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root/radiance/ray/src/px/pcond4.c
Revision: 3.3
Committed: Fri Oct 4 16:10:43 1996 UTC (27 years, 7 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 3.2: +234 -0 lines
Log Message:
finally got variable acuity working

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     t2 = acos(t2);
103     t2 = 1./(t2*t2);
104     copycolor(ctmp, fovscan(y)[x]);
105     scalecolor(ctmp, t2);
106     addcolor(vsum, ctmp);
107     t2sum += t2;
108     }
109     /* VADAPT of original is subtracted in addveil() */
110     scalecolor(vsum, VADAPT/t2sum);
111     copycolor(veilscan(py)[px], vsum);
112     }
113     }
114    
115    
116     addveil(sl, y) /* add veil to scanline */
117     COLOR *sl;
118     int y;
119     {
120     int vx, vy;
121     double dx, dy;
122     double lv, uv;
123     register int x, i;
124    
125     vy = dy = (y+.5)/numscans(&inpres)*fvyr - .5;
126     if (vy >= fvyr-1) vy--;
127     dy -= (double)vy;
128     for (x = 0; x < scanlen(&inpres); x++) {
129     vx = dx = (x+.5)/scanlen(&inpres)*fvxr - .5;
130     if (vx >= fvxr-1) vx--;
131     dx -= (double)vx;
132     for (i = 0; i < 3; i++) {
133     lv = (1.-dy)*colval(veilscan(vy)[vx],i) +
134     dy*colval(veilscan(vy+1)[vx],i);
135     uv = (1.-dy)*colval(veilscan(vy)[vx+1],i) +
136     dy*colval(veilscan(vy+1)[vx+1],i);
137     colval(sl[x],i) = (1.-VADAPT)*colval(sl[x],i) +
138     (1.-dx)*lv + dx*uv;
139     }
140     }
141 greg 3.3 }
142    
143    
144     /****************** ACUITY STUFF *******************/
145    
146     typedef struct scanbar {
147     short sampr; /* sample area size (power of 2) */
148     short nscans; /* number of scanlines in this bar */
149     int len; /* individual scanline length */
150     struct scanbar *next; /* next higher resolution scanbar */
151     int nread; /* number of scanlines loaded */
152     /* followed by the scanline data */
153     } SCANBAR;
154    
155     #define bscan(sb,y) ((COLOR *)((sb)+1)+((y)%(sb)->nscans)*(sb)->len)
156    
157     SCANBAR *rootbar; /* root scan bar (lowest resolution) */
158    
159     float *inpacuD; /* input acuity data (cycles/degree) */
160    
161     #define tsampr(x,y) inpacuD[(y)*fvxr+(x)]
162    
163    
164     double
165     hacuity(La) /* return visual acuity in cycles/degree */
166     double La;
167     { /* data due to S. Shaler (we should fit it!) */
168     #define NPOINTS 20
169     static float l10lum[NPOINTS] = {
170     -3.10503,-2.66403,-2.37703,-2.09303,-1.64403,-1.35803,
171     -1.07403,-0.67203,-0.38503,-0.10103,0.29397,0.58097,0.86497,
172     1.25697,1.54397,1.82797,2.27597,2.56297,2.84697,3.24897
173     };
174     static float resfreq[NPOINTS] = {
175     2.09,3.28,3.79,4.39,6.11,8.83,10.94,18.66,23.88,31.05,37.42,
176     37.68,41.60,43.16,45.30,47.00,48.43,48.32,51.06,51.09
177     };
178     double l10La;
179     register int i;
180     /* interpolate/extrapolate data */
181     l10La = log10(La);
182     for (i = 0; i < NPOINTS-2 && l10lum[i+1] <= l10La; i++)
183     ;
184     return( ( (l10lum[i+1] - l10La)*resfreq[i] +
185     (l10La - l10lum[i])*resfreq[i+1] ) /
186     (l10lum[i+1] - l10lum[i]) );
187     #undef NPOINTS
188     }
189    
190    
191     COLOR *
192     getascan(sb, y) /* find/read scanline y for scanbar sb */
193     register SCANBAR *sb;
194     int y;
195     {
196     register COLOR *sl0, *sl1, *mysl;
197     register int i;
198    
199     if (y < sb->nread - sb->nscans) {
200     fprintf(stderr, "%s: internal - cannot backspace in getascan\n",
201     progname);
202     exit(1);
203     }
204     for ( ; y >= sb->nread; sb->nread++) { /* read as necessary */
205     mysl = bscan(sb, sb->nread);
206     if (sb->sampr == 1) {
207     if (freadscan(mysl, sb->len, infp) < 0) {
208     fprintf(stderr, "%s: %s: scanline read error\n",
209     progname, infn);
210     exit(1);
211     }
212     } else {
213     sl0 = getascan(sb->next, 2*y);
214     sl1 = getascan(sb->next, 2*y+1);
215     for (i = 0; i < sb->len; i++) {
216     copycolor(mysl[i], sl0[2*i]);
217     addcolor(mysl[i], sl0[2*i+1]);
218     addcolor(mysl[i], sl1[2*i]);
219     addcolor(mysl[i], sl1[2*i+1]);
220     scalecolor(mysl[i], 0.25);
221     }
222     }
223     }
224     return(bscan(sb, y));
225     }
226    
227    
228     acuscan(scln, y) /* get acuity-sampled scanline */
229     COLOR *scln;
230     int y;
231     {
232     double sr;
233     double dx, dy;
234     int ix, iy;
235     register int x;
236     /* compute foveal y position */
237     iy = dy = (y+.5)/numscans(&inpres)*fvyr - .5;
238     if (iy >= fvyr-1) iy--;
239     dy -= (double)iy;
240     for (x = 0; x < scanlen(&inpres); x++) {
241     /* compute foveal x position */
242     ix = dx = (x+.5)/scanlen(&inpres)*fvxr - .5;
243     if (ix >= fvxr-1) ix--;
244     dx -= (double)ix;
245     /* interpolate sample rate */
246     sr = (1.-dy)*((1.-dx)*tsampr(ix,iy) + dx*tsampr(ix+1,iy)) +
247     dy*((1.-dx)*tsampr(ix,iy+1) + dx*tsampr(ix+1,iy+1));
248    
249     acusample(scln[x], x, y, sr); /* compute sample */
250     }
251     }
252    
253    
254     acusample(col, x, y, sr) /* interpolate sample at (x,y) using rate sr */
255     COLOR col;
256     int x, y;
257     double sr;
258     {
259     COLOR c1;
260     double d;
261     register SCANBAR *sb0;
262    
263     for (sb0 = rootbar; sb0->next != NULL && sb0->next->sampr > sr;
264     sb0 = sb0->next)
265     ;
266     ascanval(col, x, y, sb0);
267     if (sb0->next == NULL) /* don't extrapolate highest */
268     return;
269     ascanval(c1, x, y, sb0->next);
270     d = (sb0->sampr - sr)/(sb0->sampr - sb0->next->sampr);
271     scalecolor(col, 1.-d);
272     scalecolor(c1, d);
273     addcolor(col, c1);
274     }
275    
276    
277     ascanval(col, x, y, sb) /* interpolate scanbar at orig. coords (x,y) */
278     COLOR col;
279     int x, y;
280     SCANBAR *sb;
281     {
282     COLOR *sl0, *sl1, c1, c1y;
283     double dx, dy;
284     int ix, iy;
285    
286     ix = dx = (x+.5)/sb->sampr - .5;
287     if (ix >= sb->len-1) ix--;
288     dx -= (double)ix;
289     iy = dy = (y+.5)/sb->sampr - .5;
290     if (iy >= numscans(&inpres)/sb->sampr-1) iy--;
291     dy -= (double)iy;
292     /* get scanlines */
293     sl0 = getascan(sb, iy);
294     sl1 = getascan(sb, iy+1);
295     /* 2D linear interpolation */
296     copycolor(col, sl0[ix]);
297     scalecolor(col, 1.-dx);
298     copycolor(c1, sl0[ix+1]);
299     scalecolor(c1, dx);
300     addcolor(col, c1);
301     copycolor(c1y, sl1[ix]);
302     scalecolor(c1y, 1.-dx);
303     copycolor(c1, sl1[ix+1]);
304     scalecolor(c1, dx);
305     addcolor(c1y, c1);
306     scalecolor(col, 1.-dy);
307     scalecolor(c1y, dy);
308     addcolor(col, c1y);
309     }
310    
311    
312     SCANBAR *
313     sballoc(sr, ns, sl) /* allocate scanbar */
314     int sr; /* sampling rate */
315     int ns; /* number of scanlines */
316     int sl; /* original scanline length */
317     {
318     register SCANBAR *sb;
319    
320     sb = (SCANBAR *)malloc(sizeof(SCANBAR)+(sl/sr)*ns*sizeof(COLOR));
321     if (sb == NULL)
322     syserror("malloc");
323     sb->nscans = ns;
324     sb->len = sl/sr;
325     sb->nread = 0;
326     if ((sb->sampr = sr) > 1)
327     sb->next = sballoc(sr/2, ns*2, sl);
328     else
329     sb->next = NULL;
330     return(sb);
331     }
332    
333    
334     initacuity() /* initialize variable acuity sampling */
335     {
336     FVECT diffx, diffy, cp;
337     double omega, maxsr;
338     register int x, y, i;
339    
340     compraydir(); /* compute ray directions */
341    
342     inpacuD = (float *)malloc(fvxr*fvyr*sizeof(float));
343     if (inpacuD == NULL)
344     syserror("malloc");
345     maxsr = 1.; /* compute internal sample rates */
346     for (y = 1; y < fvyr-1; y++)
347     for (x = 1; x < fvxr-1; x++) {
348     for (i = 0; i < 3; i++) {
349     diffx[i] = 0.5*fvxr/scanlen(&inpres) *
350     (rdirscan(y)[x+1][i] -
351     rdirscan(y)[x-1][i]);
352     diffy[i] = 0.5*fvyr/numscans(&inpres) *
353     (rdirscan(y+1)[x][i] -
354     rdirscan(y-1)[x][i]);
355     }
356     fcross(cp, diffx, diffy);
357     omega = 0.5 * sqrt(DOT(cp,cp));
358     tsampr(x,y) = PI/180. / sqrt(omega) /
359     hacuity(plum(fovscan(y)[x]));
360     if (tsampr(x,y) > maxsr)
361     maxsr = tsampr(x,y);
362     }
363     /* copy perimeter (easier) */
364     for (x = 1; x < fvxr-1; x++) {
365     tsampr(x,0) = tsampr(x,1);
366     tsampr(x,fvyr-1) = tsampr(x,fvyr-2);
367     }
368     for (y = 0; y < fvyr; y++) {
369     tsampr(y,0) = tsampr(y,1);
370     tsampr(y,fvxr-1) = tsampr(y,fvxr-2);
371     }
372     /* initialize with next power of two */
373     rootbar = sballoc(2<<(int)(log(maxsr)/log(2.)), 2, scanlen(&inpres));
374 greg 3.1 }