| 1 |
greg |
2.1 |
/* Copyright (c) 1996 Regents of the University of California */ |
| 2 |
|
|
|
| 3 |
|
|
#ifndef lint |
| 4 |
|
|
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
|
|
#endif |
| 6 |
|
|
|
| 7 |
|
|
/* |
| 8 |
|
|
* Draw small sources into image in case we missed them. |
| 9 |
|
|
*/ |
| 10 |
|
|
|
| 11 |
|
|
#include "ray.h" |
| 12 |
|
|
|
| 13 |
|
|
#include "view.h" |
| 14 |
|
|
|
| 15 |
|
|
#include "source.h" |
| 16 |
|
|
|
| 17 |
|
|
|
| 18 |
|
|
#define CLIP_ABOVE 1 |
| 19 |
|
|
#define CLIP_BELOW 2 |
| 20 |
|
|
#define CLIP_RIGHT 3 |
| 21 |
|
|
#define CLIP_LEFT 4 |
| 22 |
|
|
|
| 23 |
|
|
#define MAXVERT 10 |
| 24 |
|
|
|
| 25 |
|
|
|
| 26 |
|
|
static int |
| 27 |
|
|
inregion(p, cv, crit) /* check if vertex is in region */ |
| 28 |
|
|
FLOAT p[2]; |
| 29 |
|
|
double cv; |
| 30 |
|
|
int crit; |
| 31 |
|
|
{ |
| 32 |
|
|
switch (crit) { |
| 33 |
|
|
case CLIP_ABOVE: |
| 34 |
|
|
return(p[1] < cv); |
| 35 |
|
|
case CLIP_BELOW: |
| 36 |
|
|
return(p[1] >= cv); |
| 37 |
|
|
case CLIP_RIGHT: |
| 38 |
|
|
return(p[0] < cv); |
| 39 |
|
|
case CLIP_LEFT: |
| 40 |
|
|
return(p[0] >= cv); |
| 41 |
|
|
} |
| 42 |
|
|
return(-1); |
| 43 |
|
|
} |
| 44 |
|
|
|
| 45 |
|
|
|
| 46 |
|
|
static |
| 47 |
|
|
clipregion(a, b, cv, crit, r) /* find intersection with boundary */ |
| 48 |
|
|
register FLOAT a[2], b[2]; |
| 49 |
|
|
double cv; |
| 50 |
|
|
int crit; |
| 51 |
|
|
FLOAT r[2]; /* return value */ |
| 52 |
|
|
{ |
| 53 |
|
|
switch (crit) { |
| 54 |
|
|
case CLIP_ABOVE: |
| 55 |
|
|
case CLIP_BELOW: |
| 56 |
|
|
r[1] = cv; |
| 57 |
|
|
r[0] = a[0] + (cv-a[1])/(b[1]-a[1])*(b[0]-a[0]); |
| 58 |
|
|
return; |
| 59 |
|
|
case CLIP_RIGHT: |
| 60 |
|
|
case CLIP_LEFT: |
| 61 |
|
|
r[0] = cv; |
| 62 |
|
|
r[1] = a[1] + (cv-a[0])/(b[0]-a[0])*(b[1]-a[1]); |
| 63 |
|
|
return; |
| 64 |
|
|
} |
| 65 |
|
|
} |
| 66 |
|
|
|
| 67 |
|
|
|
| 68 |
|
|
static int |
| 69 |
|
|
hp_clip_poly(vl, nv, cv, crit, vlo) /* clip polygon to half-plane */ |
| 70 |
|
|
FLOAT vl[][2]; |
| 71 |
|
|
int nv; |
| 72 |
|
|
double cv; |
| 73 |
|
|
int crit; |
| 74 |
|
|
FLOAT vlo[][2]; /* return value */ |
| 75 |
|
|
{ |
| 76 |
|
|
FLOAT *s, *p; |
| 77 |
|
|
register int j, nvo; |
| 78 |
|
|
|
| 79 |
|
|
s = vl[nv-1]; |
| 80 |
|
|
nvo = 0; |
| 81 |
|
|
for (j = 0; j < nv; j++) { |
| 82 |
|
|
p = vl[j]; |
| 83 |
|
|
if (inregion(p, cv, crit)) { |
| 84 |
|
|
if (!inregion(s, cv, crit)) |
| 85 |
|
|
clipregion(s, p, cv, crit, vlo[nvo++]); |
| 86 |
|
|
vlo[nvo][0] = p[0]; vlo[nvo++][1] = p[1]; |
| 87 |
|
|
} else if (inregion(s, cv, crit)) |
| 88 |
|
|
clipregion(s, p, cv, crit, vlo[nvo++]); |
| 89 |
|
|
s = p; |
| 90 |
|
|
} |
| 91 |
|
|
return(nvo); |
| 92 |
|
|
} |
| 93 |
|
|
|
| 94 |
|
|
|
| 95 |
|
|
static int |
| 96 |
|
|
box_clip_poly(vl, nv, xl, xr, yb, ya, vlo) /* clip polygon to box */ |
| 97 |
|
|
FLOAT vl[MAXVERT][2]; |
| 98 |
|
|
int nv; |
| 99 |
|
|
double xl, xr, yb, ya; |
| 100 |
|
|
FLOAT vlo[MAXVERT][2]; /* return value */ |
| 101 |
|
|
{ |
| 102 |
|
|
FLOAT vlt[MAXVERT][2]; |
| 103 |
|
|
int nvt, nvo; |
| 104 |
|
|
|
| 105 |
|
|
nvt = hp_clip_poly(vl, nv, yb, CLIP_BELOW, vlt); |
| 106 |
|
|
nvo = hp_clip_poly(vlt, nvt, ya, CLIP_ABOVE, vlo); |
| 107 |
|
|
nvt = hp_clip_poly(vlo, nvo, xl, CLIP_LEFT, vlt); |
| 108 |
|
|
nvo = hp_clip_poly(vlt, nvt, xr, CLIP_RIGHT, vlo); |
| 109 |
|
|
|
| 110 |
|
|
return(nvo); |
| 111 |
|
|
} |
| 112 |
|
|
|
| 113 |
|
|
|
| 114 |
|
|
static double |
| 115 |
|
|
minw2(vl, nv, ar2) /* compute square of minimum width */ |
| 116 |
|
|
FLOAT vl[][2]; |
| 117 |
|
|
int nv; |
| 118 |
|
|
double ar2; |
| 119 |
|
|
{ |
| 120 |
|
|
double d2, w2, w2min, w2max; |
| 121 |
|
|
register FLOAT *p0, *p1, *p2; |
| 122 |
|
|
int i, j; |
| 123 |
|
|
/* find minimum for all widths */ |
| 124 |
|
|
w2min = FHUGE; |
| 125 |
|
|
p0 = vl[nv-1]; |
| 126 |
|
|
for (i = 0; i < nv; i++) { /* for each edge */ |
| 127 |
|
|
p1 = vl[i]; |
| 128 |
|
|
d2 = (p1[0]-p0[0])*(p1[0]-p0[0]) + |
| 129 |
|
|
(p1[1]-p0[1])*(p1[1]-p0[1])*ar2; |
| 130 |
|
|
w2max = 0.; /* find maximum for this side */ |
| 131 |
|
|
for (j = 1; j < nv-1; j++) { |
| 132 |
|
|
p2 = vl[(i+j)%nv]; |
| 133 |
|
|
w2 = (p1[0]-p0[0])*(p2[1]-p0[1]) - |
| 134 |
|
|
(p1[1]-p0[1])*(p2[0]-p0[0]); |
| 135 |
|
|
w2 = w2*w2*ar2/d2; /* triangle height squared */ |
| 136 |
|
|
if (w2 > w2max) |
| 137 |
|
|
w2max = w2; |
| 138 |
|
|
} |
| 139 |
|
|
if (w2max < w2min) /* global min. based on local max.'s */ |
| 140 |
|
|
w2min = w2max; |
| 141 |
|
|
p0 = p1; |
| 142 |
|
|
} |
| 143 |
|
|
return(w2min); |
| 144 |
|
|
} |
| 145 |
|
|
|
| 146 |
|
|
|
| 147 |
|
|
static |
| 148 |
|
|
convex_center(vl, nv, cv) /* compute center of convex polygon */ |
| 149 |
|
|
register FLOAT vl[][2]; |
| 150 |
|
|
int nv; |
| 151 |
|
|
FLOAT cv[2]; /* return value */ |
| 152 |
|
|
{ |
| 153 |
|
|
register int i; |
| 154 |
|
|
/* simple average (suboptimal) */ |
| 155 |
|
|
cv[0] = cv[1] = 0.; |
| 156 |
|
|
for (i = 0; i < nv; i++) { |
| 157 |
|
|
cv[0] += vl[i][0]; |
| 158 |
|
|
cv[1] += vl[i][1]; |
| 159 |
|
|
} |
| 160 |
|
|
cv[0] /= (double)nv; |
| 161 |
|
|
cv[1] /= (double)nv; |
| 162 |
|
|
} |
| 163 |
|
|
|
| 164 |
|
|
|
| 165 |
|
|
static double |
| 166 |
|
|
poly_area(vl, nv) /* compute area of polygon */ |
| 167 |
|
|
register FLOAT vl[][2]; |
| 168 |
|
|
int nv; |
| 169 |
|
|
{ |
| 170 |
|
|
double a; |
| 171 |
|
|
FLOAT v0[2], v1[2]; |
| 172 |
|
|
register int i; |
| 173 |
|
|
|
| 174 |
|
|
a = 0.; |
| 175 |
|
|
v0[0] = vl[1][0] - vl[0][0]; |
| 176 |
|
|
v0[1] = vl[1][1] - vl[0][1]; |
| 177 |
|
|
for (i = 2; i < nv; i++) { |
| 178 |
|
|
v1[0] = vl[i][0] - vl[0][0]; |
| 179 |
|
|
v1[1] = vl[i][1] - vl[0][1]; |
| 180 |
|
|
a += v0[0]*v1[1] - v0[1]*v1[0]; |
| 181 |
|
|
v0[0] = v1[0]; v0[1] = v1[1]; |
| 182 |
|
|
} |
| 183 |
|
|
return(a * (a >= 0. ? .5 : -.5)); |
| 184 |
|
|
} |
| 185 |
|
|
|
| 186 |
|
|
|
| 187 |
|
|
static int |
| 188 |
|
|
convex_hull(vl, nv, vlo) /* compute polygon's convex hull */ |
| 189 |
|
|
FLOAT vl[][2]; |
| 190 |
|
|
int nv; |
| 191 |
|
|
FLOAT vlo[][2]; /* return value */ |
| 192 |
|
|
{ |
| 193 |
|
|
int nvo, nvt; |
| 194 |
|
|
FLOAT vlt[MAXVERT][2]; |
| 195 |
|
|
double voa, vta; |
| 196 |
|
|
register int i, j; |
| 197 |
|
|
/* start with original polygon */ |
| 198 |
|
|
for (i = nvo = nv; i--; ) { |
| 199 |
|
|
vlo[i][0] = vl[i][0]; vlo[i][1] = vl[i][1]; |
| 200 |
|
|
} |
| 201 |
|
|
voa = poly_area(vlo, nvo); /* compute its area */ |
| 202 |
|
|
for (i = 0; i < nvo; i++) { /* for each output vertex */ |
| 203 |
|
|
for (j = 0; j < i; j++) { |
| 204 |
|
|
vlt[j][0] = vlo[j][0]; vlt[j][1] = vlo[j][1]; |
| 205 |
|
|
} |
| 206 |
|
|
nvt = nvo - 1; /* make poly w/o vertex */ |
| 207 |
|
|
for (j = i; j < nvt; j++) { |
| 208 |
|
|
vlt[j][0] = vlo[j+1][0]; vlt[j][1] = vlo[j+1][1]; |
| 209 |
|
|
} |
| 210 |
|
|
vta = poly_area(vlt, nvt); |
| 211 |
|
|
if (vta >= voa) { /* is simpler poly bigger? */ |
| 212 |
|
|
voa = vta; /* then use it */ |
| 213 |
|
|
for (j = nvo = nvt; j--; ) { |
| 214 |
|
|
vlo[j][0] = vlt[j][0]; vlo[j][1] = vlt[j][1]; |
| 215 |
|
|
} |
| 216 |
|
|
i--; /* next adjust */ |
| 217 |
|
|
} |
| 218 |
|
|
} |
| 219 |
|
|
return(nvo); |
| 220 |
|
|
} |
| 221 |
|
|
|
| 222 |
|
|
|
| 223 |
|
|
int |
| 224 |
|
|
sourcepoly(vw, sn, sp) /* compute image polygon for source */ |
| 225 |
|
|
VIEW *vw; |
| 226 |
|
|
int sn; |
| 227 |
|
|
FLOAT sp[MAXVERT][2]; |
| 228 |
|
|
{ |
| 229 |
|
|
static char cubeord[8][6] = {{1,3,2,6,4,5},{0,4,5,7,3,2}, |
| 230 |
|
|
{0,1,3,7,6,4},{0,1,5,7,6,2}, |
| 231 |
|
|
{0,2,6,7,5,1},{0,4,6,7,3,1}, |
| 232 |
|
|
{0,2,3,7,5,4},{1,5,4,6,2,3}}; |
| 233 |
|
|
register SRCREC *s = source + sn; |
| 234 |
|
|
FVECT ap, ip; |
| 235 |
|
|
FLOAT pt[6][2]; |
| 236 |
|
|
int dir; |
| 237 |
|
|
register int i, j; |
| 238 |
|
|
|
| 239 |
|
|
if (s->sflags & (SDISTANT|SFLAT)) { |
| 240 |
|
|
if (s->sflags & SDISTANT && vw->type == VT_PAR) |
| 241 |
|
|
return(0); /* all or nothing case */ |
| 242 |
|
|
if (s->sflags & SFLAT) { |
| 243 |
|
|
for (i = 0; i < 3; i++) |
| 244 |
|
|
ap[i] = s->sloc[i] - vw->vp[i]; |
| 245 |
|
|
if (DOT(ap, s->snorm) >= 0.) |
| 246 |
|
|
return(0); /* source faces away */ |
| 247 |
|
|
} |
| 248 |
|
|
for (j = 0; j < 4; j++) { /* four corners */ |
| 249 |
|
|
for (i = 0; i < 3; i++) { |
| 250 |
|
|
ap[i] = s->sloc[i]; |
| 251 |
|
|
if (j==1|j==2) ap[i] += s->ss[SU][i]; |
| 252 |
|
|
else ap[i] -= s->ss[SU][i]; |
| 253 |
|
|
if (j==2|j==3) ap[i] += s->ss[SV][i]; |
| 254 |
|
|
else ap[i] -= s->ss[SV][i]; |
| 255 |
|
|
if (s->sflags & SDISTANT) { |
| 256 |
|
|
ap[i] *= 1. + vw->vfore; |
| 257 |
|
|
ap[i] += vw->vp[i]; |
| 258 |
|
|
} |
| 259 |
|
|
} |
| 260 |
|
|
viewloc(ip, vw, ap); /* find image point */ |
| 261 |
|
|
if (ip[2] <= 0.) |
| 262 |
|
|
return(0); /* in front of view */ |
| 263 |
|
|
sp[j][0] = ip[0]; sp[j][1] = ip[1]; |
| 264 |
|
|
} |
| 265 |
|
|
return(4); |
| 266 |
|
|
} |
| 267 |
|
|
/* identify furthest corner */ |
| 268 |
|
|
for (i = 0; i < 3; i++) |
| 269 |
|
|
ap[i] = s->sloc[i] - vw->vp[i]; |
| 270 |
|
|
dir = (DOT(ap,s->ss[SU])>0.) | |
| 271 |
|
|
(DOT(ap,s->ss[SV])>0.)<<1 | |
| 272 |
|
|
(DOT(ap,s->ss[SW])>0.)<<2 ; |
| 273 |
|
|
/* order vertices based on this */ |
| 274 |
|
|
for (j = 0; j < 6; j++) { |
| 275 |
|
|
for (i = 0; i < 3; i++) { |
| 276 |
|
|
ap[i] = s->sloc[i]; |
| 277 |
|
|
if (cubeord[dir][j] & 1) ap[i] += s->ss[SU][i]; |
| 278 |
|
|
else ap[i] -= s->ss[SU][i]; |
| 279 |
|
|
if (cubeord[dir][j] & 2) ap[i] += s->ss[SV][i]; |
| 280 |
|
|
else ap[i] -= s->ss[SV][i]; |
| 281 |
|
|
if (cubeord[dir][j] & 4) ap[i] += s->ss[SW][i]; |
| 282 |
|
|
else ap[i] -= s->ss[SW][i]; |
| 283 |
|
|
} |
| 284 |
|
|
viewloc(ip, vw, ap); /* find image point */ |
| 285 |
|
|
if (ip[2] <= 0.) |
| 286 |
|
|
return(0); /* in front of view */ |
| 287 |
|
|
pt[j][0] = ip[0]; pt[j][1] = ip[1]; |
| 288 |
|
|
} |
| 289 |
|
|
return(convex_hull(pt, 6, sp)); /* make sure it's convex */ |
| 290 |
|
|
} |
| 291 |
|
|
|
| 292 |
|
|
|
| 293 |
|
|
/* add sources smaller than rad to computed subimage */ |
| 294 |
|
|
drawsources(vw, xr, yr, pic, zbf, x0, xsiz, y0, ysiz, rad) |
| 295 |
|
|
VIEW *vw; /* full image view */ |
| 296 |
|
|
int xr, yr; /* full image dimensions */ |
| 297 |
|
|
COLOR *pic[]; /* subimage pixel value array */ |
| 298 |
|
|
float *zbf[]; /* subimage distance array (opt.) */ |
| 299 |
|
|
int x0, xsiz, y0, ysiz; /* origin and size of subimage */ |
| 300 |
|
|
int rad; /* source sample size */ |
| 301 |
|
|
{ |
| 302 |
|
|
int sn; |
| 303 |
|
|
FLOAT spoly[MAXVERT][2], ppoly[MAXVERT][2]; |
| 304 |
|
|
int nsv, npv; |
| 305 |
|
|
int xmin, xmax, ymin, ymax, x, y, i; |
| 306 |
|
|
FLOAT cxy[2]; |
| 307 |
|
|
double pa; |
| 308 |
|
|
RAY sr; |
| 309 |
|
|
/* loop through all sources */ |
| 310 |
|
|
for (sn = 0; sn < nsources; sn++) { |
| 311 |
|
|
/* compute image polygon for source */ |
| 312 |
|
|
if (!(nsv = sourcepoly(vw, sn, spoly))) |
| 313 |
|
|
continue; |
| 314 |
greg |
2.2 |
/* big enough for standard sampling? */ |
| 315 |
|
|
if (minw2(spoly, nsv, vw->vn2/vw->hn2) > (double)rad*rad/xr/xr) |
| 316 |
|
|
continue; |
| 317 |
greg |
2.1 |
/* clip source poly to subimage */ |
| 318 |
|
|
nsv = box_clip_poly(spoly, nsv, |
| 319 |
|
|
(double)x0/xr, (double)(x0+xsiz)/xr, |
| 320 |
|
|
(double)y0/yr, (double)(y0+ysiz)/yr, spoly); |
| 321 |
|
|
if (!nsv) |
| 322 |
|
|
continue; |
| 323 |
|
|
/* find common subimage (BBox) */ |
| 324 |
|
|
xmin = x0 + xsiz; xmax = x0; |
| 325 |
|
|
ymin = y0 + ysiz; ymax = y0; |
| 326 |
|
|
for (i = 0; i < nsv; i++) { |
| 327 |
|
|
if ((double)xmin/xr > spoly[i][0]) |
| 328 |
|
|
xmin = spoly[i][0]*xr + FTINY; |
| 329 |
|
|
if ((double)xmax/xr < spoly[i][0]) |
| 330 |
|
|
xmax = spoly[i][0]*xr - FTINY; |
| 331 |
|
|
if ((double)ymin/yr > spoly[i][1]) |
| 332 |
|
|
ymin = spoly[i][1]*yr + FTINY; |
| 333 |
|
|
if ((double)ymax/yr < spoly[i][1]) |
| 334 |
|
|
ymax = spoly[i][1]*yr - FTINY; |
| 335 |
|
|
} |
| 336 |
|
|
/* evaluate each pixel in BBox */ |
| 337 |
|
|
for (y = ymin; y <= ymax; y++) |
| 338 |
|
|
for (x = xmin; x <= xmax; x++) { |
| 339 |
|
|
/* subarea for pixel */ |
| 340 |
|
|
npv = box_clip_poly(spoly, nsv, |
| 341 |
|
|
(double)x/xr, (x+1.)/xr, |
| 342 |
|
|
(double)y/yr, (y+1.)/yr, ppoly); |
| 343 |
|
|
if (!npv) |
| 344 |
|
|
continue; /* no overlap */ |
| 345 |
|
|
convex_center(ppoly, npv, cxy); |
| 346 |
|
|
if ((sr.rmax = viewray(sr.rorg, sr.rdir, vw, |
| 347 |
|
|
cxy[0], cxy[1])) < -FTINY) |
| 348 |
|
|
continue; /* not in view */ |
| 349 |
|
|
if (source[sn].sflags & SSPOT && |
| 350 |
greg |
2.2 |
spotout(&sr, source[sn].sl.s)) |
| 351 |
greg |
2.1 |
continue; /* outside spot */ |
| 352 |
|
|
rayorigin(&sr, NULL, SHADOW, 1.0); |
| 353 |
|
|
sr.rsrc = sn; |
| 354 |
|
|
rayvalue(&sr); /* compute value */ |
| 355 |
|
|
if (bright(sr.rcol) <= FTINY) |
| 356 |
|
|
continue; /* missed/blocked */ |
| 357 |
|
|
/* modify pixel */ |
| 358 |
|
|
if (zbf[y-y0] != NULL && |
| 359 |
|
|
sr.rt < zbf[y-y0][x-x0]) |
| 360 |
|
|
zbf[y-y0][x-x0] = sr.rt; |
| 361 |
|
|
pa = poly_area(ppoly, npv); |
| 362 |
|
|
scalecolor(sr.rcol, pa*xr*yr); |
| 363 |
|
|
scalecolor(pic[y-y0][x-x0], (1.-pa*xr*yr)); |
| 364 |
|
|
addcolor(pic[y-y0][x-x0], sr.rcol); |
| 365 |
|
|
} |
| 366 |
|
|
} |
| 367 |
|
|
} |
