25 |
|
register SRCINDEX *si; /* source index (modified to current) */ |
26 |
|
{ |
27 |
|
int cent[3], size[3], parr[2]; |
28 |
+ |
SRCREC *srcp; |
29 |
|
FVECT vpos; |
30 |
|
double d; |
31 |
|
register int i; |
52 |
|
if (!skipparts(cent, size, parr, si->spt)) |
53 |
|
error(CONSISTENCY, "bad source partition in nextssamp"); |
54 |
|
/* compute sample */ |
55 |
+ |
srcp = source + si->sn; |
56 |
|
if (dstrsrc > FTINY) { /* jitter sample */ |
57 |
|
dimlist[ndims] = si->sn + 8831; |
58 |
|
dimlist[ndims+1] = si->sp + 3109; |
59 |
|
d = urand(ilhash(dimlist,ndims+2)+samplendx); |
60 |
< |
if (source[si->sn].sflags & SFLAT) { |
60 |
> |
if (srcp->sflags & SFLAT) { |
61 |
|
multisamp(vpos, 2, d); |
62 |
< |
vpos[2] = 0.5; |
62 |
> |
vpos[SW] = 0.5; |
63 |
|
} else |
64 |
|
multisamp(vpos, 3, d); |
65 |
|
for (i = 0; i < 3; i++) |
70 |
|
|
71 |
|
for (i = 0; i < 3; i++) |
72 |
|
vpos[i] += (double)cent[i]/MAXSPART; |
73 |
+ |
/* avoid circular aiming failures */ |
74 |
+ |
if ((srcp->sflags & SCIR) && (si->np > 1 || dstrsrc > 0.7)) { |
75 |
+ |
FVECT trim; |
76 |
+ |
if (srcp->sflags & (SFLAT|SDISTANT)) { |
77 |
+ |
d = 1.12837917; /* correct setflatss() */ |
78 |
+ |
trim[SU] = d*sqrt(1.0 - 0.5*vpos[SV]*vpos[SV]); |
79 |
+ |
trim[SV] = d*sqrt(1.0 - 0.5*vpos[SU]*vpos[SU]); |
80 |
+ |
trim[SW] = 0.0; |
81 |
+ |
} else { |
82 |
+ |
trim[SW] = trim[SU] = vpos[SU]*vpos[SU]; |
83 |
+ |
d = vpos[SV]*vpos[SV]; |
84 |
+ |
if (d > trim[SW]) trim[SW] = d; |
85 |
+ |
trim[SU] += d; |
86 |
+ |
d = vpos[SW]*vpos[SW]; |
87 |
+ |
if (d > trim[SW]) trim[SW] = d; |
88 |
+ |
trim[SU] += d; |
89 |
+ |
if (trim[SU] > FTINY*FTINY) { |
90 |
+ |
d = 1.0/0.7236; /* correct sphsetsrc() */ |
91 |
+ |
trim[SW] = trim[SV] = trim[SU] = |
92 |
+ |
d*sqrt(trim[SW]/trim[SU]); |
93 |
+ |
} else |
94 |
+ |
trim[SW] = trim[SV] = trim[SU] = 0.0; |
95 |
+ |
} |
96 |
+ |
for (i = 0; i < 3; i++) |
97 |
+ |
vpos[i] *= trim[i]; |
98 |
+ |
} |
99 |
|
/* compute direction */ |
100 |
|
for (i = 0; i < 3; i++) |
101 |
< |
r->rdir[i] = source[si->sn].sloc[i] + |
102 |
< |
vpos[SU]*source[si->sn].ss[SU][i] + |
103 |
< |
vpos[SV]*source[si->sn].ss[SV][i] + |
104 |
< |
vpos[SW]*source[si->sn].ss[SW][i]; |
101 |
> |
r->rdir[i] = srcp->sloc[i] + |
102 |
> |
vpos[SU]*srcp->ss[SU][i] + |
103 |
> |
vpos[SV]*srcp->ss[SV][i] + |
104 |
> |
vpos[SW]*srcp->ss[SW][i]; |
105 |
|
|
106 |
< |
if (!(source[si->sn].sflags & SDISTANT)) |
106 |
> |
if (!(srcp->sflags & SDISTANT)) |
107 |
|
for (i = 0; i < 3; i++) |
108 |
|
r->rdir[i] -= r->rorg[i]; |
109 |
|
/* compute distance */ |
111 |
|
goto nextsample; /* at source! */ |
112 |
|
|
113 |
|
/* compute sample size */ |
114 |
< |
if (source[si->sn].sflags & SFLAT) { |
114 |
> |
if (srcp->sflags & SFLAT) { |
115 |
|
si->dom = sflatform(si->sn, r->rdir); |
116 |
|
si->dom *= size[SU]*size[SV]/(MAXSPART*(double)MAXSPART); |
117 |
< |
} else if (source[si->sn].sflags & SCYL) { |
117 |
> |
} else if (srcp->sflags & SCYL) { |
118 |
|
si->dom = scylform(si->sn, r->rdir); |
119 |
|
si->dom *= size[SU]/(double)MAXSPART; |
120 |
|
} else { |
121 |
|
si->dom = size[SU]*size[SV]*(double)size[SW] / |
122 |
|
(MAXSPART*MAXSPART*(double)MAXSPART) ; |
123 |
|
} |
124 |
< |
if (source[si->sn].sflags & SDISTANT) { |
125 |
< |
si->dom *= source[si->sn].ss2; |
124 |
> |
if (srcp->sflags & SDISTANT) { |
125 |
> |
si->dom *= srcp->ss2; |
126 |
|
return(FHUGE); |
127 |
|
} |
128 |
|
if (si->dom <= 1e-4) |
129 |
|
goto nextsample; /* behind source? */ |
130 |
< |
si->dom *= source[si->sn].ss2/(d*d); |
130 |
> |
si->dom *= srcp->ss2/(d*d); |
131 |
|
return(d); /* sample OK, return distance */ |
132 |
|
} |
133 |
|
|