Geometry Boost List: [ggl] Hello + some newbie questions

Subject: [ggl] Hello + some newbie questions
From: Barend (barend)
Date: 2009-05-05 20:10:38

Hi,

>>>> It is an automatic conversion of proj4 code. [...]
>>>>         
>>> Do you mean automatic that the code of PROJ.4 is automatically
>>> processed by some script/program and C++ template-based output
>>> is generated?
>>>       
>> Sure. I saw yesterdaynight that you editted one or two files and was
>> this morning starting a mail about this (didn't finish yet), pasted here:
>>
>> "One thing more about this. These types of warnings sometimes come from
>> the projection sources. They are converted automatically, so they origin
>> from the proj4 sources. This should actually not be corrected here but
>> either in the conversion program (not a beauty) or should be turned off
>> by pragma (in MS) or compiler flag (?)"
>>     
>
> Personally, I like the fixing option :-)
>   
OK, have to be done per case. But it makes sense.
>
>   
> Where would you propose to start changing it?
> I mean, which parts are not generated for sure?
> Or we can defer this after the projection generator program is updated.
>   
All in "proj" is generated. I'll change the program soon, it is not much 
work.
>
>
>   
>> The coordinate types are now always double but should be changed to
>> extracted-from-point-type, where it can be a big number.
>>
>> 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?
>   
Sure, as you've done in the other files.
>> The functions forward/inverse return true/false and I will come back to
>> these.
>>     
>
> OK
>   
Let's do it now shortly: should they raise an exception here? It is here 
different than in WKT. The point might be not in reach of the 
projection. That is not really "exceptional", it just can happen. Should 
it then raise an exception? It is not really an error. However, 
propagating true/false is also not that nice.
So what will we do here... We've to think about this carefully.

Regards, Barend

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/ggl/attachments/20090505/05aa3fcb/attachment.html