| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: holo.c,v 3.20 2003/07/27 22:12:02 schorsch Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Routines for converting holodeck coordinates, etc. |
| 6 |
* |
| 7 |
* 10/22/97 GWLarson |
| 8 |
*/ |
| 9 |
|
| 10 |
#include "holo.h" |
| 11 |
|
| 12 |
float hd_depthmap[DCINF-DCLIN]; |
| 13 |
|
| 14 |
int hdwg0[6] = {1,1,2,2,0,0}; |
| 15 |
int hdwg1[6] = {2,2,0,0,1,1}; |
| 16 |
|
| 17 |
static double logstep; |
| 18 |
|
| 19 |
|
| 20 |
extern void |
| 21 |
hdcompgrid( /* compute derived grid vector and index */ |
| 22 |
register HOLO *hp |
| 23 |
) |
| 24 |
{ |
| 25 |
double d; |
| 26 |
register int i, j; |
| 27 |
/* initialize depth map */ |
| 28 |
if (hd_depthmap[0] < 1.) { |
| 29 |
d = 1. + .5/DCLIN; |
| 30 |
for (i = 0; i < DCINF-DCLIN; i++) { |
| 31 |
hd_depthmap[i] = d; |
| 32 |
d *= 1. + 1./DCLIN; |
| 33 |
} |
| 34 |
logstep = log(1. + 1./DCLIN); |
| 35 |
} |
| 36 |
/* compute grid coordinate vectors */ |
| 37 |
for (i = 0; i < 3; i++) { |
| 38 |
fcross(hp->wg[i], hp->xv[(i+1)%3], hp->xv[(i+2)%3]); |
| 39 |
d = DOT(hp->wg[i],hp->xv[i]); |
| 40 |
if ((d <= FTINY) & (d >= -FTINY)) |
| 41 |
error(USER, "degenerate holodeck section"); |
| 42 |
d = hp->grid[i] / d; |
| 43 |
hp->wg[i][0] *= d; hp->wg[i][1] *= d; hp->wg[i][2] *= d; |
| 44 |
} |
| 45 |
/* compute linear depth range */ |
| 46 |
hp->tlin = VLEN(hp->xv[0]) + VLEN(hp->xv[1]) + VLEN(hp->xv[2]); |
| 47 |
/* compute wall super-indices from grid */ |
| 48 |
hp->wi[0] = 1; /**** index values begin at 1 ****/ |
| 49 |
for (i = 1; i < 6; i++) { |
| 50 |
hp->wi[i] = 0; |
| 51 |
for (j = i; j < 6; j++) |
| 52 |
hp->wi[i] += hp->grid[hdwg0[j]] * hp->grid[hdwg1[j]]; |
| 53 |
hp->wi[i] *= hp->grid[hdwg0[i-1]] * hp->grid[hdwg1[i-1]]; |
| 54 |
hp->wi[i] += hp->wi[i-1]; |
| 55 |
} |
| 56 |
} |
| 57 |
|
| 58 |
|
| 59 |
extern int |
| 60 |
hdbcoord( /* compute beam coordinates from index */ |
| 61 |
GCOORD gc[2], /* returned */ |
| 62 |
register HOLO *hp, |
| 63 |
register int i |
| 64 |
) |
| 65 |
{ |
| 66 |
register int j, n; |
| 67 |
int n2, reverse; |
| 68 |
GCOORD g2[2]; |
| 69 |
/* check range */ |
| 70 |
if ((i < 1) | (i > nbeams(hp))) |
| 71 |
return(0); |
| 72 |
if ( (reverse = i >= hp->wi[5]) ) |
| 73 |
i -= hp->wi[5] - 1; |
| 74 |
for (j = 0; j < 5; j++) /* find w0 */ |
| 75 |
if (hp->wi[j+1] > i) |
| 76 |
break; |
| 77 |
i -= hp->wi[gc[0].w=j]; |
| 78 |
/* find w1 */ |
| 79 |
n2 = hp->grid[hdwg0[j]] * hp->grid[hdwg1[j]]; |
| 80 |
while (++j < 5) { |
| 81 |
n = n2 * hp->grid[hdwg0[j]] * hp->grid[hdwg1[j]]; |
| 82 |
if (n > i) |
| 83 |
break; |
| 84 |
i -= n; |
| 85 |
} |
| 86 |
gc[1].w = j; |
| 87 |
/* find position on w0 */ |
| 88 |
n2 = hp->grid[hdwg0[j]] * hp->grid[hdwg1[j]]; |
| 89 |
n = i / n2; |
| 90 |
gc[0].i[1] = n / hp->grid[hdwg0[gc[0].w]]; |
| 91 |
gc[0].i[0] = n - gc[0].i[1]*hp->grid[hdwg0[gc[0].w]]; |
| 92 |
i -= n*n2; |
| 93 |
/* find position on w1 */ |
| 94 |
gc[1].i[1] = i / hp->grid[hdwg0[gc[1].w]]; |
| 95 |
gc[1].i[0] = i - gc[1].i[1]*hp->grid[hdwg0[gc[1].w]]; |
| 96 |
if (reverse) { |
| 97 |
*g2 = *(gc+1); |
| 98 |
*(gc+1) = *gc; |
| 99 |
*gc = *g2; |
| 100 |
} |
| 101 |
return(1); /* we're done */ |
| 102 |
} |
| 103 |
|
| 104 |
|
| 105 |
extern int |
| 106 |
hdbindex( /* compute index from beam coordinates */ |
| 107 |
register HOLO *hp, |
| 108 |
register GCOORD gc[2] |
| 109 |
) |
| 110 |
{ |
| 111 |
GCOORD g2[2]; |
| 112 |
int reverse; |
| 113 |
register int i, j; |
| 114 |
/* check ordering and limits */ |
| 115 |
if ( (reverse = gc[0].w > gc[1].w) ) { |
| 116 |
*g2 = *(gc+1); |
| 117 |
*(g2+1) = *gc; |
| 118 |
gc = g2; |
| 119 |
} else if (gc[0].w == gc[1].w) |
| 120 |
return(0); |
| 121 |
if ((gc[0].w < 0) | (gc[1].w > 5)) |
| 122 |
return(0); |
| 123 |
i = 0; /* compute index */ |
| 124 |
for (j = gc[0].w+1; j < gc[1].w; j++) |
| 125 |
i += hp->grid[hdwg0[j]] * hp->grid[hdwg1[j]]; |
| 126 |
i *= hp->grid[hdwg0[gc[0].w]] * hp->grid[hdwg1[gc[0].w]]; |
| 127 |
i += hp->wi[gc[0].w]; |
| 128 |
i += (hp->grid[hdwg0[gc[0].w]]*gc[0].i[1] + gc[0].i[0]) * |
| 129 |
hp->grid[hdwg0[gc[1].w]] * hp->grid[hdwg1[gc[1].w]] ; |
| 130 |
i += hp->grid[hdwg0[gc[1].w]]*gc[1].i[1] + gc[1].i[0]; |
| 131 |
if (reverse) |
| 132 |
i += hp->wi[5] - 1; |
| 133 |
return(i); |
| 134 |
} |
| 135 |
|
| 136 |
|
| 137 |
extern void |
| 138 |
hdcell( /* compute cell coordinates */ |
| 139 |
register FVECT cp[4], /* returned (may be passed as FVECT cp[2][2]) */ |
| 140 |
register HOLO *hp, |
| 141 |
register GCOORD *gc |
| 142 |
) |
| 143 |
{ |
| 144 |
register RREAL *v; |
| 145 |
double d; |
| 146 |
/* compute common component */ |
| 147 |
VCOPY(cp[0], hp->orig); |
| 148 |
if (gc->w & 1) { |
| 149 |
v = hp->xv[gc->w>>1]; |
| 150 |
cp[0][0] += v[0]; cp[0][1] += v[1]; cp[0][2] += v[2]; |
| 151 |
} |
| 152 |
v = hp->xv[hdwg0[gc->w]]; |
| 153 |
d = (double)gc->i[0] / hp->grid[hdwg0[gc->w]]; |
| 154 |
VSUM(cp[0], cp[0], v, d); |
| 155 |
v = hp->xv[hdwg1[gc->w]]; |
| 156 |
d = (double)gc->i[1] / hp->grid[hdwg1[gc->w]]; |
| 157 |
VSUM(cp[0], cp[0], v, d); |
| 158 |
/* compute x1 sums */ |
| 159 |
v = hp->xv[hdwg0[gc->w]]; |
| 160 |
d = 1.0 / hp->grid[hdwg0[gc->w]]; |
| 161 |
VSUM(cp[1], cp[0], v, d); |
| 162 |
VSUM(cp[3], cp[0], v, d); |
| 163 |
/* compute y1 sums */ |
| 164 |
v = hp->xv[hdwg1[gc->w]]; |
| 165 |
d = 1.0 / hp->grid[hdwg1[gc->w]]; |
| 166 |
VSUM(cp[2], cp[0], v, d); |
| 167 |
VSUM(cp[3], cp[3], v, d); |
| 168 |
} |
| 169 |
|
| 170 |
|
| 171 |
extern int |
| 172 |
hdlseg( /* compute line segment for beam */ |
| 173 |
register int lseg[2][3], |
| 174 |
register HOLO *hp, |
| 175 |
GCOORD gc[2] |
| 176 |
) |
| 177 |
{ |
| 178 |
register int k; |
| 179 |
|
| 180 |
for (k = 0; k < 2; k++) { /* compute end points */ |
| 181 |
lseg[k][gc[k].w>>1] = gc[k].w&1 ? hp->grid[gc[k].w>>1]-1 : 0 ; |
| 182 |
lseg[k][hdwg0[gc[k].w]] = gc[k].i[0]; |
| 183 |
lseg[k][hdwg1[gc[k].w]] = gc[k].i[1]; |
| 184 |
} |
| 185 |
return(1); |
| 186 |
} |
| 187 |
|
| 188 |
|
| 189 |
extern unsigned int |
| 190 |
hdcode( /* compute depth code for d */ |
| 191 |
HOLO *hp, |
| 192 |
double d |
| 193 |
) |
| 194 |
{ |
| 195 |
double tl = hp->tlin; |
| 196 |
register long c; |
| 197 |
|
| 198 |
if (d <= 0.) |
| 199 |
return(0); |
| 200 |
if (d >= .99*FHUGE) |
| 201 |
return(DCINF); |
| 202 |
if (d < tl) |
| 203 |
return((unsigned)(d*DCLIN/tl)); |
| 204 |
c = (long)(log(d/tl)/logstep) + DCLIN; |
| 205 |
return(c > DCINF ? (unsigned)DCINF : (unsigned)c); |
| 206 |
} |
| 207 |
|
| 208 |
|
| 209 |
extern void |
| 210 |
hdgrid( /* compute grid coordinates */ |
| 211 |
FVECT gp, /* returned */ |
| 212 |
register HOLO *hp, |
| 213 |
FVECT wp |
| 214 |
) |
| 215 |
{ |
| 216 |
FVECT vt; |
| 217 |
|
| 218 |
VSUB(vt, wp, hp->orig); |
| 219 |
gp[0] = DOT(vt, hp->wg[0]); |
| 220 |
gp[1] = DOT(vt, hp->wg[1]); |
| 221 |
gp[2] = DOT(vt, hp->wg[2]); |
| 222 |
} |
| 223 |
|
| 224 |
|
| 225 |
extern void |
| 226 |
hdworld( /* compute world coordinates */ |
| 227 |
register FVECT wp, |
| 228 |
register HOLO *hp, |
| 229 |
FVECT gp |
| 230 |
) |
| 231 |
{ |
| 232 |
register double d; |
| 233 |
|
| 234 |
d = gp[0]/hp->grid[0]; |
| 235 |
VSUM(wp, hp->orig, hp->xv[0], d); |
| 236 |
|
| 237 |
d = gp[1]/hp->grid[1]; |
| 238 |
VSUM(wp, wp, hp->xv[1], d); |
| 239 |
|
| 240 |
d = gp[2]/hp->grid[2]; |
| 241 |
VSUM(wp, wp, hp->xv[2], d); |
| 242 |
} |
| 243 |
|
| 244 |
|
| 245 |
extern double |
| 246 |
hdray( /* compute ray within a beam */ |
| 247 |
FVECT ro, |
| 248 |
FVECT rd, /* returned */ |
| 249 |
HOLO *hp, |
| 250 |
GCOORD gc[2], |
| 251 |
BYTE r[2][2] |
| 252 |
) |
| 253 |
{ |
| 254 |
FVECT cp[4], p[2]; |
| 255 |
register int i, j; |
| 256 |
double d0, d1; |
| 257 |
/* compute entry and exit points */ |
| 258 |
for (i = 0; i < 2; i++) { |
| 259 |
hdcell(cp, hp, gc+i); |
| 260 |
d0 = (1./256.)*(r[i][0]+.5); |
| 261 |
d1 = (1./256.)*(r[i][1]+.5); |
| 262 |
for (j = 0; j < 3; j++) |
| 263 |
p[i][j] = (1.-d0-d1)*cp[0][j] + |
| 264 |
d0*cp[1][j] + d1*cp[2][j]; |
| 265 |
} |
| 266 |
VCOPY(ro, p[0]); /* assign ray origin and direction */ |
| 267 |
VSUB(rd, p[1], p[0]); |
| 268 |
return(normalize(rd)); /* return maximum inside distance */ |
| 269 |
} |
| 270 |
|
| 271 |
|
| 272 |
extern double |
| 273 |
hdinter( /* compute ray intersection with section */ |
| 274 |
register GCOORD gc[2], /* returned */ |
| 275 |
BYTE r[2][2], /* returned (optional) */ |
| 276 |
double *ed, /* returned (optional) */ |
| 277 |
register HOLO *hp, |
| 278 |
FVECT ro, |
| 279 |
FVECT rd /* normalization of rd affects distances */ |
| 280 |
) |
| 281 |
{ |
| 282 |
FVECT p[2], vt; |
| 283 |
double d, t0, t1, d0, d1; |
| 284 |
register RREAL *v; |
| 285 |
register int i; |
| 286 |
/* first, intersect walls */ |
| 287 |
gc[0].w = gc[1].w = -1; |
| 288 |
t0 = -FHUGE; t1 = FHUGE; |
| 289 |
VSUB(vt, ro, hp->orig); |
| 290 |
for (i = 0; i < 3; i++) { /* for each wall pair */ |
| 291 |
d = -DOT(rd, hp->wg[i]); /* plane distance */ |
| 292 |
if (d <= FTINY && d >= -FTINY) /* check for parallel */ |
| 293 |
continue; |
| 294 |
d1 = DOT(vt, hp->wg[i]); /* ray distances */ |
| 295 |
d0 = d1 / d; |
| 296 |
d1 = (d1 - hp->grid[i]) / d; |
| 297 |
if (d < 0) { /* check against best */ |
| 298 |
if (d0 > t0) { |
| 299 |
t0 = d0; |
| 300 |
gc[0].w = i<<1; |
| 301 |
} |
| 302 |
if (d1 < t1) { |
| 303 |
t1 = d1; |
| 304 |
gc[1].w = i<<1 | 1; |
| 305 |
} |
| 306 |
} else { |
| 307 |
if (d1 > t0) { |
| 308 |
t0 = d1; |
| 309 |
gc[0].w = i<<1 | 1; |
| 310 |
} |
| 311 |
if (d0 < t1) { |
| 312 |
t1 = d0; |
| 313 |
gc[1].w = i<<1; |
| 314 |
} |
| 315 |
} |
| 316 |
} |
| 317 |
if ((gc[0].w < 0) | (gc[1].w < 0)) /* paranoid check */ |
| 318 |
return(FHUGE); |
| 319 |
/* compute intersections */ |
| 320 |
VSUM(p[0], ro, rd, t0); |
| 321 |
VSUM(p[1], ro, rd, t1); |
| 322 |
/* now, compute grid coordinates */ |
| 323 |
for (i = 0; i < 2; i++) { |
| 324 |
VSUB(vt, p[i], hp->orig); |
| 325 |
v = hp->wg[hdwg0[gc[i].w]]; |
| 326 |
d = DOT(vt, v); |
| 327 |
if (d < 0 || d >= hp->grid[hdwg0[gc[i].w]]) |
| 328 |
return(FHUGE); /* outside wall */ |
| 329 |
gc[i].i[0] = d; |
| 330 |
if (r != NULL) |
| 331 |
r[i][0] = 256. * (d - gc[i].i[0]); |
| 332 |
v = hp->wg[hdwg1[gc[i].w]]; |
| 333 |
d = DOT(vt, v); |
| 334 |
if (d < 0 || d >= hp->grid[hdwg1[gc[i].w]]) |
| 335 |
return(FHUGE); /* outside wall */ |
| 336 |
gc[i].i[1] = d; |
| 337 |
if (r != NULL) |
| 338 |
r[i][1] = 256. * (d - gc[i].i[1]); |
| 339 |
} |
| 340 |
if (ed != NULL) /* assign distance to exit point */ |
| 341 |
*ed = t1; |
| 342 |
return(t0); /* return distance to entry point */ |
| 343 |
} |
