[jira] [Closed] (SIS-49) ArrayIndexOutOfBoundsException caused by method getCircularRegionApproximation(int numberOfPoints) in LatLonPointRadius class

["Martin Desruisseaux (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/SIS-49?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Martin Desruisseaux closed SIS-49.
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> ArrayIndexOutOfBoundsException caused by method getCircularRegionApproximation(int numberOfPoints) in LatLonPointRadius class
> -----------------------------------------------------------------------------------------------------------------------------
>
>                 Key: SIS-49
>                 URL: https://issues.apache.org/jira/browse/SIS-49
>             Project: Spatial Information Systems
>          Issue Type: Bug
>          Components: Geometry objects
>            Reporter: Ross Laidlaw
>            Assignee: Ross Laidlaw
>            Priority: Minor
>              Labels: gsoc2012
>             Fix For: 0.3
>
>         Attachments: SIS-49.rlaidlaw.2012-07-06.patch.txt
>
>
> The method public LatLon[] getCircularRegionApproximation(int numberOfPoints) throws an ArrayIndexOutOfBoundsException under certain conditions.  This is because of an error in the following loop:
> {code}
> LatLon[] points = new LatLon[numberOfPoints + 1];
> for (int i = 0; i < 360; i += (360 / numberOfPoints)) 
> {
>   points[i] = DistanceUtils.getPointOnGreatCircle(this.center.getLat(),
>       this.center.getLon(), radius, i);
> }
> {code}
> The exception arises because integer i is used as the array index for the points array, but the value of i jumps up by (360/numberOfPoints) on every iteration of the loop.  For example, if numberOfPoints is 10, then i will increase by 36 each time, resulting in the exception.  The points array size is set before the loop to 'numberOfPoints + 1'.
> As an experiment, I changed the loop as shown below and this appeared to fix the problem.  There may be a more elegant solution:
> {code}
> LatLon[] points = new LatLon[numberOfPoints + 1];
> for (int i = 0, j = 0; i < 360; i += (360 / numberOfPoints), j++) 
> {
>   points[j] = DistanceUtils.getPointOnGreatCircle(this.center.getLat(),
>       this.center.getLon(), radius, i);
> }
> {code}



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