[
https://issues.apache.org/jira/browse/GEOMETRY-29?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16791829#comment-16791829
]
Matt Juntunen commented on GEOMETRY-29:
---------------------------------------
{quote}I don't see the use cases for hashCode and equals for values based on
doubles.
{quote}
I agree that in many situations fuzzy comparison of doubles is preferred, but I
don't think that means we should not implement these methods. A situation where
I might rely on these methods is when reuniting split subhyperplanes in order
to generate the boundary of a BSP tree. Each subhyperplane has a hyperplane
that embeds it, and there may be many subhyperplanes in the tree with exactly
equal hyperplanes. In this case, I would actually use the hyperplanes as keys
in a map in order to find all subhyperplanes that lie in the same hyperplane.
In regard to fuzzy comparisons, the {{Vector?D}} classes allow this
functionality through an overloaded {{equals}} method that takes a
{{DoublePrecisionContext}}. We have not implemented this in any of the
hyperplane classes since it hasn't seemed to be needed at this point. It's also
a bit complicated by the fact that the hyperplane classes include their own
{{DoublePrecisionContext}} so there isn't an immediately obvious method
overload opportunity, not to mention the issue of which hyperplane's precision
context to use when performing the comparison.
> Plane API cleanup
> -----------------
>
> Key: GEOMETRY-29
> URL: https://issues.apache.org/jira/browse/GEOMETRY-29
> Project: Apache Commons Geometry
> Issue Type: Improvement
> Reporter: Matt Juntunen
> Priority: Major
>
> The following changes should be made to the
> {{o.a.c.g.euclidean.threed.Plane}} class:
> * make the class immutable
> * use well-named factory methods instead of constructor overloads
> * provide a factory method to create a plane with user-supplied {{u}} and
> {{v}} axes. The current implementation allows the normal to be provided but
> chooses its own planar axes (see {{setFrame}}).
> * add {{equals}}, {{hashCode}}, and {{toString}} methods.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
