| 1 | greg | 2.1 | #ifndef lint | 
| 2 | greg | 2.5 | static const char       RCSid[] = "$Id$"; | 
| 3 | greg | 2.1 | #endif | 
| 4 |  |  | /* | 
| 5 |  |  | * Draw small sources into image in case we missed them. | 
| 6 | greg | 2.5 | * | 
| 7 |  |  | *  External symbols declared in ray.h | 
| 8 |  |  | */ | 
| 9 |  |  |  | 
| 10 | greg | 2.6 | #include "copyright.h" | 
| 11 | greg | 2.1 |  | 
| 12 |  |  | #include  "ray.h" | 
| 13 |  |  |  | 
| 14 |  |  | #include  "view.h" | 
| 15 |  |  |  | 
| 16 |  |  | #include  "source.h" | 
| 17 |  |  |  | 
| 18 |  |  |  | 
| 19 |  |  | #define CLIP_ABOVE      1 | 
| 20 |  |  | #define CLIP_BELOW      2 | 
| 21 |  |  | #define CLIP_RIGHT      3 | 
| 22 |  |  | #define CLIP_LEFT       4 | 
| 23 |  |  |  | 
| 24 |  |  | #define MAXVERT         10 | 
| 25 |  |  |  | 
| 26 | greg | 2.3 | typedef struct splist { | 
| 27 |  |  | struct splist   *next;                  /* next source in list */ | 
| 28 |  |  | int     sn;                             /* source number */ | 
| 29 |  |  | short   nv;                             /* number of vertices */ | 
| 30 |  |  | FLOAT   vl[3][2];                       /* vertex array (last) */ | 
| 31 |  |  | } SPLIST;                               /* source polygon list */ | 
| 32 | greg | 2.1 |  | 
| 33 | greg | 2.3 | extern VIEW     ourview;                /* our view parameters */ | 
| 34 |  |  | extern int      hres, vres;             /* our image resolution */ | 
| 35 |  |  | static SPLIST   *sphead = NULL;         /* our list of source polys */ | 
| 36 |  |  |  | 
| 37 |  |  |  | 
| 38 | greg | 2.1 | static int | 
| 39 |  |  | inregion(p, cv, crit)                   /* check if vertex is in region */ | 
| 40 |  |  | FLOAT   p[2]; | 
| 41 |  |  | double  cv; | 
| 42 |  |  | int     crit; | 
| 43 |  |  | { | 
| 44 |  |  | switch (crit) { | 
| 45 |  |  | case CLIP_ABOVE: | 
| 46 |  |  | return(p[1] < cv); | 
| 47 |  |  | case CLIP_BELOW: | 
| 48 |  |  | return(p[1] >= cv); | 
| 49 |  |  | case CLIP_RIGHT: | 
| 50 |  |  | return(p[0] < cv); | 
| 51 |  |  | case CLIP_LEFT: | 
| 52 |  |  | return(p[0] >= cv); | 
| 53 |  |  | } | 
| 54 |  |  | return(-1); | 
| 55 |  |  | } | 
| 56 |  |  |  | 
| 57 |  |  |  | 
| 58 |  |  | static | 
| 59 |  |  | clipregion(a, b, cv, crit, r)           /* find intersection with boundary */ | 
| 60 |  |  | register FLOAT  a[2], b[2]; | 
| 61 |  |  | double  cv; | 
| 62 |  |  | int     crit; | 
| 63 |  |  | FLOAT   r[2];   /* return value */ | 
| 64 |  |  | { | 
| 65 |  |  | switch (crit) { | 
| 66 |  |  | case CLIP_ABOVE: | 
| 67 |  |  | case CLIP_BELOW: | 
| 68 |  |  | r[1] = cv; | 
| 69 |  |  | r[0] = a[0] + (cv-a[1])/(b[1]-a[1])*(b[0]-a[0]); | 
| 70 |  |  | return; | 
| 71 |  |  | case CLIP_RIGHT: | 
| 72 |  |  | case CLIP_LEFT: | 
| 73 |  |  | r[0] = cv; | 
| 74 |  |  | r[1] = a[1] + (cv-a[0])/(b[0]-a[0])*(b[1]-a[1]); | 
| 75 |  |  | return; | 
| 76 |  |  | } | 
| 77 |  |  | } | 
| 78 |  |  |  | 
| 79 |  |  |  | 
| 80 |  |  | static int | 
| 81 |  |  | hp_clip_poly(vl, nv, cv, crit, vlo)     /* clip polygon to half-plane */ | 
| 82 |  |  | FLOAT   vl[][2]; | 
| 83 |  |  | int     nv; | 
| 84 |  |  | double  cv; | 
| 85 |  |  | int     crit; | 
| 86 |  |  | FLOAT   vlo[][2];       /* return value */ | 
| 87 |  |  | { | 
| 88 |  |  | FLOAT   *s, *p; | 
| 89 |  |  | register int    j, nvo; | 
| 90 |  |  |  | 
| 91 |  |  | s = vl[nv-1]; | 
| 92 |  |  | nvo = 0; | 
| 93 |  |  | for (j = 0; j < nv; j++) { | 
| 94 |  |  | p = vl[j]; | 
| 95 |  |  | if (inregion(p, cv, crit)) { | 
| 96 |  |  | if (!inregion(s, cv, crit)) | 
| 97 |  |  | clipregion(s, p, cv, crit, vlo[nvo++]); | 
| 98 |  |  | vlo[nvo][0] = p[0]; vlo[nvo++][1] = p[1]; | 
| 99 |  |  | } else if (inregion(s, cv, crit)) | 
| 100 |  |  | clipregion(s, p, cv, crit, vlo[nvo++]); | 
| 101 |  |  | s = p; | 
| 102 |  |  | } | 
| 103 |  |  | return(nvo); | 
| 104 |  |  | } | 
| 105 |  |  |  | 
| 106 |  |  |  | 
| 107 |  |  | static int | 
| 108 |  |  | box_clip_poly(vl, nv, xl, xr, yb, ya, vlo)      /* clip polygon to box */ | 
| 109 |  |  | FLOAT   vl[MAXVERT][2]; | 
| 110 |  |  | int     nv; | 
| 111 |  |  | double  xl, xr, yb, ya; | 
| 112 |  |  | FLOAT   vlo[MAXVERT][2];        /* return value */ | 
| 113 |  |  | { | 
| 114 |  |  | FLOAT   vlt[MAXVERT][2]; | 
| 115 |  |  | int     nvt, nvo; | 
| 116 |  |  |  | 
| 117 |  |  | nvt = hp_clip_poly(vl, nv, yb, CLIP_BELOW, vlt); | 
| 118 |  |  | nvo = hp_clip_poly(vlt, nvt, ya, CLIP_ABOVE, vlo); | 
| 119 |  |  | nvt = hp_clip_poly(vlo, nvo, xl, CLIP_LEFT, vlt); | 
| 120 |  |  | nvo = hp_clip_poly(vlt, nvt, xr, CLIP_RIGHT, vlo); | 
| 121 |  |  |  | 
| 122 |  |  | return(nvo); | 
| 123 |  |  | } | 
| 124 |  |  |  | 
| 125 |  |  |  | 
| 126 |  |  | static double | 
| 127 |  |  | minw2(vl, nv, ar2)                      /* compute square of minimum width */ | 
| 128 |  |  | FLOAT   vl[][2]; | 
| 129 |  |  | int     nv; | 
| 130 |  |  | double  ar2; | 
| 131 |  |  | { | 
| 132 |  |  | double  d2, w2, w2min, w2max; | 
| 133 |  |  | register FLOAT  *p0, *p1, *p2; | 
| 134 |  |  | int     i, j; | 
| 135 |  |  | /* find minimum for all widths */ | 
| 136 |  |  | w2min = FHUGE; | 
| 137 |  |  | p0 = vl[nv-1]; | 
| 138 |  |  | for (i = 0; i < nv; i++) {      /* for each edge */ | 
| 139 |  |  | p1 = vl[i]; | 
| 140 |  |  | d2 = (p1[0]-p0[0])*(p1[0]-p0[0]) + | 
| 141 |  |  | (p1[1]-p0[1])*(p1[1]-p0[1])*ar2; | 
| 142 |  |  | w2max = 0.;             /* find maximum for this side */ | 
| 143 |  |  | for (j = 1; j < nv-1; j++) { | 
| 144 |  |  | p2 = vl[(i+j)%nv]; | 
| 145 |  |  | w2 = (p1[0]-p0[0])*(p2[1]-p0[1]) - | 
| 146 |  |  | (p1[1]-p0[1])*(p2[0]-p0[0]); | 
| 147 |  |  | w2 = w2*w2*ar2/d2;      /* triangle height squared */ | 
| 148 |  |  | if (w2 > w2max) | 
| 149 |  |  | w2max = w2; | 
| 150 |  |  | } | 
| 151 |  |  | if (w2max < w2min)      /* global min. based on local max.'s */ | 
| 152 |  |  | w2min = w2max; | 
| 153 |  |  | p0 = p1; | 
| 154 |  |  | } | 
| 155 |  |  | return(w2min); | 
| 156 |  |  | } | 
| 157 |  |  |  | 
| 158 |  |  |  | 
| 159 |  |  | static | 
| 160 |  |  | convex_center(vl, nv, cv)               /* compute center of convex polygon */ | 
| 161 |  |  | register FLOAT  vl[][2]; | 
| 162 |  |  | int     nv; | 
| 163 |  |  | FLOAT   cv[2];          /* return value */ | 
| 164 |  |  | { | 
| 165 |  |  | register int    i; | 
| 166 |  |  | /* simple average (suboptimal) */ | 
| 167 |  |  | cv[0] = cv[1] = 0.; | 
| 168 |  |  | for (i = 0; i < nv; i++) { | 
| 169 |  |  | cv[0] += vl[i][0]; | 
| 170 |  |  | cv[1] += vl[i][1]; | 
| 171 |  |  | } | 
| 172 |  |  | cv[0] /= (double)nv; | 
| 173 |  |  | cv[1] /= (double)nv; | 
| 174 |  |  | } | 
| 175 |  |  |  | 
| 176 |  |  |  | 
| 177 |  |  | static double | 
| 178 |  |  | poly_area(vl, nv)                       /* compute area of polygon */ | 
| 179 |  |  | register FLOAT  vl[][2]; | 
| 180 |  |  | int     nv; | 
| 181 |  |  | { | 
| 182 |  |  | double  a; | 
| 183 |  |  | FLOAT   v0[2], v1[2]; | 
| 184 |  |  | register int    i; | 
| 185 |  |  |  | 
| 186 |  |  | a = 0.; | 
| 187 |  |  | v0[0] = vl[1][0] - vl[0][0]; | 
| 188 |  |  | v0[1] = vl[1][1] - vl[0][1]; | 
| 189 |  |  | for (i = 2; i < nv; i++) { | 
| 190 |  |  | v1[0] = vl[i][0] - vl[0][0]; | 
| 191 |  |  | v1[1] = vl[i][1] - vl[0][1]; | 
| 192 |  |  | a += v0[0]*v1[1] - v0[1]*v1[0]; | 
| 193 |  |  | v0[0] = v1[0]; v0[1] = v1[1]; | 
| 194 |  |  | } | 
| 195 |  |  | return(a * (a >= 0. ? .5 : -.5)); | 
| 196 |  |  | } | 
| 197 |  |  |  | 
| 198 |  |  |  | 
| 199 |  |  | static int | 
| 200 |  |  | convex_hull(vl, nv, vlo)                /* compute polygon's convex hull */ | 
| 201 |  |  | FLOAT   vl[][2]; | 
| 202 |  |  | int     nv; | 
| 203 |  |  | FLOAT   vlo[][2];       /* return value */ | 
| 204 |  |  | { | 
| 205 |  |  | int     nvo, nvt; | 
| 206 |  |  | FLOAT   vlt[MAXVERT][2]; | 
| 207 |  |  | double  voa, vta; | 
| 208 |  |  | register int    i, j; | 
| 209 |  |  | /* start with original polygon */ | 
| 210 |  |  | for (i = nvo = nv; i--; ) { | 
| 211 |  |  | vlo[i][0] = vl[i][0]; vlo[i][1] = vl[i][1]; | 
| 212 |  |  | } | 
| 213 |  |  | voa = poly_area(vlo, nvo);      /* compute its area */ | 
| 214 |  |  | for (i = 0; i < nvo; i++) {             /* for each output vertex */ | 
| 215 |  |  | for (j = 0; j < i; j++) { | 
| 216 |  |  | vlt[j][0] = vlo[j][0]; vlt[j][1] = vlo[j][1]; | 
| 217 |  |  | } | 
| 218 |  |  | nvt = nvo - 1;                  /* make poly w/o vertex */ | 
| 219 |  |  | for (j = i; j < nvt; j++) { | 
| 220 |  |  | vlt[j][0] = vlo[j+1][0]; vlt[j][1] = vlo[j+1][1]; | 
| 221 |  |  | } | 
| 222 |  |  | vta = poly_area(vlt, nvt); | 
| 223 |  |  | if (vta >= voa) {               /* is simpler poly bigger? */ | 
| 224 |  |  | voa = vta;                      /* then use it */ | 
| 225 |  |  | for (j = nvo = nvt; j--; ) { | 
| 226 |  |  | vlo[j][0] = vlt[j][0]; vlo[j][1] = vlt[j][1]; | 
| 227 |  |  | } | 
| 228 |  |  | i--;                            /* next adjust */ | 
| 229 |  |  | } | 
| 230 |  |  | } | 
| 231 |  |  | return(nvo); | 
| 232 |  |  | } | 
| 233 |  |  |  | 
| 234 |  |  |  | 
| 235 | greg | 2.3 | static | 
| 236 |  |  | spinsert(sn, vl, nv)                    /* insert new source polygon */ | 
| 237 |  |  | int     sn; | 
| 238 |  |  | FLOAT   vl[][2]; | 
| 239 |  |  | int     nv; | 
| 240 |  |  | { | 
| 241 |  |  | register SPLIST *spn; | 
| 242 |  |  | register int    i; | 
| 243 |  |  |  | 
| 244 |  |  | if (nv < 3) | 
| 245 |  |  | return; | 
| 246 |  |  | if (nv > 3) | 
| 247 |  |  | spn = (SPLIST *)malloc(sizeof(SPLIST)+sizeof(FLOAT)*2*(nv-3)); | 
| 248 |  |  | else | 
| 249 |  |  | spn = (SPLIST *)malloc(sizeof(SPLIST)); | 
| 250 |  |  | if (spn == NULL) | 
| 251 |  |  | error(SYSTEM, "out of memory in spinsert"); | 
| 252 |  |  | spn->sn = sn; | 
| 253 |  |  | for (i = spn->nv = nv; i--; ) { | 
| 254 |  |  | spn->vl[i][0] = vl[i][0]; spn->vl[i][1] = vl[i][1]; | 
| 255 |  |  | } | 
| 256 |  |  | spn->next = sphead;             /* push onto global list */ | 
| 257 |  |  | sphead = spn; | 
| 258 |  |  | } | 
| 259 |  |  |  | 
| 260 |  |  |  | 
| 261 | greg | 2.1 | int | 
| 262 | greg | 2.3 | sourcepoly(sn, sp)                      /* compute image polygon for source */ | 
| 263 | greg | 2.1 | int     sn; | 
| 264 |  |  | FLOAT   sp[MAXVERT][2]; | 
| 265 |  |  | { | 
| 266 |  |  | static char     cubeord[8][6] = {{1,3,2,6,4,5},{0,4,5,7,3,2}, | 
| 267 |  |  | {0,1,3,7,6,4},{0,1,5,7,6,2}, | 
| 268 |  |  | {0,2,6,7,5,1},{0,4,6,7,3,1}, | 
| 269 |  |  | {0,2,3,7,5,4},{1,5,4,6,2,3}}; | 
| 270 |  |  | register SRCREC *s = source + sn; | 
| 271 |  |  | FVECT   ap, ip; | 
| 272 |  |  | FLOAT   pt[6][2]; | 
| 273 |  |  | int     dir; | 
| 274 |  |  | register int    i, j; | 
| 275 |  |  |  | 
| 276 |  |  | if (s->sflags & (SDISTANT|SFLAT)) { | 
| 277 | greg | 2.3 | if (s->sflags & SDISTANT && ourview.type == VT_PAR) | 
| 278 | greg | 2.1 | return(0);              /* all or nothing case */ | 
| 279 |  |  | if (s->sflags & SFLAT) { | 
| 280 |  |  | for (i = 0; i < 3; i++) | 
| 281 | greg | 2.3 | ap[i] = s->sloc[i] - ourview.vp[i]; | 
| 282 | greg | 2.1 | if (DOT(ap, s->snorm) >= 0.) | 
| 283 |  |  | return(0);      /* source faces away */ | 
| 284 |  |  | } | 
| 285 |  |  | for (j = 0; j < 4; j++) {       /* four corners */ | 
| 286 |  |  | for (i = 0; i < 3; i++) { | 
| 287 |  |  | ap[i] = s->sloc[i]; | 
| 288 |  |  | if (j==1|j==2) ap[i] += s->ss[SU][i]; | 
| 289 |  |  | else ap[i] -= s->ss[SU][i]; | 
| 290 |  |  | if (j==2|j==3) ap[i] += s->ss[SV][i]; | 
| 291 |  |  | else ap[i] -= s->ss[SV][i]; | 
| 292 |  |  | if (s->sflags & SDISTANT) { | 
| 293 | greg | 2.3 | ap[i] *= 1. + ourview.vfore; | 
| 294 |  |  | ap[i] += ourview.vp[i]; | 
| 295 | greg | 2.1 | } | 
| 296 |  |  | } | 
| 297 | greg | 2.3 | viewloc(ip, &ourview, ap);      /* find image point */ | 
| 298 | greg | 2.1 | if (ip[2] <= 0.) | 
| 299 |  |  | return(0);              /* in front of view */ | 
| 300 |  |  | sp[j][0] = ip[0]; sp[j][1] = ip[1]; | 
| 301 |  |  | } | 
| 302 |  |  | return(4); | 
| 303 |  |  | } | 
| 304 |  |  | /* identify furthest corner */ | 
| 305 |  |  | for (i = 0; i < 3; i++) | 
| 306 | greg | 2.3 | ap[i] = s->sloc[i] - ourview.vp[i]; | 
| 307 | greg | 2.1 | dir =   (DOT(ap,s->ss[SU])>0.) | | 
| 308 |  |  | (DOT(ap,s->ss[SV])>0.)<<1 | | 
| 309 |  |  | (DOT(ap,s->ss[SW])>0.)<<2 ; | 
| 310 |  |  | /* order vertices based on this */ | 
| 311 |  |  | for (j = 0; j < 6; j++) { | 
| 312 |  |  | for (i = 0; i < 3; i++) { | 
| 313 |  |  | ap[i] = s->sloc[i]; | 
| 314 |  |  | if (cubeord[dir][j] & 1) ap[i] += s->ss[SU][i]; | 
| 315 |  |  | else ap[i] -= s->ss[SU][i]; | 
| 316 |  |  | if (cubeord[dir][j] & 2) ap[i] += s->ss[SV][i]; | 
| 317 |  |  | else ap[i] -= s->ss[SV][i]; | 
| 318 |  |  | if (cubeord[dir][j] & 4) ap[i] += s->ss[SW][i]; | 
| 319 |  |  | else ap[i] -= s->ss[SW][i]; | 
| 320 |  |  | } | 
| 321 | greg | 2.3 | viewloc(ip, &ourview, ap);      /* find image point */ | 
| 322 | greg | 2.1 | if (ip[2] <= 0.) | 
| 323 |  |  | return(0);              /* in front of view */ | 
| 324 |  |  | pt[j][0] = ip[0]; pt[j][1] = ip[1]; | 
| 325 |  |  | } | 
| 326 |  |  | return(convex_hull(pt, 6, sp));         /* make sure it's convex */ | 
| 327 |  |  | } | 
| 328 |  |  |  | 
| 329 |  |  |  | 
| 330 | greg | 2.3 | /* initialize by finding sources smaller than rad */ | 
| 331 |  |  | init_drawsources(rad) | 
| 332 |  |  | int     rad;                            /* source sample size */ | 
| 333 |  |  | { | 
| 334 |  |  | FLOAT   spoly[MAXVERT][2]; | 
| 335 |  |  | int     nsv; | 
| 336 |  |  | register SPLIST *sp; | 
| 337 |  |  | register int    i; | 
| 338 |  |  | /* free old source list if one */ | 
| 339 |  |  | for (sp = sphead; sp != NULL; sp = sphead) { | 
| 340 |  |  | sphead = sp->next; | 
| 341 | greg | 2.5 | free((void *)sp); | 
| 342 | greg | 2.3 | } | 
| 343 |  |  | /* loop through all sources */ | 
| 344 |  |  | for (i = nsources; i--; ) { | 
| 345 |  |  | /* compute image polygon for source */ | 
| 346 |  |  | if (!(nsv = sourcepoly(i, spoly))) | 
| 347 |  |  | continue; | 
| 348 |  |  | /* clip to image boundaries */ | 
| 349 |  |  | if (!(nsv = box_clip_poly(spoly, nsv, 0., 1., 0., 1., spoly))) | 
| 350 |  |  | continue; | 
| 351 |  |  | /* big enough for standard sampling? */ | 
| 352 |  |  | if (minw2(spoly, nsv, ourview.vn2/ourview.hn2) > | 
| 353 |  |  | (double)rad*rad/hres/hres) | 
| 354 |  |  | continue; | 
| 355 |  |  | /* OK, add to our list */ | 
| 356 |  |  | spinsert(i, spoly, nsv); | 
| 357 |  |  | } | 
| 358 |  |  | } | 
| 359 |  |  |  | 
| 360 | greg | 2.5 | void                    /* add sources smaller than rad to computed subimage */ | 
| 361 | greg | 2.3 | drawsources(pic, zbf, x0, xsiz, y0, ysiz) | 
| 362 | greg | 2.1 | COLOR   *pic[];                         /* subimage pixel value array */ | 
| 363 |  |  | float   *zbf[];                         /* subimage distance array (opt.) */ | 
| 364 |  |  | int     x0, xsiz, y0, ysiz;             /* origin and size of subimage */ | 
| 365 |  |  | { | 
| 366 |  |  | FLOAT   spoly[MAXVERT][2], ppoly[MAXVERT][2]; | 
| 367 |  |  | int     nsv, npv; | 
| 368 | greg | 2.3 | int     xmin, xmax, ymin, ymax, x, y; | 
| 369 | greg | 2.1 | FLOAT   cxy[2]; | 
| 370 | gregl | 2.4 | double  w; | 
| 371 | greg | 2.1 | RAY     sr; | 
| 372 | greg | 2.3 | register SPLIST *sp; | 
| 373 |  |  | register int    i; | 
| 374 |  |  | /* check each source in our list */ | 
| 375 |  |  | for (sp = sphead; sp != NULL; sp = sp->next) { | 
| 376 | greg | 2.1 | /* clip source poly to subimage */ | 
| 377 | greg | 2.3 | nsv = box_clip_poly(sp->vl, sp->nv, | 
| 378 |  |  | (double)x0/hres, (double)(x0+xsiz)/hres, | 
| 379 |  |  | (double)y0/vres, (double)(y0+ysiz)/vres, spoly); | 
| 380 | greg | 2.1 | if (!nsv) | 
| 381 |  |  | continue; | 
| 382 |  |  | /* find common subimage (BBox) */ | 
| 383 |  |  | xmin = x0 + xsiz; xmax = x0; | 
| 384 |  |  | ymin = y0 + ysiz; ymax = y0; | 
| 385 |  |  | for (i = 0; i < nsv; i++) { | 
| 386 | greg | 2.3 | if ((double)xmin/hres > spoly[i][0]) | 
| 387 |  |  | xmin = spoly[i][0]*hres + FTINY; | 
| 388 |  |  | if ((double)xmax/hres < spoly[i][0]) | 
| 389 |  |  | xmax = spoly[i][0]*hres - FTINY; | 
| 390 |  |  | if ((double)ymin/vres > spoly[i][1]) | 
| 391 |  |  | ymin = spoly[i][1]*vres + FTINY; | 
| 392 |  |  | if ((double)ymax/vres < spoly[i][1]) | 
| 393 |  |  | ymax = spoly[i][1]*vres - FTINY; | 
| 394 | greg | 2.1 | } | 
| 395 |  |  | /* evaluate each pixel in BBox */ | 
| 396 |  |  | for (y = ymin; y <= ymax; y++) | 
| 397 |  |  | for (x = xmin; x <= xmax; x++) { | 
| 398 |  |  | /* subarea for pixel */ | 
| 399 |  |  | npv = box_clip_poly(spoly, nsv, | 
| 400 | greg | 2.3 | (double)x/hres, (x+1.)/hres, | 
| 401 |  |  | (double)y/vres, (y+1.)/vres, | 
| 402 |  |  | ppoly); | 
| 403 | greg | 2.1 | if (!npv) | 
| 404 |  |  | continue;       /* no overlap */ | 
| 405 |  |  | convex_center(ppoly, npv, cxy); | 
| 406 | greg | 2.3 | if ((sr.rmax = viewray(sr.rorg,sr.rdir,&ourview, | 
| 407 |  |  | cxy[0],cxy[1])) < -FTINY) | 
| 408 | greg | 2.1 | continue;       /* not in view */ | 
| 409 | greg | 2.3 | if (source[sp->sn].sflags & SSPOT && | 
| 410 |  |  | spotout(&sr, source[sp->sn].sl.s)) | 
| 411 | greg | 2.1 | continue;       /* outside spot */ | 
| 412 |  |  | rayorigin(&sr, NULL, SHADOW, 1.0); | 
| 413 | greg | 2.3 | sr.rsrc = sp->sn; | 
| 414 | greg | 2.1 | rayvalue(&sr);          /* compute value */ | 
| 415 |  |  | if (bright(sr.rcol) <= FTINY) | 
| 416 |  |  | continue;       /* missed/blocked */ | 
| 417 |  |  | /* modify pixel */ | 
| 418 |  |  | if (zbf[y-y0] != NULL && | 
| 419 | gregl | 2.4 | sr.rt < 0.999*zbf[y-y0][x-x0]) | 
| 420 | greg | 2.1 | zbf[y-y0][x-x0] = sr.rt; | 
| 421 | gregl | 2.4 | else if (!bigdiff(sr.rcol, pic[y-y0][x-x0], | 
| 422 |  |  | 0.001)) /* source sample */ | 
| 423 |  |  | setcolor(pic[y-y0][x-x0], 0., 0., 0.); | 
| 424 |  |  | w = poly_area(ppoly, npv) * hres * vres; | 
| 425 |  |  | scalecolor(sr.rcol, w); | 
| 426 |  |  | scalecolor(pic[y-y0][x-x0], 1.-w); | 
| 427 | greg | 2.1 | addcolor(pic[y-y0][x-x0], sr.rcol); | 
| 428 |  |  | } | 
| 429 |  |  | } | 
| 430 |  |  | } |