1 |
greg |
3.2 |
#ifndef lint |
2 |
greg |
3.3 |
static const char RCSid[] = "$Id: bsdf_t.c,v 3.2 2011/02/18 00:41:44 greg Exp $"; |
3 |
greg |
3.2 |
#endif |
4 |
greg |
3.1 |
/* |
5 |
|
|
* bsdf_t.c |
6 |
|
|
* |
7 |
|
|
* Definitions for variable-resolution BSDF trees |
8 |
|
|
* |
9 |
|
|
* Created by Greg Ward on 2/2/11. |
10 |
|
|
* |
11 |
|
|
*/ |
12 |
|
|
|
13 |
greg |
3.3 |
#include "rtio.h" |
14 |
greg |
3.1 |
#include <stdlib.h> |
15 |
greg |
3.3 |
#include <math.h> |
16 |
|
|
#include <ctype.h> |
17 |
greg |
3.1 |
#include "ezxml.h" |
18 |
|
|
#include "bsdf.h" |
19 |
|
|
#include "bsdf_t.h" |
20 |
|
|
|
21 |
|
|
/* Allocate a new scattering distribution node */ |
22 |
|
|
static SDNode * |
23 |
|
|
SDnewNode(int nd, int lg) |
24 |
|
|
{ |
25 |
|
|
SDNode *st; |
26 |
|
|
|
27 |
|
|
if (nd <= 0) { |
28 |
|
|
strcpy(SDerrorDetail, "Zero dimension BSDF node request"); |
29 |
|
|
return NULL; |
30 |
|
|
} |
31 |
|
|
if (nd > SD_MAXDIM) { |
32 |
|
|
sprintf(SDerrorDetail, "Illegal BSDF dimension (%d > %d)", |
33 |
|
|
nd, SD_MAXDIM); |
34 |
|
|
return NULL; |
35 |
|
|
} |
36 |
|
|
if (lg < 0) { |
37 |
|
|
st = (SDNode *)malloc(sizeof(SDNode) + |
38 |
|
|
((1<<nd) - 1)*sizeof(st->u.t[0])); |
39 |
|
|
if (st != NULL) |
40 |
|
|
memset(st->u.t, 0, (1<<nd)*sizeof(st->u.t[0])); |
41 |
|
|
} else |
42 |
|
|
st = (SDNode *)malloc(sizeof(SDNode) + |
43 |
|
|
((1 << nd*lg) - 1)*sizeof(st->u.v[0])); |
44 |
|
|
|
45 |
|
|
if (st == NULL) { |
46 |
|
|
if (lg < 0) |
47 |
|
|
sprintf(SDerrorDetail, |
48 |
|
|
"Cannot allocate %d branch BSDF tree", nd); |
49 |
|
|
else |
50 |
|
|
sprintf(SDerrorDetail, |
51 |
|
|
"Cannot allocate %d BSDF leaves", 1 << nd*lg); |
52 |
|
|
return NULL; |
53 |
|
|
} |
54 |
|
|
st->ndim = nd; |
55 |
|
|
st->log2GR = lg; |
56 |
|
|
return st; |
57 |
|
|
} |
58 |
|
|
|
59 |
|
|
/* Free an SD tree */ |
60 |
|
|
static void |
61 |
|
|
SDfreeTree(void *p) |
62 |
|
|
{ |
63 |
|
|
SDNode *st = (SDNode *)p; |
64 |
|
|
int i; |
65 |
|
|
|
66 |
|
|
if (st == NULL) |
67 |
|
|
return; |
68 |
|
|
for (i = (st->log2GR < 0) << st->ndim; i--; ) |
69 |
|
|
SDfreeTree(st->u.t[i]); |
70 |
|
|
free((void *)st); |
71 |
|
|
} |
72 |
|
|
|
73 |
|
|
/* Add up N-dimensional hypercube array values over the given box */ |
74 |
|
|
static double |
75 |
|
|
SDiterSum(const float *va, int nd, int siz, const int *imin, const int *imax) |
76 |
|
|
{ |
77 |
|
|
double sum = .0; |
78 |
|
|
unsigned skipsiz = 1; |
79 |
|
|
int i; |
80 |
|
|
|
81 |
|
|
for (i = nd; --i > 0; ) |
82 |
|
|
skipsiz *= siz; |
83 |
|
|
if (skipsiz == 1) |
84 |
|
|
for (i = *imin; i < *imax; i++) |
85 |
|
|
sum += va[i]; |
86 |
|
|
else |
87 |
|
|
for (i = *imin; i < *imax; i++) |
88 |
|
|
sum += SDiterSum(va + i*skipsiz, |
89 |
|
|
nd-1, siz, imin+1, imax+1); |
90 |
|
|
return sum; |
91 |
|
|
} |
92 |
|
|
|
93 |
|
|
/* Average BSDF leaves over an orthotope defined by the unit hypercube */ |
94 |
|
|
static double |
95 |
|
|
SDavgBox(const SDNode *st, const double *bmin, const double *bmax) |
96 |
|
|
{ |
97 |
|
|
int imin[SD_MAXDIM], imax[SD_MAXDIM]; |
98 |
|
|
unsigned n; |
99 |
|
|
int i; |
100 |
|
|
|
101 |
|
|
if (!st) |
102 |
|
|
return .0; |
103 |
|
|
/* check box limits */ |
104 |
|
|
for (i = st->ndim; i--; ) { |
105 |
|
|
if (bmin[i] >= 1.) |
106 |
|
|
return .0; |
107 |
|
|
if (bmax[i] <= .0) |
108 |
|
|
return .0; |
109 |
|
|
if (bmin[i] >= bmax[i]) |
110 |
|
|
return .0; |
111 |
|
|
} |
112 |
|
|
if (st->log2GR < 0) { /* iterate on subtree */ |
113 |
|
|
double sum = .0, wsum = 1e-20; |
114 |
|
|
double sbmin[SD_MAXDIM], sbmax[SD_MAXDIM], w; |
115 |
|
|
|
116 |
|
|
for (n = 1 << st->ndim; n--; ) { |
117 |
|
|
w = 1.; |
118 |
|
|
for (i = st->ndim; i--; ) { |
119 |
|
|
sbmin[i] = 2.*bmin[i]; |
120 |
|
|
sbmax[i] = 2.*bmax[i]; |
121 |
|
|
if (n & 1<<i) { |
122 |
|
|
sbmin[i] -= 1.; |
123 |
|
|
sbmax[i] -= 1.; |
124 |
|
|
} |
125 |
|
|
if (sbmin[i] < .0) sbmin[i] = .0; |
126 |
|
|
if (sbmax[i] > 1.) sbmax[i] = 1.; |
127 |
|
|
w *= sbmax[i] - sbmin[i]; |
128 |
|
|
} |
129 |
|
|
if (w > 1e-10) { |
130 |
|
|
sum += w * SDavgBox(st->u.t[n], sbmin, sbmax); |
131 |
|
|
wsum += w; |
132 |
|
|
} |
133 |
|
|
} |
134 |
|
|
return sum / wsum; |
135 |
|
|
} |
136 |
|
|
n = 1; /* iterate over leaves */ |
137 |
|
|
for (i = st->ndim; i--; ) { |
138 |
|
|
imin[i] = (bmin[i] <= .0) ? 0 |
139 |
|
|
: (int)((1 << st->log2GR)*bmin[i]); |
140 |
|
|
imax[i] = (bmax[i] >= 1.) ? (1 << st->log2GR) |
141 |
|
|
: (int)((1 << st->log2GR)*bmax[i] + .999999); |
142 |
|
|
n *= imax[i] - imin[i]; |
143 |
|
|
} |
144 |
|
|
if (!n) |
145 |
|
|
return .0; |
146 |
|
|
|
147 |
|
|
return SDiterSum(st->u.v, st->ndim, 1 << st->log2GR, imin, imax) / |
148 |
|
|
(double)n; |
149 |
|
|
} |
150 |
|
|
|
151 |
|
|
/* Load a variable-resolution BSDF tree from an open XML file */ |
152 |
|
|
SDError |
153 |
|
|
SDloadTre(SDData *sd, ezxml_t fl) |
154 |
|
|
{ |
155 |
|
|
return SDEsupport; |
156 |
|
|
} |
157 |
|
|
|
158 |
|
|
/* Variable resolution BSDF methods */ |
159 |
|
|
const SDFunc SDhandleTre = { |
160 |
|
|
NULL, |
161 |
|
|
NULL, |
162 |
|
|
NULL, |
163 |
|
|
NULL, |
164 |
|
|
&SDfreeTree, |
165 |
|
|
}; |