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/* Copyright (c) 1991 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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static const char RCSid[] = "$Id$"; |
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#endif |
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|
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/* |
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* Routines to compute "ambient" values using Monte Carlo |
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* |
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* Hessian calculations based on "Practical Hessian-Based Error Control |
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* for Irradiance Caching" by Schwarzhaupt, Wann Jensen, & Jarosz |
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* from ACM SIGGRAPH Asia 2012 conference proceedings. |
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* |
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* Added book-keeping optimization to avoid calculations that would |
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* cancel due to traversal both directions on edges that are adjacent |
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* to same-valued triangles. This cuts about half of Hessian math. |
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* |
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* Declarations of external symbols in ambient.h |
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*/ |
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|
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#include "ray.h" |
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#include "copyright.h" |
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|
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#include "ray.h" |
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#include "ambient.h" |
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|
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#include "random.h" |
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|
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#ifndef MINADIV |
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#define MINADIV 7 /* minimum # divisions in each dimension */ |
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#endif |
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|
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typedef struct { |
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short t, p; /* theta, phi indices */ |
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COLOR v; /* value sum */ |
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float r; /* 1/distance sum */ |
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float k; /* variance for this division */ |
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int n; /* number of subsamples */ |
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} AMBSAMP; /* ambient sample division */ |
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FVECT p; /* intersection point */ |
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float d; /* reciprocal distance */ |
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SCOLOR v; /* hemisphere sample value */ |
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} AMBSAMP; /* sample value */ |
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|
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typedef struct { |
35 |
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FVECT ux, uy, uz; /* x, y and z axis directions */ |
36 |
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short nt, np; /* number of theta and phi directions */ |
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RAY *rp; /* originating ray sample */ |
36 |
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int ns; /* number of samples per axis */ |
37 |
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int sampOK; /* acquired full sample set? */ |
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SCOLOR acoef; /* division contribution coefficient */ |
39 |
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SCOLOR acol; /* accumulated color */ |
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FVECT ux, uy; /* tangent axis unit vectors */ |
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AMBSAMP sa[1]; /* sample array (extends struct) */ |
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} AMBHEMI; /* ambient sample hemisphere */ |
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|
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extern double sin(), cos(), sqrt(); |
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#define AI(h,i,j) ((i)*(h)->ns + (j)) |
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#define ambsam(h,i,j) (h)->sa[AI(h,i,j)] |
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|
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typedef struct { |
48 |
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FVECT r_i, r_i1, e_i, rcp, rI2_eJ2; |
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double I1, I2; |
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} FFTRI; /* vectors and coefficients for Hessian calculation */ |
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|
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|
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static int |
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ambcmp(d1, d2) /* decreasing order */ |
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AMBSAMP *d1, *d2; |
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ambcollision( /* proposed direciton collides? */ |
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AMBHEMI *hp, |
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int i, |
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int j, |
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FVECT dv |
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) |
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{ |
61 |
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if (d1->k < d2->k) |
62 |
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return(1); |
63 |
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if (d1->k > d2->k) |
64 |
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return(-1); |
65 |
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return(0); |
61 |
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double cos_thresh; |
62 |
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int ii, jj; |
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/* min. spacing = 1/4th division */ |
64 |
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cos_thresh = (PI/4.)/(double)hp->ns; |
65 |
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cos_thresh = 1. - .5*cos_thresh*cos_thresh; |
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/* check existing neighbors */ |
67 |
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for (ii = i-1; ii <= i+1; ii++) { |
68 |
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if (ii < 0) continue; |
69 |
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if (ii >= hp->ns) break; |
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for (jj = j-1; jj <= j+1; jj++) { |
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AMBSAMP *ap; |
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FVECT avec; |
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double dprod; |
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if (jj < 0) continue; |
75 |
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if (jj >= hp->ns) break; |
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if ((ii==i) & (jj==j)) continue; |
77 |
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ap = &ambsam(hp,ii,jj); |
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if (ap->d <= .5/FHUGE) |
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continue; /* no one home */ |
80 |
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VSUB(avec, ap->p, hp->rp->rop); |
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dprod = DOT(avec, dv); |
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if (dprod >= cos_thresh*VLEN(avec)) |
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return(1); /* collision */ |
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} |
85 |
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} |
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return(0); /* nothing to worry about */ |
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} |
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|
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|
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static int |
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ambnorm(d1, d2) /* standard order */ |
92 |
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AMBSAMP *d1, *d2; |
91 |
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ambsample( /* initial ambient division sample */ |
92 |
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AMBHEMI *hp, |
93 |
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int i, |
94 |
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int j, |
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int n |
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) |
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{ |
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register int c; |
98 |
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AMBSAMP *ap = &ambsam(hp,i,j); |
99 |
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RAY ar; |
100 |
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int hlist[3], ii; |
101 |
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RREAL spt[2]; |
102 |
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double zd; |
103 |
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/* generate hemispherical sample */ |
104 |
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/* ambient coefficient for weight */ |
105 |
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if (ambacc > FTINY) |
106 |
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setscolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL); |
107 |
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else |
108 |
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copyscolor(ar.rcoef, hp->acoef); |
109 |
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if (rayorigin(&ar, AMBIENT, hp->rp, ar.rcoef) < 0) |
110 |
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return(0); |
111 |
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if (ambacc > FTINY) { |
112 |
> |
smultscolor(ar.rcoef, hp->acoef); |
113 |
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scalescolor(ar.rcoef, 1./AVGREFL); |
114 |
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} |
115 |
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hlist[0] = hp->rp->rno; |
116 |
> |
hlist[1] = j; |
117 |
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hlist[2] = i; |
118 |
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multisamp(spt, 2, urand(ilhash(hlist,3)+n)); |
119 |
> |
resample: |
120 |
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square2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns); |
121 |
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zd = sqrt(1. - spt[0]*spt[0] - spt[1]*spt[1]); |
122 |
> |
for (ii = 3; ii--; ) |
123 |
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ar.rdir[ii] = spt[0]*hp->ux[ii] + |
124 |
> |
spt[1]*hp->uy[ii] + |
125 |
> |
zd*hp->rp->ron[ii]; |
126 |
> |
checknorm(ar.rdir); |
127 |
> |
/* avoid coincident samples */ |
128 |
> |
if (!n && ambcollision(hp, i, j, ar.rdir)) { |
129 |
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spt[0] = frandom(); spt[1] = frandom(); |
130 |
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goto resample; /* reject this sample */ |
131 |
> |
} |
132 |
> |
dimlist[ndims++] = AI(hp,i,j) + 90171; |
133 |
> |
rayvalue(&ar); /* evaluate ray */ |
134 |
> |
ndims--; |
135 |
> |
zd = raydistance(&ar); |
136 |
> |
if (zd <= FTINY) |
137 |
> |
return(0); /* should never happen */ |
138 |
> |
smultscolor(ar.rcol, ar.rcoef); /* apply coefficient */ |
139 |
> |
if (zd*ap->d < 1.0) /* new/closer distance? */ |
140 |
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ap->d = 1.0/zd; |
141 |
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if (!n) { /* record first vertex & value */ |
142 |
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if (zd > 10.0*thescene.cusize + 1000.) |
143 |
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zd = 10.0*thescene.cusize + 1000.; |
144 |
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VSUM(ap->p, ar.rorg, ar.rdir, zd); |
145 |
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copyscolor(ap->v, ar.rcol); |
146 |
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} else { /* else update recorded value */ |
147 |
> |
sopscolor(hp->acol, -=, ap->v); |
148 |
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zd = 1.0/(double)(n+1); |
149 |
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scalescolor(ar.rcol, zd); |
150 |
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zd *= (double)n; |
151 |
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scalescolor(ap->v, zd); |
152 |
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saddscolor(ap->v, ar.rcol); |
153 |
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} |
154 |
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saddscolor(hp->acol, ap->v); /* add to our sum */ |
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return(1); |
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} |
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|
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if (c = d1->t - d2->t) |
159 |
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return(c); |
160 |
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return(d1->p - d2->p); |
158 |
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|
159 |
> |
/* Estimate variance based on ambient division differences */ |
160 |
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static float * |
161 |
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getambdiffs(AMBHEMI *hp) |
162 |
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{ |
163 |
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const double normf = 1./bright(hp->acoef); |
164 |
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float *earr = (float *)calloc(hp->ns*hp->ns, sizeof(float)); |
165 |
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float *ep; |
166 |
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AMBSAMP *ap; |
167 |
> |
double b, b1, d2; |
168 |
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int i, j; |
169 |
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|
170 |
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if (earr == NULL) /* out of memory? */ |
171 |
> |
return(NULL); |
172 |
> |
/* sum squared neighbor diffs */ |
173 |
> |
for (ap = hp->sa, ep = earr, i = 0; i < hp->ns; i++) |
174 |
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for (j = 0; j < hp->ns; j++, ap++, ep++) { |
175 |
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b = pbright(ap[0].v); |
176 |
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if (i) { /* from above */ |
177 |
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b1 = pbright(ap[-hp->ns].v); |
178 |
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d2 = b - b1; |
179 |
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d2 *= d2*normf/(b + b1 + FTINY); |
180 |
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ep[0] += d2; |
181 |
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ep[-hp->ns] += d2; |
182 |
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} |
183 |
> |
if (!j) continue; |
184 |
> |
/* from behind */ |
185 |
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b1 = pbright(ap[-1].v); |
186 |
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d2 = b - b1; |
187 |
> |
d2 *= d2*normf/(b + b1 + FTINY); |
188 |
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ep[0] += d2; |
189 |
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ep[-1] += d2; |
190 |
> |
if (!i) continue; |
191 |
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/* diagonal */ |
192 |
> |
b1 = pbright(ap[-hp->ns-1].v); |
193 |
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d2 = b - b1; |
194 |
> |
d2 *= d2*normf/(b + b1 + FTINY); |
195 |
> |
ep[0] += d2; |
196 |
> |
ep[-hp->ns-1] += d2; |
197 |
> |
} |
198 |
> |
/* correct for number of neighbors */ |
199 |
> |
earr[0] *= 8./3.; |
200 |
> |
earr[hp->ns-1] *= 8./3.; |
201 |
> |
earr[(hp->ns-1)*hp->ns] *= 8./3.; |
202 |
> |
earr[(hp->ns-1)*hp->ns + hp->ns-1] *= 8./3.; |
203 |
> |
for (i = 1; i < hp->ns-1; i++) { |
204 |
> |
earr[i*hp->ns] *= 8./5.; |
205 |
> |
earr[i*hp->ns + hp->ns-1] *= 8./5.; |
206 |
> |
} |
207 |
> |
for (j = 1; j < hp->ns-1; j++) { |
208 |
> |
earr[j] *= 8./5.; |
209 |
> |
earr[(hp->ns-1)*hp->ns + j] *= 8./5.; |
210 |
> |
} |
211 |
> |
return(earr); |
212 |
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} |
213 |
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|
214 |
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|
215 |
< |
divsample(dp, h, r) /* sample a division */ |
216 |
< |
register AMBSAMP *dp; |
217 |
< |
AMBHEMI *h; |
60 |
< |
RAY *r; |
215 |
> |
/* Perform super-sampling on hemisphere (introduces bias) */ |
216 |
> |
static void |
217 |
> |
ambsupersamp(AMBHEMI *hp, int cnt) |
218 |
|
{ |
219 |
< |
RAY ar; |
220 |
< |
int hlist[3]; |
221 |
< |
double spt[2]; |
222 |
< |
double xd, yd, zd; |
66 |
< |
double b2; |
67 |
< |
double phi; |
68 |
< |
register int i; |
219 |
> |
float *earr = getambdiffs(hp); |
220 |
> |
double e2rem = 0; |
221 |
> |
float *ep; |
222 |
> |
int i, j, n, nss; |
223 |
|
|
224 |
< |
if (rayorigin(&ar, r, AMBIENT, AVGREFL) < 0) |
225 |
< |
return(-1); |
226 |
< |
hlist[0] = r->rno; |
227 |
< |
hlist[1] = dp->t; |
228 |
< |
hlist[2] = dp->p; |
229 |
< |
multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n)); |
230 |
< |
zd = sqrt((dp->t + spt[0])/h->nt); |
231 |
< |
phi = 2.0*PI * (dp->p + spt[1])/h->np; |
232 |
< |
xd = cos(phi) * zd; |
233 |
< |
yd = sin(phi) * zd; |
234 |
< |
zd = sqrt(1.0 - zd*zd); |
235 |
< |
for (i = 0; i < 3; i++) |
236 |
< |
ar.rdir[i] = xd*h->ux[i] + |
237 |
< |
yd*h->uy[i] + |
238 |
< |
zd*h->uz[i]; |
239 |
< |
dimlist[ndims++] = dp->t*h->np + dp->p + 90171; |
240 |
< |
rayvalue(&ar); |
87 |
< |
ndims--; |
88 |
< |
addcolor(dp->v, ar.rcol); |
89 |
< |
if (ar.rt > FTINY && ar.rt < FHUGE) |
90 |
< |
dp->r += 1.0/ar.rt; |
91 |
< |
/* (re)initialize error */ |
92 |
< |
if (dp->n++) { |
93 |
< |
b2 = bright(dp->v)/dp->n - bright(ar.rcol); |
94 |
< |
b2 = b2*b2 + dp->k*((dp->n-1)*(dp->n-1)); |
95 |
< |
dp->k = b2/(dp->n*dp->n); |
96 |
< |
} else |
97 |
< |
dp->k = 0.0; |
98 |
< |
return(0); |
224 |
> |
if (earr == NULL) /* just skip calc. if no memory */ |
225 |
> |
return; |
226 |
> |
/* accumulate estimated variances */ |
227 |
> |
for (ep = earr + hp->ns*hp->ns; ep > earr; ) |
228 |
> |
e2rem += *--ep; |
229 |
> |
ep = earr; /* perform super-sampling */ |
230 |
> |
for (i = 0; i < hp->ns; i++) |
231 |
> |
for (j = 0; j < hp->ns; j++) { |
232 |
> |
if (e2rem <= FTINY) |
233 |
> |
goto done; /* nothing left to do */ |
234 |
> |
nss = *ep/e2rem*cnt + frandom(); |
235 |
> |
for (n = 1; n <= nss && ambsample(hp,i,j,n); n++) |
236 |
> |
if (!--cnt) goto done; |
237 |
> |
e2rem -= *ep++; /* update remainder */ |
238 |
> |
} |
239 |
> |
done: |
240 |
> |
free(earr); |
241 |
|
} |
242 |
|
|
243 |
|
|
244 |
< |
double |
245 |
< |
doambient(acol, r, wt, pg, dg) /* compute ambient component */ |
246 |
< |
COLOR acol; |
247 |
< |
RAY *r; |
248 |
< |
double wt; |
249 |
< |
FVECT pg, dg; |
244 |
> |
static AMBHEMI * |
245 |
> |
samp_hemi( /* sample indirect hemisphere */ |
246 |
> |
SCOLOR rcol, |
247 |
> |
RAY *r, |
248 |
> |
double wt |
249 |
> |
) |
250 |
|
{ |
251 |
< |
double b, d; |
252 |
< |
AMBHEMI hemi; |
253 |
< |
AMBSAMP *div; |
254 |
< |
AMBSAMP dnew; |
255 |
< |
register AMBSAMP *dp; |
256 |
< |
double arad; |
257 |
< |
int ndivs, ns; |
258 |
< |
register int i, j; |
259 |
< |
/* initialize color */ |
260 |
< |
setcolor(acol, 0.0, 0.0, 0.0); |
261 |
< |
/* initialize hemisphere */ |
262 |
< |
inithemi(&hemi, r, wt); |
263 |
< |
ndivs = hemi.nt * hemi.np; |
264 |
< |
if (ndivs == 0) |
265 |
< |
return(0.0); |
266 |
< |
/* set number of super-samples */ |
267 |
< |
ns = ambssamp * wt + 0.5; |
268 |
< |
if (ns > 0 || pg != NULL || dg != NULL) { |
269 |
< |
div = (AMBSAMP *)malloc(ndivs*sizeof(AMBSAMP)); |
270 |
< |
if (div == NULL) |
271 |
< |
error(SYSTEM, "out of memory in doambient"); |
272 |
< |
} else |
273 |
< |
div = NULL; |
274 |
< |
/* sample the divisions */ |
275 |
< |
arad = 0.0; |
276 |
< |
if ((dp = div) == NULL) |
277 |
< |
dp = &dnew; |
278 |
< |
for (i = 0; i < hemi.nt; i++) |
279 |
< |
for (j = 0; j < hemi.np; j++) { |
280 |
< |
dp->t = i; dp->p = j; |
281 |
< |
setcolor(dp->v, 0.0, 0.0, 0.0); |
282 |
< |
dp->r = 0.0; |
283 |
< |
dp->n = 0; |
284 |
< |
if (divsample(dp, &hemi, r) < 0) |
285 |
< |
goto oopsy; |
286 |
< |
if (div != NULL) |
287 |
< |
dp++; |
288 |
< |
else { |
289 |
< |
addcolor(acol, dp->v); |
290 |
< |
arad += dp->r; |
149 |
< |
} |
150 |
< |
} |
151 |
< |
if (ns > 0) { /* perform super-sampling */ |
152 |
< |
comperrs(div, &hemi); /* compute errors */ |
153 |
< |
qsort(div, ndivs, sizeof(AMBSAMP), ambcmp); /* sort divs */ |
154 |
< |
/* super-sample */ |
155 |
< |
for (i = ns; i > 0; i--) { |
156 |
< |
copystruct(&dnew, div); |
157 |
< |
if (divsample(&dnew, &hemi, r) < 0) |
158 |
< |
goto oopsy; |
159 |
< |
/* reinsert */ |
160 |
< |
dp = div; |
161 |
< |
j = ndivs < i ? ndivs : i; |
162 |
< |
while (--j > 0 && dnew.k < dp[1].k) { |
163 |
< |
copystruct(dp, dp+1); |
164 |
< |
dp++; |
165 |
< |
} |
166 |
< |
copystruct(dp, &dnew); |
167 |
< |
} |
168 |
< |
if (pg != NULL || dg != NULL) /* restore order */ |
169 |
< |
qsort(div, ndivs, sizeof(AMBSAMP), ambnorm); |
251 |
> |
AMBHEMI *hp; |
252 |
> |
double d; |
253 |
> |
int n, i, j; |
254 |
> |
/* insignificance check */ |
255 |
> |
d = sintens(rcol); |
256 |
> |
if (d <= FTINY) |
257 |
> |
return(NULL); |
258 |
> |
/* set number of divisions */ |
259 |
> |
if (ambacc <= FTINY && |
260 |
> |
wt > (d *= 0.8*r->rweight/(ambdiv*minweight))) |
261 |
> |
wt = d; /* avoid ray termination */ |
262 |
> |
n = sqrt(ambdiv * wt) + 0.5; |
263 |
> |
i = 1 + (MINADIV-1)*(ambacc > FTINY); |
264 |
> |
if (n < i) /* use minimum number of samples? */ |
265 |
> |
n = i; |
266 |
> |
/* allocate sampling array */ |
267 |
> |
hp = (AMBHEMI *)malloc(sizeof(AMBHEMI) + sizeof(AMBSAMP)*(n*n - 1)); |
268 |
> |
if (hp == NULL) |
269 |
> |
error(SYSTEM, "out of memory in samp_hemi"); |
270 |
> |
hp->rp = r; |
271 |
> |
hp->ns = n; |
272 |
> |
scolorblack(hp->acol); |
273 |
> |
memset(hp->sa, 0, sizeof(AMBSAMP)*n*n); |
274 |
> |
hp->sampOK = 0; |
275 |
> |
/* assign coefficient */ |
276 |
> |
copyscolor(hp->acoef, rcol); |
277 |
> |
d = 1.0/(n*n); |
278 |
> |
scalescolor(hp->acoef, d); |
279 |
> |
/* make tangent plane axes */ |
280 |
> |
if (!getperpendicular(hp->ux, r->ron, 1)) |
281 |
> |
error(CONSISTENCY, "bad ray direction in samp_hemi"); |
282 |
> |
VCROSS(hp->uy, r->ron, hp->ux); |
283 |
> |
/* sample divisions */ |
284 |
> |
for (i = hp->ns; i--; ) |
285 |
> |
for (j = hp->ns; j--; ) |
286 |
> |
hp->sampOK += ambsample(hp, i, j, 0); |
287 |
> |
copyscolor(rcol, hp->acol); |
288 |
> |
if (!hp->sampOK) { /* utter failure? */ |
289 |
> |
free(hp); |
290 |
> |
return(NULL); |
291 |
|
} |
292 |
< |
/* compute returned values */ |
293 |
< |
if (div != NULL) { |
294 |
< |
for (i = ndivs, dp = div; i-- > 0; dp++) { |
174 |
< |
arad += dp->r; |
175 |
< |
if (dp->n > 1) { |
176 |
< |
b = 1.0/dp->n; |
177 |
< |
scalecolor(dp->v, b); |
178 |
< |
dp->r *= b; |
179 |
< |
dp->n = 1; |
180 |
< |
} |
181 |
< |
addcolor(acol, dp->v); |
182 |
< |
} |
183 |
< |
b = bright(acol); |
184 |
< |
if (b > FTINY) { |
185 |
< |
b = ndivs/b; |
186 |
< |
if (pg != NULL) { |
187 |
< |
posgradient(pg, div, &hemi); |
188 |
< |
for (i = 0; i < 3; i++) |
189 |
< |
pg[i] *= b; |
190 |
< |
} |
191 |
< |
if (dg != NULL) { |
192 |
< |
dirgradient(dg, div, &hemi); |
193 |
< |
for (i = 0; i < 3; i++) |
194 |
< |
dg[i] *= b; |
195 |
< |
} |
196 |
< |
} else { |
197 |
< |
if (pg != NULL) |
198 |
< |
for (i = 0; i < 3; i++) |
199 |
< |
pg[i] = 0.0; |
200 |
< |
if (dg != NULL) |
201 |
< |
for (i = 0; i < 3; i++) |
202 |
< |
dg[i] = 0.0; |
203 |
< |
} |
204 |
< |
free((char *)div); |
292 |
> |
if (hp->sampOK < hp->ns*hp->ns) { |
293 |
> |
hp->sampOK *= -1; /* soft failure */ |
294 |
> |
return(hp); |
295 |
|
} |
296 |
< |
b = 1.0/ndivs; |
297 |
< |
scalecolor(acol, b); |
298 |
< |
if (arad <= FTINY) |
299 |
< |
arad = FHUGE; |
300 |
< |
else |
301 |
< |
arad = (ndivs+ns)/arad; |
212 |
< |
if (arad > maxarad) |
213 |
< |
arad = maxarad; |
214 |
< |
else if (arad < minarad) |
215 |
< |
arad = minarad; |
216 |
< |
arad /= sqrt(wt); |
217 |
< |
if (pg != NULL) { /* clip pos. gradient if too large */ |
218 |
< |
d = 4.0*DOT(pg,pg)*arad*arad; |
219 |
< |
if (d > 1.0) { |
220 |
< |
d = 1.0/sqrt(d); |
221 |
< |
for (i = 0; i < 3; i++) |
222 |
< |
pg[i] *= d; |
223 |
< |
} |
296 |
> |
if (hp->sampOK <= MINADIV*MINADIV) |
297 |
> |
return(hp); /* don't bother super-sampling */ |
298 |
> |
n = ambssamp*wt + 0.5; |
299 |
> |
if (n > 8) { /* perform super-sampling? */ |
300 |
> |
ambsupersamp(hp, n); |
301 |
> |
copyscolor(rcol, hp->acol); |
302 |
|
} |
303 |
< |
return(arad); |
226 |
< |
oopsy: |
227 |
< |
if (div != NULL) |
228 |
< |
free((char *)div); |
229 |
< |
return(0.0); |
303 |
> |
return(hp); /* all is well */ |
304 |
|
} |
305 |
|
|
306 |
|
|
307 |
< |
inithemi(hp, r, wt) /* initialize sampling hemisphere */ |
308 |
< |
register AMBHEMI *hp; |
309 |
< |
RAY *r; |
236 |
< |
double wt; |
307 |
> |
/* Return brightness of farthest ambient sample */ |
308 |
> |
static double |
309 |
> |
back_ambval(AMBHEMI *hp, const int n1, const int n2, const int n3) |
310 |
|
{ |
311 |
< |
register int i; |
312 |
< |
/* set number of divisions */ |
313 |
< |
hp->nt = sqrt(ambdiv * wt / PI) + 0.5; |
314 |
< |
hp->np = PI * hp->nt; |
315 |
< |
/* make axes */ |
316 |
< |
VCOPY(hp->uz, r->ron); |
317 |
< |
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0; |
318 |
< |
for (i = 0; i < 3; i++) |
246 |
< |
if (hp->uz[i] < 0.6 && hp->uz[i] > -0.6) |
247 |
< |
break; |
248 |
< |
if (i >= 3) |
249 |
< |
error(CONSISTENCY, "bad ray direction in inithemi"); |
250 |
< |
hp->uy[i] = 1.0; |
251 |
< |
fcross(hp->ux, hp->uy, hp->uz); |
252 |
< |
normalize(hp->ux); |
253 |
< |
fcross(hp->uy, hp->uz, hp->ux); |
311 |
> |
if (hp->sa[n1].d <= hp->sa[n2].d) { |
312 |
> |
if (hp->sa[n1].d <= hp->sa[n3].d) |
313 |
> |
return(hp->sa[n1].v[0]); |
314 |
> |
return(hp->sa[n3].v[0]); |
315 |
> |
} |
316 |
> |
if (hp->sa[n2].d <= hp->sa[n3].d) |
317 |
> |
return(hp->sa[n2].v[0]); |
318 |
> |
return(hp->sa[n3].v[0]); |
319 |
|
} |
320 |
|
|
321 |
|
|
322 |
< |
comperrs(da, hp) /* compute initial error estimates */ |
323 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
324 |
< |
register AMBHEMI *hp; |
322 |
> |
/* Compute vectors and coefficients for Hessian/gradient calcs */ |
323 |
> |
static void |
324 |
> |
comp_fftri(FFTRI *ftp, AMBHEMI *hp, const int n0, const int n1) |
325 |
|
{ |
326 |
< |
double b, b2; |
327 |
< |
int i, j; |
328 |
< |
register AMBSAMP *dp; |
329 |
< |
/* sum differences from neighbors */ |
330 |
< |
dp = da; |
331 |
< |
for (i = 0; i < hp->nt; i++) |
332 |
< |
for (j = 0; j < hp->np; j++) { |
333 |
< |
#ifdef DEBUG |
334 |
< |
if (dp->t != i || dp->p != j) |
335 |
< |
error(CONSISTENCY, |
336 |
< |
"division order in comperrs"); |
337 |
< |
#endif |
338 |
< |
b = bright(dp[0].v); |
339 |
< |
if (i > 0) { /* from above */ |
340 |
< |
b2 = bright(dp[-hp->np].v) - b; |
341 |
< |
b2 *= b2 * 0.25; |
342 |
< |
dp[0].k += b2; |
343 |
< |
dp[-hp->np].k += b2; |
344 |
< |
} |
280 |
< |
if (j > 0) { /* from behind */ |
281 |
< |
b2 = bright(dp[-1].v) - b; |
282 |
< |
b2 *= b2 * 0.25; |
283 |
< |
dp[0].k += b2; |
284 |
< |
dp[-1].k += b2; |
285 |
< |
} else { /* around */ |
286 |
< |
b2 = bright(dp[hp->np-1].v) - b; |
287 |
< |
b2 *= b2 * 0.25; |
288 |
< |
dp[0].k += b2; |
289 |
< |
dp[hp->np-1].k += b2; |
290 |
< |
} |
291 |
< |
dp++; |
292 |
< |
} |
293 |
< |
/* divide by number of neighbors */ |
294 |
< |
dp = da; |
295 |
< |
for (j = 0; j < hp->np; j++) /* top row */ |
296 |
< |
(dp++)->k *= 1.0/3.0; |
297 |
< |
if (hp->nt < 2) |
298 |
< |
return; |
299 |
< |
for (i = 1; i < hp->nt-1; i++) /* central region */ |
300 |
< |
for (j = 0; j < hp->np; j++) |
301 |
< |
(dp++)->k *= 0.25; |
302 |
< |
for (j = 0; j < hp->np; j++) /* bottom row */ |
303 |
< |
(dp++)->k *= 1.0/3.0; |
326 |
> |
double rdot_cp, dot_e, dot_er, rdot_r, rdot_r1, J2; |
327 |
> |
int ii; |
328 |
> |
|
329 |
> |
VSUB(ftp->r_i, hp->sa[n0].p, hp->rp->rop); |
330 |
> |
VSUB(ftp->r_i1, hp->sa[n1].p, hp->rp->rop); |
331 |
> |
VSUB(ftp->e_i, hp->sa[n1].p, hp->sa[n0].p); |
332 |
> |
VCROSS(ftp->rcp, ftp->r_i, ftp->r_i1); |
333 |
> |
rdot_cp = 1.0/DOT(ftp->rcp,ftp->rcp); |
334 |
> |
dot_e = DOT(ftp->e_i,ftp->e_i); |
335 |
> |
dot_er = DOT(ftp->e_i, ftp->r_i); |
336 |
> |
rdot_r = 1.0/DOT(ftp->r_i,ftp->r_i); |
337 |
> |
rdot_r1 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
338 |
> |
ftp->I1 = acos( DOT(ftp->r_i, ftp->r_i1) * sqrt(rdot_r*rdot_r1) ) * |
339 |
> |
sqrt( rdot_cp ); |
340 |
> |
ftp->I2 = ( DOT(ftp->e_i, ftp->r_i1)*rdot_r1 - dot_er*rdot_r + |
341 |
> |
dot_e*ftp->I1 )*0.5*rdot_cp; |
342 |
> |
J2 = ( 0.5*(rdot_r - rdot_r1) - dot_er*ftp->I2 ) / dot_e; |
343 |
> |
for (ii = 3; ii--; ) |
344 |
> |
ftp->rI2_eJ2[ii] = ftp->I2*ftp->r_i[ii] + J2*ftp->e_i[ii]; |
345 |
|
} |
346 |
|
|
347 |
|
|
348 |
< |
posgradient(gv, da, hp) /* compute position gradient */ |
349 |
< |
FVECT gv; |
350 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
310 |
< |
AMBHEMI *hp; |
348 |
> |
/* Compose 3x3 matrix from two vectors */ |
349 |
> |
static void |
350 |
> |
compose_matrix(FVECT mat[3], FVECT va, FVECT vb) |
351 |
|
{ |
352 |
< |
register int i, j; |
353 |
< |
double b, d; |
354 |
< |
double mag0, mag1; |
355 |
< |
double phi, cosp, sinp, xd, yd; |
356 |
< |
register AMBSAMP *dp; |
352 |
> |
mat[0][0] = 2.0*va[0]*vb[0]; |
353 |
> |
mat[1][1] = 2.0*va[1]*vb[1]; |
354 |
> |
mat[2][2] = 2.0*va[2]*vb[2]; |
355 |
> |
mat[0][1] = mat[1][0] = va[0]*vb[1] + va[1]*vb[0]; |
356 |
> |
mat[0][2] = mat[2][0] = va[0]*vb[2] + va[2]*vb[0]; |
357 |
> |
mat[1][2] = mat[2][1] = va[1]*vb[2] + va[2]*vb[1]; |
358 |
> |
} |
359 |
|
|
360 |
< |
xd = yd = 0.0; |
361 |
< |
for (j = 0; j < hp->np; j++) { |
362 |
< |
dp = da + j; |
363 |
< |
mag0 = mag1 = 0.0; |
364 |
< |
for (i = 0; i < hp->nt; i++) { |
365 |
< |
#ifdef DEBUG |
366 |
< |
if (dp->t != i || dp->p != j) |
367 |
< |
error(CONSISTENCY, |
368 |
< |
"division order in posgradient"); |
369 |
< |
#endif |
370 |
< |
b = bright(dp->v); |
371 |
< |
if (i > 0) { |
372 |
< |
d = dp[-hp->np].r; |
373 |
< |
if (dp[0].r > d) d = dp[0].r; |
374 |
< |
d *= 1.0 - sqrt((double)i/hp->nt); |
375 |
< |
mag0 += d*(b - bright(dp[-hp->np].v)); |
376 |
< |
} |
377 |
< |
if (j > 0) { |
378 |
< |
d = dp[-1].r; |
379 |
< |
if (dp[0].r > d) d = dp[0].r; |
380 |
< |
mag1 += d*(b - bright(dp[-1].v)); |
381 |
< |
} else { |
382 |
< |
d = dp[hp->np-1].r; |
383 |
< |
if (dp[0].r > d) d = dp[0].r; |
384 |
< |
mag1 += d*(b - bright(dp[hp->np-1].v)); |
385 |
< |
} |
386 |
< |
dp += hp->np; |
360 |
> |
|
361 |
> |
/* Compute partial 3x3 Hessian matrix for edge */ |
362 |
> |
static void |
363 |
> |
comp_hessian(FVECT hess[3], FFTRI *ftp, FVECT nrm) |
364 |
> |
{ |
365 |
> |
FVECT ncp; |
366 |
> |
FVECT m1[3], m2[3], m3[3], m4[3]; |
367 |
> |
double d1, d2, d3, d4; |
368 |
> |
double I3, J3, K3; |
369 |
> |
int i, j; |
370 |
> |
/* compute intermediate coefficients */ |
371 |
> |
d1 = 1.0/DOT(ftp->r_i,ftp->r_i); |
372 |
> |
d2 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
373 |
> |
d3 = 1.0/DOT(ftp->e_i,ftp->e_i); |
374 |
> |
d4 = DOT(ftp->e_i, ftp->r_i); |
375 |
> |
I3 = ( DOT(ftp->e_i, ftp->r_i1)*d2*d2 - d4*d1*d1 + 3.0/d3*ftp->I2 ) |
376 |
> |
/ ( 4.0*DOT(ftp->rcp,ftp->rcp) ); |
377 |
> |
J3 = 0.25*d3*(d1*d1 - d2*d2) - d4*d3*I3; |
378 |
> |
K3 = d3*(ftp->I2 - I3/d1 - 2.0*d4*J3); |
379 |
> |
/* intermediate matrices */ |
380 |
> |
VCROSS(ncp, nrm, ftp->e_i); |
381 |
> |
compose_matrix(m1, ncp, ftp->rI2_eJ2); |
382 |
> |
compose_matrix(m2, ftp->r_i, ftp->r_i); |
383 |
> |
compose_matrix(m3, ftp->e_i, ftp->e_i); |
384 |
> |
compose_matrix(m4, ftp->r_i, ftp->e_i); |
385 |
> |
d1 = DOT(nrm, ftp->rcp); |
386 |
> |
d2 = -d1*ftp->I2; |
387 |
> |
d1 *= 2.0; |
388 |
> |
for (i = 3; i--; ) /* final matrix sum */ |
389 |
> |
for (j = 3; j--; ) { |
390 |
> |
hess[i][j] = m1[i][j] + d1*( I3*m2[i][j] + K3*m3[i][j] + |
391 |
> |
2.0*J3*m4[i][j] ); |
392 |
> |
hess[i][j] += d2*(i==j); |
393 |
> |
hess[i][j] *= -1.0/PI; |
394 |
> |
} |
395 |
> |
} |
396 |
> |
|
397 |
> |
|
398 |
> |
/* Reverse hessian calculation result for edge in other direction */ |
399 |
> |
static void |
400 |
> |
rev_hessian(FVECT hess[3]) |
401 |
> |
{ |
402 |
> |
int i; |
403 |
> |
|
404 |
> |
for (i = 3; i--; ) { |
405 |
> |
hess[i][0] = -hess[i][0]; |
406 |
> |
hess[i][1] = -hess[i][1]; |
407 |
> |
hess[i][2] = -hess[i][2]; |
408 |
> |
} |
409 |
> |
} |
410 |
> |
|
411 |
> |
|
412 |
> |
/* Add to radiometric Hessian from the given triangle */ |
413 |
> |
static void |
414 |
> |
add2hessian(FVECT hess[3], FVECT ehess1[3], |
415 |
> |
FVECT ehess2[3], FVECT ehess3[3], double v) |
416 |
> |
{ |
417 |
> |
int i, j; |
418 |
> |
|
419 |
> |
for (i = 3; i--; ) |
420 |
> |
for (j = 3; j--; ) |
421 |
> |
hess[i][j] += v*( ehess1[i][j] + ehess2[i][j] + ehess3[i][j] ); |
422 |
> |
} |
423 |
> |
|
424 |
> |
|
425 |
> |
/* Compute partial displacement form factor gradient for edge */ |
426 |
> |
static void |
427 |
> |
comp_gradient(FVECT grad, FFTRI *ftp, FVECT nrm) |
428 |
> |
{ |
429 |
> |
FVECT ncp; |
430 |
> |
double f1; |
431 |
> |
int i; |
432 |
> |
|
433 |
> |
f1 = 2.0*DOT(nrm, ftp->rcp); |
434 |
> |
VCROSS(ncp, nrm, ftp->e_i); |
435 |
> |
for (i = 3; i--; ) |
436 |
> |
grad[i] = (0.5/PI)*( ftp->I1*ncp[i] + f1*ftp->rI2_eJ2[i] ); |
437 |
> |
} |
438 |
> |
|
439 |
> |
|
440 |
> |
/* Reverse gradient calculation result for edge in other direction */ |
441 |
> |
static void |
442 |
> |
rev_gradient(FVECT grad) |
443 |
> |
{ |
444 |
> |
grad[0] = -grad[0]; |
445 |
> |
grad[1] = -grad[1]; |
446 |
> |
grad[2] = -grad[2]; |
447 |
> |
} |
448 |
> |
|
449 |
> |
|
450 |
> |
/* Add to displacement gradient from the given triangle */ |
451 |
> |
static void |
452 |
> |
add2gradient(FVECT grad, FVECT egrad1, FVECT egrad2, FVECT egrad3, double v) |
453 |
> |
{ |
454 |
> |
int i; |
455 |
> |
|
456 |
> |
for (i = 3; i--; ) |
457 |
> |
grad[i] += v*( egrad1[i] + egrad2[i] + egrad3[i] ); |
458 |
> |
} |
459 |
> |
|
460 |
> |
|
461 |
> |
/* Compute anisotropic radii and eigenvector directions */ |
462 |
> |
static void |
463 |
> |
eigenvectors(FVECT uv[2], float ra[2], FVECT hessian[3]) |
464 |
> |
{ |
465 |
> |
double hess2[2][2]; |
466 |
> |
FVECT a, b; |
467 |
> |
double evalue[2], slope1, xmag1; |
468 |
> |
int i; |
469 |
> |
/* project Hessian to sample plane */ |
470 |
> |
for (i = 3; i--; ) { |
471 |
> |
a[i] = DOT(hessian[i], uv[0]); |
472 |
> |
b[i] = DOT(hessian[i], uv[1]); |
473 |
> |
} |
474 |
> |
hess2[0][0] = DOT(uv[0], a); |
475 |
> |
hess2[0][1] = DOT(uv[0], b); |
476 |
> |
hess2[1][0] = DOT(uv[1], a); |
477 |
> |
hess2[1][1] = DOT(uv[1], b); |
478 |
> |
/* compute eigenvalue(s) */ |
479 |
> |
i = quadratic(evalue, 1.0, -hess2[0][0]-hess2[1][1], |
480 |
> |
hess2[0][0]*hess2[1][1]-hess2[0][1]*hess2[1][0]); |
481 |
> |
if (i == 1) /* double-root (circle) */ |
482 |
> |
evalue[1] = evalue[0]; |
483 |
> |
if (!i || ((evalue[0] = fabs(evalue[0])) <= FTINY*FTINY) | |
484 |
> |
((evalue[1] = fabs(evalue[1])) <= FTINY*FTINY) ) { |
485 |
> |
ra[0] = ra[1] = maxarad; |
486 |
> |
return; |
487 |
> |
} |
488 |
> |
if (evalue[0] > evalue[1]) { |
489 |
> |
ra[0] = sqrt(sqrt(4.0/evalue[0])); |
490 |
> |
ra[1] = sqrt(sqrt(4.0/evalue[1])); |
491 |
> |
slope1 = evalue[1]; |
492 |
> |
} else { |
493 |
> |
ra[0] = sqrt(sqrt(4.0/evalue[1])); |
494 |
> |
ra[1] = sqrt(sqrt(4.0/evalue[0])); |
495 |
> |
slope1 = evalue[0]; |
496 |
> |
} |
497 |
> |
/* compute unit eigenvectors */ |
498 |
> |
if (fabs(hess2[0][1]) <= FTINY) |
499 |
> |
return; /* uv OK as is */ |
500 |
> |
slope1 = (slope1 - hess2[0][0]) / hess2[0][1]; |
501 |
> |
xmag1 = sqrt(1.0/(1.0 + slope1*slope1)); |
502 |
> |
for (i = 3; i--; ) { |
503 |
> |
b[i] = xmag1*uv[0][i] + slope1*xmag1*uv[1][i]; |
504 |
> |
a[i] = slope1*xmag1*uv[0][i] - xmag1*uv[1][i]; |
505 |
> |
} |
506 |
> |
VCOPY(uv[0], a); |
507 |
> |
VCOPY(uv[1], b); |
508 |
> |
} |
509 |
> |
|
510 |
> |
|
511 |
> |
static void |
512 |
> |
ambHessian( /* anisotropic radii & pos. gradient */ |
513 |
> |
AMBHEMI *hp, |
514 |
> |
FVECT uv[2], /* returned */ |
515 |
> |
float ra[2], /* returned (optional) */ |
516 |
> |
float pg[2] /* returned (optional) */ |
517 |
> |
) |
518 |
> |
{ |
519 |
> |
static char memerrmsg[] = "out of memory in ambHessian()"; |
520 |
> |
FVECT (*hessrow)[3] = NULL; |
521 |
> |
FVECT *gradrow = NULL; |
522 |
> |
FVECT hessian[3]; |
523 |
> |
FVECT gradient; |
524 |
> |
FFTRI fftr; |
525 |
> |
int i, j; |
526 |
> |
/* be sure to assign unit vectors */ |
527 |
> |
VCOPY(uv[0], hp->ux); |
528 |
> |
VCOPY(uv[1], hp->uy); |
529 |
> |
/* clock-wise vertex traversal from sample POV */ |
530 |
> |
if (ra != NULL) { /* initialize Hessian row buffer */ |
531 |
> |
hessrow = (FVECT (*)[3])malloc(sizeof(FVECT)*3*(hp->ns-1)); |
532 |
> |
if (hessrow == NULL) |
533 |
> |
error(SYSTEM, memerrmsg); |
534 |
> |
memset(hessian, 0, sizeof(hessian)); |
535 |
> |
} else if (pg == NULL) /* bogus call? */ |
536 |
> |
return; |
537 |
> |
if (pg != NULL) { /* initialize form factor row buffer */ |
538 |
> |
gradrow = (FVECT *)malloc(sizeof(FVECT)*(hp->ns-1)); |
539 |
> |
if (gradrow == NULL) |
540 |
> |
error(SYSTEM, memerrmsg); |
541 |
> |
memset(gradient, 0, sizeof(gradient)); |
542 |
> |
} |
543 |
> |
/* compute first row of edges */ |
544 |
> |
for (j = 0; j < hp->ns-1; j++) { |
545 |
> |
comp_fftri(&fftr, hp, AI(hp,0,j), AI(hp,0,j+1)); |
546 |
> |
if (hessrow != NULL) |
547 |
> |
comp_hessian(hessrow[j], &fftr, hp->rp->ron); |
548 |
> |
if (gradrow != NULL) |
549 |
> |
comp_gradient(gradrow[j], &fftr, hp->rp->ron); |
550 |
> |
} |
551 |
> |
/* sum each row of triangles */ |
552 |
> |
for (i = 0; i < hp->ns-1; i++) { |
553 |
> |
FVECT hesscol[3]; /* compute first vertical edge */ |
554 |
> |
FVECT gradcol; |
555 |
> |
comp_fftri(&fftr, hp, AI(hp,i,0), AI(hp,i+1,0)); |
556 |
> |
if (hessrow != NULL) |
557 |
> |
comp_hessian(hesscol, &fftr, hp->rp->ron); |
558 |
> |
if (gradrow != NULL) |
559 |
> |
comp_gradient(gradcol, &fftr, hp->rp->ron); |
560 |
> |
for (j = 0; j < hp->ns-1; j++) { |
561 |
> |
FVECT hessdia[3]; /* compute triangle contributions */ |
562 |
> |
FVECT graddia; |
563 |
> |
double backg; |
564 |
> |
backg = back_ambval(hp, AI(hp,i,j), |
565 |
> |
AI(hp,i,j+1), AI(hp,i+1,j)); |
566 |
> |
/* diagonal (inner) edge */ |
567 |
> |
comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j)); |
568 |
> |
if (hessrow != NULL) { |
569 |
> |
comp_hessian(hessdia, &fftr, hp->rp->ron); |
570 |
> |
rev_hessian(hesscol); |
571 |
> |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
572 |
|
} |
573 |
< |
if (hp->nt > 1) { |
574 |
< |
mag0 /= (double)hp->np; |
575 |
< |
mag1 /= (double)hp->nt; |
573 |
> |
if (gradrow != NULL) { |
574 |
> |
comp_gradient(graddia, &fftr, hp->rp->ron); |
575 |
> |
rev_gradient(gradcol); |
576 |
> |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
577 |
|
} |
578 |
< |
phi = 2.0*PI * (double)j/hp->np; |
579 |
< |
cosp = cos(phi); sinp = sin(phi); |
580 |
< |
xd += mag0*cosp - mag1*sinp; |
581 |
< |
yd += mag0*sinp + mag1*cosp; |
578 |
> |
/* initialize edge in next row */ |
579 |
> |
comp_fftri(&fftr, hp, AI(hp,i+1,j+1), AI(hp,i+1,j)); |
580 |
> |
if (hessrow != NULL) |
581 |
> |
comp_hessian(hessrow[j], &fftr, hp->rp->ron); |
582 |
> |
if (gradrow != NULL) |
583 |
> |
comp_gradient(gradrow[j], &fftr, hp->rp->ron); |
584 |
> |
/* new column edge & paired triangle */ |
585 |
> |
backg = back_ambval(hp, AI(hp,i+1,j+1), |
586 |
> |
AI(hp,i+1,j), AI(hp,i,j+1)); |
587 |
> |
comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j+1)); |
588 |
> |
if (hessrow != NULL) { |
589 |
> |
comp_hessian(hesscol, &fftr, hp->rp->ron); |
590 |
> |
rev_hessian(hessdia); |
591 |
> |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
592 |
> |
if (i < hp->ns-2) |
593 |
> |
rev_hessian(hessrow[j]); |
594 |
> |
} |
595 |
> |
if (gradrow != NULL) { |
596 |
> |
comp_gradient(gradcol, &fftr, hp->rp->ron); |
597 |
> |
rev_gradient(graddia); |
598 |
> |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
599 |
> |
if (i < hp->ns-2) |
600 |
> |
rev_gradient(gradrow[j]); |
601 |
> |
} |
602 |
> |
} |
603 |
|
} |
604 |
< |
for (i = 0; i < 3; i++) |
605 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/PI; |
604 |
> |
/* release row buffers */ |
605 |
> |
if (hessrow != NULL) free(hessrow); |
606 |
> |
if (gradrow != NULL) free(gradrow); |
607 |
> |
|
608 |
> |
if (ra != NULL) /* extract eigenvectors & radii */ |
609 |
> |
eigenvectors(uv, ra, hessian); |
610 |
> |
if (pg != NULL) { /* tangential position gradient */ |
611 |
> |
pg[0] = DOT(gradient, uv[0]); |
612 |
> |
pg[1] = DOT(gradient, uv[1]); |
613 |
> |
} |
614 |
|
} |
615 |
|
|
616 |
|
|
617 |
< |
dirgradient(gv, da, hp) /* compute direction gradient */ |
618 |
< |
FVECT gv; |
619 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
363 |
< |
AMBHEMI *hp; |
617 |
> |
/* Compute direction gradient from a hemispherical sampling */ |
618 |
> |
static void |
619 |
> |
ambdirgrad(AMBHEMI *hp, FVECT uv[2], float dg[2]) |
620 |
|
{ |
621 |
< |
register int i, j; |
622 |
< |
double mag; |
623 |
< |
double phi, xd, yd; |
624 |
< |
register AMBSAMP *dp; |
621 |
> |
AMBSAMP *ap; |
622 |
> |
double dgsum[2]; |
623 |
> |
int n; |
624 |
> |
FVECT vd; |
625 |
> |
double gfact; |
626 |
|
|
627 |
< |
xd = yd = 0.0; |
628 |
< |
for (j = 0; j < hp->np; j++) { |
629 |
< |
dp = da + j; |
630 |
< |
mag = 0.0; |
631 |
< |
for (i = 0; i < hp->nt; i++) { |
632 |
< |
#ifdef DEBUG |
633 |
< |
if (dp->t != i || dp->p != j) |
634 |
< |
error(CONSISTENCY, |
635 |
< |
"division order in dirgradient"); |
636 |
< |
#endif |
637 |
< |
mag += sqrt((i+.5)/hp->nt)*bright(dp->v); |
638 |
< |
dp += hp->np; |
627 |
> |
dgsum[0] = dgsum[1] = 0.0; /* sum values times -tan(theta) */ |
628 |
> |
for (ap = hp->sa, n = hp->ns*hp->ns; n--; ap++) { |
629 |
> |
/* use vector for azimuth + 90deg */ |
630 |
> |
VSUB(vd, ap->p, hp->rp->rop); |
631 |
> |
/* brightness over cosine factor */ |
632 |
> |
gfact = ap->v[0] / DOT(hp->rp->ron, vd); |
633 |
> |
/* sine = proj_radius/vd_length */ |
634 |
> |
dgsum[0] -= DOT(uv[1], vd) * gfact; |
635 |
> |
dgsum[1] += DOT(uv[0], vd) * gfact; |
636 |
> |
} |
637 |
> |
dg[0] = dgsum[0] / (hp->ns*hp->ns); |
638 |
> |
dg[1] = dgsum[1] / (hp->ns*hp->ns); |
639 |
> |
} |
640 |
> |
|
641 |
> |
|
642 |
> |
/* Compute potential light leak direction flags for cache value */ |
643 |
> |
static uint32 |
644 |
> |
ambcorral(AMBHEMI *hp, FVECT uv[2], const double r0, const double r1) |
645 |
> |
{ |
646 |
> |
const double max_d = 1.0/(minarad*ambacc + 0.001); |
647 |
> |
const double ang_res = 0.5*PI/hp->ns; |
648 |
> |
const double ang_step = ang_res/((int)(16/PI*ang_res) + 1.01); |
649 |
> |
double avg_d = 0; |
650 |
> |
uint32 flgs = 0; |
651 |
> |
FVECT vec; |
652 |
> |
double u, v; |
653 |
> |
double ang, a1; |
654 |
> |
int i, j; |
655 |
> |
/* don't bother for a few samples */ |
656 |
> |
if (hp->ns < 8) |
657 |
> |
return(0); |
658 |
> |
/* check distances overhead */ |
659 |
> |
for (i = hp->ns*3/4; i-- > hp->ns>>2; ) |
660 |
> |
for (j = hp->ns*3/4; j-- > hp->ns>>2; ) |
661 |
> |
avg_d += ambsam(hp,i,j).d; |
662 |
> |
avg_d *= 4.0/(hp->ns*hp->ns); |
663 |
> |
if (avg_d*r0 >= 1.0) /* ceiling too low for corral? */ |
664 |
> |
return(0); |
665 |
> |
if (avg_d >= max_d) /* insurance */ |
666 |
> |
return(0); |
667 |
> |
/* else circle around perimeter */ |
668 |
> |
for (i = 0; i < hp->ns; i++) |
669 |
> |
for (j = 0; j < hp->ns; j += !i|(i==hp->ns-1) ? 1 : hp->ns-1) { |
670 |
> |
AMBSAMP *ap = &ambsam(hp,i,j); |
671 |
> |
if ((ap->d <= FTINY) | (ap->d >= max_d)) |
672 |
> |
continue; /* too far or too near */ |
673 |
> |
VSUB(vec, ap->p, hp->rp->rop); |
674 |
> |
u = DOT(vec, uv[0]); |
675 |
> |
v = DOT(vec, uv[1]); |
676 |
> |
if ((r0*r0*u*u + r1*r1*v*v) * ap->d*ap->d <= u*u + v*v) |
677 |
> |
continue; /* occluder outside ellipse */ |
678 |
> |
ang = atan2a(v, u); /* else set direction flags */ |
679 |
> |
for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step) |
680 |
> |
flgs |= 1L<<(int)(16/PI*(a1 + 2.*PI*(a1 < 0))); |
681 |
> |
} |
682 |
> |
return(flgs); |
683 |
> |
} |
684 |
> |
|
685 |
> |
|
686 |
> |
int |
687 |
> |
doambient( /* compute ambient component */ |
688 |
> |
SCOLOR rcol, /* input/output color */ |
689 |
> |
RAY *r, |
690 |
> |
double wt, |
691 |
> |
FVECT uv[2], /* returned (optional) */ |
692 |
> |
float ra[2], /* returned (optional) */ |
693 |
> |
float pg[2], /* returned (optional) */ |
694 |
> |
float dg[2], /* returned (optional) */ |
695 |
> |
uint32 *crlp /* returned (optional) */ |
696 |
> |
) |
697 |
> |
{ |
698 |
> |
AMBHEMI *hp = samp_hemi(rcol, r, wt); |
699 |
> |
FVECT my_uv[2]; |
700 |
> |
double d, K; |
701 |
> |
AMBSAMP *ap; |
702 |
> |
int i; |
703 |
> |
/* clear return values */ |
704 |
> |
if (uv != NULL) |
705 |
> |
memset(uv, 0, sizeof(FVECT)*2); |
706 |
> |
if (ra != NULL) |
707 |
> |
ra[0] = ra[1] = 0.0; |
708 |
> |
if (pg != NULL) |
709 |
> |
pg[0] = pg[1] = 0.0; |
710 |
> |
if (dg != NULL) |
711 |
> |
dg[0] = dg[1] = 0.0; |
712 |
> |
if (crlp != NULL) |
713 |
> |
*crlp = 0; |
714 |
> |
if (hp == NULL) /* sampling falure? */ |
715 |
> |
return(0); |
716 |
> |
|
717 |
> |
if ((ra == NULL) & (pg == NULL) & (dg == NULL) || |
718 |
> |
(hp->sampOK < 0) | (hp->ns < MINADIV)) { |
719 |
> |
free(hp); /* Hessian not requested/possible */ |
720 |
> |
return(-1); /* value-only return value */ |
721 |
> |
} |
722 |
> |
if ((d = scolor_mean(rcol)) > FTINY) { |
723 |
> |
d = 0.99*(hp->ns*hp->ns)/d; /* normalize avg. values */ |
724 |
> |
K = 0.01; |
725 |
> |
} else { /* or fall back on geometric Hessian */ |
726 |
> |
K = 1.0; |
727 |
> |
pg = NULL; |
728 |
> |
dg = NULL; |
729 |
> |
crlp = NULL; |
730 |
> |
} |
731 |
> |
ap = hp->sa; /* single channel from here on... */ |
732 |
> |
for (i = hp->ns*hp->ns; i--; ap++) |
733 |
> |
ap->v[0] = scolor_mean(ap->v)*d + K; |
734 |
> |
|
735 |
> |
if (uv == NULL) /* make sure we have axis pointers */ |
736 |
> |
uv = my_uv; |
737 |
> |
/* compute radii & pos. gradient */ |
738 |
> |
ambHessian(hp, uv, ra, pg); |
739 |
> |
|
740 |
> |
if (dg != NULL) /* compute direction gradient */ |
741 |
> |
ambdirgrad(hp, uv, dg); |
742 |
> |
|
743 |
> |
if (ra != NULL) { /* scale/clamp radii */ |
744 |
> |
if (pg != NULL) { |
745 |
> |
if (ra[0]*(d = fabs(pg[0])) > 1.0) |
746 |
> |
ra[0] = 1.0/d; |
747 |
> |
if (ra[1]*(d = fabs(pg[1])) > 1.0) |
748 |
> |
ra[1] = 1.0/d; |
749 |
> |
if (ra[0] > ra[1]) |
750 |
> |
ra[0] = ra[1]; |
751 |
|
} |
752 |
< |
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
753 |
< |
xd += mag * cos(phi); |
754 |
< |
yd += mag * sin(phi); |
752 |
> |
if (ra[0] < minarad) { |
753 |
> |
ra[0] = minarad; |
754 |
> |
if (ra[1] < minarad) |
755 |
> |
ra[1] = minarad; |
756 |
> |
} |
757 |
> |
ra[0] *= d = 1.0/sqrt(wt); |
758 |
> |
if ((ra[1] *= d) > 2.0*ra[0]) |
759 |
> |
ra[1] = 2.0*ra[0]; |
760 |
> |
if (ra[1] > maxarad) { |
761 |
> |
ra[1] = maxarad; |
762 |
> |
if (ra[0] > maxarad) |
763 |
> |
ra[0] = maxarad; |
764 |
> |
} |
765 |
> |
/* flag encroached directions */ |
766 |
> |
if (crlp != NULL) /* XXX doesn't update with changes to ambacc */ |
767 |
> |
*crlp = ambcorral(hp, uv, ra[0]*ambacc, ra[1]*ambacc); |
768 |
> |
if (pg != NULL) { /* cap gradient if necessary */ |
769 |
> |
d = pg[0]*pg[0]*ra[0]*ra[0] + pg[1]*pg[1]*ra[1]*ra[1]; |
770 |
> |
if (d > 1.0) { |
771 |
> |
d = 1.0/sqrt(d); |
772 |
> |
pg[0] *= d; |
773 |
> |
pg[1] *= d; |
774 |
> |
} |
775 |
> |
} |
776 |
|
} |
777 |
< |
for (i = 0; i < 3; i++) |
778 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])*PI/(hp->nt*hp->np); |
777 |
> |
free(hp); /* clean up and return */ |
778 |
> |
return(1); |
779 |
|
} |