| 10 |  |  | 
| 11 |  | #include "pcond.h" | 
| 12 |  |  | 
| 13 | + | /************** VEILING STUFF *****************/ | 
| 14 |  |  | 
| 15 |  | #define VADAPT          0.08            /* fraction of adaptation from veil */ | 
| 16 |  |  | 
| 138 |  | (1.-dx)*lv + dx*uv; | 
| 139 |  | } | 
| 140 |  | } | 
| 141 | + | } | 
| 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 |  | } |