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root/radiance/ray/src/hd/rhpict2.c
Revision: 3.2
Committed: Fri Mar 5 17:03:38 1999 UTC (25 years, 1 month ago) by gwlarson
Content type: text/plain
Branch: MAIN
Changes since 3.1: +239 -7 lines
Log Message:
added kernel and occlusion culling

File Contents

# Content
1 /* Copyright (c) 1999 Silicon Graphics, Inc. */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ SGI";
5 #endif
6
7 /*
8 * Rendering routines for rhpict.
9 */
10
11 #include "holo.h"
12 #include "view.h"
13
14 #ifndef DEPS
15 #define DEPS 0.01 /* depth epsilon */
16 #endif
17 #ifndef MAXRAD
18 #define MAXRAD 64 /* maximum kernel radius */
19 #endif
20 #ifndef NNEIGH
21 #define NNEIGH 7 /* find this many neighbors */
22 #endif
23
24 #define NINF 16382
25
26 #define MAXRAD2 (MAXRAD*MAXRAD+1)
27
28 #define G0NORM 0.286 /* ground zero normalization (1/x integral) */
29
30 #ifndef FL4OP
31 #define FL4OP(f,i,op) ((f)[(i)>>5] op (1L<<((i)&0x1f)))
32 #define CHK4(f,i) FL4OP(f,i,&)
33 #define SET4(f,i) FL4OP(f,i,|=)
34 #define CLR4(f,i) FL4OP(f,i,&=~)
35 #define TGL4(f,i) FL4OP(f,i,^=)
36 #define FL4NELS(n) (((n)+0x1f)>>5)
37 #define CLR4ALL(f,n) bzero((char *)(f),FL4NELS(n)*sizeof(int4))
38 #endif
39
40 static int4 *pixFlags; /* pixel occupancy flags */
41 static float pixWeight[MAXRAD2]; /* pixel weighting function */
42
43 extern VIEW myview; /* current output view */
44 extern COLOR *mypixel; /* pixels being rendered */
45 extern float *myweight; /* weights (used to compute final pixels) */
46 extern float *mydepth; /* depth values (visibility culling) */
47 extern int hres, vres; /* current horizontal and vertical res. */
48
49
50 pixBeam(bp, hb) /* render a particular beam */
51 BEAM *bp;
52 register HDBEAMI *hb;
53 {
54 GCOORD gc[2];
55 register RAYVAL *rv;
56 FVECT rorg, rdir, wp, ip;
57 double d, prox;
58 COLOR col;
59 int n;
60 register int4 p;
61
62 if (!hdbcoord(gc, hb->h, hb->b))
63 error(CONSISTENCY, "bad beam in render_beam");
64 for (n = bp->nrm, rv = hdbray(bp); n--; rv++) {
65 /* reproject each sample */
66 hdray(rorg, rdir, hb->h, gc, rv->r);
67 if (rv->d < DCINF) {
68 d = hddepth(hb->h, rv->d);
69 VSUM(wp, rorg, rdir, d);
70 VSUB(ip, wp, myview.vp);
71 d = DOT(ip,rdir);
72 prox = d*d/DOT(ip,ip); /* cos(diff_angle)^32 */
73 prox *= prox; prox *= prox; prox *= prox; prox *= prox;
74 } else {
75 if (myview.type == VT_PAR || myview.vaft > FTINY)
76 continue; /* inf. off view */
77 VSUM(wp, myview.vp, rdir, FHUGE);
78 prox = 1.;
79 }
80 viewloc(ip, &myview, wp); /* frustum clipping */
81 if (ip[2] < 0.)
82 continue;
83 if (ip[0] < 0. || ip[0] >= 1.)
84 continue;
85 if (ip[1] < 0. || ip[1] >= 1.)
86 continue;
87 if (myview.vaft > FTINY && ip[2] > myview.vaft - myview.vfore)
88 continue; /* not exact for VT_PER */
89 p = (int)(ip[1]*vres)*hres + (int)(ip[0]*hres);
90 if (mydepth[p] > FTINY) { /* check depth */
91 if (ip[2] > mydepth[p]*(1.+DEPS))
92 continue;
93 if (ip[2] < mydepth[p]*(1.-DEPS)) {
94 setcolor(mypixel[p], 0., 0., 0.);
95 myweight[p] = 0.;
96 }
97 }
98 colr_color(col, rv->v);
99 scalecolor(col, prox);
100 addcolor(mypixel[p], col);
101 myweight[p] += prox;
102 mydepth[p] = ip[2];
103 }
104 }
105
106
107 int
108 kill_occl(h, v, nl, n) /* check for occlusion errors */
109 int h, v;
110 short nl[NNEIGH][2];
111 int n;
112 {
113 short forequad[2][2];
114 int d;
115 register int4 i;
116
117 if (n <= 0)
118 return(1);
119 forequad[0][0] = forequad[0][1] = forequad[1][0] = forequad[1][1] = 0;
120 for (i = n; i--; ) {
121 d = (h-nl[i][0])*(h-nl[i][0]) + (v-nl[i][1])*(v-nl[i][1]);
122 if (mydepth[nl[i][1]*hres+nl[i][0]] <
123 mydepth[v*hres+h]*(1.-DEPS*d))
124 forequad[nl[i][0]<h][nl[i][1]<v] = 1;
125 }
126 if (forequad[0][0]+forequad[0][1]+forequad[1][0]+forequad[1][1] > 1) {
127 i = v*hres + h;
128 setcolor(mypixel[i], 0., 0., 0.);
129 myweight[i] = 0.; /* occupancy reset afterwards */
130 }
131 return(1);
132 }
133
134
135 int
136 grow_samp(h, v, nl, n) /* grow sample point appropriately */
137 int h, v;
138 register short nl[NNEIGH][2];
139 int n;
140 {
141 COLOR mykern[MAXRAD2];
142 float mykw[MAXRAD2];
143 int4 maxr2;
144 double w;
145 register int4 p, r2;
146 int maxr, h2, v2;
147
148 if (n <= 0)
149 return(1);
150 p = v*hres + h; /* build kernel values */
151 maxr2 = (h-nl[n-1][0])*(h-nl[n-1][0]) + (v-nl[n-1][1])*(v-nl[n-1][1]);
152 DCHECK(maxr2>=MAXRAD2, CONSISTENCY, "out of range neighbor");
153 for (r2 = maxr2+1; --r2; ) {
154 copycolor(mykern[r2], mypixel[p]);
155 mykw[r2] = pixWeight[r2];
156 if (2*r2 >= maxr2) /* soften skirt */
157 mykw[r2] *= (2*(maxr2-r2)+1.0)/maxr2;
158 scalecolor(mykern[r2], mykw[r2]);
159 }
160 maxr = sqrt((double)maxr2) + .99; /* stamp out that kernel */
161 for (v2 = v-maxr; v2 <= v+maxr; v2++) {
162 if (v2 < 0) continue;
163 if (v2 >= vres) break;
164 for (h2 = h-maxr; h2 <= h+maxr; h2++) {
165 if (h2 < 0) continue;
166 if (h2 >= hres) break;
167 r2 = (v2-v)*(v2-v) + (h2-h)*(h2-h);
168 if (r2 > maxr2) continue;
169 if (CHK4(pixFlags, v2*hres+h2))
170 continue; /* occupied */
171 addcolor(mypixel[v2*hres+h2], mykern[r2]);
172 myweight[v2*hres+h2] += mykw[r2]*myweight[v*hres+h];
173 }
174 }
175 return(1);
176 }
177
178
179 pixFlush() /* done with beams -- flush pixel values */
180 {
181 reset_flags(); /* set occupancy flags */
182 meet_neighbors(kill_occl); /* eliminate occlusion errors */
183 reset_flags(); /* reset occupancy flags */
184 if (pixWeight[0] <= FTINY) { /* initialize weighting function */
185 register int r;
186 for (r = MAXRAD2; --r; )
187 pixWeight[r] = G0NORM/sqrt((double)r);
188 pixWeight[0] = 1.;
189 }
190 meet_neighbors(grow_samp); /* grow valid samples over image */
191 free((char *)pixFlags); /* free pixel flags */
192 pixFlags = NULL;
193 }
194
195
196 reset_flags() /* allocate/set/reset occupancy flags */
197 {
198 register int p;
199
200 if (pixFlags == NULL) {
201 pixFlags = (int4 *)calloc(FL4NELS(hres*vres), sizeof(int4));
202 CHECK(pixFlags==NULL, SYSTEM, "out of memory in reset_flags");
203 } else
204 CLR4ALL(pixFlags, hres*vres);
205 for (p = hres*vres; p--; )
206 if (myweight[p] > FTINY)
207 SET4(pixFlags, p);
208 }
209
210
211 int
212 findneigh(nl, h, v, rnl) /* find NNEIGH neighbors for pixel */
213 short nl[NNEIGH][2];
214 int h, v;
215 register short (*rnl)[NNEIGH];
216 {
217 int nn = 0;
218 int4 d, ld, nd[NNEIGH+1];
219 int n, hoff;
220 register int h2, n2;
221
222 ld = MAXRAD2;
223 for (hoff = 1; hoff < hres; hoff = (hoff<0) - hoff) {
224 h2 = h + hoff;
225 if (h2 < 0 | h2 >= hres)
226 continue;
227 if ((h2-h)*(h2-h) >= ld)
228 break;
229 for (n = 0; n < NNEIGH && rnl[h2][n] < NINF; n++) {
230 d = (h2-h)*(h2-h) + (v-rnl[h2][n])*(v-rnl[h2][n]);
231 if (d >= ld)
232 continue;
233 for (n2 = nn; ; n2--) { /* insert neighbor */
234 if (!n2 || d >= nd[n2-1]) {
235 nd[n2] = d;
236 nl[n2][0] = h2;
237 nl[n2][1] = rnl[h2][n];
238 break;
239 }
240 nd[n2] = nd[n2-1];
241 nl[n2][0] = nl[n2-1][0];
242 nl[n2][1] = nl[n2-1][1];
243 }
244 if (nn < NNEIGH)
245 nn++;
246 else
247 ld = nd[NNEIGH-1];
248 }
249 }
250 return(nn);
251 }
252
253
254 meet_neighbors(nf) /* run through samples and their neighbors */
255 int (*nf)();
256 {
257 short ln[NNEIGH][2];
258 int h, v, n, v2;
259 register short (*rnl)[NNEIGH];
260 /* initialize bottom row list */
261 rnl = (short (*)[NNEIGH])malloc(NNEIGH*sizeof(short)*hres);
262 CHECK(rnl==NULL, SYSTEM, "out of memory in meet_neighbors");
263 for (h = 0; h < hres; h++) {
264 for (n = v = 0; v < vres; v++)
265 if (CHK4(pixFlags, v*hres+h)) {
266 rnl[h][n++] = v;
267 if (n >= NNEIGH)
268 break;
269 }
270 while (n < NNEIGH)
271 rnl[h][n++] = NINF;
272 }
273 v = 0; /* do each row */
274 for ( ; ; ) {
275 for (h = 0; h < hres; h++) {
276 if (!CHK4(pixFlags, v*hres+h))
277 continue; /* no one home */
278 n = findneigh(ln, h, v, rnl);
279 (*nf)(h, v, ln, n); /* call on neighbors */
280 }
281 if (++v >= vres) /* reinitialize row list */
282 break;
283 for (h = 0; h < hres; h++)
284 for (v2 = rnl[h][NNEIGH-1]+1; v2 < vres; v2++) {
285 if (v2 - v > v - rnl[h][0])
286 break; /* not close enough */
287 if (CHK4(pixFlags, v2*hres+h)) {
288 for (n = 0; n < NNEIGH-1; n++)
289 rnl[h][n] = rnl[h][n+1];
290 rnl[h][NNEIGH-1] = v2;
291 }
292 }
293 }
294 free((char *)rnl); /* free row list */
295 }