diff options
author | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
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committer | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
commit | 07e77936d535e58b0aeb4f2a11400c1050556739 (patch) | |
tree | fb50fad6436ecbc159505bee73a92cd289b99a07 /src/base/math/atan2.c | |
parent | b48327d357e0818d1a6ae2a064cfa7d1567e1242 (diff) |
Feat: added math library
Used Plan9's libc as starting point. This cleans up dangling references
due to loss of libc.
Diffstat (limited to 'src/base/math/atan2.c')
-rw-r--r-- | src/base/math/atan2.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/base/math/atan2.c b/src/base/math/atan2.c new file mode 100644 index 0000000..a681a80 --- /dev/null +++ b/src/base/math/atan2.c @@ -0,0 +1,24 @@ +#include <u.h> +#include <base.h> +/* + atan2 discovers what quadrant the angle + is in and calls atan. +*/ + +double +math·atan2(double arg1, double arg2) +{ + + if(arg1+arg2 == arg1) { + if(arg1 >= 0) + return math·PIO2; + return -math·PIO2; + } + arg1 = math·atan(arg1/arg2); + if(arg2 < 0) { + if(arg1 <= 0) + return arg1 + math·PI; + return arg1 - math·PI; + } + return arg1; +} |