[postgis-devel] ForceRHR doesn't?
Michael Fuhr
mike at fuhr.org
Sat Mar 11 22:06:57 PST 2006
On Sat, Mar 11, 2006 at 09:49:04PM -0800, Paul Ramsey wrote:
> "Right hand rule" means "if I walk along the boundary of the polygon
> with my right hand extended, it is always inside the polygon". So
> the external rings go clockwise, and the internal rings go anti-
> clockwise.
Is there disagreement in the field on that or does the definition
vary depending on context? I've found that definition as well as
the opposite; hence my confusion. Maybe the documentation should
explain exactly what "Force polygons of the collection to obey
Right-Hand-Rule" means.
> And it looks like you found a silly bug, since ForceRHR should not be
> calling an unconditional reverse.
That's the main point: ForceRHR doesn't seem to be doing what it
should be.
Thanks.
--
Michael Fuhr
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