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root/radiance/ray/src/rt/data.c
Revision: 1.5
Committed: Tue Apr 3 17:48:46 1990 UTC (34 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.4: +16 -4 lines
Log Message:
Added check for pixel aspect ratio in getpict()

File Contents

# User Rev Content
1 greg 1.1 /* Copyright (c) 1986 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * data.c - routines dealing with interpolated data.
9     *
10     * 6/4/86
11     */
12    
13     #include "standard.h"
14    
15     #include "color.h"
16    
17     #include "data.h"
18    
19    
20     extern char *libpath; /* library search path */
21    
22     static DATARRAY *dlist = NULL; /* data array list */
23    
24     static DATARRAY *plist = NULL; /* picture list */
25    
26    
27     DATARRAY *
28     getdata(dname) /* get data array dname */
29     char *dname;
30     {
31     char *dfname;
32     FILE *fp;
33     int asize;
34 greg 1.4 register int i, j;
35 greg 1.1 register DATARRAY *dp;
36     /* look for array in list */
37     for (dp = dlist; dp != NULL; dp = dp->next)
38     if (!strcmp(dname, dp->name))
39     return(dp); /* found! */
40    
41     /*
42     * If we haven't loaded the data already, we will look
43     * for it in the directorys specified by the library path.
44     *
45     * The file has the following format:
46     *
47 greg 1.4 * N
48 greg 1.1 * beg0 end0 n0
49     * beg1 end1 n1
50     * . . .
51 greg 1.4 * begN endN nN
52 greg 1.1 * data, later dimensions changing faster
53     * . . .
54     *
55 greg 1.4 * For irregularly spaced points, the following can be
56     * substituted for begi endi ni:
57     *
58     * @ ni p0i p1i .. pni
59 greg 1.1 */
60    
61 greg 1.2 if ((dfname = getpath(dname, libpath, R_OK)) == NULL) {
62 greg 1.1 sprintf(errmsg, "cannot find data file \"%s\"", dname);
63     error(USER, errmsg);
64     }
65     if ((dp = (DATARRAY *)malloc(sizeof(DATARRAY))) == NULL)
66     goto memerr;
67    
68     dp->name = savestr(dname);
69    
70     if ((fp = fopen(dfname, "r")) == NULL) {
71     sprintf(errmsg, "cannot open data file \"%s\"", dfname);
72     error(SYSTEM, errmsg);
73     }
74     /* get dimensions */
75     if (fscanf(fp, "%d", &dp->nd) != 1)
76     goto scanerr;
77     if (dp->nd <= 0 || dp->nd > MAXDIM) {
78     sprintf(errmsg, "bad number of dimensions for \"%s\"", dname);
79     error(USER, errmsg);
80     }
81     asize = 1;
82     for (i = 0; i < dp->nd; i++) {
83     if (fscanf(fp, "%lf %lf %d",
84     &dp->dim[i].org, &dp->dim[i].siz,
85 greg 1.4 &dp->dim[i].ne) == 3) {
86     dp->dim[i].siz -= dp->dim[i].org;
87     dp->dim[i].p = NULL;
88     } else if (fscanf(fp, "@ %d", &dp->dim[i].ne) == 1) {
89     dp->dim[i].p = (double *)malloc(dp->dim[i].ne*sizeof(double));
90     if (dp->dim[i].p == NULL)
91     goto memerr;
92     for (j = 0; j < dp->dim[i].ne; j++)
93     if (fscanf(fp, "%lf", &dp->dim[i].p[j]) != 1)
94     goto scanerr;
95     for (j = 1; j < dp->dim[i].ne-1; j++)
96     if ((dp->dim[i].p[j-1] < dp->dim[i].p[j]) !=
97     (dp->dim[i].p[j] < dp->dim[i].p[j+1]))
98     goto scanerr;
99     dp->dim[i].org = dp->dim[i].p[0];
100     dp->dim[i].siz = dp->dim[i].p[dp->dim[i].ne-1]
101     - dp->dim[i].p[0];
102     } else
103 greg 1.1 goto scanerr;
104 greg 1.4 if (dp->dim[i].siz == 0.0 || dp->dim[i].ne < 2)
105     goto scanerr;
106 greg 1.1 asize *= dp->dim[i].ne;
107     }
108     if ((dp->arr = (DATATYPE *)malloc(asize*sizeof(DATATYPE))) == NULL)
109     goto memerr;
110    
111     for (i = 0; i < asize; i++)
112     if (fscanf(fp, DSCANF, &dp->arr[i]) != 1)
113     goto scanerr;
114    
115     fclose(fp);
116     dp->next = dlist;
117     return(dlist = dp);
118    
119     memerr:
120     error(SYSTEM, "out of memory in getdata");
121     scanerr:
122     sprintf(errmsg, "%s in data file \"%s\"",
123     feof(fp) ? "unexpected EOF" : "bad format", dfname);
124     error(USER, errmsg);
125     }
126    
127    
128 greg 1.5 static double inpaspect; /* aspect ratio of input picture */
129    
130     static
131     headaspect(s) /* check string for aspect ratio */
132     char *s;
133     {
134     if (isaspect(s))
135     inpaspect *= aspectval(s);
136     }
137    
138    
139 greg 1.1 DATARRAY *
140     getpict(pname) /* get picture pname */
141     char *pname;
142     {
143     extern char *libpath;
144     char *pfname;
145     FILE *fp;
146     COLOR *scanin;
147     int width, height;
148     int x, y;
149     register int i;
150     register DATARRAY *pp;
151     /* look for array in list */
152     for (pp = plist; pp != NULL; pp = pp->next)
153     if (!strcmp(pname, pp->name))
154     return(pp); /* found! */
155    
156 greg 1.2 if ((pfname = getpath(pname, libpath, R_OK)) == NULL) {
157 greg 1.1 sprintf(errmsg, "cannot find picture file \"%s\"", pname);
158     error(USER, errmsg);
159     }
160     if ((pp = (DATARRAY *)calloc(3, sizeof(DATARRAY))) == NULL)
161     goto memerr;
162    
163     pp[0].name =
164     pp[1].name =
165     pp[2].name = savestr(pname);
166    
167     if ((fp = fopen(pfname, "r")) == NULL) {
168     sprintf(errmsg, "cannot open picture file \"%s\"", pfname);
169     error(SYSTEM, errmsg);
170     }
171     /* get dimensions */
172 greg 1.5 inpaspect = 1.0;
173     getheader(fp, headaspect);
174 greg 1.3 if (fgetresolu(&width, &height, fp) != (YMAJOR|YDECR))
175 greg 1.1 goto readerr;
176     for (i = 0; i < 3; i++) {
177     pp[i].nd = 2;
178     pp[i].dim[0].ne = width;
179     pp[i].dim[1].ne = height;
180     pp[i].dim[0].org =
181     pp[i].dim[1].org = 0.0;
182 greg 1.5 if (width <= height*inpaspect) {
183 greg 1.1 pp[i].dim[0].siz = 1.0;
184 greg 1.5 pp[i].dim[1].siz = inpaspect*(double)height/width;
185 greg 1.1 } else {
186 greg 1.5 pp[i].dim[0].siz = (double)width/height/inpaspect;
187 greg 1.1 pp[i].dim[1].siz = 1.0;
188     }
189     pp[i].arr = (DATATYPE *)malloc(width*height*sizeof(DATATYPE));
190     if (pp[i].arr == NULL)
191     goto memerr;
192     }
193     /* load picture */
194     if ((scanin = (COLOR *)malloc(width*sizeof(COLOR))) == NULL)
195     goto memerr;
196     for (y = height-1; y >= 0; y--) {
197     if (freadscan(scanin, width, fp) < 0)
198     goto readerr;
199     for (x = 0; x < width; x++)
200     for (i = 0; i < 3; i++)
201     pp[i].arr[x*height+y] = colval(scanin[x],i);
202     }
203     free((char *)scanin);
204     fclose(fp);
205     pp[0].next =
206     pp[1].next =
207     pp[2].next = plist;
208     return(plist = pp);
209    
210     memerr:
211     error(SYSTEM, "out of memory in getpict");
212     readerr:
213     sprintf(errmsg, "bad picture file \"%s\"", pfname);
214     error(USER, errmsg);
215     }
216    
217    
218     freedata(dname) /* free memory associated with dname */
219     char *dname;
220     {
221     register DATARRAY *dp, *dpl;
222 greg 1.4 register int i;
223 greg 1.1
224     for (dpl = NULL, dp = dlist; dp != NULL; dpl = dp, dp = dp->next)
225     if (!strcmp(dname, dp->name)) {
226     if (dpl == NULL)
227     dlist = dp->next;
228     else
229     dpl->next = dp->next;
230     free((char *)dp->arr);
231 greg 1.4 for (i = 0; i < dp->nd; i++)
232     if (dp->dim[i].p != NULL)
233     free((char *)dp->dim[i].p);
234 greg 1.1 freestr(dp->name);
235     free((char *)dp);
236     return;
237     }
238     }
239    
240    
241     freepict(pname) /* free memory associated with pname */
242     char *pname;
243     {
244     register DATARRAY *pp, *ppl;
245    
246     for (ppl = NULL, pp = plist; pp != NULL; ppl = pp, pp = pp->next)
247     if (!strcmp(pname, pp->name)) {
248     if (ppl == NULL)
249     plist = pp->next;
250     else
251     ppl->next = pp->next;
252     free((char *)pp[0].arr);
253     free((char *)pp[1].arr);
254     free((char *)pp[2].arr);
255     freestr(pp[0].name);
256     free((char *)pp);
257     return;
258     }
259     }
260    
261    
262     double
263     datavalue(dp, pt) /* interpolate data value at a point */
264     register DATARRAY *dp;
265     double *pt;
266     {
267     DATARRAY sd;
268     int asize;
269     register int i;
270     double x, y, y0, y1;
271 greg 1.4 /* set up dimensions for recursion */
272 greg 1.1 sd.nd = dp->nd - 1;
273     asize = 1;
274     for (i = 0; i < sd.nd; i++) {
275     sd.dim[i].org = dp->dim[i+1].org;
276     sd.dim[i].siz = dp->dim[i+1].siz;
277 greg 1.4 sd.dim[i].p = dp->dim[i+1].p;
278 greg 1.1 asize *= sd.dim[i].ne = dp->dim[i+1].ne;
279     }
280 greg 1.4 /* get independent variable */
281     if (dp->dim[0].p == NULL) { /* evenly spaced points */
282     x = (pt[0] - dp->dim[0].org)/dp->dim[0].siz;
283     x = x * (dp->dim[0].ne - 1);
284     i = x;
285     if (i < 0)
286     i = 0;
287     else if (i > dp->dim[0].ne - 2)
288     i = dp->dim[0].ne - 2;
289     } else { /* unevenly spaced points */
290     if (dp->dim[0].siz > 0.0)
291     for (i = 0; i < dp->dim[0].ne; i++)
292     if (pt[0] < dp->dim[0].p[i])
293     break;
294     else
295     for (i = 0; i < dp->dim[0].ne; i++)
296     if (pt[0] >= dp->dim[0].p[i])
297     break;
298     if (i <= 0)
299     i = 0;
300     else if (i >= dp->dim[0].ne)
301     i = dp->dim[0].ne - 2;
302     else
303     i--;
304     x = i + (pt[0] - dp->dim[0].p[i]) /
305     (dp->dim[0].p[i+1] - dp->dim[0].p[i]);
306     }
307     /* get dependent variable */
308 greg 1.1 if (dp->nd == 1) {
309     y0 = dp->arr[i];
310     y1 = dp->arr[i+1];
311     } else {
312     sd.arr = &dp->arr[i*asize];
313     y0 = datavalue(&sd, pt+1);
314     sd.arr = &dp->arr[(i+1)*asize];
315     y1 = datavalue(&sd, pt+1);
316     }
317     /*
318     * Extrapolate as far as one division, then
319     * taper off harmonically to zero.
320     */
321     if (x > i+2)
322     y = (2*y1-y0)/(x-i-1);
323     else if (x < i-1)
324     y = (2*y0-y1)/(i-x);
325     else
326     y = y0*((i+1)-x) + y1*(x-i);
327    
328     return(y);
329     }