Geometry Boost List: [ggl] Polygon DP simplification

Subject: [ggl] Polygon DP simplification
From: V D (zedxz2)
Date: 2011-10-05 14:18:24

Interesting, I will look into that.

Thanks Mateusz,

-v

On Oct 5, 2011, at 3:23 AM, Mateusz Loskot wrote:

> On 05/10/11 00:35, V D wrote:
>> Hi,
>> 
>> Anyone had any luck specifying a distance strategy to DP ?
> 
> I have tried, quickly and with no luck.
> 
> Apparently, something weird is going on around the distance:pythagoras definitions. The following example works as expected:
> 
> /////////////////////////////////////////////////////////
> namespace bg = boost::geometry;
> 
> typedef bg::strategy::distance::projected_point
>   <point_xy, point_xy> distance_strategy_type;
> typedef bg::strategy::simplify::douglas_peucker
>   <point_xy, distance_strategy_type> simplify_strategy_type;
> 
> BOOST_CONCEPT_ASSERT((bg::concept::SimplifyStrategy<simplify_strategy_type>));
> 
> bg::simplify(original_1, simplified_1, 1.0 / 2048.0, simplify_strategy_type());
> /////////////////////////////////////////////////////////
> 
> However, replacing
> typedef bg::strategy::distance::projected_point
> with
> typedef bg::strategy::distance::pythagoras
> causes compilation errors.
> 
> Both, projected_point and pythagoras are supposed to be equally valid citizens here, but the latter seems to be misdefined as it does not fulfil the concept definition.
> 
> Perhaps there is a reason for that, but I lack of background information here. So, I'd suggest to wait for Barend.
> 
> Best regards,
> -- 
> Mateusz Loskot, http://mateusz.loskot.net
> Charter Member of OSGeo, http://osgeo.org
> Member of ACCU, http://accu.org