1 |
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/* |
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/* Copyright (c) 1989 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* gensurf.c - program to generate functional surfaces |
9 |
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* |
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* Parametric functions x(s,t), y(s,t) and z(s,t) |
17 |
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*/ |
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#include <stdio.h> |
20 |
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#include "fvect.h" |
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#define XNAME "X_" /* x function name */ |
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#define YNAME "Y_" /* y function name */ |
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|
28 |
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#define FTINY 1e-7 |
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|
30 |
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#define vertex(p) printf(vformat, (p)[0], (p)[1], (p)[2]) |
30 |
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#define ABS(x) ((x)>=0 ? (x) : -(x)) |
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|
32 |
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#define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2]) |
33 |
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|
34 |
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char vformat[] = "%15.9g %15.9g %15.9g\n"; |
35 |
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char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n"; |
36 |
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char texname[] = "Phong"; |
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|
38 |
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double funvalue(), dist2(), fdot(), l_hermite(), argument(); |
38 |
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int smooth = 0; /* apply smoothing? */ |
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40 |
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char *modname, *surfname; |
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double funvalue(), l_hermite(), argument(); |
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|
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typedef struct { |
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FVECT p; /* vertex position */ |
46 |
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FVECT n; /* average normal */ |
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} POINT; |
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|
49 |
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|
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main(argc, argv) |
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int argc; |
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char *argv[]; |
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{ |
54 |
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static double *xyz[4]; |
39 |
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double *row0, *row1, *dp; |
40 |
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double v1[3], v2[3], vc1[3], vc2[3]; |
41 |
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double a1, a2; |
54 |
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POINT *row0, *row1, *row2, *rp; |
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int i, j, m, n; |
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char stmp[256]; |
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double d; |
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register int k; |
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|
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varset("PI", PI); |
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funset("hermite", 5, l_hermite); |
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scompile(NULL, argv[++i]); |
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else if (!strcmp(argv[i], "-f")) |
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fcompile(argv[++i]); |
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else if (!strcmp(argv[i], "-s")) |
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smooth++; |
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else |
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goto userror; |
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|
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modname = argv[1]; |
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surfname = argv[2]; |
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sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]); |
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scompile(NULL, stmp); |
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sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]); |
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if (m <= 0 || n <= 0) |
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goto userror; |
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|
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row0 = (double *)malloc((n+1)*3*sizeof(double)); |
88 |
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row1 = (double *)malloc((n+1)*3*sizeof(double)); |
89 |
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if (row0 == NULL || row1 == NULL) { |
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row0 = (POINT *)malloc((n+3)*sizeof(POINT)); |
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row1 = (POINT *)malloc((n+3)*sizeof(POINT)); |
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row2 = (POINT *)malloc((n+3)*sizeof(POINT)); |
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if (row0 == NULL || row1 == NULL || row2 == NULL) { |
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fprintf(stderr, "%s: out of memory\n", argv[0]); |
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quit(1); |
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} |
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row0++; row1++; row2++; |
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/* print header */ |
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printhead(argc, argv); |
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|
98 |
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comprow(0.0, row1, n); /* compute zeroeth row */ |
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|
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/* initialize */ |
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comprow(-1.0/m, row0, n); |
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comprow(0.0, row1, n); |
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comprow(1.0/m, row2, n); |
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compnorms(row0, row1, row2, n); |
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/* for each row */ |
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for (i = 0; i < m; i++) { |
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/* compute next row */ |
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dp = row0; |
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rp = row0; |
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row0 = row1; |
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row1 = dp; |
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comprow((double)(i+1)/m, row1, n); |
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row1 = row2; |
108 |
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row2 = rp; |
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comprow((double)(i+2)/m, row2, n); |
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compnorms(row0, row1, row2, n); |
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|
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for (j = 0; j < n; j++) { |
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/* get vertices */ |
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xyz[0] = row0 + 3*j; |
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xyz[1] = row1 + 3*j; |
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xyz[2] = xyz[0] + 3; |
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xyz[3] = xyz[1] + 3; |
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/* rotate vertices */ |
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if (dist2(xyz[0],xyz[3]) < dist2(xyz[1],xyz[2])-FTINY) { |
98 |
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dp = xyz[0]; |
99 |
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xyz[0] = xyz[1]; |
100 |
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xyz[1] = xyz[3]; |
101 |
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xyz[3] = xyz[2]; |
102 |
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xyz[2] = dp; |
103 |
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} |
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/* get normals */ |
105 |
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for (k = 0; k < 3; k++) { |
106 |
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v1[k] = xyz[1][k] - xyz[0][k]; |
107 |
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v2[k] = xyz[2][k] - xyz[0][k]; |
108 |
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} |
109 |
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fcross(vc1, v1, v2); |
110 |
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a1 = fdot(vc1, vc1); |
111 |
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for (k = 0; k < 3; k++) { |
112 |
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v1[k] = xyz[2][k] - xyz[3][k]; |
113 |
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v2[k] = xyz[1][k] - xyz[3][k]; |
114 |
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} |
115 |
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fcross(vc2, v1, v2); |
116 |
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a2 = fdot(vc2, vc2); |
117 |
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/* check coplanar */ |
118 |
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if (a1 > FTINY*FTINY && a2 > FTINY*FTINY) { |
119 |
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d = fdot(vc1, vc2); |
120 |
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if (d*d/a1/a2 >= 1.0-FTINY*FTINY) { |
121 |
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if (d > 0.0) { /* coplanar */ |
122 |
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printf( |
123 |
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"\n%s polygon %s.%d.%d\n", |
124 |
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argv[1], argv[2], i+1, j+1); |
125 |
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printf("0\n0\n12\n"); |
126 |
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vertex(xyz[0]); |
127 |
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vertex(xyz[1]); |
128 |
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vertex(xyz[3]); |
129 |
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vertex(xyz[2]); |
130 |
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} /* else overlapped */ |
131 |
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continue; |
132 |
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} /* else bent */ |
133 |
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} |
134 |
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/* check triangles */ |
135 |
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if (a1 > FTINY*FTINY) { |
136 |
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printf("\n%s polygon %s.%da%d\n", |
137 |
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argv[1], argv[2], i+1, j+1); |
138 |
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printf("0\n0\n9\n"); |
139 |
< |
vertex(xyz[0]); |
140 |
< |
vertex(xyz[1]); |
141 |
< |
vertex(xyz[2]); |
142 |
< |
} |
143 |
< |
if (a2 > FTINY*FTINY) { |
144 |
< |
printf("\n%s polygon %s.%db%d\n", |
145 |
< |
argv[1], argv[2], i+1, j+1); |
146 |
< |
printf("0\n0\n9\n"); |
147 |
< |
vertex(xyz[2]); |
148 |
< |
vertex(xyz[1]); |
149 |
< |
vertex(xyz[3]); |
150 |
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} |
113 |
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/* put polygons */ |
114 |
> |
if ((i+j) & 1) |
115 |
> |
putsquare(&row0[j], &row1[j], |
116 |
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&row0[j+1], &row1[j+1]); |
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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 |
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} |
121 |
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} |
122 |
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|
124 |
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|
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userror: |
126 |
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fprintf(stderr, "Usage: %s material name ", argv[0]); |
127 |
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fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-e expr] [-f file]\n"); |
127 |
> |
fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n"); |
128 |
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quit(1); |
129 |
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} |
130 |
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|
132 |
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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 |
+ |
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 |
+ |
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 |
+ |
/* compute normal interpolation */ |
152 |
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axis = norminterp(norm, p0, p1, p2, p3); |
153 |
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|
154 |
+ |
/* put out quadrilateral? */ |
155 |
+ |
if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) { |
156 |
+ |
printf("\n%s ", modname); |
157 |
+ |
if (axis != -1) { |
158 |
+ |
printf("texfunc %s\n", texname); |
159 |
+ |
printf(tsargs); |
160 |
+ |
printf("0\n13\t%d\n", axis); |
161 |
+ |
pvect(norm[0]); |
162 |
+ |
pvect(norm[1]); |
163 |
+ |
pvect(norm[2]); |
164 |
+ |
fvsum(v1, norm[3], vc1, -0.5); |
165 |
+ |
fvsum(v1, v1, vc2, -0.5); |
166 |
+ |
pvect(v1); |
167 |
+ |
printf("\n%s ", texname); |
168 |
+ |
} |
169 |
+ |
printf("polygon %s.%d\n", surfname, ++nout); |
170 |
+ |
printf("0\n0\n12\n"); |
171 |
+ |
pvect(p0->p); |
172 |
+ |
pvect(p1->p); |
173 |
+ |
pvect(p3->p); |
174 |
+ |
pvect(p2->p); |
175 |
+ |
return; |
176 |
+ |
} |
177 |
+ |
/* put out triangles? */ |
178 |
+ |
if (ok1) { |
179 |
+ |
printf("\n%s ", modname); |
180 |
+ |
if (axis != -1) { |
181 |
+ |
printf("texfunc %s\n", texname); |
182 |
+ |
printf(tsargs); |
183 |
+ |
printf("0\n13\t%d\n", axis); |
184 |
+ |
pvect(norm[0]); |
185 |
+ |
pvect(norm[1]); |
186 |
+ |
pvect(norm[2]); |
187 |
+ |
fvsum(v1, norm[3], vc1, -1.0); |
188 |
+ |
pvect(v1); |
189 |
+ |
printf("\n%s ", texname); |
190 |
+ |
} |
191 |
+ |
printf("polygon %s.%d\n", surfname, ++nout); |
192 |
+ |
printf("0\n0\n9\n"); |
193 |
+ |
pvect(p0->p); |
194 |
+ |
pvect(p1->p); |
195 |
+ |
pvect(p2->p); |
196 |
+ |
} |
197 |
+ |
if (ok2) { |
198 |
+ |
printf("\n%s ", modname); |
199 |
+ |
if (axis != -1) { |
200 |
+ |
printf("texfunc %s\n", texname); |
201 |
+ |
printf(tsargs); |
202 |
+ |
printf("0\n13\t%d\n", axis); |
203 |
+ |
pvect(norm[0]); |
204 |
+ |
pvect(norm[1]); |
205 |
+ |
pvect(norm[2]); |
206 |
+ |
fvsum(v2, norm[3], vc2, -1.0); |
207 |
+ |
pvect(v2); |
208 |
+ |
printf("\n%s ", texname); |
209 |
+ |
} |
210 |
+ |
printf("polygon %s.%d\n", surfname, ++nout); |
211 |
+ |
printf("0\n0\n9\n"); |
212 |
+ |
pvect(p2->p); |
213 |
+ |
pvect(p1->p); |
214 |
+ |
pvect(p3->p); |
215 |
+ |
} |
216 |
+ |
} |
217 |
+ |
|
218 |
+ |
|
219 |
|
comprow(s, row, siz) /* compute row of values */ |
220 |
|
double s; |
221 |
< |
register double *row; |
221 |
> |
register POINT *row; |
222 |
|
int siz; |
223 |
|
{ |
224 |
< |
double st[2], step; |
225 |
< |
|
224 |
> |
double st[2]; |
225 |
> |
register int i; |
226 |
> |
/* compute one past each end */ |
227 |
|
st[0] = s; |
228 |
< |
st[1] = 0.0; |
229 |
< |
step = 1.0 / siz; |
228 |
> |
for (i = -1; i <= siz+1; i++) { |
229 |
> |
st[1] = (double)i/siz; |
230 |
> |
row[i].p[0] = funvalue(XNAME, 2, st); |
231 |
> |
row[i].p[1] = funvalue(YNAME, 2, st); |
232 |
> |
row[i].p[2] = funvalue(ZNAME, 2, st); |
233 |
> |
} |
234 |
> |
} |
235 |
> |
|
236 |
> |
|
237 |
> |
compnorms(r0, r1, r2, siz) /* compute row of averaged normals */ |
238 |
> |
register POINT *r0, *r1, *r2; |
239 |
> |
int siz; |
240 |
> |
{ |
241 |
> |
FVECT v1, v2, vc; |
242 |
> |
register int i; |
243 |
> |
|
244 |
> |
if (!smooth) /* not needed if no smoothing */ |
245 |
> |
return; |
246 |
> |
/* compute middle points */ |
247 |
|
while (siz-- >= 0) { |
248 |
< |
*row++ = funvalue(XNAME, 2, st); |
249 |
< |
*row++ = funvalue(YNAME, 2, st); |
250 |
< |
*row++ = funvalue(ZNAME, 2, st); |
251 |
< |
st[1] += step; |
248 |
> |
fvsum(v1, r2[0].p, r1[0].p, -1.0); |
249 |
> |
fvsum(v2, r1[1].p, r1[0].p, -1.0); |
250 |
> |
fcross(r1[0].n, v1, v2); |
251 |
> |
fvsum(v1, r0[0].p, r1[0].p, -1.0); |
252 |
> |
fcross(vc, v2, v1); |
253 |
> |
fvsum(r1[0].n, r1[0].n, vc, 1.0); |
254 |
> |
fvsum(v2, r1[-1].p, r1[0].p, -1.0); |
255 |
> |
fcross(vc, v1, v2); |
256 |
> |
fvsum(r1[0].n, r1[0].n, vc, 1.0); |
257 |
> |
fvsum(v1, r2[0].p, r1[0].p, -1.0); |
258 |
> |
fcross(vc, v2, v1); |
259 |
> |
fvsum(r1[0].n, r1[0].n, vc, 1.0); |
260 |
> |
normalize(r1[0].n); |
261 |
> |
r0++; r1++; r2++; |
262 |
|
} |
263 |
+ |
} |
264 |
+ |
|
265 |
+ |
|
266 |
+ |
int |
267 |
+ |
norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */ |
268 |
+ |
register FVECT resmat[4]; |
269 |
+ |
POINT *p0, *p1, *p2, *p3; |
270 |
+ |
{ |
271 |
+ |
#define u ((ax+1)%3) |
272 |
+ |
#define v ((ax+2)%3) |
273 |
+ |
|
274 |
+ |
register int ax; |
275 |
+ |
double eqnmat[4][4]; |
276 |
+ |
FVECT v1; |
277 |
+ |
register int i, j; |
278 |
+ |
|
279 |
+ |
if (!smooth) /* no interpolation if no smoothing */ |
280 |
+ |
return(-1); |
281 |
+ |
/* find dominant axis */ |
282 |
+ |
VCOPY(v1, p0->n); |
283 |
+ |
fvsum(v1, v1, p1->n, 1.0); |
284 |
+ |
fvsum(v1, v1, p2->n, 1.0); |
285 |
+ |
fvsum(v1, v1, p3->n, 1.0); |
286 |
+ |
ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1; |
287 |
+ |
ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2; |
288 |
+ |
/* assign equation matrix */ |
289 |
+ |
eqnmat[0][0] = p0->p[u]*p0->p[v]; |
290 |
+ |
eqnmat[0][1] = p0->p[u]; |
291 |
+ |
eqnmat[0][2] = p0->p[v]; |
292 |
+ |
eqnmat[0][3] = 1.0; |
293 |
+ |
eqnmat[1][0] = p1->p[u]*p1->p[v]; |
294 |
+ |
eqnmat[1][1] = p1->p[u]; |
295 |
+ |
eqnmat[1][2] = p1->p[v]; |
296 |
+ |
eqnmat[1][3] = 1.0; |
297 |
+ |
eqnmat[2][0] = p2->p[u]*p2->p[v]; |
298 |
+ |
eqnmat[2][1] = p2->p[u]; |
299 |
+ |
eqnmat[2][2] = p2->p[v]; |
300 |
+ |
eqnmat[2][3] = 1.0; |
301 |
+ |
eqnmat[3][0] = p3->p[u]*p3->p[v]; |
302 |
+ |
eqnmat[3][1] = p3->p[u]; |
303 |
+ |
eqnmat[3][2] = p3->p[v]; |
304 |
+ |
eqnmat[3][3] = 1.0; |
305 |
+ |
/* invert matrix (solve system) */ |
306 |
+ |
if (!invmat(eqnmat, eqnmat)) |
307 |
+ |
return(-1); /* no solution */ |
308 |
+ |
/* compute result matrix */ |
309 |
+ |
for (j = 0; j < 4; j++) |
310 |
+ |
for (i = 0; i < 3; i++) |
311 |
+ |
resmat[j][i] = eqnmat[j][0]*p0->n[i] + |
312 |
+ |
eqnmat[j][1]*p1->n[i] + |
313 |
+ |
eqnmat[j][2]*p2->n[i] + |
314 |
+ |
eqnmat[j][3]*p3->n[i]; |
315 |
+ |
return(ax); |
316 |
+ |
|
317 |
+ |
#undef u |
318 |
+ |
#undef v |
319 |
+ |
} |
320 |
+ |
|
321 |
+ |
|
322 |
+ |
/* |
323 |
+ |
* invmat - computes the inverse of mat into inverse. Returns 1 |
324 |
+ |
* if there exists an inverse, 0 otherwise. It uses Gaussian Elimination |
325 |
+ |
* method. |
326 |
+ |
*/ |
327 |
+ |
|
328 |
+ |
invmat(inverse,mat) |
329 |
+ |
double mat[4][4],inverse[4][4]; |
330 |
+ |
{ |
331 |
+ |
#define SWAP(a,b,t) (t=a,a=b,b=t) |
332 |
+ |
|
333 |
+ |
double m4tmp[4][4]; |
334 |
+ |
register int i,j,k; |
335 |
+ |
register double temp; |
336 |
+ |
|
337 |
+ |
bcopy(mat, m4tmp, sizeof(m4tmp)); |
338 |
+ |
/* set inverse to identity */ |
339 |
+ |
for (i = 0; i < 4; i++) |
340 |
+ |
for (j = 0; j < 4; j++) |
341 |
+ |
inverse[i][j] = i==j ? 1.0 : 0.0; |
342 |
+ |
|
343 |
+ |
for(i = 0; i < 4; i++) { |
344 |
+ |
/* Look for raw with largest pivot and swap raws */ |
345 |
+ |
temp = FTINY; j = -1; |
346 |
+ |
for(k = i; k < 4; k++) |
347 |
+ |
if(ABS(m4tmp[k][i]) > temp) { |
348 |
+ |
temp = ABS(m4tmp[k][i]); |
349 |
+ |
j = k; |
350 |
+ |
} |
351 |
+ |
if(j == -1) /* No replacing raw -> no inverse */ |
352 |
+ |
return(0); |
353 |
+ |
if (j != i) |
354 |
+ |
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 |
+ |
|
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 |
+ |
|
376 |
+ |
#undef SWAP |
377 |
|
} |
378 |
|
|
379 |
|
|