| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: srcdraw.c,v 2.20 2018/11/13 19:58:33 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Draw small sources into image in case we missed them. |
| 6 |
* |
| 7 |
* External symbols declared in ray.h |
| 8 |
*/ |
| 9 |
|
| 10 |
#include "copyright.h" |
| 11 |
|
| 12 |
#include "ray.h" |
| 13 |
#include "view.h" |
| 14 |
#include "otypes.h" |
| 15 |
#include "otspecial.h" |
| 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 |
typedef struct splist { |
| 27 |
struct splist *next; /* next source in list */ |
| 28 |
int sn; /* source number */ |
| 29 |
short nv; /* number of vertices */ |
| 30 |
RREAL vl[3][2]; /* vertex array (last) */ |
| 31 |
} SPLIST; /* source polygon list */ |
| 32 |
|
| 33 |
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 |
static int inregion(RREAL p[2], double cv, int crit); |
| 38 |
static void clipregion(RREAL a[2], RREAL b[2], double cv, int crit, RREAL r[2]); |
| 39 |
static int hp_clip_poly(RREAL vl[][2], int nv, double cv, int crit, |
| 40 |
RREAL vlo[][2]); |
| 41 |
static int box_clip_poly(RREAL vl[MAXVERT][2], int nv, |
| 42 |
double xl, double xr, double yb, double ya, RREAL vlo[MAXVERT][2]); |
| 43 |
static double minw2(RREAL vl[][2], int nv, double ar2); |
| 44 |
static void convex_center(RREAL vl[][2], int nv, RREAL cv[2]); |
| 45 |
static double poly_area(RREAL vl[][2], int nv); |
| 46 |
static int convex_hull(RREAL vl[][2], int nv, RREAL vlo[][2]); |
| 47 |
static void spinsert(int sn, RREAL vl[][2], int nv); |
| 48 |
static int sourcepoly(int sn, RREAL sp[MAXVERT][2]); |
| 49 |
|
| 50 |
|
| 51 |
static int |
| 52 |
inregion( /* check if vertex is in region */ |
| 53 |
RREAL p[2], |
| 54 |
double cv, |
| 55 |
int crit |
| 56 |
) |
| 57 |
{ |
| 58 |
switch (crit) { |
| 59 |
case CLIP_ABOVE: |
| 60 |
return(p[1] < cv); |
| 61 |
case CLIP_BELOW: |
| 62 |
return(p[1] >= cv); |
| 63 |
case CLIP_RIGHT: |
| 64 |
return(p[0] < cv); |
| 65 |
case CLIP_LEFT: |
| 66 |
return(p[0] >= cv); |
| 67 |
} |
| 68 |
return(-1); |
| 69 |
} |
| 70 |
|
| 71 |
|
| 72 |
static void |
| 73 |
clipregion( /* find intersection with boundary */ |
| 74 |
RREAL a[2], |
| 75 |
RREAL b[2], |
| 76 |
double cv, |
| 77 |
int crit, |
| 78 |
RREAL r[2] /* return value */ |
| 79 |
) |
| 80 |
{ |
| 81 |
switch (crit) { |
| 82 |
case CLIP_ABOVE: |
| 83 |
case CLIP_BELOW: |
| 84 |
r[1] = cv; |
| 85 |
r[0] = a[0] + (cv-a[1])/(b[1]-a[1])*(b[0]-a[0]); |
| 86 |
return; |
| 87 |
case CLIP_RIGHT: |
| 88 |
case CLIP_LEFT: |
| 89 |
r[0] = cv; |
| 90 |
r[1] = a[1] + (cv-a[0])/(b[0]-a[0])*(b[1]-a[1]); |
| 91 |
return; |
| 92 |
} |
| 93 |
} |
| 94 |
|
| 95 |
|
| 96 |
static int |
| 97 |
hp_clip_poly( /* clip polygon to half-plane */ |
| 98 |
RREAL vl[][2], |
| 99 |
int nv, |
| 100 |
double cv, |
| 101 |
int crit, |
| 102 |
RREAL vlo[][2] /* return value */ |
| 103 |
) |
| 104 |
{ |
| 105 |
RREAL *s, *p; |
| 106 |
int j, nvo; |
| 107 |
|
| 108 |
s = vl[nv-1]; |
| 109 |
nvo = 0; |
| 110 |
for (j = 0; j < nv; j++) { |
| 111 |
p = vl[j]; |
| 112 |
if (inregion(p, cv, crit)) { |
| 113 |
if (!inregion(s, cv, crit)) |
| 114 |
clipregion(s, p, cv, crit, vlo[nvo++]); |
| 115 |
vlo[nvo][0] = p[0]; vlo[nvo++][1] = p[1]; |
| 116 |
} else if (inregion(s, cv, crit)) |
| 117 |
clipregion(s, p, cv, crit, vlo[nvo++]); |
| 118 |
s = p; |
| 119 |
} |
| 120 |
return(nvo); |
| 121 |
} |
| 122 |
|
| 123 |
|
| 124 |
static int |
| 125 |
box_clip_poly( /* clip polygon to box */ |
| 126 |
RREAL vl[MAXVERT][2], |
| 127 |
int nv, |
| 128 |
double xl, |
| 129 |
double xr, |
| 130 |
double yb, |
| 131 |
double ya, |
| 132 |
RREAL vlo[MAXVERT][2] /* return value */ |
| 133 |
) |
| 134 |
{ |
| 135 |
RREAL vlt[MAXVERT][2]; |
| 136 |
int nvt, nvo; |
| 137 |
|
| 138 |
nvt = hp_clip_poly(vl, nv, yb, CLIP_BELOW, vlt); |
| 139 |
nvo = hp_clip_poly(vlt, nvt, ya, CLIP_ABOVE, vlo); |
| 140 |
nvt = hp_clip_poly(vlo, nvo, xl, CLIP_LEFT, vlt); |
| 141 |
nvo = hp_clip_poly(vlt, nvt, xr, CLIP_RIGHT, vlo); |
| 142 |
|
| 143 |
return(nvo); |
| 144 |
} |
| 145 |
|
| 146 |
|
| 147 |
static double |
| 148 |
minw2( /* compute square of minimum width */ |
| 149 |
RREAL vl[][2], |
| 150 |
int nv, |
| 151 |
double ar2 |
| 152 |
) |
| 153 |
{ |
| 154 |
double d2, w2, w2min, w2max; |
| 155 |
RREAL *p0, *p1, *p2; |
| 156 |
int i, j; |
| 157 |
/* find minimum for all widths */ |
| 158 |
w2min = FHUGE; |
| 159 |
p0 = vl[nv-1]; |
| 160 |
for (i = 0; i < nv; i++) { /* for each edge */ |
| 161 |
p1 = vl[i]; |
| 162 |
d2 = (p1[0]-p0[0])*(p1[0]-p0[0]) + |
| 163 |
(p1[1]-p0[1])*(p1[1]-p0[1])*ar2; |
| 164 |
w2max = 0.; /* find maximum for this side */ |
| 165 |
for (j = 1; j < nv-1; j++) { |
| 166 |
p2 = vl[(i+j)%nv]; |
| 167 |
w2 = (p1[0]-p0[0])*(p2[1]-p0[1]) - |
| 168 |
(p1[1]-p0[1])*(p2[0]-p0[0]); |
| 169 |
w2 = w2*w2*ar2/d2; /* triangle height squared */ |
| 170 |
if (w2 > w2max) |
| 171 |
w2max = w2; |
| 172 |
} |
| 173 |
if (w2max < w2min) /* global min. based on local max.'s */ |
| 174 |
w2min = w2max; |
| 175 |
p0 = p1; |
| 176 |
} |
| 177 |
return(w2min); |
| 178 |
} |
| 179 |
|
| 180 |
|
| 181 |
static void |
| 182 |
convex_center( /* compute center of convex polygon */ |
| 183 |
RREAL vl[][2], |
| 184 |
int nv, |
| 185 |
RREAL cv[2] /* return value */ |
| 186 |
) |
| 187 |
{ |
| 188 |
int i; |
| 189 |
/* simple average (suboptimal) */ |
| 190 |
cv[0] = cv[1] = 0.; |
| 191 |
for (i = 0; i < nv; i++) { |
| 192 |
cv[0] += vl[i][0]; |
| 193 |
cv[1] += vl[i][1]; |
| 194 |
} |
| 195 |
cv[0] /= (double)nv; |
| 196 |
cv[1] /= (double)nv; |
| 197 |
} |
| 198 |
|
| 199 |
|
| 200 |
static double |
| 201 |
poly_area( /* compute area of polygon */ |
| 202 |
RREAL vl[][2], |
| 203 |
int nv |
| 204 |
) |
| 205 |
{ |
| 206 |
double a; |
| 207 |
RREAL v0[2], v1[2]; |
| 208 |
int i; |
| 209 |
|
| 210 |
a = 0.; |
| 211 |
v0[0] = vl[1][0] - vl[0][0]; |
| 212 |
v0[1] = vl[1][1] - vl[0][1]; |
| 213 |
for (i = 2; i < nv; i++) { |
| 214 |
v1[0] = vl[i][0] - vl[0][0]; |
| 215 |
v1[1] = vl[i][1] - vl[0][1]; |
| 216 |
a += v0[0]*v1[1] - v0[1]*v1[0]; |
| 217 |
v0[0] = v1[0]; v0[1] = v1[1]; |
| 218 |
} |
| 219 |
return(a * (a >= 0. ? .5 : -.5)); |
| 220 |
} |
| 221 |
|
| 222 |
|
| 223 |
static int |
| 224 |
convex_hull( /* compute polygon's convex hull */ |
| 225 |
RREAL vl[][2], |
| 226 |
int nv, |
| 227 |
RREAL vlo[][2] /* return value */ |
| 228 |
) |
| 229 |
{ |
| 230 |
int nvo, nvt; |
| 231 |
RREAL vlt[MAXVERT][2]; |
| 232 |
double voa, vta; |
| 233 |
int i, j; |
| 234 |
/* start with original polygon */ |
| 235 |
for (i = nvo = nv; i--; ) { |
| 236 |
vlo[i][0] = vl[i][0]; vlo[i][1] = vl[i][1]; |
| 237 |
} |
| 238 |
voa = poly_area(vlo, nvo); /* compute its area */ |
| 239 |
for (i = 0; i < nvo; i++) { /* for each output vertex */ |
| 240 |
for (j = 0; j < i; j++) { |
| 241 |
vlt[j][0] = vlo[j][0]; vlt[j][1] = vlo[j][1]; |
| 242 |
} |
| 243 |
nvt = nvo - 1; /* make poly w/o vertex */ |
| 244 |
for (j = i; j < nvt; j++) { |
| 245 |
vlt[j][0] = vlo[j+1][0]; vlt[j][1] = vlo[j+1][1]; |
| 246 |
} |
| 247 |
vta = poly_area(vlt, nvt); |
| 248 |
if (vta >= voa) { /* is simpler poly bigger? */ |
| 249 |
voa = vta; /* then use it */ |
| 250 |
for (j = nvo = nvt; j--; ) { |
| 251 |
vlo[j][0] = vlt[j][0]; vlo[j][1] = vlt[j][1]; |
| 252 |
} |
| 253 |
i--; /* next adjust */ |
| 254 |
} |
| 255 |
} |
| 256 |
return(nvo); |
| 257 |
} |
| 258 |
|
| 259 |
|
| 260 |
static void |
| 261 |
spinsert( /* insert new source polygon */ |
| 262 |
int sn, |
| 263 |
RREAL vl[][2], |
| 264 |
int nv |
| 265 |
) |
| 266 |
{ |
| 267 |
SPLIST *spn; |
| 268 |
int i; |
| 269 |
|
| 270 |
if (nv < 3) |
| 271 |
return; |
| 272 |
if (nv > 3) |
| 273 |
spn = (SPLIST *)malloc(sizeof(SPLIST)+sizeof(RREAL)*2*(nv-3)); |
| 274 |
else |
| 275 |
spn = (SPLIST *)malloc(sizeof(SPLIST)); |
| 276 |
if (spn == NULL) |
| 277 |
error(SYSTEM, "out of memory in spinsert"); |
| 278 |
spn->sn = sn; |
| 279 |
for (i = spn->nv = nv; i--; ) { |
| 280 |
spn->vl[i][0] = vl[i][0]; spn->vl[i][1] = vl[i][1]; |
| 281 |
} |
| 282 |
spn->next = sphead; /* push onto global list */ |
| 283 |
sphead = spn; |
| 284 |
} |
| 285 |
|
| 286 |
|
| 287 |
static int |
| 288 |
sourcepoly( /* compute image polygon for source */ |
| 289 |
int sn, |
| 290 |
RREAL sp[MAXVERT][2] |
| 291 |
) |
| 292 |
{ |
| 293 |
static short cubeord[8][6] = {{1,3,2,6,4,5},{0,4,5,7,3,2}, |
| 294 |
{0,1,3,7,6,4},{0,1,5,7,6,2}, |
| 295 |
{0,2,6,7,5,1},{0,4,6,7,3,1}, |
| 296 |
{0,2,3,7,5,4},{1,5,4,6,2,3}}; |
| 297 |
SRCREC *s = source + sn; |
| 298 |
FVECT ap, ip; |
| 299 |
RREAL pt[6][2]; |
| 300 |
int dir; |
| 301 |
int i, j; |
| 302 |
|
| 303 |
if (s->sflags & (SDISTANT|SFLAT)) { |
| 304 |
if (s->sflags & SDISTANT) { |
| 305 |
if (ourview.type == VT_PAR) |
| 306 |
return(0); /* all or nothing case */ |
| 307 |
if (s->srad >= 0.05) |
| 308 |
return(0); /* should never be a problem */ |
| 309 |
} |
| 310 |
if (s->sflags & SFLAT) { |
| 311 |
for (i = 0; i < 3; i++) |
| 312 |
ap[i] = s->sloc[i] - ourview.vp[i]; |
| 313 |
if (DOT(ap, s->snorm) >= 0.) |
| 314 |
return(0); /* source faces away */ |
| 315 |
} |
| 316 |
for (j = 0; j < 4; j++) { /* four corners */ |
| 317 |
for (i = 0; i < 3; i++) { |
| 318 |
ap[i] = s->sloc[i]; |
| 319 |
if ((j==1)|(j==2)) ap[i] += s->ss[SU][i]; |
| 320 |
else ap[i] -= s->ss[SU][i]; |
| 321 |
if ((j==2)|(j==3)) ap[i] += s->ss[SV][i]; |
| 322 |
else ap[i] -= s->ss[SV][i]; |
| 323 |
if (s->sflags & SDISTANT) { |
| 324 |
ap[i] *= 1. + ourview.vfore; |
| 325 |
ap[i] += ourview.vp[i]; |
| 326 |
} |
| 327 |
} |
| 328 |
/* find image point */ |
| 329 |
if (viewloc(ip, &ourview, ap) != VL_GOOD) |
| 330 |
return(0); /* in front of view */ |
| 331 |
sp[j][0] = ip[0]; sp[j][1] = ip[1]; |
| 332 |
} |
| 333 |
return(4); |
| 334 |
} |
| 335 |
/* identify furthest corner */ |
| 336 |
for (i = 0; i < 3; i++) |
| 337 |
ap[i] = s->sloc[i] - ourview.vp[i]; |
| 338 |
dir = (DOT(ap,s->ss[SU])>0.) | |
| 339 |
(DOT(ap,s->ss[SV])>0.)<<1 | |
| 340 |
(DOT(ap,s->ss[SW])>0.)<<2 ; |
| 341 |
/* order vertices based on this */ |
| 342 |
for (j = 0; j < 6; j++) { |
| 343 |
for (i = 0; i < 3; i++) { |
| 344 |
ap[i] = s->sloc[i]; |
| 345 |
if (cubeord[dir][j] & 1) ap[i] += s->ss[SU][i]; |
| 346 |
else ap[i] -= s->ss[SU][i]; |
| 347 |
if (cubeord[dir][j] & 2) ap[i] += s->ss[SV][i]; |
| 348 |
else ap[i] -= s->ss[SV][i]; |
| 349 |
if (cubeord[dir][j] & 4) ap[i] += s->ss[SW][i]; |
| 350 |
else ap[i] -= s->ss[SW][i]; |
| 351 |
} |
| 352 |
/* find image point */ |
| 353 |
if (viewloc(ip, &ourview, ap) != VL_GOOD) |
| 354 |
return(0); /* in front of view */ |
| 355 |
pt[j][0] = ip[0]; pt[j][1] = ip[1]; |
| 356 |
} |
| 357 |
return(convex_hull(pt, 6, sp)); /* make sure it's convex */ |
| 358 |
} |
| 359 |
|
| 360 |
|
| 361 |
/* initialize by finding sources smaller than rad */ |
| 362 |
void |
| 363 |
init_drawsources( |
| 364 |
int rad /* source sample size */ |
| 365 |
) |
| 366 |
{ |
| 367 |
RREAL spoly[MAXVERT][2]; |
| 368 |
int nsv; |
| 369 |
SPLIST *sp; |
| 370 |
int i; |
| 371 |
/* free old source list if one */ |
| 372 |
for (sp = sphead; sp != NULL; sp = sphead) { |
| 373 |
sphead = sp->next; |
| 374 |
free((void *)sp); |
| 375 |
} |
| 376 |
/* loop through all sources */ |
| 377 |
for (i = nsources; i--; ) { |
| 378 |
/* skip illum's */ |
| 379 |
if (findmaterial(source[i].so)->otype == MAT_ILLUM) |
| 380 |
continue; |
| 381 |
/* compute image polygon for source */ |
| 382 |
if (!(nsv = sourcepoly(i, spoly))) |
| 383 |
continue; |
| 384 |
/* clip to image boundaries */ |
| 385 |
if (!(nsv = box_clip_poly(spoly, nsv, 0., 1., 0., 1., spoly))) |
| 386 |
continue; |
| 387 |
/* big enough for standard sampling? */ |
| 388 |
if (minw2(spoly, nsv, ourview.vn2/ourview.hn2) > |
| 389 |
(double)rad*rad/hres/hres) |
| 390 |
continue; |
| 391 |
/* OK, add to our list */ |
| 392 |
spinsert(i, spoly, nsv); |
| 393 |
} |
| 394 |
} |
| 395 |
|
| 396 |
void /* add sources smaller than rad to computed subimage */ |
| 397 |
drawsources( |
| 398 |
COLOR *pic[], /* subimage pixel value array */ |
| 399 |
float *zbf[], /* subimage distance array (opt.) */ |
| 400 |
int x0, /* origin and size of subimage */ |
| 401 |
int xsiz, |
| 402 |
int y0, |
| 403 |
int ysiz |
| 404 |
) |
| 405 |
{ |
| 406 |
RREAL spoly[MAXVERT][2], ppoly[MAXVERT][2]; |
| 407 |
int nsv, npv; |
| 408 |
int xmin, xmax, ymin, ymax, x, y; |
| 409 |
RREAL cxy[2]; |
| 410 |
double w; |
| 411 |
RAY sr; |
| 412 |
SPLIST *sp; |
| 413 |
int i; |
| 414 |
/* check each source in our list */ |
| 415 |
for (sp = sphead; sp != NULL; sp = sp->next) { |
| 416 |
/* clip source poly to subimage */ |
| 417 |
nsv = box_clip_poly(sp->vl, sp->nv, |
| 418 |
(double)x0/hres, (double)(x0+xsiz)/hres, |
| 419 |
(double)y0/vres, (double)(y0+ysiz)/vres, spoly); |
| 420 |
if (!nsv) |
| 421 |
continue; |
| 422 |
/* find common subimage (BBox) */ |
| 423 |
xmin = x0 + xsiz; xmax = x0; |
| 424 |
ymin = y0 + ysiz; ymax = y0; |
| 425 |
for (i = 0; i < nsv; i++) { |
| 426 |
if ((double)xmin/hres > spoly[i][0]) |
| 427 |
xmin = spoly[i][0]*hres + FTINY; |
| 428 |
if ((double)xmax/hres < spoly[i][0]) |
| 429 |
xmax = spoly[i][0]*hres - FTINY; |
| 430 |
if ((double)ymin/vres > spoly[i][1]) |
| 431 |
ymin = spoly[i][1]*vres + FTINY; |
| 432 |
if ((double)ymax/vres < spoly[i][1]) |
| 433 |
ymax = spoly[i][1]*vres - FTINY; |
| 434 |
} |
| 435 |
/* evaluate each pixel in BBox */ |
| 436 |
for (y = ymin; y <= ymax; y++) |
| 437 |
for (x = xmin; x <= xmax; x++) { |
| 438 |
/* subarea for pixel */ |
| 439 |
npv = box_clip_poly(spoly, nsv, |
| 440 |
(double)x/hres, (x+1.)/hres, |
| 441 |
(double)y/vres, (y+1.)/vres, |
| 442 |
ppoly); |
| 443 |
if (!npv) |
| 444 |
continue; /* no overlap */ |
| 445 |
convex_center(ppoly, npv, cxy); |
| 446 |
if ((sr.rmax = viewray(sr.rorg,sr.rdir,&ourview, |
| 447 |
cxy[0],cxy[1])) < -FTINY) |
| 448 |
continue; /* not in view */ |
| 449 |
if (source[sp->sn].sflags & SSPOT && |
| 450 |
spotout(&sr, source[sp->sn].sl.s)) |
| 451 |
continue; /* outside spot */ |
| 452 |
rayorigin(&sr, SHADOW, NULL, NULL); |
| 453 |
sr.rsrc = sp->sn; |
| 454 |
rayvalue(&sr); /* compute value */ |
| 455 |
if (bright(sr.rcol) <= FTINY) |
| 456 |
continue; /* missed/blocked */ |
| 457 |
/* modify pixel */ |
| 458 |
w = poly_area(ppoly, npv) * hres * vres; |
| 459 |
if (zbf[y-y0] != NULL && |
| 460 |
sr.rxt < 0.99*zbf[y-y0][x-x0]) { |
| 461 |
zbf[y-y0][x-x0] = sr.rxt; |
| 462 |
} else if (!bigdiff(sr.rcol, pic[y-y0][x-x0], |
| 463 |
0.01)) { /* source sample */ |
| 464 |
scalecolor(pic[y-y0][x-x0], w); |
| 465 |
continue; |
| 466 |
} |
| 467 |
scalecolor(sr.rcol, w); |
| 468 |
scalecolor(pic[y-y0][x-x0], 1.-w); |
| 469 |
addcolor(pic[y-y0][x-x0], sr.rcol); |
| 470 |
} |
| 471 |
} |
| 472 |
} |
