1 |
/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ SGI"; |
5 |
#endif |
6 |
|
7 |
/* |
8 |
* Holodeck beam tracking for display process |
9 |
*/ |
10 |
|
11 |
#include "rholo.h" |
12 |
#include "rhdisp.h" |
13 |
#include "rhdriver.h" |
14 |
|
15 |
#ifndef MAXDIST |
16 |
#define MAXDIST 42 /* maximum distance outside section */ |
17 |
#endif |
18 |
|
19 |
#define MAXVOXEL 16 /* maximum number of active voxels */ |
20 |
|
21 |
typedef struct { |
22 |
int hd; /* holodeck section number (-1 if inactive) */ |
23 |
int i[3]; /* voxel index (may be outside section) */ |
24 |
} VOXL; /* a voxel */ |
25 |
|
26 |
static VOXL voxel[MAXVOXEL] = {{-1}}; /* current voxel list */ |
27 |
|
28 |
#define CBEAMBLK 1024 /* cbeam allocation block size */ |
29 |
|
30 |
static struct beamcomp { |
31 |
unsigned int2 wants; /* flags telling which voxels want us */ |
32 |
unsigned int2 hd; /* holodeck section number */ |
33 |
int4 bi; /* beam index */ |
34 |
int4 nr; /* number of samples desired */ |
35 |
} *cbeam = NULL; /* current beam list */ |
36 |
|
37 |
static int ncbeams = 0; /* number of sorted beams in cbeam */ |
38 |
static int xcbeams = 0; /* extra (unregistered) beams past ncbeams */ |
39 |
static int maxcbeam = 0; /* size of cbeam array */ |
40 |
|
41 |
struct cellact { |
42 |
short vi; /* voxel index */ |
43 |
short add; /* zero means delete */ |
44 |
short rev; /* reverse ray direction? */ |
45 |
VIEW *vp; /* view for image */ |
46 |
short hr, vr; /* image resolution */ |
47 |
}; /* action for cell */ |
48 |
|
49 |
struct beamact { |
50 |
struct cellact ca; /* cell action */ |
51 |
GCOORD gc; /* grid coordinate */ |
52 |
}; /* beam origin and action */ |
53 |
|
54 |
|
55 |
int |
56 |
newcbeam() /* allocate new entry at end of cbeam array */ |
57 |
{ |
58 |
int i; |
59 |
|
60 |
if ((i = ncbeams + xcbeams++) >= maxcbeam) { /* grow array */ |
61 |
maxcbeam += CBEAMBLK; |
62 |
if (cbeam == NULL) |
63 |
cbeam = (struct beamcomp *)malloc( |
64 |
maxcbeam*sizeof(struct beamcomp) ); |
65 |
else |
66 |
cbeam = (struct beamcomp *)realloc( (char *)cbeam, |
67 |
maxcbeam*sizeof(struct beamcomp) ); |
68 |
if (cbeam == NULL) |
69 |
error(SYSTEM, "out of memory in newcbeam"); |
70 |
} |
71 |
return(i); |
72 |
} |
73 |
|
74 |
|
75 |
int |
76 |
cbeamcmp(cb1, cb2) /* compare two cbeam entries for sort: keep orphans */ |
77 |
register struct beamcomp *cb1, *cb2; |
78 |
{ |
79 |
register int c; |
80 |
|
81 |
if ((c = cb1->bi - cb2->bi)) /* sort on beam index first */ |
82 |
return(c); |
83 |
return(cb1->hd - cb2->hd); /* use hd to resolve matches */ |
84 |
} |
85 |
|
86 |
|
87 |
int |
88 |
cbeamcmp2(cb1, cb2) /* compare two cbeam entries for sort: no orphans */ |
89 |
register struct beamcomp *cb1, *cb2; |
90 |
{ |
91 |
register int c; |
92 |
|
93 |
if (!cb1->wants) /* put orphans at the end, unsorted */ |
94 |
return(cb2->wants); |
95 |
if (!cb2->wants) |
96 |
return(-1); |
97 |
if ((c = cb1->bi - cb2->bi)) /* sort on beam index first */ |
98 |
return(c); |
99 |
return(cb1->hd - cb2->hd); /* use hd to resolve matches */ |
100 |
} |
101 |
|
102 |
|
103 |
int |
104 |
findcbeam(hd, bi) /* find the specified beam in our sorted list */ |
105 |
int hd, bi; |
106 |
{ |
107 |
struct beamcomp cb; |
108 |
register struct beamcomp *p; |
109 |
|
110 |
if (ncbeams <= 0) |
111 |
return(-1); |
112 |
cb.wants = 0; cb.hd = hd; cb.bi = bi; cb.nr = 0; |
113 |
p = (struct beamcomp *)bsearch((char *)&cb, (char *)cbeam, ncbeams, |
114 |
sizeof(struct beamcomp), cbeamcmp); |
115 |
if (p == NULL) |
116 |
return(-1); |
117 |
return(p - cbeam); |
118 |
} |
119 |
|
120 |
|
121 |
int |
122 |
getcbeam(hd, bi) /* get the specified beam, allocating as necessary */ |
123 |
register int hd; |
124 |
int bi; |
125 |
{ |
126 |
register int n; |
127 |
/* first, look in sorted list */ |
128 |
if ((n = findcbeam(hd, bi)) >= 0) |
129 |
return(n); |
130 |
/* linear search through xcbeams to be sure */ |
131 |
for (n = ncbeams+xcbeams; n-- > ncbeams; ) |
132 |
if (cbeam[n].bi == bi && cbeam[n].hd == hd) |
133 |
return(n); |
134 |
/* check legality */ |
135 |
if (hd < 0 | hd >= HDMAX || hdlist[hd] == NULL) |
136 |
error(INTERNAL, "illegal holodeck number in getcbeam"); |
137 |
if (bi < 1 | bi > nbeams(hdlist[hd])) |
138 |
error(INTERNAL, "illegal beam index in getcbeam"); |
139 |
n = newcbeam(); /* allocate and assign */ |
140 |
cbeam[n].wants = cbeam[n].nr = 0; cbeam[n].hd = hd; cbeam[n].bi = bi; |
141 |
return(n); |
142 |
} |
143 |
|
144 |
|
145 |
cbeamsort(adopt) /* sort our beam list, possibly turning out orphans */ |
146 |
int adopt; |
147 |
{ |
148 |
register int i; |
149 |
|
150 |
if (!(ncbeams += xcbeams)) |
151 |
return; |
152 |
xcbeams = 0; |
153 |
qsort((char *)cbeam, ncbeams, sizeof(struct beamcomp), |
154 |
adopt ? cbeamcmp : cbeamcmp2); |
155 |
if (adopt) |
156 |
return; |
157 |
for (i = ncbeams; i--; ) /* identify orphans */ |
158 |
if (cbeam[i].wants) |
159 |
break; |
160 |
xcbeams = ncbeams - ++i; /* put orphans after ncbeams */ |
161 |
ncbeams = i; |
162 |
} |
163 |
|
164 |
|
165 |
cbeamop(op, bl, n) /* update beams on server list */ |
166 |
int op; |
167 |
register struct beamcomp *bl; |
168 |
int n; |
169 |
{ |
170 |
register PACKHEAD *pa; |
171 |
register int i; |
172 |
|
173 |
if (n <= 0) |
174 |
return; |
175 |
pa = (PACKHEAD *)malloc(n*sizeof(PACKHEAD)); |
176 |
if (pa == NULL) |
177 |
error(SYSTEM, "out of memory in cbeamop"); |
178 |
for (i = 0; i < n; i++) { |
179 |
pa[i].hd = bl[i].hd; |
180 |
pa[i].bi = bl[i].bi; |
181 |
pa[i].nr = bl[i].nr; |
182 |
pa[i].nc = 0; |
183 |
} |
184 |
serv_request(op, n*sizeof(PACKHEAD), (char *)pa); |
185 |
free((char *)pa); |
186 |
} |
187 |
|
188 |
|
189 |
add_voxels(vp) /* add voxels corresponding to view point */ |
190 |
FVECT vp; |
191 |
{ |
192 |
int first, n, rfl = 0; |
193 |
FVECT gp; |
194 |
double d; |
195 |
int dist, bestd = 0x7fff; |
196 |
VOXL vox; |
197 |
register int i, j, k; |
198 |
/* count voxels in list already */ |
199 |
for (first = 0; first < MAXVOXEL && voxel[first].hd >= 0; first++) |
200 |
; |
201 |
/* find closest voxels */ |
202 |
for (n = first, i = 0; n < MAXVOXEL && hdlist[i]; i++) { |
203 |
hdgrid(gp, hdlist[i], vp); |
204 |
for (j = 0; n < MAXVOXEL && j < 8; j++) { |
205 |
dist = 0; |
206 |
for (k = 0; k < 3; k++) { |
207 |
d = gp[k] - .5 + (j>>k & 1); |
208 |
if (d < 0.) |
209 |
dist += -(vox.i[k] = (int)d - 1); |
210 |
else if ((vox.i[k] = d) >= hdlist[i]->grid[k]) |
211 |
dist += vox.i[k] - |
212 |
hdlist[i]->grid[k] + 1; |
213 |
} |
214 |
if (dist > bestd) /* others were closer */ |
215 |
continue; |
216 |
if (dist < bestd) { /* start closer list */ |
217 |
n = first; |
218 |
bestd = dist; |
219 |
rfl = 0; |
220 |
} |
221 |
/* check if already in list */ |
222 |
for (k = first; k--; ) |
223 |
if (voxel[k].hd == i && |
224 |
voxel[k].i[0] == vox.i[0] && |
225 |
voxel[k].i[1] == vox.i[1] && |
226 |
voxel[k].i[2] == vox.i[2]) |
227 |
break; |
228 |
if (k >= 0) { |
229 |
rfl |= 1<<k; |
230 |
continue; |
231 |
} |
232 |
vox.hd = i; /* add this voxel */ |
233 |
copystruct(&voxel[n], &vox); |
234 |
rfl |= 1<<n++; |
235 |
} |
236 |
} |
237 |
/* check for really stupid move */ |
238 |
if (bestd > MAXDIST) { |
239 |
error(COMMAND, "move past outer limits"); |
240 |
return(0); |
241 |
} |
242 |
if (n < MAXVOXEL) |
243 |
voxel[n].hd = -1; |
244 |
return(rfl); |
245 |
} |
246 |
|
247 |
|
248 |
int |
249 |
dobeam(gcp, bp) /* express interest or disintrest in a beam */ |
250 |
GCOORD *gcp; |
251 |
register struct beamact *bp; |
252 |
{ |
253 |
GCOORD gc[2]; |
254 |
int bi, i, n; |
255 |
/* compute beam index */ |
256 |
if (bp->ca.rev) { |
257 |
copystruct(gc, &bp->gc); |
258 |
copystruct(gc+1, gcp); |
259 |
} else { |
260 |
copystruct(gc, gcp); |
261 |
copystruct(gc+1, &bp->gc); |
262 |
} |
263 |
if ((bi = hdbindex(hdlist[voxel[bp->ca.vi].hd], gc)) <= 0) |
264 |
error(CONSISTENCY, "bad grid coordinate in dobeam"); |
265 |
if (bp->ca.add) { /* add it in */ |
266 |
i = getcbeam(voxel[bp->ca.vi].hd, bi); |
267 |
cbeam[i].wants |= 1<<bp->ca.vi; /* say we want it */ |
268 |
n = npixels(bp->ca.vp, bp->ca.hr, bp->ca.vr, |
269 |
hdlist[cbeam[i].hd], cbeam[i].bi); |
270 |
if (n > cbeam[i].nr) |
271 |
cbeam[i].nr = n; |
272 |
return(i == ncbeams+xcbeams-1); /* return 1 if totally new */ |
273 |
} |
274 |
/* else delete it */ |
275 |
i = findcbeam(voxel[bp->ca.vi].hd, bi); |
276 |
if (i >= 0 && cbeam[i].wants & 1<<bp->ca.vi) { |
277 |
cbeam[i].wants &= ~(1<<bp->ca.vi); /* we don't want it */ |
278 |
if (!cbeam[i].wants) |
279 |
cbeam[i].nr = 0; |
280 |
return(1); /* indicate change */ |
281 |
} |
282 |
return(0); |
283 |
} |
284 |
|
285 |
|
286 |
|
287 |
int |
288 |
docell(gcp, cap) /* find beams corresponding to cell and voxel */ |
289 |
GCOORD *gcp; |
290 |
register struct cellact *cap; |
291 |
{ |
292 |
register HOLO *hp = hdlist[voxel[cap->vi].hd]; |
293 |
FVECT org, dir[4]; |
294 |
FVECT vgp, cgp, vc; |
295 |
FVECT v1, v2; |
296 |
struct beamact bo; |
297 |
int axmax, j; |
298 |
double d, avmax; |
299 |
register int i; |
300 |
/* compute cell center */ |
301 |
cgp[gcp->w>>1] = gcp->w&1 ? hp->grid[gcp->w>>1] : 0 ; |
302 |
cgp[hdwg0[gcp->w]] = gcp->i[0] + .5; |
303 |
cgp[hdwg1[gcp->w]] = gcp->i[1] + .5; |
304 |
hdworld(org, hp, cgp); |
305 |
/* compute direction to voxel center */ |
306 |
for (i = 3; i--; ) |
307 |
vgp[i] = voxel[cap->vi].i[i] + .5; |
308 |
hdworld(vc, hp, vgp); |
309 |
for (i = 3; i--; ) |
310 |
vc[i] -= org[i]; |
311 |
/* compute maximum area axis */ |
312 |
axmax = -1; avmax = 0; |
313 |
for (i = 3; i--; ) { |
314 |
d = vgp[i] - cgp[i]; |
315 |
if (d < 0.) d = -d; |
316 |
if (d > avmax) { |
317 |
avmax = d; |
318 |
axmax = i; |
319 |
} |
320 |
} |
321 |
#ifdef DEBUG |
322 |
if (axmax < 0.) |
323 |
error(CONSISTENCY, "botched axis computation in docell"); |
324 |
#endif |
325 |
/* compute offset vectors */ |
326 |
d = 0.5/hp->grid[j=(axmax+1)%3]; |
327 |
for (i = 3; i--; ) |
328 |
v1[i] = hp->xv[j][i] * d; |
329 |
d = 0.5/hp->grid[j=(axmax+2)%3]; |
330 |
if (DOT(hp->wg[axmax], vc) < 0.) |
331 |
d = -d; /* reverse vertex order */ |
332 |
for (i = 3; i--; ) |
333 |
v2[i] = hp->xv[j][i] * d; |
334 |
/* compute voxel pyramid */ |
335 |
for (i = 3; i--; ) { |
336 |
dir[0][i] = vc[i] - v1[i] - v2[i]; |
337 |
dir[1][i] = vc[i] + v1[i] - v2[i]; |
338 |
dir[2][i] = vc[i] + v1[i] + v2[i]; |
339 |
dir[3][i] = vc[i] - v1[i] + v2[i]; |
340 |
} |
341 |
/* visit beams for opposite cells */ |
342 |
copystruct(&bo.ca, cap); |
343 |
copystruct(&bo.gc, gcp); |
344 |
return(visit_cells(org, dir, hp, dobeam, &bo)); |
345 |
} |
346 |
|
347 |
|
348 |
int |
349 |
doview(cap) /* visit cells for a given view */ |
350 |
struct cellact *cap; |
351 |
{ |
352 |
int orient; |
353 |
FVECT org, dir[4]; |
354 |
/* compute view pyramid */ |
355 |
orient = viewpyramid(org, dir, hdlist[voxel[cap->vi].hd], cap->vp); |
356 |
if (!orient) |
357 |
error(INTERNAL, "unusable view in doview"); |
358 |
cap->rev = orient < 0; |
359 |
/* visit cells within pyramid */ |
360 |
return(visit_cells(org, dir, hdlist[voxel[cap->vi].hd], docell, cap)); |
361 |
} |
362 |
|
363 |
|
364 |
beam_init() /* clear beam list for new view(s) */ |
365 |
{ |
366 |
register int i; |
367 |
/* clear desire flags */ |
368 |
for (i = ncbeams+xcbeams; i--; ) |
369 |
cbeam[i].wants = cbeam[i].nr = 0; |
370 |
voxel[0].hd = -1; /* clear voxel list */ |
371 |
} |
372 |
|
373 |
|
374 |
beam_view(vn, hr, vr) /* add beam view (if advisable) */ |
375 |
VIEW *vn; |
376 |
int hr, vr; |
377 |
{ |
378 |
struct cellact ca; |
379 |
int vfl; |
380 |
/* sort our list */ |
381 |
cbeamsort(1); |
382 |
/* add new voxels */ |
383 |
vfl = add_voxels(vn->vp); |
384 |
if (!vfl) |
385 |
return(0); |
386 |
ca.vp = vn; ca.hr = hr; ca.vr = vr; |
387 |
ca.add = 1; /* update our beam list */ |
388 |
for (ca.vi = 0; vfl; vfl >>= 1, ca.vi++) |
389 |
if (vfl & 1) |
390 |
doview(&ca); |
391 |
return(1); |
392 |
} |
393 |
|
394 |
|
395 |
int |
396 |
beam_sync(all) /* update beam list on server */ |
397 |
int all; |
398 |
{ |
399 |
/* sort list to put orphans at end */ |
400 |
cbeamsort(0); |
401 |
if (all) |
402 |
cbeamop(DR_NEWSET, cbeam, ncbeams); |
403 |
else |
404 |
cbeamop(DR_ADJSET, cbeam, ncbeams+xcbeams); |
405 |
xcbeams = 0; /* truncate our list */ |
406 |
return(ncbeams); |
407 |
} |