2 |
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static const char RCSid[] = "$Id$"; |
3 |
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#endif |
4 |
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/* |
5 |
< |
* Compute a 4-byte direction code (int32 type defined in standard.h). |
5 |
> |
* Compute a 4-byte direction code (externals defined in rtmath.h). |
6 |
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* |
7 |
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* Mean accuracy is 0.0022 degrees, with a maximum error of 0.0058 degrees. |
8 |
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*/ |
9 |
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|
10 |
< |
#include "standard.h" |
10 |
> |
#include "rtmath.h" |
11 |
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|
12 |
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#define DCSCALE 11585.2 /* (1<<13)*sqrt(2) */ |
13 |
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#define FXNEG 01 |
33 |
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dc |= FXNEG<<i; |
34 |
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} else |
35 |
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cd[i] = (int)(dv[i] * DCSCALE); |
36 |
+ |
if (!(cd[0] | cd[1] | cd[2])) |
37 |
+ |
return(0); /* zero normal */ |
38 |
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if (cd[0] <= cd[1]) { |
39 |
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dc |= F1X | cd[0] << F1SFT; |
40 |
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cm = cd[1]; |
46 |
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dc |= F2Z | cd[2] << F2SFT; |
47 |
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else |
48 |
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dc |= cm << F2SFT; |
49 |
< |
if (!dc) /* don't generate 0 code */ |
49 |
> |
if (!dc) /* don't generate 0 code normally */ |
50 |
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dc = F1X; |
51 |
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return(dc); |
52 |
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} |
59 |
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{ |
60 |
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double d1, d2, der; |
61 |
|
|
62 |
+ |
if (!dc) { /* special code for zero normal */ |
63 |
+ |
dv[0] = dv[1] = dv[2] = 0.; |
64 |
+ |
return; |
65 |
+ |
} |
66 |
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d1 = ((dc>>F1SFT & FMASK)+.5)*(1./DCSCALE); |
67 |
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d2 = ((dc>>F2SFT & FMASK)+.5)*(1./DCSCALE); |
68 |
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der = sqrt(1. - d1*d1 - d2*d2); |