
Geometry : 
Subject: [ggl] Hello + some newbie questions
From: Mateusz Loskot (mateusz)
Date: 20090505 18:14:00
Mateusz Loskot wrote:
> Barend Gehrels wrote:
>>
>> The constants HALFPI etc should be replaced by / forwarded to
>> boost::math::constants::pi<T> / 2.0 etc (this should also be done
>> for our own ggl::math)
>
> Do you propose to keep constants like
>
> static double const pi = ...
>
> but to change their values to boost::math:: stuff?
>
> Or remove out own constants and use boost::math::* directly in all
> ggl:: code?
I have applied (r685, r686) use of boost::math::constants for PI and for
HALF.
Also, I constqualified intermediate results in functions, to be sure
compilers will always optimize these values.
I think the ggl::math::hav function could be template for easy
interchangeable use with float and double types:
template <typename T>
inline T hav(T const& theta)
{
using boost::math::constants::half;
T const sn = std::sin(half<T>() * theta);
return sn * sn;
}
Same ggl::math::sqrt.
What you think?
Best regards,
 Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org
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