utils: introduce atan2vector (no users yet)

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/funcs.scad.cpp b/funcs.scad.cpp
index 92292bebc3db62a31cc802f2b1a0406815d65b95..5857c933a837f888bf22faedda5b455e6df0e973 100644 (file)
--- a/funcs.scad.cpp
+++ b/funcs.scad.cpp
@@ -16,6 +16,8 @@ function vectorlen(v)   = sqrt(vsq(0) + vsq(1) + vsq(2));
 function unitvector2d(v) = v / vectorlen2d(v);
 function unitvector(v)   = v / vectorlen(v);
 
+function atan2vector(v) = atan2(v[1], v[0]);
+
 // | m[0][0] m[0][1] |
 // | m[1][0] m[1][1] |
 function determinant2(m) = (m[0][0] * m[1][1] - m[0][1] * m[1][0]);