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root/radiance/ray/src/common/xf.c
Revision: 1.8
Committed: Tue Feb 20 18:02:30 1990 UTC (34 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.7: +13 -7 lines
Log Message:
moved array and index back before transformation

File Contents

# Content
1 /* Copyright (c) 1986 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * xf.c - routines to convert transform arguments into 4X4 matrix.
9 *
10 * 1/28/86
11 */
12
13
14 #define PI 3.14159265358979323846
15 #define d2r(a) ((PI/180.)*(a))
16
17 #define checkarg(a,n) if (av[i][a] || i+n >= ac) goto done
18
19
20 int
21 xf(retmat, retsca, ac, av) /* get transform specification */
22 double retmat[4][4];
23 double *retsca;
24 int ac;
25 char *av[];
26 {
27 double atof(), sin(), cos();
28 double xfmat[4][4], m4[4][4];
29 double xfsca, dtmp;
30 int i, icnt;
31
32 setident4(retmat);
33 *retsca = 1.0;
34
35 icnt = 1;
36 setident4(xfmat);
37 xfsca = 1.0;
38
39 for (i = 0; i < ac && av[i][0] == '-'; i++) {
40
41 setident4(m4);
42
43 switch (av[i][1]) {
44
45 case 't': /* translate */
46 checkarg(2,3);
47 m4[3][0] = atof(av[++i]);
48 m4[3][1] = atof(av[++i]);
49 m4[3][2] = atof(av[++i]);
50 break;
51
52 case 'r': /* rotate */
53 switch (av[i][2]) {
54 case 'x':
55 checkarg(3,1);
56 dtmp = d2r(atof(av[++i]));
57 m4[1][1] = m4[2][2] = cos(dtmp);
58 m4[2][1] = -(m4[1][2] = sin(dtmp));
59 break;
60 case 'y':
61 checkarg(3,1);
62 dtmp = d2r(atof(av[++i]));
63 m4[0][0] = m4[2][2] = cos(dtmp);
64 m4[0][2] = -(m4[2][0] = sin(dtmp));
65 break;
66 case 'z':
67 checkarg(3,1);
68 dtmp = d2r(atof(av[++i]));
69 m4[0][0] = m4[1][1] = cos(dtmp);
70 m4[1][0] = -(m4[0][1] = sin(dtmp));
71 break;
72 default:
73 return(i);
74 }
75 break;
76
77 case 's': /* scale */
78 checkarg(2,1);
79 dtmp = atof(av[i+1]);
80 if (dtmp == 0.0) goto done;
81 i++;
82 xfsca *=
83 m4[0][0] =
84 m4[1][1] =
85 m4[2][2] = dtmp;
86 break;
87
88 case 'm': /* mirror */
89 switch (av[i][2]) {
90 case 'x':
91 checkarg(3,0);
92 xfsca *=
93 m4[0][0] = -1.0;
94 break;
95 case 'y':
96 checkarg(3,0);
97 xfsca *=
98 m4[1][1] = -1.0;
99 break;
100 case 'z':
101 checkarg(3,0);
102 xfsca *=
103 m4[2][2] = -1.0;
104 break;
105 default:
106 return(i);
107 }
108 break;
109
110 case 'i': /* iterate */
111 checkarg(2,1);
112 while (icnt-- > 0) {
113 multmat4(retmat, retmat, xfmat);
114 *retsca *= xfsca;
115 }
116 icnt = atoi(av[++i]);
117 setident4(xfmat);
118 xfsca = 1.0;
119 continue;
120
121 default:
122 return(i);
123
124 }
125 multmat4(xfmat, xfmat, m4);
126 }
127 done:
128 while (icnt-- > 0) {
129 multmat4(retmat, retmat, xfmat);
130 *retsca *= xfsca;
131 }
132 return(i);
133 }
134
135
136 #ifdef INVXF
137 int
138 invxf(retmat, retsca, ac, av) /* invert transform specification */
139 double retmat[4][4];
140 double *retsca;
141 int ac;
142 char *av[];
143 {
144 double atof(), sin(), cos();
145 double xfmat[4][4], m4[4][4];
146 double xfsca, dtmp;
147 int i, icnt;
148
149 setident4(retmat);
150 *retsca = 1.0;
151
152 icnt = 1;
153 setident4(xfmat);
154 xfsca = 1.0;
155
156 for (i = 0; i < ac && av[i][0] == '-'; i++) {
157
158 setident4(m4);
159
160 switch (av[i][1]) {
161
162 case 't': /* translate */
163 checkarg(2,3);
164 m4[3][0] = -atof(av[++i]);
165 m4[3][1] = -atof(av[++i]);
166 m4[3][2] = -atof(av[++i]);
167 break;
168
169 case 'r': /* rotate */
170 switch (av[i][2]) {
171 case 'x':
172 checkarg(3,1);
173 dtmp = -d2r(atof(av[++i]));
174 m4[1][1] = m4[2][2] = cos(dtmp);
175 m4[2][1] = -(m4[1][2] = sin(dtmp));
176 break;
177 case 'y':
178 checkarg(3,1);
179 dtmp = -d2r(atof(av[++i]));
180 m4[0][0] = m4[2][2] = cos(dtmp);
181 m4[0][2] = -(m4[2][0] = sin(dtmp));
182 break;
183 case 'z':
184 checkarg(3,1);
185 dtmp = -d2r(atof(av[++i]));
186 m4[0][0] = m4[1][1] = cos(dtmp);
187 m4[1][0] = -(m4[0][1] = sin(dtmp));
188 break;
189 default:
190 return(i);
191 }
192 break;
193
194 case 's': /* scale */
195 checkarg(2,1);
196 dtmp = atof(av[i+1]);
197 if (dtmp == 0.0) goto done;
198 i++;
199 xfsca *=
200 m4[0][0] =
201 m4[1][1] =
202 m4[2][2] = 1.0 / dtmp;
203 break;
204
205 case 'm': /* mirror */
206 switch (av[i][2]) {
207 case 'x':
208 checkarg(3,0);
209 xfsca *=
210 m4[0][0] = -1.0;
211 break;
212 case 'y':
213 checkarg(3,0);
214 xfsca *=
215 m4[1][1] = -1.0;
216 break;
217 case 'z':
218 checkarg(3,0);
219 xfsca *=
220 m4[2][2] = -1.0;
221 break;
222 default:
223 return(i);
224 }
225 break;
226
227 case 'i': /* iterate */
228 checkarg(2,1);
229 while (icnt-- > 0) {
230 multmat4(retmat, xfmat, retmat);
231 *retsca *= xfsca;
232 }
233 icnt = atoi(av[++i]);
234 setident4(xfmat);
235 xfsca = 1.0;
236 break;
237
238 default:
239 return(i);
240
241 }
242 multmat4(xfmat, m4, xfmat); /* left multiply */
243 }
244 done:
245 while (icnt-- > 0) {
246 multmat4(retmat, xfmat, retmat);
247 *retsca *= xfsca;
248 }
249 return(i);
250 }
251 #endif