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 |
/************** VEILING STUFF *****************/ |
14 |
|
15 |
#define VADAPT 0.08 /* fraction of adaptation from veil */ |
16 |
|
17 |
static COLOR *veilimg = NULL; /* veiling image */ |
18 |
|
19 |
#define veilscan(y) (veilimg+(y)*fvxr) |
20 |
|
21 |
static float (*raydir)[3] = NULL; /* ray direction for each pixel */ |
22 |
|
23 |
#define rdirscan(y) (raydir+(y)*fvxr) |
24 |
|
25 |
|
26 |
compraydir() /* compute ray directions */ |
27 |
{ |
28 |
FVECT rorg, rdir; |
29 |
double h, v; |
30 |
register int x, y; |
31 |
|
32 |
if (raydir != NULL) /* already done? */ |
33 |
return; |
34 |
raydir = (float (*)[3])malloc(fvxr*fvyr*3*sizeof(float)); |
35 |
if (raydir == NULL) |
36 |
syserror("malloc"); |
37 |
|
38 |
for (y = 0; y < fvyr; y++) { |
39 |
switch (inpres.or) { |
40 |
case YMAJOR: case YMAJOR|XDECR: |
41 |
v = (y+.5)/fvyr; break; |
42 |
case YMAJOR|YDECR: case YMAJOR|YDECR|XDECR: |
43 |
v = 1. - (y+.5)/fvyr; break; |
44 |
case 0: case YDECR: |
45 |
h = (y+.5)/fvyr; break; |
46 |
case XDECR: case XDECR|YDECR: |
47 |
h = 1. - (y+.5)/fvyr; break; |
48 |
} |
49 |
for (x = 0; x < fvxr; x++) { |
50 |
switch (inpres.or) { |
51 |
case YMAJOR: case YMAJOR|YDECR: |
52 |
h = (x+.5)/fvxr; break; |
53 |
case YMAJOR|XDECR: case YMAJOR|XDECR|YDECR: |
54 |
h = 1. - (x+.5)/fvxr; break; |
55 |
case 0: case XDECR: |
56 |
v = (x+.5)/fvxr; break; |
57 |
case YDECR: case YDECR|XDECR: |
58 |
v = 1. - (x+.5)/fvxr; break; |
59 |
} |
60 |
if (viewray(rorg, rdir, &ourview, h, v) |
61 |
>= -FTINY) { |
62 |
rdirscan(y)[x][0] = rdir[0]; |
63 |
rdirscan(y)[x][1] = rdir[1]; |
64 |
rdirscan(y)[x][2] = rdir[2]; |
65 |
} else { |
66 |
rdirscan(y)[x][0] = |
67 |
rdirscan(y)[x][1] = |
68 |
rdirscan(y)[x][2] = 0.0; |
69 |
} |
70 |
} |
71 |
} |
72 |
} |
73 |
|
74 |
|
75 |
compveil() /* compute veiling image */ |
76 |
{ |
77 |
double t2, t2sum; |
78 |
COLOR ctmp, vsum; |
79 |
int px, py; |
80 |
register int x, y; |
81 |
|
82 |
if (veilimg != NULL) /* already done? */ |
83 |
return; |
84 |
/* compute ray directions */ |
85 |
compraydir(); |
86 |
/* compute veil image */ |
87 |
veilimg = (COLOR *)malloc(fvxr*fvyr*sizeof(COLOR)); |
88 |
if (veilimg == NULL) |
89 |
syserror("malloc"); |
90 |
for (py = 0; py < fvyr; py++) |
91 |
for (px = 0; px < fvxr; px++) { |
92 |
t2sum = 0.; |
93 |
setcolor(vsum, 0., 0., 0.); |
94 |
for (y = 0; y < fvyr; y++) |
95 |
for (x = 0; x < fvxr; x++) { |
96 |
if (x == px && y == py) continue; |
97 |
t2 = DOT(rdirscan(py)[px], |
98 |
rdirscan(y)[x]); |
99 |
if (t2 <= FTINY) continue; |
100 |
/* use approximation instead |
101 |
t2 = acos(t2); |
102 |
t2 = 1./(t2*t2); |
103 |
*/ |
104 |
t2 = .5 / (1. - t2); |
105 |
copycolor(ctmp, fovscan(y)[x]); |
106 |
scalecolor(ctmp, t2); |
107 |
addcolor(vsum, ctmp); |
108 |
t2sum += t2; |
109 |
} |
110 |
/* VADAPT of original is subtracted in addveil() */ |
111 |
scalecolor(vsum, VADAPT/t2sum); |
112 |
copycolor(veilscan(py)[px], vsum); |
113 |
} |
114 |
/* modify FOV sample image */ |
115 |
for (y = 0; y < fvyr; y++) |
116 |
for (x = 0; x < fvxr; x++) { |
117 |
scalecolor(fovscan(y)[x], 1.-VADAPT); |
118 |
addcolor(fovscan(y)[x], veilscan(y)[x]); |
119 |
} |
120 |
comphist(); /* recompute histogram */ |
121 |
} |
122 |
|
123 |
|
124 |
addveil(sl, y) /* add veil to scanline */ |
125 |
COLOR *sl; |
126 |
int y; |
127 |
{ |
128 |
int vx, vy; |
129 |
double dx, dy; |
130 |
double lv, uv; |
131 |
register int x, i; |
132 |
|
133 |
vy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; |
134 |
while (vy >= fvyr-1) vy--; |
135 |
dy -= (double)vy; |
136 |
for (x = 0; x < scanlen(&inpres); x++) { |
137 |
vx = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; |
138 |
while (vx >= fvxr-1) vx--; |
139 |
dx -= (double)vx; |
140 |
for (i = 0; i < 3; i++) { |
141 |
lv = (1.-dy)*colval(veilscan(vy)[vx],i) + |
142 |
dy*colval(veilscan(vy+1)[vx],i); |
143 |
uv = (1.-dy)*colval(veilscan(vy)[vx+1],i) + |
144 |
dy*colval(veilscan(vy+1)[vx+1],i); |
145 |
colval(sl[x],i) = (1.-VADAPT)*colval(sl[x],i) + |
146 |
(1.-dx)*lv + dx*uv; |
147 |
} |
148 |
} |
149 |
} |
150 |
|
151 |
|
152 |
/****************** ACUITY STUFF *******************/ |
153 |
|
154 |
typedef struct { |
155 |
short sampe; /* sample area size (exponent of 2) */ |
156 |
short nscans; /* number of scanlines in this bar */ |
157 |
int len; /* individual scanline length */ |
158 |
int nread; /* number of scanlines loaded */ |
159 |
COLOR *sdata; /* scanbar data */ |
160 |
} SCANBAR; |
161 |
|
162 |
#define bscan(sb,y) ((COLOR *)(sb)->sdata+((y)%(sb)->nscans)*(sb)->len) |
163 |
|
164 |
SCANBAR *rootbar; /* root scan bar (lowest resolution) */ |
165 |
|
166 |
float *inpacuD; /* input acuity data (cycles/degree) */ |
167 |
|
168 |
#define tsampr(x,y) inpacuD[(y)*fvxr+(x)] |
169 |
|
170 |
|
171 |
double |
172 |
hacuity(La) /* return visual acuity in cycles/degree */ |
173 |
double La; |
174 |
{ /* data due to S. Shaler (we should fit it!) */ |
175 |
#define NPOINTS 20 |
176 |
static float l10lum[NPOINTS] = { |
177 |
-3.10503,-2.66403,-2.37703,-2.09303,-1.64403,-1.35803, |
178 |
-1.07403,-0.67203,-0.38503,-0.10103,0.29397,0.58097,0.86497, |
179 |
1.25697,1.54397,1.82797,2.27597,2.56297,2.84697,3.24897 |
180 |
}; |
181 |
static float resfreq[NPOINTS] = { |
182 |
2.09,3.28,3.79,4.39,6.11,8.83,10.94,18.66,23.88,31.05,37.42, |
183 |
37.68,41.60,43.16,45.30,47.00,48.43,48.32,51.06,51.09 |
184 |
}; |
185 |
double l10La; |
186 |
register int i; |
187 |
/* check limits */ |
188 |
if (La <= 7.85e-4) |
189 |
return(resfreq[0]); |
190 |
if (La >= 1.78e3) |
191 |
return(resfreq[NPOINTS-1]); |
192 |
/* interpolate data */ |
193 |
l10La = log10(La); |
194 |
for (i = 0; i < NPOINTS-2 && l10lum[i+1] <= l10La; i++) |
195 |
; |
196 |
return( ( (l10lum[i+1] - l10La)*resfreq[i] + |
197 |
(l10La - l10lum[i])*resfreq[i+1] ) / |
198 |
(l10lum[i+1] - l10lum[i]) ); |
199 |
#undef NPOINTS |
200 |
} |
201 |
|
202 |
|
203 |
COLOR * |
204 |
getascan(sb, y) /* find/read scanline y for scanbar sb */ |
205 |
register SCANBAR *sb; |
206 |
int y; |
207 |
{ |
208 |
register COLOR *sl0, *sl1, *mysl; |
209 |
register int i; |
210 |
|
211 |
if (y < sb->nread - sb->nscans) /* too far back? */ |
212 |
return(NULL); |
213 |
for ( ; y >= sb->nread; sb->nread++) { /* read as necessary */ |
214 |
mysl = bscan(sb, sb->nread); |
215 |
if (sb->sampe == 0) { |
216 |
if (freadscan(mysl, sb->len, infp) < 0) { |
217 |
fprintf(stderr, "%s: %s: scanline read error\n", |
218 |
progname, infn); |
219 |
exit(1); |
220 |
} |
221 |
} else { |
222 |
sl0 = getascan(sb+1, 2*y); |
223 |
if (sl0 == NULL) |
224 |
return(NULL); |
225 |
sl1 = getascan(sb+1, 2*y+1); |
226 |
for (i = 0; i < sb->len; i++) { |
227 |
copycolor(mysl[i], sl0[2*i]); |
228 |
addcolor(mysl[i], sl0[2*i+1]); |
229 |
addcolor(mysl[i], sl1[2*i]); |
230 |
addcolor(mysl[i], sl1[2*i+1]); |
231 |
scalecolor(mysl[i], 0.25); |
232 |
} |
233 |
} |
234 |
} |
235 |
return(bscan(sb, y)); |
236 |
} |
237 |
|
238 |
|
239 |
acuscan(scln, y) /* get acuity-sampled scanline */ |
240 |
COLOR *scln; |
241 |
int y; |
242 |
{ |
243 |
double sr; |
244 |
double dx, dy; |
245 |
int ix, iy; |
246 |
register int x; |
247 |
/* compute foveal y position */ |
248 |
iy = dy = (y+.5)/numscans(&inpres)*fvyr - .5; |
249 |
while (iy >= fvyr-1) iy--; |
250 |
dy -= (double)iy; |
251 |
for (x = 0; x < scanlen(&inpres); x++) { |
252 |
/* compute foveal x position */ |
253 |
ix = dx = (x+.5)/scanlen(&inpres)*fvxr - .5; |
254 |
while (ix >= fvxr-1) ix--; |
255 |
dx -= (double)ix; |
256 |
/* interpolate sample rate */ |
257 |
sr = (1.-dy)*((1.-dx)*tsampr(ix,iy) + dx*tsampr(ix+1,iy)) + |
258 |
dy*((1.-dx)*tsampr(ix,iy+1) + dx*tsampr(ix+1,iy+1)); |
259 |
|
260 |
acusample(scln[x], x, y, sr); /* compute sample */ |
261 |
} |
262 |
} |
263 |
|
264 |
|
265 |
acusample(col, x, y, sr) /* interpolate sample at (x,y) using rate sr */ |
266 |
COLOR col; |
267 |
int x, y; |
268 |
double sr; |
269 |
{ |
270 |
COLOR c1; |
271 |
double d; |
272 |
register SCANBAR *sb0; |
273 |
|
274 |
for (sb0 = rootbar; sb0->sampe != 0 && 1<<sb0[1].sampe > sr; sb0++) |
275 |
; |
276 |
ascanval(col, x, y, sb0); |
277 |
if (sb0->sampe == 0) /* don't extrapolate highest */ |
278 |
return; |
279 |
ascanval(c1, x, y, sb0+1); |
280 |
d = ((1<<sb0->sampe) - sr)/(1<<sb0[1].sampe); |
281 |
scalecolor(col, 1.-d); |
282 |
scalecolor(c1, d); |
283 |
addcolor(col, c1); |
284 |
} |
285 |
|
286 |
|
287 |
ascanval(col, x, y, sb) /* interpolate scanbar at orig. coords (x,y) */ |
288 |
COLOR col; |
289 |
int x, y; |
290 |
SCANBAR *sb; |
291 |
{ |
292 |
COLOR *sl0, *sl1, c1, c1y; |
293 |
double dx, dy; |
294 |
int ix, iy; |
295 |
|
296 |
if (sb->sampe == 0) { /* no need to interpolate */ |
297 |
sl0 = getascan(sb, y); |
298 |
copycolor(col, sl0[x]); |
299 |
return; |
300 |
} |
301 |
/* compute coordinates for sb */ |
302 |
ix = dx = (x+.5)/(1<<sb->sampe) - .5; |
303 |
while (ix >= sb->len-1) ix--; |
304 |
dx -= (double)ix; |
305 |
iy = dy = (y+.5)/(1<<sb->sampe) - .5; |
306 |
while (iy >= (numscans(&inpres)>>sb->sampe)-1) iy--; |
307 |
dy -= (double)iy; |
308 |
/* get scanlines */ |
309 |
sl0 = getascan(sb, iy); |
310 |
#ifdef DEBUG |
311 |
if (sl0 == NULL) { |
312 |
fprintf(stderr, "%s: internal - cannot backspace in ascanval\n", |
313 |
progname); |
314 |
abort(); |
315 |
} |
316 |
#endif |
317 |
sl1 = getascan(sb, iy+1); |
318 |
/* 2D linear interpolation */ |
319 |
copycolor(col, sl0[ix]); |
320 |
scalecolor(col, 1.-dx); |
321 |
copycolor(c1, sl0[ix+1]); |
322 |
scalecolor(c1, dx); |
323 |
addcolor(col, c1); |
324 |
copycolor(c1y, sl1[ix]); |
325 |
scalecolor(c1y, 1.-dx); |
326 |
copycolor(c1, sl1[ix+1]); |
327 |
scalecolor(c1, dx); |
328 |
addcolor(c1y, c1); |
329 |
scalecolor(col, 1.-dy); |
330 |
scalecolor(c1y, dy); |
331 |
addcolor(col, c1y); |
332 |
for (ix = 0; ix < 3; ix++) /* make sure no negative */ |
333 |
if (colval(col,ix) < 0.) |
334 |
colval(col,ix) = 0.; |
335 |
} |
336 |
|
337 |
|
338 |
SCANBAR * |
339 |
sballoc(se, ns, sl) /* allocate scanbar */ |
340 |
int se; /* sampling rate exponent */ |
341 |
int ns; /* number of scanlines */ |
342 |
int sl; /* original scanline length */ |
343 |
{ |
344 |
SCANBAR *sbarr; |
345 |
register SCANBAR *sb; |
346 |
|
347 |
sbarr = sb = (SCANBAR *)malloc((se+1)*sizeof(SCANBAR)); |
348 |
if (sb == NULL) |
349 |
syserror("malloc"); |
350 |
do { |
351 |
sb->sampe = se; |
352 |
sb->len = sl>>se; |
353 |
sb->nscans = ns; |
354 |
sb->sdata = (COLOR *)malloc(sb->len*ns*sizeof(COLOR)); |
355 |
if (sb->sdata == NULL) |
356 |
syserror("malloc"); |
357 |
sb->nread = 0; |
358 |
ns <<= 1; |
359 |
sb++; |
360 |
} while (--se >= 0); |
361 |
return(sbarr); |
362 |
} |
363 |
|
364 |
|
365 |
initacuity() /* initialize variable acuity sampling */ |
366 |
{ |
367 |
FVECT diffx, diffy, cp; |
368 |
double omega, maxsr; |
369 |
register int x, y, i; |
370 |
|
371 |
compraydir(); /* compute ray directions */ |
372 |
|
373 |
inpacuD = (float *)malloc(fvxr*fvyr*sizeof(float)); |
374 |
if (inpacuD == NULL) |
375 |
syserror("malloc"); |
376 |
maxsr = 1.; /* compute internal sample rates */ |
377 |
for (y = 1; y < fvyr-1; y++) |
378 |
for (x = 1; x < fvxr-1; x++) { |
379 |
for (i = 0; i < 3; i++) { |
380 |
diffx[i] = 0.5*fvxr/scanlen(&inpres) * |
381 |
(rdirscan(y)[x+1][i] - |
382 |
rdirscan(y)[x-1][i]); |
383 |
diffy[i] = 0.5*fvyr/numscans(&inpres) * |
384 |
(rdirscan(y+1)[x][i] - |
385 |
rdirscan(y-1)[x][i]); |
386 |
} |
387 |
fcross(cp, diffx, diffy); |
388 |
omega = 0.5 * sqrt(DOT(cp,cp)); |
389 |
if (omega <= FTINY*FTINY) |
390 |
tsampr(x,y) = 1.; |
391 |
else if ((tsampr(x,y) = PI/180. / sqrt(omega) / |
392 |
hacuity(plum(fovscan(y)[x]))) > maxsr) |
393 |
maxsr = tsampr(x,y); |
394 |
} |
395 |
/* copy perimeter (easier) */ |
396 |
for (x = 1; x < fvxr-1; x++) { |
397 |
tsampr(x,0) = tsampr(x,1); |
398 |
tsampr(x,fvyr-1) = tsampr(x,fvyr-2); |
399 |
} |
400 |
for (y = 0; y < fvyr; y++) { |
401 |
tsampr(0,y) = tsampr(1,y); |
402 |
tsampr(fvxr-1,y) = tsampr(fvxr-2,y); |
403 |
} |
404 |
/* initialize with next power of two */ |
405 |
rootbar = sballoc((int)(log(maxsr)/log(2.))+1, 2, scanlen(&inpres)); |
406 |
} |