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root/radiance/ray/src/px/pcond4.c
Revision: 3.8
Committed: Tue Oct 8 12:48:00 1996 UTC (27 years, 6 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 3.7: +30 -27 lines
Log Message:
Changed definition of SCANBAR to make code slightly more logical.

File Contents

# User Rev Content
1 greg 3.1 /* Copyright (c) 1996 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * Routines for veiling glare and loss of acuity.
9     */
10    
11     #include "pcond.h"
12    
13 greg 3.3 /************** VEILING STUFF *****************/
14 greg 3.1
15     #define VADAPT 0.08 /* fraction of adaptation from veil */
16    
17     extern COLOR *fovimg; /* foveal (1 degree) averaged image */
18     extern short fvxr, fvyr; /* foveal image resolution */
19    
20     #define fovscan(y) (fovimg+(y)*fvxr)
21    
22     static COLOR *veilimg; /* veiling image */
23    
24     #define veilscan(y) (veilimg+(y)*fvxr)
25    
26 greg 3.2 static float (*raydir)[3] = NULL; /* ray direction for each pixel */
27 greg 3.1
28     #define rdirscan(y) (raydir+(y)*fvxr)
29    
30    
31     compraydir() /* compute ray directions */
32     {
33 greg 3.2 FVECT rorg, rdir;
34 greg 3.1 double h, v;
35     register int x, y;
36    
37     if (raydir != NULL) /* already done? */
38     return;
39 greg 3.2 raydir = (float (*)[3])malloc(fvxr*fvyr*3*sizeof(float));
40 greg 3.1 if (raydir == NULL)
41     syserror("malloc");
42    
43     for (y = 0; y < fvyr; y++) {
44     switch (inpres.or) {
45     case YMAJOR: case YMAJOR|XDECR:
46     v = (y+.5)/fvyr; break;
47     case YMAJOR|YDECR: case YMAJOR|YDECR|XDECR:
48     v = 1. - (y+.5)/fvyr; break;
49     case 0: case YDECR:
50     h = (y+.5)/fvyr; break;
51     case XDECR: case XDECR|YDECR:
52     h = 1. - (y+.5)/fvyr; break;
53     }
54     for (x = 0; x < fvxr; x++) {
55     switch (inpres.or) {
56     case YMAJOR: case YMAJOR|YDECR:
57     h = (x+.5)/fvxr; break;
58     case YMAJOR|XDECR: case YMAJOR|XDECR|YDECR:
59     h = 1. - (x+.5)/fvxr; break;
60     case 0: case XDECR:
61     v = (x+.5)/fvxr; break;
62     case YDECR: case YDECR|XDECR:
63     v = 1. - (x+.5)/fvxr; break;
64     }
65 greg 3.2 if (viewray(rorg, rdir, &ourview, h, v)
66     >= -FTINY) {
67     rdirscan(y)[x][0] = rdir[0];
68     rdirscan(y)[x][1] = rdir[1];
69     rdirscan(y)[x][2] = rdir[2];
70     } else {
71 greg 3.1 rdirscan(y)[x][0] =
72     rdirscan(y)[x][1] =
73     rdirscan(y)[x][2] = 0.0;
74     }
75     }
76     }
77     }
78    
79    
80     compveil() /* compute veiling image */
81     {
82     double t2, t2sum;
83     COLOR ctmp, vsum;
84     int px, py;
85     register int x, y;
86     /* compute ray directions */
87     compraydir();
88     /* compute veil image */
89     veilimg = (COLOR *)malloc(fvxr*fvyr*sizeof(COLOR));
90     if (veilimg == NULL)
91     syserror("malloc");
92     for (py = 0; py < fvyr; py++)
93     for (px = 0; px < fvxr; px++) {
94     t2sum = 0.;
95     setcolor(vsum, 0., 0., 0.);
96     for (y = 0; y < fvyr; y++)
97     for (x = 0; x < fvxr; x++) {
98     if (x == px && y == py) continue;
99     t2 = DOT(rdirscan(py)[px],
100     rdirscan(y)[x]);
101     if (t2 <= FTINY) continue;
102 greg 3.4 /* use approximation instead
103 greg 3.1 t2 = acos(t2);
104     t2 = 1./(t2*t2);
105 greg 3.4 */
106     t2 = .5 / (1. - t2);
107 greg 3.1 copycolor(ctmp, fovscan(y)[x]);
108     scalecolor(ctmp, t2);
109     addcolor(vsum, ctmp);
110     t2sum += t2;
111     }
112     /* VADAPT of original is subtracted in addveil() */
113     scalecolor(vsum, VADAPT/t2sum);
114     copycolor(veilscan(py)[px], vsum);
115     }
116     }
117    
118    
119     addveil(sl, y) /* add veil to scanline */
120     COLOR *sl;
121     int y;
122     {
123     int vx, vy;
124     double dx, dy;
125     double lv, uv;
126     register int x, i;
127    
128     vy = dy = (y+.5)/numscans(&inpres)*fvyr - .5;
129 greg 3.7 while (vy >= fvyr-1) vy--;
130 greg 3.1 dy -= (double)vy;
131     for (x = 0; x < scanlen(&inpres); x++) {
132     vx = dx = (x+.5)/scanlen(&inpres)*fvxr - .5;
133 greg 3.7 while (vx >= fvxr-1) vx--;
134 greg 3.1 dx -= (double)vx;
135     for (i = 0; i < 3; i++) {
136     lv = (1.-dy)*colval(veilscan(vy)[vx],i) +
137     dy*colval(veilscan(vy+1)[vx],i);
138     uv = (1.-dy)*colval(veilscan(vy)[vx+1],i) +
139     dy*colval(veilscan(vy+1)[vx+1],i);
140     colval(sl[x],i) = (1.-VADAPT)*colval(sl[x],i) +
141     (1.-dx)*lv + dx*uv;
142     }
143     }
144 greg 3.3 }
145    
146    
147     /****************** ACUITY STUFF *******************/
148    
149 greg 3.8 typedef struct {
150     short sampe; /* sample area size (exponent of 2) */
151 greg 3.3 short nscans; /* number of scanlines in this bar */
152     int len; /* individual scanline length */
153     int nread; /* number of scanlines loaded */
154 greg 3.8 COLOR *sdata; /* scanbar data */
155 greg 3.3 } SCANBAR;
156    
157 greg 3.8 #define bscan(sb,y) ((COLOR *)(sb)->sdata+((y)%(sb)->nscans)*(sb)->len)
158 greg 3.3
159     SCANBAR *rootbar; /* root scan bar (lowest resolution) */
160    
161     float *inpacuD; /* input acuity data (cycles/degree) */
162    
163     #define tsampr(x,y) inpacuD[(y)*fvxr+(x)]
164    
165    
166     double
167     hacuity(La) /* return visual acuity in cycles/degree */
168     double La;
169     { /* data due to S. Shaler (we should fit it!) */
170     #define NPOINTS 20
171     static float l10lum[NPOINTS] = {
172     -3.10503,-2.66403,-2.37703,-2.09303,-1.64403,-1.35803,
173     -1.07403,-0.67203,-0.38503,-0.10103,0.29397,0.58097,0.86497,
174     1.25697,1.54397,1.82797,2.27597,2.56297,2.84697,3.24897
175     };
176     static float resfreq[NPOINTS] = {
177     2.09,3.28,3.79,4.39,6.11,8.83,10.94,18.66,23.88,31.05,37.42,
178     37.68,41.60,43.16,45.30,47.00,48.43,48.32,51.06,51.09
179     };
180     double l10La;
181     register int i;
182 greg 3.5 /* check limits */
183     if (La <= 7.85e-4)
184     return(resfreq[0]);
185     if (La >= 1.78e3)
186     return(resfreq[NPOINTS-1]);
187     /* interpolate data */
188 greg 3.3 l10La = log10(La);
189     for (i = 0; i < NPOINTS-2 && l10lum[i+1] <= l10La; i++)
190     ;
191     return( ( (l10lum[i+1] - l10La)*resfreq[i] +
192     (l10La - l10lum[i])*resfreq[i+1] ) /
193     (l10lum[i+1] - l10lum[i]) );
194     #undef NPOINTS
195     }
196    
197    
198     COLOR *
199     getascan(sb, y) /* find/read scanline y for scanbar sb */
200     register SCANBAR *sb;
201     int y;
202     {
203     register COLOR *sl0, *sl1, *mysl;
204     register int i;
205    
206 greg 3.6 if (y < sb->nread - sb->nscans) /* too far back? */
207     return(NULL);
208 greg 3.3 for ( ; y >= sb->nread; sb->nread++) { /* read as necessary */
209     mysl = bscan(sb, sb->nread);
210 greg 3.8 if (sb->sampe == 0) {
211 greg 3.3 if (freadscan(mysl, sb->len, infp) < 0) {
212     fprintf(stderr, "%s: %s: scanline read error\n",
213     progname, infn);
214     exit(1);
215     }
216     } else {
217 greg 3.8 sl0 = getascan(sb+1, 2*y);
218 greg 3.6 if (sl0 == NULL)
219     return(NULL);
220 greg 3.8 sl1 = getascan(sb+1, 2*y+1);
221 greg 3.3 for (i = 0; i < sb->len; i++) {
222     copycolor(mysl[i], sl0[2*i]);
223     addcolor(mysl[i], sl0[2*i+1]);
224     addcolor(mysl[i], sl1[2*i]);
225     addcolor(mysl[i], sl1[2*i+1]);
226     scalecolor(mysl[i], 0.25);
227     }
228     }
229     }
230     return(bscan(sb, y));
231     }
232    
233    
234     acuscan(scln, y) /* get acuity-sampled scanline */
235     COLOR *scln;
236     int y;
237     {
238     double sr;
239     double dx, dy;
240     int ix, iy;
241     register int x;
242     /* compute foveal y position */
243     iy = dy = (y+.5)/numscans(&inpres)*fvyr - .5;
244     if (iy >= fvyr-1) iy--;
245     dy -= (double)iy;
246     for (x = 0; x < scanlen(&inpres); x++) {
247     /* compute foveal x position */
248     ix = dx = (x+.5)/scanlen(&inpres)*fvxr - .5;
249     if (ix >= fvxr-1) ix--;
250     dx -= (double)ix;
251     /* interpolate sample rate */
252     sr = (1.-dy)*((1.-dx)*tsampr(ix,iy) + dx*tsampr(ix+1,iy)) +
253     dy*((1.-dx)*tsampr(ix,iy+1) + dx*tsampr(ix+1,iy+1));
254    
255     acusample(scln[x], x, y, sr); /* compute sample */
256     }
257     }
258    
259    
260     acusample(col, x, y, sr) /* interpolate sample at (x,y) using rate sr */
261     COLOR col;
262     int x, y;
263     double sr;
264     {
265     COLOR c1;
266     double d;
267     register SCANBAR *sb0;
268    
269 greg 3.8 for (sb0 = rootbar; sb0->sampe != 0 && 1<<sb0[1].sampe > sr; sb0++)
270 greg 3.3 ;
271     ascanval(col, x, y, sb0);
272 greg 3.8 if (sb0->sampe == 0) /* don't extrapolate highest */
273 greg 3.3 return;
274 greg 3.8 ascanval(c1, x, y, sb0+1);
275     d = ((1<<sb0->sampe) - sr)/(1<<sb0[1].sampe);
276 greg 3.3 scalecolor(col, 1.-d);
277     scalecolor(c1, d);
278     addcolor(col, c1);
279     }
280    
281    
282     ascanval(col, x, y, sb) /* interpolate scanbar at orig. coords (x,y) */
283     COLOR col;
284     int x, y;
285     SCANBAR *sb;
286     {
287     COLOR *sl0, *sl1, c1, c1y;
288     double dx, dy;
289     int ix, iy;
290    
291 greg 3.8 if (sb->sampe == 0) { /* no need to interpolate */
292 greg 3.6 sl0 = getascan(sb, y);
293     copycolor(col, sl0[x]);
294     return;
295     }
296     /* compute coordinates for sb */
297 greg 3.8 ix = dx = (x+.5)/(1<<sb->sampe) - .5;
298 greg 3.7 while (ix >= sb->len-1) ix--;
299 greg 3.3 dx -= (double)ix;
300 greg 3.8 iy = dy = (y+.5)/(1<<sb->sampe) - .5;
301     while (iy >= (numscans(&inpres)>>sb->sampe)-1) iy--;
302 greg 3.3 dy -= (double)iy;
303     /* get scanlines */
304     sl0 = getascan(sb, iy);
305 greg 3.6 if (sl0 == NULL) {
306     fprintf(stderr, "%s: internal - cannot backspace in ascanval\n",
307     progname);
308     exit(1);
309     }
310 greg 3.3 sl1 = getascan(sb, iy+1);
311     /* 2D linear interpolation */
312     copycolor(col, sl0[ix]);
313     scalecolor(col, 1.-dx);
314     copycolor(c1, sl0[ix+1]);
315     scalecolor(c1, dx);
316     addcolor(col, c1);
317     copycolor(c1y, sl1[ix]);
318     scalecolor(c1y, 1.-dx);
319     copycolor(c1, sl1[ix+1]);
320     scalecolor(c1, dx);
321     addcolor(c1y, c1);
322     scalecolor(col, 1.-dy);
323     scalecolor(c1y, dy);
324     addcolor(col, c1y);
325     }
326    
327    
328     SCANBAR *
329     sballoc(sr, ns, sl) /* allocate scanbar */
330     int sr; /* sampling rate */
331     int ns; /* number of scanlines */
332     int sl; /* original scanline length */
333     {
334 greg 3.8 SCANBAR *sbarr;
335 greg 3.3 register SCANBAR *sb;
336    
337 greg 3.8 sbarr = sb = (SCANBAR *)malloc((sr+1)*sizeof(SCANBAR));
338 greg 3.3 if (sb == NULL)
339     syserror("malloc");
340 greg 3.8 do {
341     sb->sdata = (COLOR *)malloc((sl>>sr)*ns*sizeof(COLOR));
342     if (sb->sdata == NULL)
343     syserror("malloc");
344     sb->sampe = sr;
345     sb->nscans = ns;
346     sb->len = sl>>sr;
347     sb->nread = 0;
348     ns <<= 1;
349     sb++;
350     } while (--sr >= 0);
351     return(sbarr);
352 greg 3.3 }
353    
354    
355     initacuity() /* initialize variable acuity sampling */
356     {
357     FVECT diffx, diffy, cp;
358     double omega, maxsr;
359     register int x, y, i;
360    
361     compraydir(); /* compute ray directions */
362    
363     inpacuD = (float *)malloc(fvxr*fvyr*sizeof(float));
364     if (inpacuD == NULL)
365     syserror("malloc");
366     maxsr = 1.; /* compute internal sample rates */
367     for (y = 1; y < fvyr-1; y++)
368     for (x = 1; x < fvxr-1; x++) {
369     for (i = 0; i < 3; i++) {
370     diffx[i] = 0.5*fvxr/scanlen(&inpres) *
371     (rdirscan(y)[x+1][i] -
372     rdirscan(y)[x-1][i]);
373     diffy[i] = 0.5*fvyr/numscans(&inpres) *
374     (rdirscan(y+1)[x][i] -
375     rdirscan(y-1)[x][i]);
376     }
377     fcross(cp, diffx, diffy);
378     omega = 0.5 * sqrt(DOT(cp,cp));
379 greg 3.4 if (omega <= FTINY)
380     tsampr(x,y) = 1.;
381     else if ((tsampr(x,y) = PI/180. / sqrt(omega) /
382     hacuity(plum(fovscan(y)[x]))) > maxsr)
383 greg 3.3 maxsr = tsampr(x,y);
384     }
385     /* copy perimeter (easier) */
386     for (x = 1; x < fvxr-1; x++) {
387     tsampr(x,0) = tsampr(x,1);
388     tsampr(x,fvyr-1) = tsampr(x,fvyr-2);
389     }
390     for (y = 0; y < fvyr; y++) {
391     tsampr(y,0) = tsampr(y,1);
392     tsampr(y,fvxr-1) = tsampr(y,fvxr-2);
393     }
394     /* initialize with next power of two */
395 greg 3.8 rootbar = sballoc((int)(log(maxsr)/log(2.))+1, 2, scanlen(&inpres));
396 greg 3.1 }