ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/util/rttree_reduce.c
(Generate patch)

Comparing ray/src/util/rttree_reduce.c (file contents):
Revision 2.1 by greg, Thu May 26 15:32:02 2011 UTC vs.
Revision 2.3 by greg, Wed Jun 1 16:51:03 2011 UTC

# Line 11 | Line 11 | static const char RCSid[] = "$Id$";
11   #include "rterror.h"
12   #include "platform.h"
13   #include <stdlib.h>
14 + #include <math.h>
15  
16   float   *datarr;                /* our loaded BSDF data array */
17   int     ttrank = 4;             /* tensor tree rank */
18   int     log2g = 4;              /* log2 of grid resolution */
19   int     infmt = 'a';            /* input format ('a','f','d') */
20 < double  tthresh = .05;          /* relative acceptance threshold */
20 > double  pctcull = 99.;          /* target culling percentile */
21  
22   #define dval3(ix,ox,oy)         datarr[((((ix)<<log2g)+(ox))<<log2g)+(oy)]
23   #define dval4(ix,iy,ox,oy)      datarr[((((((ix)<<log2g)+(iy))<<log2g)+(ox))<<log2g)+(oy)]
24  
24 – #define above_threshold(tp)     ((tp)->vmax - (tp)->vmin > 2.*tthresh*(tp)->vavg)
25 –
25   /* Tensor tree node */
26   typedef struct ttree_s {
27          float           vmin, vmax;     /* value extrema */
# Line 30 | Line 29 | typedef struct ttree_s {
29          struct ttree_s  *kid;           /* 2^ttrank children */
30   } TNODE;
31  
32 + #define HISTLEN         300     /* histogram resolution */
33 + #define HISTMAX         10.     /* maximum recorded measure in histogram */
34 +
35 + int     histo[HISTLEN];         /* histogram freq. of variance measure */
36 +
37 + double  tthresh;                /* acceptance threshold (TBD) */
38 +
39 + #define var_measure(tp)         ( ((tp)->vmax - (tp)->vmin) / \
40 +                                        (sqrt((tp)->vavg) + .03) )
41 + #define above_threshold(tp)     (var_measure(tp) > tthresh)
42 +
43   /* Allocate a new set of children for the given node (no checks) */
44   static void
45   new_kids(TNODE *pn)
# Line 77 | Line 87 | build_tree(TNODE *tp, const int bmin[], int l2s)
87                          tp->vavg += val;
88                  }
89                  tp->vavg /= (float)(1<<ttrank);
90 +                                        /* record stats */
91 +                i = (HISTLEN/HISTMAX) * var_measure(tp);
92 +                if (i >= HISTLEN) i = HISTLEN-1;
93 +                ++histo[i];
94                  return;
95          }
96          --l2s;                          /* else still branching */
# Line 92 | Line 106 | build_tree(TNODE *tp, const int bmin[], int l2s)
106                  tp->vavg += tp->kid[i].vavg;
107          }
108          tp->vavg /= (float)(1<<ttrank);
95 –                                        /* is variation above threshold? */
96 –        if (!above_threshold(tp))
97 –                free_kids(tp);          /* if not, trim branches */
109   }
110  
111 + /* Set our trimming threshold */
112 + static void
113 + set_threshold()
114 + {
115 +        int     hsum = 0;
116 +        int     i;
117 +
118 +        for (i = HISTLEN; i--; )
119 +                hsum += histo[i];
120 +        hsum = pctcull*.01 * (double)hsum;
121 +        for (i = 0; hsum > 0; i++)
122 +                hsum -= histo[i];
123 +        tthresh = (HISTMAX/HISTLEN) * i;
124 + }
125 +
126 + /* Trim our tree according to the current threshold */
127 + static void
128 + trim_tree(TNODE *tp)
129 + {
130 +        if (tp->kid == NULL)
131 +                return;
132 +        if (above_threshold(tp)) {      /* keeping branches? */
133 +                int     i = 1<<ttrank;
134 +                while (i--)
135 +                        trim_tree(tp->kid+i);
136 +                return;
137 +        }
138 +        free_kids(tp);                  /* else trim at this point */
139 + }
140 +
141   /* Print a tensor tree from the given hypercube */
142   static void
143   print_tree(const TNODE *tp, const int bmin[], int l2s)
# Line 275 | Line 316 | main(int argc, char *argv[])
316                                  goto userr;
317                          break;
318                  case 't':
319 <                        tthresh = atof(argv[++i]);
320 <                        if (tthresh <= 0)
319 >                        pctcull = atof(argv[++i]);
320 >                        if ((pctcull < 0) | (pctcull >= 100.))
321                                  goto userr;
322                          break;
323                  case 'f':
# Line 307 | Line 348 | main(int argc, char *argv[])
348          gtree.kid = NULL;               /* create our tree */
349          bmin[0] = bmin[1] = bmin[2] = bmin[3] = 0;
350          build_tree(&gtree, bmin, log2g);
351 +                                        /* compute threshold & trim tree */
352 +        set_threshold();
353 +        trim_tree(&gtree);
354                                          /* format to stdout */
355          print_tree(&gtree, bmin, log2g);
356          /* Clean up isn't necessary for main()...
# Line 315 | Line 359 | main(int argc, char *argv[])
359          */
360          return(0);
361   userr:
362 <        fprintf(stderr, "Usage: %s [-h][-f{a|f|d}][-r {3|4}][-g log2grid][-t thresh] [input]\n",
362 >        fprintf(stderr, "Usage: %s [-h][-f{a|f|d}][-r {3|4}][-g log2grid][-t trim%%] [input]\n",
363                          argv[0]);
364          return(1);
365   }

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines