Geometry Boost List: Re: [geometry] Reading shapefiles...

Subject: Re: [geometry] Reading shapefiles...
From: Barend Gehrels (barend_at_[hidden])
Date: 2013-03-20 12:59:01

I forgot one thing (see below):

On 20-3-2013 17:50, Barend Gehrels wrote:
> Hi Tommy,
>
>
> On 20-3-2013 11:44, tommys wrote:
>> I'm new to Boost.Geometry
>
> Welcome to the list!
>
>>   and the first thing I had on my mind was to read
>> data from my shapefiles. I'm aware that GIS is not part of Boost 1.53 
>> but is
>> available as an extension, and I've found shape_reader and 
>> shp_read_object,
>> which I thought would do the job. However, I get compilation errors and
>> after having glanced through the code it looks like it simply cannot 
>> work -
>> or am I missing something? Some parts of the code seems to do quite a 
>> lot,
>> like read_polygon::apply, while other, like read_shapefile is lacking 
>> and
>> have comments like: create shape_reader instead of doing it.
>
> Yes, that might be, this is simply not finished and because there are 
> not yet unit tests for them, I believe you if it is not compiling 
> anymore. I will have a look, to get them compilable/runnable should be 
> easy for me (finishing is another thing).
>
>>   Are there any
>> plans to wrap this up?
>
> We're currently focussing on other parts (spatial index, fixing errors 
> / adding unsupported combinations, buffer, internal tag design) ... 
> Actually you are the first to ask questions about this, which is nice 
> because basically the system to read/write shapefiles (with help of 
> shapelib) like this felt very good to me.
>
>
>> Btw, any ideas when GIS will be an official part of
>> Boost.Geometry?
>
> That will be done gradually, projections is also a large thing which 
> needs some design decisions about the model of the earth. I cannot 
> give any concrete date.
>

The example x05_shapelib_example is not using the objects, but shapelib 
directly. This example can be compiled and run. For real usage, with 
complex polygons (having holes etc), the difficulty is to build a proper 
multi-polygon from the (possibly unrelated) set of rings in a shapefile...

Regards, Barend