[OpenJDK 2D-Dev] ArcIterator#btan(double)

[Ralph Hummeling]

Dear Krishna,

I'd love to. How do I best do that?


Kind regards,

Ralph Hummeling
+316 5758 1679
Hummeling Engineering BV
www.hummeling.com

On 13/08/18 08:39, Krishna Addepalli wrote:
> Dear Ralph,
> 
> Thanks for pointing this out, could you also come up with a patch for the same?
> 
> Thanks,
> Krishna
> 
> -----Original Message-----
> From: Ralph Hummeling <engineering at hummeling.com>
> Sent: Friday, July 20, 2018 8:25 PM
> To: 2d-dev at openjdk.java.net
> Cc: james.graham at oracle.com
> Subject: [OpenJDK 2D-Dev] ArcIterator#btan(double)
> 
> Dear Java 2D dev team,
> 
> I came across your java.awt.geom.ArcIterator class in which an arc Bezier control point segment length is determined in method btan(double). You arrive at the following equation:
> 4/3*(1 - cos(a/2))/(sin(a/2))
> 
> It is mentioned that this can return NaN for small "a" and so it is written as:
> 4/3*(sin(a/2))/(1 + cos(a/2))
> 
> Please note that this relation can also be written as follows:
> 4/3*tan(a/4)
> 
> A performance increase and no NaN issues ;-)
> 
> 
> Kind regards,
> 
> Ralph Hummeling
> +316 5758 1679
> Hummeling Engineering BV
> www.hummeling.com
>