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author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2016-05-11 19:17:50 -0400 |
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committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2016-06-02 15:13:35 -0400 |
commit | aeab4cc920a92ab5b9e019de1439f887501348d5 (patch) | |
tree | d7a7b54b0b177513f0d647a877af06b3f1cabb17 | |
parent | 822c26b3e9655019d3d3d18bedd2bc185c8709ad (diff) | |
download | opus-aeab4cc920a92ab5b9e019de1439f887501348d5.tar.gz |
Simplifying fast_atan2f()
-rw-r--r-- | src/analysis.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/src/analysis.c b/src/analysis.c index fae0c660..95e79964 100644 --- a/src/analysis.c +++ b/src/analysis.c @@ -115,26 +115,20 @@ static const int extra_bands[NB_TOT_BANDS+1] = { #define cE ((float)M_PI/2) static OPUS_INLINE float fast_atan2f(float y, float x) { float x2, y2; - /* Should avoid underflow on the values we'll get */ - if (ABS16(x)+ABS16(y)<1e-9f) - { - x*=1e12f; - y*=1e12f; - } x2 = x*x; y2 = y*y; + /* For very small values, we don't care about the answer, so + we can just return 0. */ + if (x2 + y2 < 1e-18f) + { + return 0; + } if(x2<y2){ float den = (y2 + cB*x2) * (y2 + cC*x2); - if (den!=0) - return -x*y*(y2 + cA*x2) / den + (y<0 ? -cE : cE); - else - return (y<0 ? -cE : cE); + return -x*y*(y2 + cA*x2) / den + (y<0 ? -cE : cE); }else{ float den = (x2 + cB*y2) * (x2 + cC*y2); - if (den!=0) - return x*y*(x2 + cA*y2) / den + (y<0 ? -cE : cE) - (x*y<0 ? -cE : cE); - else - return (y<0 ? -cE : cE) - (x*y<0 ? -cE : cE); + return x*y*(x2 + cA*y2) / den + (y<0 ? -cE : cE) - (x*y<0 ? -cE : cE); } } |