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Groups > comp.lang.java.programmer > #19148

Re: rectangle contains point

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On Friday, October 5, 2012 2:23:18 PM UTC-5, Eric Sosman wrote:
> On 10/5/2012 3:00 PM, bob smith wrote:
> 
> > So, I have a rectangle class as follows:
> 
> >
> 
> > public class My_Rectangle {
> 
> > 	double x, y, width, height;
> 
> > 	AffineTransform aft;
> 
> >
> 
> > Anyone know a good strategy for checking if a point is in the rectangle?
> 
> >
> 
> > The main difficulty is the transform.
> 
> 
> 
>      I'll assume that x/y/width/height represent an untransformed
> 
> rectangle, and that you want to test whether the point is inside
> 
> the quadrilateral formed by transforming the rectangle with aft.
> 
> If that's the question, I see two approaches:
> 
> 
> 
>      - Transform the rectangle and represent the result as a
> 
>        Polygon, then use Polygon's contains() method.
> 
> 
> 
>      - Inverse-transform the point and test whether the transformed
> 
>        point is inside the original rectangle.
> 
> 
> 
>      If that's not the question, please explain more fully.
> 
> 
> 
> -- 
> 
> Eric Sosman
> 
> esosman@comcast-dot-net.invalid

Excellent ideas.  I went with inverse transform, and it works.

Thanks.

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Thread

rectangle contains point bob smith <bob@coolfone.comze.com> - 2012-10-05 12:00 -0700
  Re: rectangle contains point markspace <-@.> - 2012-10-05 12:20 -0700
  Re: rectangle contains point Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-05 15:23 -0400
    Re: rectangle contains point bob smith <bob@coolfone.comze.com> - 2012-10-05 14:16 -0700
  Re: rectangle contains point Jeff Higgins <jeff@invalid.invalid> - 2012-10-05 15:43 -0400

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