Note about how angle of vec2d is calculated #274

Author: viblo

CHANGELOG.rst

@@ -9,7 +9,7 @@ Changelog
    
    New feature: ShapeFilter.rejects_collision()
    New feature: Added Vec2d.polar_tuple
-   Optimized Vec2d.angle and Vec2d.angle_degrees
+   Optimized Vec2d.angle and Vec2d.angle_degrees (note that the optimized versions treat 0 length vectors with x and/or y equal to -0 slightly differently.)
    Improved vec2d documentation 
    
    

pymunk/vec2d.py

@@ -357,6 +357,8 @@ def rotated_degrees(self, angle_degrees: float) -> "Vec2d":
     def angle(self) -> float:
         """The angle (in radians) of the vector.
 
+        Angle calculated with atan2(y, x).
+
         >>> '%.2f' % Vec2d(-1, 0).angle
         '3.14'
         >>> Vec2d(0, 0).angle