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> |
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#include <GL/glx.h> |
15 |
#include <GL/glu.h> |
16 |
|
17 |
#include "random.h" |
18 |
#include "rhd_odraw.h" |
19 |
|
20 |
#ifndef DEPTHEPS |
21 |
#define DEPTHEPS 0.02 /* depth epsilon */ |
22 |
#endif |
23 |
#ifndef SAMPSPERBLOCK |
24 |
#define SAMPSPERBLOCK 1024 /* target samples per image block */ |
25 |
#endif |
26 |
#ifndef SFREEFRAC |
27 |
#define SFREEFRAC 0.2 /* fraction to free at a time */ |
28 |
#endif |
29 |
#ifndef MAXFAN |
30 |
#define MAXFAN 32 /* maximum arms in a triangle fan */ |
31 |
#endif |
32 |
#ifndef MINFAN |
33 |
#define MINFAN 4 /* minimum arms in a triangle fan */ |
34 |
#endif |
35 |
#ifndef FANSIZE |
36 |
#define FANSIZE 3.5 /* fan sizing factor */ |
37 |
#endif |
38 |
|
39 |
#define NEWMAP 01 /* need to recompute mapping */ |
40 |
#define NEWRGB 02 /* need to remap RGB values */ |
41 |
#define NEWHIST 04 /* clear histogram as well */ |
42 |
|
43 |
struct ODview *odView; /* our view list */ |
44 |
int odNViews; /* number of views in our list */ |
45 |
|
46 |
struct ODsamp odS; /* sample values */ |
47 |
|
48 |
static int needmapping; /* what needs doing with tone map */ |
49 |
|
50 |
|
51 |
#define SAMP32 (32*(2*sizeof(short)+sizeof(union ODfunion)+sizeof(TMbright)+\ |
52 |
6*sizeof(BYTE))+sizeof(int4)) |
53 |
|
54 |
int |
55 |
odInit(n) /* initialize drawing routines */ |
56 |
int n; |
57 |
{ |
58 |
int nbytes, i, j, k, nextsamp, count, blockdiv; |
59 |
int res[2]; |
60 |
|
61 |
if (odNViews) { /* deallocate view structures */ |
62 |
for (i = 0; i < odNViews; i++) { |
63 |
free((char *)odView[i].bmap); |
64 |
if (odView[i].emap != NULL) |
65 |
free((char *)odView[i].emap); |
66 |
} |
67 |
free((char *)odView); |
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odView = NULL; |
69 |
odNViews = 0; |
70 |
} |
71 |
if (n && n != odS.nsamp) { |
72 |
/* round space up to nearest power of 2 */ |
73 |
nbytes = (n+31)/32 * SAMP32; |
74 |
for (i = 1024; nbytes > i-8; i <<= 1) |
75 |
; |
76 |
n = (i-8)/SAMP32 * 32; |
77 |
needmapping = NEWHIST; |
78 |
} |
79 |
if (n != odS.nsamp) { /* (re)allocate sample array */ |
80 |
if (odS.nsamp) |
81 |
free(odS.base); |
82 |
odS.nsamp = 0; |
83 |
if (!n) |
84 |
return(0); |
85 |
nbytes = (n+31)/32 * SAMP32; |
86 |
odS.base = (char *)malloc(nbytes); |
87 |
if (odS.base == NULL) |
88 |
return(0); |
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/* assign larger alignment types earlier */ |
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odS.f = (union ODfunion *)odS.base; |
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odS.redraw = (int4 *)(odS.f + n); |
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odS.ip = (short (*)[2])(odS.redraw + n/32); |
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odS.brt = (TMbright *)(odS.ip + n); |
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odS.chr = (BYTE (*)[3])(odS.brt + n); |
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odS.rgb = (BYTE (*)[3])(odS.chr + n); |
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odS.nsamp = n; |
97 |
} |
98 |
if (!n) |
99 |
return(0); |
100 |
/* allocate view information */ |
101 |
count = 0; /* count pixels */ |
102 |
for (i = 0; dev_auxview(i, res) != NULL; i++) |
103 |
count += res[0]*res[1]; |
104 |
odView = (struct ODview *)malloc(i*sizeof(struct ODview)); |
105 |
if (odView == NULL) |
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return(0); |
107 |
odNViews = i; |
108 |
blockdiv = sqrt(count/(n/SAMPSPERBLOCK)) + 0.5; |
109 |
if (blockdiv < 8) blockdiv = 8; |
110 |
nextsamp = 0; count /= blockdiv*blockdiv; /* # blocks */ |
111 |
while (i--) { /* initialize each view */ |
112 |
odView[i].emap = NULL; |
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odView[i].dmap = NULL; |
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dev_auxview(i, res); |
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odView[i].hhi = res[0]; |
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odView[i].hlow = (res[0] + blockdiv/2) / blockdiv; |
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if (odView[i].hlow < 1) odView[i].hlow = 1; |
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odView[i].vhi = res[1]; |
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odView[i].vlow = (res[1] + blockdiv/2) / blockdiv; |
120 |
if (odView[i].vlow < 1) odView[i].vlow = 1; |
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j = odView[i].hlow*odView[i].vlow; |
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odView[i].bmap = (struct ODblock *)malloc( |
123 |
j * sizeof(struct ODblock)); |
124 |
if (odView[i].bmap == NULL) |
125 |
return(0); |
126 |
DCHECK(count<=0 | nextsamp>=n, |
127 |
CONSISTENCY, "counter botch in odInit"); |
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if (!i) count = j; |
129 |
while (j--) { /* initialize blocks & free lists */ |
130 |
odView[i].bmap[j].pthresh = FHUGE; |
131 |
odView[i].bmap[j].first = k = nextsamp; |
132 |
nextsamp += odView[i].bmap[j].nsamp = |
133 |
(n - nextsamp)/count--; |
134 |
odView[i].bmap[j].free = k; |
135 |
while (++k < nextsamp) |
136 |
odS.nextfree(k-1) = k; |
137 |
odS.nextfree(k-1) = ENDFREE; |
138 |
odView[i].bmap[j].nused = 0; |
139 |
} |
140 |
} |
141 |
CLR4ALL(odS.redraw, odS.nsamp); /* clear redraw flags */ |
142 |
for (i = odS.nsamp; i--; ) { /* clear values */ |
143 |
odS.ip[i][0] = odS.ip[i][1] = -1; |
144 |
odS.brt[i] = TM_NOBRT; |
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} |
146 |
needmapping |= NEWMAP; /* compute new map on update */ |
147 |
return(odS.nsamp); /* return number of samples */ |
148 |
} |
149 |
|
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#undef SAMP32 |
151 |
|
152 |
|
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int |
154 |
sampcmp(s0, s1) /* sample order, descending proximity */ |
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int *s0, *s1; |
156 |
{ |
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register double diff = odS.closeness(*s1) - odS.closeness(*s0); |
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|
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return (diff > FTINY ? 1 : diff < -FTINY ? -1 : 0); |
160 |
} |
161 |
|
162 |
|
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int |
164 |
odAllocBlockSamp(vn, hh, vh, prox) /* allocate sample from block */ |
165 |
int vn, hh, vh; |
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double prox; |
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{ |
168 |
int si[SAMPSPERBLOCK+SAMPSPERBLOCK/4]; |
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int hl, vl; |
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VIEW *vw; |
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FVECT ro, rd; |
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int res[2]; |
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register struct ODblock *bp; |
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register int i, j; |
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/* get block */ |
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hl = hh*odView[vn].hlow/odView[vn].hhi; |
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vl = vh*odView[vn].vlow/odView[vn].vhi; |
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bp = odView[vn].bmap + vl*odView[vn].hlow + hl; |
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if (prox > bp->pthresh) |
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return(-1); /* worse than free list occupants */ |
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/* check for duplicate pixel */ |
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for (i = bp->first+bp->nsamp; i-- > bp->first; ) |
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if (hh == odS.ip[i][0] && vh == odS.ip[i][1]) { /* found it! */ |
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/* search free list for it */ |
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if (i == bp->free) |
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break; /* special case */ |
187 |
if (bp->free != ENDFREE) |
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for (j = bp->free; odS.nextfree(j) != ENDFREE; |
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j = odS.nextfree(j)) |
190 |
if (odS.nextfree(j) == i) { |
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odS.nextfree(j) = |
192 |
odS.nextfree(i); |
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bp->nused++; |
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goto gotit; |
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} |
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if (prox >= 0.999*odS.closeness(i)) |
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return(-1); /* previous sample is fine */ |
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goto gotit; |
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} |
200 |
if (bp->free != ENDFREE) { /* allocate from free list */ |
201 |
i = bp->free; |
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bp->free = odS.nextfree(i); |
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bp->nused++; |
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goto gotit; |
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} |
206 |
DCHECK(bp->nsamp<=0, CONSISTENCY, |
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"no available samples in odAllocBlockSamp"); |
208 |
DCHECK(bp->nsamp > sizeof(si)/sizeof(si[0]), CONSISTENCY, |
209 |
"too many samples in odAllocBlockSamp"); |
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/* free some samples */ |
211 |
if ((vw = dev_auxview(vn, res)) == NULL) |
212 |
error(CONSISTENCY, "bad view number in odAllocBlockSamp"); |
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for (i = bp->nsamp; i--; ) /* figure out which are worse */ |
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si[i] = bp->first + i; |
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qsort((char *)si, bp->nsamp, sizeof(int), sampcmp); |
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i = bp->nsamp*SFREEFRAC + .5; /* put them into free list */ |
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if (i >= bp->nsamp) i = bp->nsamp-1; /* paranoia */ |
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bp->pthresh = odS.closeness(si[i]); /* new proximity threshold */ |
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while (--i > 0) { |
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odS.nextfree(si[i]) = bp->free; |
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bp->free = si[i]; |
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bp->nused--; |
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} |
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i = si[0]; /* use worst sample */ |
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gotit: |
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odS.ip[i][0] = hh; |
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odS.ip[i][1] = vh; |
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odS.closeness(i) = prox; |
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return(i); |
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} |
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|
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|
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odSample(c, d, p) /* add a sample value */ |
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COLR c; |
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FVECT d, p; |
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{ |
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FVECT disp; |
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double d0, d1, h, v, prox; |
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register VIEW *vw; |
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int hh, vh; |
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int res[2]; |
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register int i, id; |
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|
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DCHECK(odS.nsamp<=0, CONSISTENCY, "no samples allocated in odSample"); |
245 |
/* add value to each view */ |
246 |
for (i = 0; (vw = dev_auxview(i, res)) != NULL; i++) { |
247 |
DCHECK(i>=odNViews, CONSISTENCY, "too many views in odSample"); |
248 |
CHECK(vw->type!=VT_PER, INTERNAL, |
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"cannot handle non-perspective views"); |
250 |
if (p != NULL) { /* compute view position */ |
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VSUB(disp, p, vw->vp); |
252 |
d0 = DOT(disp, vw->vdir); |
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if (d0 <= vw->vfore+FTINY) |
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continue; /* too close */ |
255 |
} else { |
256 |
VCOPY(disp, d); |
257 |
d0 = DOT(disp, vw->vdir); |
258 |
if (d0 <= FTINY) /* behind view */ |
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continue; |
260 |
} |
261 |
h = DOT(disp,vw->hvec)/(d0*vw->hn2) + 0.5 - vw->hoff; |
262 |
if (h < 0. || h >= 1.) |
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continue; /* left or right */ |
264 |
v = DOT(disp,vw->vvec)/(d0*vw->vn2) + 0.5 - vw->voff; |
265 |
if (v < 0. || v >= 1.) |
266 |
continue; /* above or below */ |
267 |
hh = h * res[0]; |
268 |
vh = v * res[1]; |
269 |
if (odView[i].dmap != NULL) { /* check depth */ |
270 |
d1 = odView[i].dmap[vh*res[0] + hh]; |
271 |
if (d1 < 0.99*FHUGE && (d0 > (1.+DEPTHEPS)*d1 || |
272 |
(1.+DEPTHEPS)*d0 < d1)) |
273 |
continue; /* occlusion error */ |
274 |
} |
275 |
if (p != NULL) { /* compute closeness (sin^2) */ |
276 |
d1 = DOT(disp, d); |
277 |
prox = 1. - d1*d1/DOT(disp,disp); |
278 |
} else |
279 |
prox = 0.; |
280 |
/* allocate sample */ |
281 |
id = odAllocBlockSamp(i, hh, vh, prox); |
282 |
if (id < 0) |
283 |
continue; /* not good enough */ |
284 |
/* convert color */ |
285 |
tmCvColrs(&odS.brt[id], odS.chr[id], c, 1); |
286 |
if (imm_mode | needmapping) /* if immediate mode */ |
287 |
needmapping |= NEWRGB; /* map it later */ |
288 |
else /* else map it now */ |
289 |
tmMapPixels(odS.rgb[id], &odS.brt[id], odS.chr[id], 1); |
290 |
SET4(odS.redraw, id); /* mark for redraw */ |
291 |
} |
292 |
} |
293 |
|
294 |
|
295 |
odRemap(newhist) /* recompute tone mapping */ |
296 |
int newhist; |
297 |
{ |
298 |
needmapping |= NEWMAP|NEWRGB; |
299 |
if (newhist) |
300 |
needmapping |= NEWHIST; |
301 |
} |
302 |
|
303 |
|
304 |
odRedraw(vn, hmin, vmin, hmax, vmax) /* redraw view region */ |
305 |
int vn, hmin, vmin, hmax, vmax; |
306 |
{ |
307 |
int i, j; |
308 |
register struct ODblock *bp; |
309 |
register int k; |
310 |
|
311 |
if (vn<0 | vn>=odNViews) |
312 |
return; |
313 |
/* check view limits */ |
314 |
if (hmin < 0) hmin = 0; |
315 |
if (hmax >= odView[vn].hhi) hmax = odView[vn].hhi-1; |
316 |
if (vmin < 0) vmin = 0; |
317 |
if (vmax >= odView[vn].vhi) vmax = odView[vn].vhi-1; |
318 |
if (hmax <= hmin | vmax <= vmin) |
319 |
return; |
320 |
/* convert to low resolution */ |
321 |
hmin = hmin * odView[vn].hlow / odView[vn].hhi; |
322 |
hmax = hmax * odView[vn].hlow / odView[vn].hhi; |
323 |
vmin = vmin * odView[vn].vlow / odView[vn].vhi; |
324 |
vmax = vmax * odView[vn].vlow / odView[vn].vhi; |
325 |
/* mark block samples for redraw, inclusive */ |
326 |
for (i = hmin; i <= hmax; i++) |
327 |
for (j = vmin; j <= vmax; j++) { |
328 |
bp = odView[vn].bmap + j*odView[vn].hlow + i; |
329 |
for (k = bp->nsamp; k--; ) |
330 |
if (odS.ip[bp->first+k][0] >= 0) |
331 |
SET4(odS.redraw, bp->first+k); |
332 |
} |
333 |
} |
334 |
|
335 |
|
336 |
odDepthMap(vn, dm) /* assign depth map for view */ |
337 |
int vn; |
338 |
GLfloat *dm; |
339 |
{ |
340 |
double d0, d1; |
341 |
int i, j, hmin, hmax, vmin, vmax; |
342 |
register int k, l; |
343 |
|
344 |
if (dm == NULL) { /* free edge map */ |
345 |
if (vn<0 | vn>=odNViews) |
346 |
return; /* too late -- they're gone! */ |
347 |
if (odView[vn].emap != NULL) |
348 |
free((char *)odView[vn].emap); |
349 |
odView[vn].emap = NULL; |
350 |
odView[vn].dmap = NULL; |
351 |
return; |
352 |
} |
353 |
DCHECK(vn<0 | vn>=odNViews, CONSISTENCY, |
354 |
"bad view number in odDepthMap"); |
355 |
odView[vn].dmap = dm; /* initialize edge map */ |
356 |
if (odView[vn].emap == NULL) { |
357 |
odView[vn].emap = (int4 *)malloc( |
358 |
FL4NELS(odView[vn].hlow*odView[vn].vlow)*sizeof(int4)); |
359 |
if (odView[vn].emap == NULL) |
360 |
error(SYSTEM, "out of memory in odDepthMap"); |
361 |
} |
362 |
CLR4ALL(odView[vn].emap, odView[vn].hlow*odView[vn].vlow); |
363 |
/* compute edge map */ |
364 |
vmin = odView[vn].vhi; /* enter loopsville */ |
365 |
for (j = odView[vn].vlow; j--; ) { |
366 |
vmax = vmin; |
367 |
vmin = j*odView[vn].vhi/odView[vn].vlow; |
368 |
hmin = odView[vn].hhi; |
369 |
for (i = odView[vn].hlow; i--; ) { |
370 |
hmax = hmin; |
371 |
hmin = i*odView[vn].hhi/odView[vn].hlow; |
372 |
for (l = vmin; l < vmax; l++) { /* vertical edges */ |
373 |
d1 = dm[l*odView[vn].hhi+hmin]; |
374 |
for (k = hmin+1; k < hmax; k++) { |
375 |
d0 = d1; |
376 |
d1 = dm[l*odView[vn].hhi+k]; |
377 |
if (d0 > (1.+DEPTHEPS)*d1 || |
378 |
(1.+DEPTHEPS)*d0 < d1) { |
379 |
SET4(odView[vn].emap, |
380 |
j*odView[vn].hlow + i); |
381 |
break; |
382 |
} |
383 |
} |
384 |
if (k < hmax) |
385 |
break; |
386 |
} |
387 |
if (l < vmax) |
388 |
continue; |
389 |
for (k = hmin; k < hmax; k++) { /* horizontal edges */ |
390 |
d1 = dm[vmin*odView[vn].hhi+k]; |
391 |
for (l = vmin+1; l < vmax; l++) { |
392 |
d0 = d1; |
393 |
d1 = dm[l*odView[vn].hhi+k]; |
394 |
if (d0 > (1.+DEPTHEPS)*d1 || |
395 |
(1.+DEPTHEPS)*d0 < d1) { |
396 |
SET4(odView[vn].emap, |
397 |
j*odView[vn].hlow + i); |
398 |
break; |
399 |
} |
400 |
} |
401 |
if (l < vmax) |
402 |
break; |
403 |
} |
404 |
} |
405 |
} |
406 |
} |
407 |
|
408 |
|
409 |
odUpdate(vn) /* update this view */ |
410 |
int vn; |
411 |
{ |
412 |
int i, j; |
413 |
register struct ODblock *bp; |
414 |
register int k; |
415 |
|
416 |
DCHECK(vn<0 | vn>=odNViews, CONSISTENCY, |
417 |
"bad view number in odUpdate"); |
418 |
/* need to do some tone mapping? */ |
419 |
if (needmapping & NEWRGB) { |
420 |
if (needmapping & NEWMAP) { |
421 |
if (needmapping & NEWHIST) |
422 |
tmClearHisto(); |
423 |
if (tmAddHisto(odS.brt,odS.nsamp,1) != TM_E_OK) |
424 |
return; |
425 |
if (tmComputeMapping(0.,0.,0.) != TM_E_OK) |
426 |
return; |
427 |
for (k = odS.nsamp; k--; ) /* redraw all */ |
428 |
if (odS.ip[k][0] >= 0) |
429 |
SET4(odS.redraw, k); |
430 |
} |
431 |
if (tmMapPixels(odS.rgb,odS.brt,odS.chr,odS.nsamp) != TM_E_OK) |
432 |
return; |
433 |
needmapping = 0; /* reset flag */ |
434 |
} |
435 |
/* draw each block in view */ |
436 |
for (j = odView[vn].vlow; j--; ) |
437 |
for (i = 0; i < odView[vn].hlow; i++) { |
438 |
/* get block */ |
439 |
bp = odView[vn].bmap + j*odView[vn].hlow + i; |
440 |
/* do quick, conservative flag check */ |
441 |
for (k = (bp->first+bp->nsamp+31)>>5; |
442 |
k-- > bp->first>>5; ) |
443 |
if (odS.redraw[k]) |
444 |
break; /* non-zero flag */ |
445 |
if (k < bp->first>>5) |
446 |
continue; /* no flags set */ |
447 |
for (k = bp->nsamp; k--; ) /* sample by sample */ |
448 |
if (CHK4(odS.redraw, bp->first+k)) { |
449 |
odDrawBlockSamp(vn, i, j, bp->first+k); |
450 |
CLR4(odS.redraw, bp->first+k); |
451 |
} |
452 |
} |
453 |
} |
454 |
|
455 |
|
456 |
#if 0 |
457 |
static |
458 |
clip_end(p, o, vp) /* clip line segment to view */ |
459 |
GLshort p[3]; |
460 |
short o[2]; |
461 |
register struct ODview *vp; |
462 |
{ |
463 |
if (p[0] < 0) { |
464 |
p[1] = -o[0]*(p[1]-o[1])/(p[0]-o[0]) + o[1]; |
465 |
p[2] = -o[0]*p[2]/(p[0]-o[0]); |
466 |
p[0] = 0; |
467 |
} else if (p[0] >= vp->hhi) { |
468 |
p[1] = (vp->hhi-1-o[0])*(p[1]-o[1])/(p[0]-o[0]) + o[1]; |
469 |
p[2] = (vp->hhi-1-o[0])*p[2]/(p[0]-o[0]); |
470 |
p[0] = vp->hhi-1; |
471 |
} |
472 |
if (p[1] < 0) { |
473 |
p[0] = -o[1]*(p[0]-o[0])/(p[1]-o[1]) + o[0]; |
474 |
p[2] = -o[1]*p[2]/(p[1]-o[1]); |
475 |
p[1] = 0; |
476 |
} else if (p[1] >= vp->vhi) { |
477 |
p[0] = (vp->vhi-1-o[1])*(p[0]-o[0])/(p[1]-o[1]) + o[0]; |
478 |
p[2] = (vp->vhi-1-o[1])*p[2]/(p[1]-o[1]); |
479 |
p[1] = vp->vhi-1; |
480 |
} |
481 |
} |
482 |
#endif |
483 |
|
484 |
|
485 |
static int |
486 |
make_arms(ar, cp, vp, sz) /* make arms for triangle fan */ |
487 |
GLshort ar[MAXFAN][3]; |
488 |
short cp[2]; |
489 |
register struct ODview *vp; |
490 |
double sz; |
491 |
{ |
492 |
int na, dv; |
493 |
double hrad, vrad, phi0, phi; |
494 |
register int i; |
495 |
|
496 |
DCHECK(sz > 1, CONSISTENCY, "super-unary size in make_arms"); |
497 |
na = MAXFAN*sz*sz + 0.5; /* keep area constant */ |
498 |
if (na < MINFAN) na = MINFAN; |
499 |
hrad = FANSIZE*sz*vp->hhi/vp->hlow; |
500 |
vrad = FANSIZE*sz*vp->vhi/vp->vlow; |
501 |
if (hrad*vrad < 2.25) |
502 |
hrad = vrad = 1.5; |
503 |
phi0 = (2.*PI) * frandom(); |
504 |
dv = OMAXDEPTH*sz + 0.5; |
505 |
for (i = 0; i < na; i++) { |
506 |
phi = phi0 + (2.*PI)*i/na; |
507 |
ar[i][0] = cp[0] + tcos(phi)*hrad + 0.5; |
508 |
ar[i][1] = cp[1] + tsin(phi)*vrad + 0.5; |
509 |
ar[i][2] = dv; |
510 |
/* clip_end(ar[i], cp, vp); */ |
511 |
} |
512 |
return(na); |
513 |
} |
514 |
|
515 |
|
516 |
static int |
517 |
depthchange(vp, x0, y0, x1, y1) /* check depth discontinuity */ |
518 |
register struct ODview *vp; |
519 |
int x0, y0, x1, y1; |
520 |
{ |
521 |
register double d0, d1; |
522 |
|
523 |
DCHECK(x0<0 | x0>=vp->hhi | y0<0 | y0>=vp->vhi, |
524 |
CONSISTENCY, "coordinates off view in depthchange"); |
525 |
|
526 |
if (x1<0 | x1>=vp->hhi | y1<0 | y1>=vp->vhi) |
527 |
return(1); |
528 |
|
529 |
d0 = vp->dmap[y0*vp->hhi + x0]; |
530 |
d1 = vp->dmap[y1*vp->hhi + x1]; |
531 |
|
532 |
return((1.+DEPTHEPS)*d0 < d1 || d0 > (1.+DEPTHEPS)*d1); |
533 |
} |
534 |
|
535 |
|
536 |
static |
537 |
clip_edge(p, o, vp) /* clip line segment to depth edge */ |
538 |
GLshort p[3]; |
539 |
short o[2]; |
540 |
register struct ODview *vp; |
541 |
{ |
542 |
int x, y, xstep, ystep, rise, rise2, run, run2, n; |
543 |
|
544 |
DCHECK(vp->dmap==NULL, CONSISTENCY, |
545 |
"clip_edge called with no depth map"); |
546 |
x = o[0]; y = o[1]; |
547 |
run = p[0] - x; |
548 |
xstep = run > 0 ? 1 : -1; |
549 |
run *= xstep; |
550 |
rise = p[1] - y; |
551 |
ystep = rise > 0 ? 1 : -1; |
552 |
rise *= ystep; |
553 |
rise2 = run2 = 0; |
554 |
if (rise > run) rise2 = 1; |
555 |
else run2 = 1; |
556 |
n = rise + run; |
557 |
while (n--) /* run out arm, checking depth */ |
558 |
if (run2 > rise2) { |
559 |
if (depthchange(vp, x, y, x+xstep, y)) |
560 |
break; |
561 |
x += xstep; |
562 |
rise2 += rise; |
563 |
} else { |
564 |
if (depthchange(vp, x, y, x, y+ystep)) |
565 |
break; |
566 |
y += ystep; |
567 |
run2 += run; |
568 |
} |
569 |
if (n < 0) /* found something? */ |
570 |
return; |
571 |
if (run > rise) |
572 |
p[2] = (x - o[0])*p[2]/(p[0] - o[0]); |
573 |
else |
574 |
p[2] = (y - o[1])*p[2]/(p[1] - o[1]); |
575 |
p[0] = x; |
576 |
p[1] = y; |
577 |
} |
578 |
|
579 |
|
580 |
static int |
581 |
getblock(vp, h, v) /* get block index */ |
582 |
register struct ODview *vp; |
583 |
register int h, v; |
584 |
{ |
585 |
if (h<0 | h>=vp->hhi | v<0 | v>=vp->vhi) |
586 |
return(-1); |
587 |
return(h*vp->hlow/vp->hhi + v*vp->vlow/vp->vhi*vp->hlow); |
588 |
} |
589 |
|
590 |
|
591 |
odDrawBlockSamp(vn, h, v, id) /* draw sample in view block */ |
592 |
int vn, h, v; |
593 |
register int id; |
594 |
{ |
595 |
GLshort arm[MAXFAN][3]; |
596 |
int narms, blockindex, bi1; |
597 |
register struct ODview *vp; |
598 |
double size; |
599 |
int home_edges; |
600 |
register int i; |
601 |
|
602 |
vp = odView + vn; |
603 |
blockindex = v*vp->hlow + h; |
604 |
DCHECK(odS.ip[id][0]*vp->hlow/vp->hhi != h | |
605 |
odS.ip[id][1]*vp->vlow/vp->vhi != v, |
606 |
CONSISTENCY, "bad sample position in odDrawBlockSamp"); |
607 |
DCHECK(vp->bmap[blockindex].nused <= 0, |
608 |
CONSISTENCY, "bad in-use count in odDrawBlockSamp"); |
609 |
/* create triangle fan */ |
610 |
size = 1./sqrt((double)vp->bmap[blockindex].nused); |
611 |
narms = make_arms(arm, odS.ip[id], vp, size); |
612 |
if (vp->emap != NULL) { /* check for edge collisions */ |
613 |
home_edges = CHK4(vp->emap, blockindex); |
614 |
for (i = 0; i < narms; i++) |
615 |
/* the following test is flawed, because we could |
616 |
* be passing through a block on a diagonal run */ |
617 |
if (home_edges || |
618 |
( (bi1 = getblock(vp, arm[i][0], arm[i][1])) |
619 |
!= blockindex && |
620 |
(bi1 < 0 || CHK4(vp->emap, bi1)) )) |
621 |
clip_edge(arm[i], odS.ip[id], vp); |
622 |
} |
623 |
/* draw triangle fan */ |
624 |
glColor3ub(odS.rgb[id][0], odS.rgb[id][1], odS.rgb[id][2]); |
625 |
glBegin(GL_TRIANGLE_FAN); |
626 |
glVertex3s((GLshort)odS.ip[id][0], (GLshort)odS.ip[id][1], (GLshort)0); |
627 |
for (i = 0; i < narms; i++) |
628 |
glVertex3sv(arm[i]); |
629 |
glVertex3sv(arm[0]); /* connect last to first */ |
630 |
glEnd(); |
631 |
} |