->p[v]; |
304 |
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eqnmat[3][3] = 1.0; |
305 |
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/* invert matrix (solve system) */ |
306 |
greg |
1.4 |
if (!invmat(eqnmat, eqnmat)) |
307 |
greg |
1.3 |
return(-1); /* no solution */ |
308 |
|
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/* compute result matrix */ |
309 |
|
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for (j = 0; j < 4; j++) |
310 |
|
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for (i = 0; i < 3; i++) |
311 |
greg |
1.4 |
resmat[j][i] = eqnmat[j][0]*p0->n[i] + |
312 |
|
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eqnmat[j][1]*p1->n[i] + |
313 |
|
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eqnmat[j][2]*p2->n[i] + |
314 |
|
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eqnmat[j][3]*p3->n[i]; |
315 |
greg |
1.3 |
return(ax); |
316 |
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317 |
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#undef u |
318 |
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#undef v |
319 |
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} |
320 |
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321 |
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|
322 |
|
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/* |
323 |
|
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* invmat - computes the inverse of mat into inverse. Returns 1 |
324 |
|
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* if there exists an inverse, 0 otherwise. It uses Gaussian Elimination |
325 |
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* method. |
326 |
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*/ |
327 |
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328 |
|
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invmat(inverse,mat) |
329 |
|
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double mat[4][4],inverse[4][4]; |
330 |
|
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{ |
331 |
|
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#define SWAP(a,b,t) (t=a,a=b,b=t) |
332 |
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|
333 |
greg |
1.4 |
double m4tmp[4][4]; |
334 |
greg |
1.3 |
register int i,j,k; |
335 |
|
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register double temp; |
336 |
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|
337 |
greg |
1.4 |
bcopy(mat, m4tmp, sizeof(m4tmp)); |
338 |
|
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/* set inverse to identity */ |
339 |
|
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for (i = 0; i < 4; i++) |
340 |
|
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for (j = 0; j < 4; j++) |
341 |
|
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inverse[i][j] = i==j ? 1.0 : 0.0; |
342 |
greg |
1.3 |
|
343 |
|
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for(i = 0; i < 4; i++) { |
344 |
greg |
1.4 |
/* Look for raw with largest pivot and swap raws */ |
345 |
|
|
temp = FTINY; j = -1; |
346 |
|
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for(k = i; k < 4; k++) |
347 |
|
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if(ABS(m4tmp[k][i]) > temp) { |
348 |
|
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temp = ABS(m4tmp[k][i]); |
349 |
|
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j = k; |
350 |
|
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} |
351 |
|
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if(j == -1) /* No replacing raw -> no inverse */ |
352 |
|
|
return(0); |
353 |
|
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if (j != i) |
354 |
|
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for(k = 0; k < 4; k++) { |
355 |
|
|
SWAP(m4tmp[i][k],m4tmp[j][k],temp); |
356 |
|
|
SWAP(inverse[i][k],inverse[j][k],temp); |
357 |
|
|
} |
358 |
greg |
1.3 |
|
359 |
|
|
temp = m4tmp[i][i]; |
360 |
|
|
for(k = 0; k < 4; k++) { |
361 |
|
|
m4tmp[i][k] /= temp; |
362 |
|
|
inverse[i][k] /= temp; |
363 |
|
|
} |
364 |
|
|
for(j = 0; j < 4; j++) { |
365 |
|
|
if(j != i) { |
366 |
|
|
temp = m4tmp[j][i]; |
367 |
|
|
for(k = 0; k < 4; k++) { |
368 |
|
|
m4tmp[j][k] -= m4tmp[i][k]*temp; |
369 |
|
|
inverse[j][k] -= inverse[i][k]*temp; |
370 |
|
|
} |
371 |
|
|
} |
372 |
|
|
} |
373 |
|
|
} |
374 |
|
|
return(1); |
375 |
greg |
1.4 |
|
376 |
greg |
1.3 |
#undef SWAP |
377 |
greg |
1.1 |
} |
378 |
|
|
|
379 |
|
|
|
380 |
|
|
eputs(msg) |
381 |
|
|
char *msg; |
382 |
|
|
{ |
383 |
|
|
fputs(msg, stderr); |
384 |
|
|
} |
385 |
|
|
|
386 |
|
|
|
387 |
|
|
wputs(msg) |
388 |
|
|
char *msg; |
389 |
|
|
{ |
390 |
|
|
eputs(msg); |
391 |
|
|
} |
392 |
|
|
|
393 |
|
|
|
394 |
|
|
quit(code) |
395 |
|
|
{ |
396 |
|
|
exit(code); |
397 |
|
|
} |
398 |
|
|
|
399 |
|
|
|
400 |
|
|
printhead(ac, av) /* print command header */ |
401 |
|
|
register int ac; |
402 |
|
|
register char **av; |
403 |
|
|
{ |
404 |
|
|
putchar('#'); |
405 |
|
|
while (ac--) { |
406 |
|
|
putchar(' '); |
407 |
|
|
fputs(*av++, stdout); |
408 |
|
|
} |
409 |
|
|
putchar('\n'); |
410 |
|
|
} |
411 |
|
|
|
412 |
|
|
|
413 |
|
|
double |
414 |
|
|
l_hermite() |
415 |
|
|
{ |
416 |
|
|
double t; |
417 |
|
|
|
418 |
|
|
t = argument(5); |
419 |
|
|
return( argument(1)*((2.0*t-3.0)*t*t+1.0) + |
420 |
|
|
argument(2)*(-2.0*t+3.0)*t*t + |
421 |
|
|
argument(3)*((t-2.0)*t+1.0)*t + |
422 |
|
|
argument(4)*(t-1.0)*t*t ); |
423 |
|
|
} |