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root/radiance/ray/src/hd/rhd_odraw.c
Revision: 3.11
Committed: Tue Dec 29 09:51:07 1998 UTC (25 years, 4 months ago) by gwlarson
Content type: text/plain
Branch: MAIN
Changes since 3.10: +43 -15 lines
Log Message:
changed to dissolve when redrawing large numbers of samples

File Contents

# User Rev Content
1 gwlarson 3.1 /* Copyright (c) 1998 Silicon Graphics, Inc. */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ SGI";
5     #endif
6    
7     /*
8     * Routines for drawing samples using depth buffer checks.
9     */
10    
11     #include "standard.h"
12    
13     #include <sys/types.h>
14     #include <GL/glx.h>
15     #include <GL/glu.h>
16    
17     #include "rhd_odraw.h"
18    
19     #ifndef DEPTHEPS
20     #define DEPTHEPS 0.02 /* depth epsilon */
21     #endif
22     #ifndef SAMPSPERBLOCK
23     #define SAMPSPERBLOCK 1024 /* target samples per image block */
24     #endif
25     #ifndef SFREEFRAC
26     #define SFREEFRAC 0.2 /* fraction to free at a time */
27     #endif
28 gwlarson 3.11 #ifndef REDRAWTHRESH
29     #define REDRAWTHRESH 10240 /* number of samples for dissolve */
30     #endif
31 gwlarson 3.1 #ifndef MAXFAN
32     #define MAXFAN 32 /* maximum arms in a triangle fan */
33     #endif
34     #ifndef MINFAN
35     #define MINFAN 4 /* minimum arms in a triangle fan */
36     #endif
37     #ifndef FANSIZE
38     #define FANSIZE 3.5 /* fan sizing factor */
39     #endif
40    
41     #define NEWMAP 01 /* need to recompute mapping */
42     #define NEWRGB 02 /* need to remap RGB values */
43 gwlarson 3.2 #define NEWHIST 04 /* clear histogram as well */
44 gwlarson 3.1
45     struct ODview *odView; /* our view list */
46     int odNViews; /* number of views in our list */
47    
48     struct ODsamp odS; /* sample values */
49    
50     static int needmapping; /* what needs doing with tone map */
51    
52    
53     #define SAMP32 (32*(2*sizeof(short)+sizeof(union ODfunion)+sizeof(TMbright)+\
54     6*sizeof(BYTE))+sizeof(int4))
55    
56     int
57     odInit(n) /* initialize drawing routines */
58     int n;
59     {
60     int nbytes, i, j, k, nextsamp, count, blockdiv;
61     int res[2];
62    
63 gwlarson 3.3 if (odNViews > 0) { /* deallocate view structures */
64     for (i = odNViews; i--; ) {
65 gwlarson 3.1 free((char *)odView[i].bmap);
66 gwlarson 3.3 free((char *)odView[i].pmap);
67 gwlarson 3.1 if (odView[i].emap != NULL)
68     free((char *)odView[i].emap);
69     }
70     free((char *)odView);
71     odView = NULL;
72     odNViews = 0;
73     }
74     if (n && n != odS.nsamp) {
75     /* round space up to nearest power of 2 */
76     nbytes = (n+31)/32 * SAMP32;
77     for (i = 1024; nbytes > i-8; i <<= 1)
78     ;
79     n = (i-8)/SAMP32 * 32;
80 gwlarson 3.2 needmapping = NEWHIST;
81 gwlarson 3.1 }
82     if (n != odS.nsamp) { /* (re)allocate sample array */
83     if (odS.nsamp)
84     free(odS.base);
85     odS.nsamp = 0;
86     if (!n)
87     return(0);
88     nbytes = (n+31)/32 * SAMP32;
89     odS.base = (char *)malloc(nbytes);
90     if (odS.base == NULL)
91     return(0);
92     /* assign larger alignment types earlier */
93     odS.f = (union ODfunion *)odS.base;
94     odS.redraw = (int4 *)(odS.f + n);
95     odS.ip = (short (*)[2])(odS.redraw + n/32);
96     odS.brt = (TMbright *)(odS.ip + n);
97     odS.chr = (BYTE (*)[3])(odS.brt + n);
98     odS.rgb = (BYTE (*)[3])(odS.chr + n);
99     odS.nsamp = n;
100     }
101     if (!n)
102     return(0);
103     /* allocate view information */
104     count = 0; /* count pixels */
105     for (i = 0; dev_auxview(i, res) != NULL; i++)
106     count += res[0]*res[1];
107     odView = (struct ODview *)malloc(i*sizeof(struct ODview));
108     if (odView == NULL)
109     return(0);
110     odNViews = i;
111     blockdiv = sqrt(count/(n/SAMPSPERBLOCK)) + 0.5;
112     if (blockdiv < 8) blockdiv = 8;
113     nextsamp = 0; count /= blockdiv*blockdiv; /* # blocks */
114     while (i--) { /* initialize each view */
115     dev_auxview(i, res);
116     odView[i].hhi = res[0];
117     odView[i].hlow = (res[0] + blockdiv/2) / blockdiv;
118     if (odView[i].hlow < 1) odView[i].hlow = 1;
119     odView[i].vhi = res[1];
120     odView[i].vlow = (res[1] + blockdiv/2) / blockdiv;
121     if (odView[i].vlow < 1) odView[i].vlow = 1;
122 gwlarson 3.3 odView[i].emap = NULL;
123     odView[i].dmap = NULL;
124     odView[i].pmap = (int4 *)calloc(FL4NELS(res[0]*res[1]),
125     sizeof(int4));
126     if (odView[i].pmap == NULL)
127     return(0);
128 gwlarson 3.1 j = odView[i].hlow*odView[i].vlow;
129     odView[i].bmap = (struct ODblock *)malloc(
130     j * sizeof(struct ODblock));
131     if (odView[i].bmap == NULL)
132     return(0);
133     DCHECK(count<=0 | nextsamp>=n,
134     CONSISTENCY, "counter botch in odInit");
135     if (!i) count = j;
136 gwlarson 3.5 odView[i].sfirst = nextsamp;
137 gwlarson 3.2 while (j--) { /* initialize blocks & free lists */
138     odView[i].bmap[j].pthresh = FHUGE;
139 gwlarson 3.1 odView[i].bmap[j].first = k = nextsamp;
140     nextsamp += odView[i].bmap[j].nsamp =
141     (n - nextsamp)/count--;
142     odView[i].bmap[j].free = k;
143     while (++k < nextsamp)
144     odS.nextfree(k-1) = k;
145     odS.nextfree(k-1) = ENDFREE;
146     odView[i].bmap[j].nused = 0;
147     }
148 gwlarson 3.5 odView[i].snext = nextsamp;
149 gwlarson 3.11 odView[i].n2redraw = 0;
150 gwlarson 3.1 }
151     CLR4ALL(odS.redraw, odS.nsamp); /* clear redraw flags */
152 gwlarson 3.2 for (i = odS.nsamp; i--; ) { /* clear values */
153 gwlarson 3.1 odS.ip[i][0] = odS.ip[i][1] = -1;
154 gwlarson 3.2 odS.brt[i] = TM_NOBRT;
155     }
156     needmapping |= NEWMAP; /* compute new map on update */
157 gwlarson 3.1 return(odS.nsamp); /* return number of samples */
158     }
159    
160     #undef SAMP32
161    
162    
163     int
164     sampcmp(s0, s1) /* sample order, descending proximity */
165     int *s0, *s1;
166     {
167     register double diff = odS.closeness(*s1) - odS.closeness(*s0);
168    
169     return (diff > FTINY ? 1 : diff < -FTINY ? -1 : 0);
170     }
171    
172    
173     int
174 gwlarson 3.2 odAllocBlockSamp(vn, hh, vh, prox) /* allocate sample from block */
175     int vn, hh, vh;
176     double prox;
177 gwlarson 3.1 {
178     int si[SAMPSPERBLOCK+SAMPSPERBLOCK/4];
179 gwlarson 3.2 int hl, vl;
180 gwlarson 3.1 VIEW *vw;
181     FVECT ro, rd;
182     int res[2];
183     register struct ODblock *bp;
184 gwlarson 3.2 register int i, j;
185     /* get block */
186     hl = hh*odView[vn].hlow/odView[vn].hhi;
187     vl = vh*odView[vn].vlow/odView[vn].vhi;
188 gwlarson 3.1 bp = odView[vn].bmap + vl*odView[vn].hlow + hl;
189 gwlarson 3.2 if (prox > bp->pthresh)
190     return(-1); /* worse than free list occupants */
191     /* check for duplicate pixel */
192 gwlarson 3.3 if (CHK4(odView[vn].pmap, vh*odView[vn].hhi + hh))
193     i = bp->first + bp->nsamp;
194     else
195 gwlarson 3.11 i = 0;
196 gwlarson 3.3 while (i-- > bp->first)
197 gwlarson 3.2 if (hh == odS.ip[i][0] && vh == odS.ip[i][1]) { /* found it! */
198     /* search free list for it */
199     if (i == bp->free)
200     break; /* special case */
201     if (bp->free != ENDFREE)
202     for (j = bp->free; odS.nextfree(j) != ENDFREE;
203     j = odS.nextfree(j))
204     if (odS.nextfree(j) == i) {
205     odS.nextfree(j) =
206     odS.nextfree(i);
207     bp->nused++;
208     goto gotit;
209     }
210 gwlarson 3.11 if (prox >= 0.99*odS.closeness(i))
211 gwlarson 3.2 return(-1); /* previous sample is fine */
212     goto gotit;
213     }
214     if (bp->free != ENDFREE) { /* allocate from free list */
215 gwlarson 3.1 i = bp->free;
216 gwlarson 3.3 if (odS.ip[i][0] >= 0 & odS.ip[i][1] >= 0)
217     CLR4(odView[vn].pmap, odS.ip[i][1]*odView[vn].hhi +
218     odS.ip[i][0]);
219 gwlarson 3.1 bp->free = odS.nextfree(i);
220     bp->nused++;
221 gwlarson 3.2 goto gotit;
222 gwlarson 3.1 }
223     DCHECK(bp->nsamp<=0, CONSISTENCY,
224     "no available samples in odAllocBlockSamp");
225     DCHECK(bp->nsamp > sizeof(si)/sizeof(si[0]), CONSISTENCY,
226     "too many samples in odAllocBlockSamp");
227     /* free some samples */
228     if ((vw = dev_auxview(vn, res)) == NULL)
229     error(CONSISTENCY, "bad view number in odAllocBlockSamp");
230     for (i = bp->nsamp; i--; ) /* figure out which are worse */
231     si[i] = bp->first + i;
232     qsort((char *)si, bp->nsamp, sizeof(int), sampcmp);
233 gwlarson 3.2 i = bp->nsamp*SFREEFRAC + .5; /* put them into free list */
234     if (i >= bp->nsamp) i = bp->nsamp-1; /* paranoia */
235     bp->pthresh = odS.closeness(si[i]); /* new proximity threshold */
236 gwlarson 3.1 while (--i > 0) {
237     odS.nextfree(si[i]) = bp->free;
238     bp->free = si[i];
239     bp->nused--;
240     }
241 gwlarson 3.2 i = si[0]; /* use worst sample */
242 gwlarson 3.3 CLR4(odView[vn].pmap, odS.ip[i][1]*odView[vn].hhi + odS.ip[i][0]);
243 gwlarson 3.2 gotit:
244     odS.ip[i][0] = hh;
245     odS.ip[i][1] = vh;
246     odS.closeness(i) = prox;
247 gwlarson 3.3 SET4(odView[vn].pmap, vh*odView[vn].hhi + hh);
248 gwlarson 3.2 return(i);
249 gwlarson 3.1 }
250    
251    
252     odSample(c, d, p) /* add a sample value */
253     COLR c;
254     FVECT d, p;
255     {
256     FVECT disp;
257 gwlarson 3.2 double d0, d1, h, v, prox;
258 gwlarson 3.1 register VIEW *vw;
259 gwlarson 3.2 int hh, vh;
260 gwlarson 3.1 int res[2];
261     register int i, id;
262    
263     DCHECK(odS.nsamp<=0, CONSISTENCY, "no samples allocated in odSample");
264     /* add value to each view */
265     for (i = 0; (vw = dev_auxview(i, res)) != NULL; i++) {
266     DCHECK(i>=odNViews, CONSISTENCY, "too many views in odSample");
267     CHECK(vw->type!=VT_PER, INTERNAL,
268     "cannot handle non-perspective views");
269     if (p != NULL) { /* compute view position */
270     VSUB(disp, p, vw->vp);
271     d0 = DOT(disp, vw->vdir);
272     if (d0 <= vw->vfore+FTINY)
273     continue; /* too close */
274     } else {
275     VCOPY(disp, d);
276     d0 = DOT(disp, vw->vdir);
277     if (d0 <= FTINY) /* behind view */
278     continue;
279     }
280     h = DOT(disp,vw->hvec)/(d0*vw->hn2) + 0.5 - vw->hoff;
281     if (h < 0. || h >= 1.)
282     continue; /* left or right */
283     v = DOT(disp,vw->vvec)/(d0*vw->vn2) + 0.5 - vw->voff;
284     if (v < 0. || v >= 1.)
285     continue; /* above or below */
286     hh = h * res[0];
287     vh = v * res[1];
288     if (odView[i].dmap != NULL) { /* check depth */
289     d1 = odView[i].dmap[vh*res[0] + hh];
290     if (d1 < 0.99*FHUGE && (d0 > (1.+DEPTHEPS)*d1 ||
291     (1.+DEPTHEPS)*d0 < d1))
292     continue; /* occlusion error */
293     }
294     if (p != NULL) { /* compute closeness (sin^2) */
295     d1 = DOT(disp, d);
296 gwlarson 3.2 prox = 1. - d1*d1/DOT(disp,disp);
297 gwlarson 3.1 } else
298 gwlarson 3.2 prox = 0.;
299     /* allocate sample */
300     id = odAllocBlockSamp(i, hh, vh, prox);
301     if (id < 0)
302     continue; /* not good enough */
303 gwlarson 3.1 /* convert color */
304     tmCvColrs(&odS.brt[id], odS.chr[id], c, 1);
305     if (imm_mode | needmapping) /* if immediate mode */
306     needmapping |= NEWRGB; /* map it later */
307     else /* else map it now */
308     tmMapPixels(odS.rgb[id], &odS.brt[id], odS.chr[id], 1);
309     SET4(odS.redraw, id); /* mark for redraw */
310 gwlarson 3.11 odView[i].n2redraw++;
311 gwlarson 3.1 }
312     }
313    
314    
315 gwlarson 3.2 odRemap(newhist) /* recompute tone mapping */
316     int newhist;
317 gwlarson 3.1 {
318     needmapping |= NEWMAP|NEWRGB;
319 gwlarson 3.2 if (newhist)
320     needmapping |= NEWHIST;
321 gwlarson 3.1 }
322    
323    
324 gwlarson 3.6 odRedrawAll() /* mark all samples for redraw */
325     {
326     register int i;
327    
328     if ((needmapping&(NEWMAP|NEWRGB)) == (NEWMAP|NEWRGB))
329     return; /* will be called later, anyway */
330     for (i = odS.nsamp; i--; )
331     if (odS.ip[i][0] >= 0)
332     SET4(odS.redraw, i);
333 gwlarson 3.11 /* not right, but not important */
334     for (i = 0; i < odNViews; i++)
335     odView[i].n2redraw = odView[i].snext - odView[i].sfirst;
336 gwlarson 3.6 }
337    
338    
339 gwlarson 3.1 odRedraw(vn, hmin, vmin, hmax, vmax) /* redraw view region */
340     int vn, hmin, vmin, hmax, vmax;
341     {
342     int i, j;
343     register struct ODblock *bp;
344     register int k;
345    
346     if (vn<0 | vn>=odNViews)
347     return;
348     /* check view limits */
349     if (hmin < 0) hmin = 0;
350     if (hmax >= odView[vn].hhi) hmax = odView[vn].hhi-1;
351     if (vmin < 0) vmin = 0;
352     if (vmax >= odView[vn].vhi) vmax = odView[vn].vhi-1;
353     if (hmax <= hmin | vmax <= vmin)
354     return;
355     /* convert to low resolution */
356     hmin = hmin * odView[vn].hlow / odView[vn].hhi;
357     hmax = hmax * odView[vn].hlow / odView[vn].hhi;
358     vmin = vmin * odView[vn].vlow / odView[vn].vhi;
359     vmax = vmax * odView[vn].vlow / odView[vn].vhi;
360     /* mark block samples for redraw, inclusive */
361     for (i = hmin; i <= hmax; i++)
362     for (j = vmin; j <= vmax; j++) {
363     bp = odView[vn].bmap + j*odView[vn].hlow + i;
364     for (k = bp->nsamp; k--; )
365 gwlarson 3.11 if (odS.ip[bp->first+k][0] >= 0) {
366 gwlarson 3.1 SET4(odS.redraw, bp->first+k);
367 gwlarson 3.11 odView[vn].n2redraw++;
368     }
369 gwlarson 3.1 }
370     }
371    
372    
373     odDepthMap(vn, dm) /* assign depth map for view */
374     int vn;
375     GLfloat *dm;
376     {
377     double d0, d1;
378     int i, j, hmin, hmax, vmin, vmax;
379     register int k, l;
380    
381     if (dm == NULL) { /* free edge map */
382 gwlarson 3.2 if (vn<0 | vn>=odNViews)
383     return; /* too late -- they're gone! */
384 gwlarson 3.1 if (odView[vn].emap != NULL)
385     free((char *)odView[vn].emap);
386     odView[vn].emap = NULL;
387     odView[vn].dmap = NULL;
388     return;
389     }
390 gwlarson 3.2 DCHECK(vn<0 | vn>=odNViews, CONSISTENCY,
391     "bad view number in odDepthMap");
392 gwlarson 3.1 odView[vn].dmap = dm; /* initialize edge map */
393     if (odView[vn].emap == NULL) {
394     odView[vn].emap = (int4 *)malloc(
395     FL4NELS(odView[vn].hlow*odView[vn].vlow)*sizeof(int4));
396     if (odView[vn].emap == NULL)
397     error(SYSTEM, "out of memory in odDepthMap");
398     }
399     CLR4ALL(odView[vn].emap, odView[vn].hlow*odView[vn].vlow);
400     /* compute edge map */
401     vmin = odView[vn].vhi; /* enter loopsville */
402     for (j = odView[vn].vlow; j--; ) {
403     vmax = vmin;
404     vmin = j*odView[vn].vhi/odView[vn].vlow;
405     hmin = odView[vn].hhi;
406     for (i = odView[vn].hlow; i--; ) {
407     hmax = hmin;
408     hmin = i*odView[vn].hhi/odView[vn].hlow;
409     for (l = vmin; l < vmax; l++) { /* vertical edges */
410     d1 = dm[l*odView[vn].hhi+hmin];
411     for (k = hmin+1; k < hmax; k++) {
412     d0 = d1;
413     d1 = dm[l*odView[vn].hhi+k];
414     if (d0 > (1.+DEPTHEPS)*d1 ||
415     (1.+DEPTHEPS)*d0 < d1) {
416     SET4(odView[vn].emap,
417     j*odView[vn].hlow + i);
418     break;
419     }
420     }
421     if (k < hmax)
422     break;
423     }
424     if (l < vmax)
425     continue;
426     for (k = hmin; k < hmax; k++) { /* horizontal edges */
427     d1 = dm[vmin*odView[vn].hhi+k];
428     for (l = vmin+1; l < vmax; l++) {
429     d0 = d1;
430     d1 = dm[l*odView[vn].hhi+k];
431     if (d0 > (1.+DEPTHEPS)*d1 ||
432     (1.+DEPTHEPS)*d0 < d1) {
433     SET4(odView[vn].emap,
434     j*odView[vn].hlow + i);
435     break;
436     }
437     }
438     if (l < vmax)
439     break;
440     }
441     }
442     }
443     }
444    
445    
446     odUpdate(vn) /* update this view */
447     int vn;
448     {
449 gwlarson 3.11 static short primes[] = {9431,6803,4177,2659,1609,887,587,251,47,1};
450     int myprime;
451     register int i, n;
452 gwlarson 3.1
453     DCHECK(vn<0 | vn>=odNViews, CONSISTENCY,
454     "bad view number in odUpdate");
455     /* need to do some tone mapping? */
456     if (needmapping & NEWRGB) {
457     if (needmapping & NEWMAP) {
458 gwlarson 3.2 if (needmapping & NEWHIST)
459     tmClearHisto();
460 gwlarson 3.6 needmapping &= ~NEWHIST;
461 gwlarson 3.1 if (tmAddHisto(odS.brt,odS.nsamp,1) != TM_E_OK)
462     return;
463     if (tmComputeMapping(0.,0.,0.) != TM_E_OK)
464     return;
465 gwlarson 3.6 needmapping &= ~NEWMAP;
466     odRedrawAll(); /* redraw everything */
467 gwlarson 3.1 }
468     if (tmMapPixels(odS.rgb,odS.brt,odS.chr,odS.nsamp) != TM_E_OK)
469     return;
470 gwlarson 3.6 needmapping &= ~NEWRGB;
471 gwlarson 3.1 }
472 gwlarson 3.11 if (odView[vn].n2redraw <= 0)
473     return;
474     #if REDRAWTHRESH
475     if (odView[vn].n2redraw < REDRAWTHRESH)
476     goto quickdraw;
477     /* pick a good prime step size */
478     n = odView[vn].snext - odView[vn].sfirst;
479     for (i = 0; primes[i]<<5 >= n; i++)
480     ;
481     while ((myprime = primes[i++]) > 1)
482     if (n % myprime)
483     break;
484     /* dissolve in new samples */
485     for (i = odView[vn].sfirst; n-- > 0; i += myprime) {
486     if (i >= odView[vn].snext)
487     i -= odView[vn].snext - odView[vn].sfirst;
488 gwlarson 3.5 if (CHK4(odS.redraw, i)) {
489     odDrawSamp(vn, i);
490     CLR4(odS.redraw, i);
491     }
492 gwlarson 3.11 }
493     odView[vn].n2redraw = 0;
494     return;
495     quickdraw: /* quicker sparse flag checking */
496     #endif
497 gwlarson 3.10 /* redraw samples at end */
498     for (i = odView[vn].snext-31; i < odView[vn].snext; i++)
499 gwlarson 3.5 if (CHK4(odS.redraw, i)) {
500     odDrawSamp(vn, i);
501     CLR4(odS.redraw, i);
502     }
503     /* faster flag checks in middle */
504 gwlarson 3.11 for (n = odView[vn].snext>>5; n-- > (odView[vn].sfirst+0x1f)>>5; )
505     for (i = 0; odS.redraw[n]; i++) /* skips faster */
506     if (odS.redraw[n] & 1L<<i) {
507     odDrawSamp(vn, (n<<5)+i);
508     odS.redraw[n] &= ~(1L<<i);
509 gwlarson 3.4 }
510 gwlarson 3.10 /* redraw samples at beginning */
511     for (i = odView[vn].sfirst; i < odView[vn].sfirst+31; i++)
512 gwlarson 3.8 if (CHK4(odS.redraw, i)) {
513     odDrawSamp(vn, i);
514     CLR4(odS.redraw, i);
515     }
516 gwlarson 3.11 odView[vn].n2redraw = 0;
517 gwlarson 3.1 }
518    
519    
520 gwlarson 3.5 /* this turned out to be unnecessary */
521 gwlarson 3.1 #if 0
522     static
523     clip_end(p, o, vp) /* clip line segment to view */
524     GLshort p[3];
525     short o[2];
526     register struct ODview *vp;
527     {
528     if (p[0] < 0) {
529     p[1] = -o[0]*(p[1]-o[1])/(p[0]-o[0]) + o[1];
530     p[2] = -o[0]*p[2]/(p[0]-o[0]);
531     p[0] = 0;
532     } else if (p[0] >= vp->hhi) {
533     p[1] = (vp->hhi-1-o[0])*(p[1]-o[1])/(p[0]-o[0]) + o[1];
534     p[2] = (vp->hhi-1-o[0])*p[2]/(p[0]-o[0]);
535     p[0] = vp->hhi-1;
536     }
537     if (p[1] < 0) {
538     p[0] = -o[1]*(p[0]-o[0])/(p[1]-o[1]) + o[0];
539     p[2] = -o[1]*p[2]/(p[1]-o[1]);
540     p[1] = 0;
541     } else if (p[1] >= vp->vhi) {
542     p[0] = (vp->vhi-1-o[1])*(p[0]-o[0])/(p[1]-o[1]) + o[0];
543     p[2] = (vp->vhi-1-o[1])*p[2]/(p[1]-o[1]);
544     p[1] = vp->vhi-1;
545     }
546     }
547     #endif
548    
549    
550     static int
551     make_arms(ar, cp, vp, sz) /* make arms for triangle fan */
552     GLshort ar[MAXFAN][3];
553     short cp[2];
554     register struct ODview *vp;
555     double sz;
556     {
557     int na, dv;
558 gwlarson 3.6 double hrad, vrad, phi;
559 gwlarson 3.1 register int i;
560    
561     DCHECK(sz > 1, CONSISTENCY, "super-unary size in make_arms");
562 gwlarson 3.9 na = MAXFAN*sz + 0.5; /* keep arc length constant */
563 gwlarson 3.1 if (na < MINFAN) na = MINFAN;
564     hrad = FANSIZE*sz*vp->hhi/vp->hlow;
565     vrad = FANSIZE*sz*vp->vhi/vp->vlow;
566     if (hrad*vrad < 2.25)
567     hrad = vrad = 1.5;
568     dv = OMAXDEPTH*sz + 0.5;
569     for (i = 0; i < na; i++) {
570 gwlarson 3.6 phi = (2.*PI)*i/na;
571 gwlarson 3.1 ar[i][0] = cp[0] + tcos(phi)*hrad + 0.5;
572     ar[i][1] = cp[1] + tsin(phi)*vrad + 0.5;
573     ar[i][2] = dv;
574     /* clip_end(ar[i], cp, vp); */
575     }
576     return(na);
577     }
578    
579    
580     static int
581     depthchange(vp, x0, y0, x1, y1) /* check depth discontinuity */
582     register struct ODview *vp;
583     int x0, y0, x1, y1;
584     {
585     register double d0, d1;
586    
587     DCHECK(x0<0 | x0>=vp->hhi | y0<0 | y0>=vp->vhi,
588     CONSISTENCY, "coordinates off view in depthchange");
589    
590     if (x1<0 | x1>=vp->hhi | y1<0 | y1>=vp->vhi)
591     return(1);
592    
593     d0 = vp->dmap[y0*vp->hhi + x0];
594     d1 = vp->dmap[y1*vp->hhi + x1];
595    
596     return((1.+DEPTHEPS)*d0 < d1 || d0 > (1.+DEPTHEPS)*d1);
597     }
598    
599    
600     static
601     clip_edge(p, o, vp) /* clip line segment to depth edge */
602     GLshort p[3];
603     short o[2];
604     register struct ODview *vp;
605     {
606     int x, y, xstep, ystep, rise, rise2, run, run2, n;
607    
608     DCHECK(vp->dmap==NULL, CONSISTENCY,
609     "clip_edge called with no depth map");
610     x = o[0]; y = o[1];
611     run = p[0] - x;
612     xstep = run > 0 ? 1 : -1;
613     run *= xstep;
614     rise = p[1] - y;
615     ystep = rise > 0 ? 1 : -1;
616     rise *= ystep;
617     rise2 = run2 = 0;
618     if (rise > run) rise2 = 1;
619     else run2 = 1;
620     n = rise + run;
621     while (n--) /* run out arm, checking depth */
622     if (run2 > rise2) {
623     x += xstep;
624     rise2 += rise;
625 gwlarson 3.7 if (depthchange(vp, x-xstep, y, x, y))
626     break;
627 gwlarson 3.1 } else {
628     y += ystep;
629     run2 += run;
630 gwlarson 3.7 if (depthchange(vp, x, y-ystep, x, y))
631     break;
632 gwlarson 3.1 }
633     if (n < 0) /* found something? */
634     return;
635     if (run > rise)
636     p[2] = (x - o[0])*p[2]/(p[0] - o[0]);
637     else
638     p[2] = (y - o[1])*p[2]/(p[1] - o[1]);
639     p[0] = x;
640     p[1] = y;
641     }
642    
643    
644     static int
645     getblock(vp, h, v) /* get block index */
646     register struct ODview *vp;
647     register int h, v;
648     {
649     if (h<0 | h>=vp->hhi | v<0 | v>=vp->vhi)
650     return(-1);
651     return(h*vp->hlow/vp->hhi + v*vp->vlow/vp->vhi*vp->hlow);
652     }
653    
654    
655 gwlarson 3.6 static int
656     blockedge(vp, bi0, bi1) /* check for edge between blocks? */
657     register struct ODview *vp;
658     register int bi0, bi1;
659     {
660 gwlarson 3.8 if (bi1 == bi0)
661     return(0); /* same block */
662 gwlarson 3.6 if (bi1 < 0)
663     return(1); /* end off view */
664     if (CHK4(vp->emap, bi1))
665 gwlarson 3.8 return(1); /* end block has edges */
666 gwlarson 3.6 if (bi1 == bi0+1 || bi1 == bi0-1 ||
667     bi1 == bi0+vp->hlow || bi1 == bi0-vp->hlow)
668     return(0); /* end in adjacent block -- no edges */
669     return(1); /* conservative for rarer case */
670     }
671    
672    
673 gwlarson 3.4 odDrawSamp(vn, id) /* draw view sample */
674     int vn;
675 gwlarson 3.1 register int id;
676     {
677     GLshort arm[MAXFAN][3];
678 gwlarson 3.6 int narms, blockindex;
679 gwlarson 3.1 register struct ODview *vp;
680     double size;
681     int home_edges;
682     register int i;
683    
684     vp = odView + vn;
685 gwlarson 3.4 blockindex = getblock(vp, odS.ip[id][0], odS.ip[id][1]);
686     DCHECK(blockindex<0, CONSISTENCY, "bad sample handed to odDrawSamp");
687 gwlarson 3.1 DCHECK(vp->bmap[blockindex].nused <= 0,
688 gwlarson 3.4 CONSISTENCY, "bad in-use count in odDrawSamp");
689 gwlarson 3.1 /* create triangle fan */
690     size = 1./sqrt((double)vp->bmap[blockindex].nused);
691     narms = make_arms(arm, odS.ip[id], vp, size);
692     if (vp->emap != NULL) { /* check for edge collisions */
693     home_edges = CHK4(vp->emap, blockindex);
694     for (i = 0; i < narms; i++)
695 gwlarson 3.6 if (home_edges || blockedge(vp, blockindex,
696     getblock(vp, arm[i][0], arm[i][1])))
697 gwlarson 3.1 clip_edge(arm[i], odS.ip[id], vp);
698     }
699     /* draw triangle fan */
700     glColor3ub(odS.rgb[id][0], odS.rgb[id][1], odS.rgb[id][2]);
701     glBegin(GL_TRIANGLE_FAN);
702     glVertex3s((GLshort)odS.ip[id][0], (GLshort)odS.ip[id][1], (GLshort)0);
703     for (i = 0; i < narms; i++)
704     glVertex3sv(arm[i]);
705     glVertex3sv(arm[0]); /* connect last to first */
706     glEnd();
707     }