[OpenLayers-Dev] Patrch for getting vector drawing working over the 180 line going.

[Tim Schaub]

On 8/18/10 3:25 PM, Phil Scadden wrote:
>
>> Please don't try to bake in any assumptions about heading in a line
>> segment.  Our geometry model is based on coordinates on a plane.  My
>> opinion is that "crossing the dateline" is application logic.
>>

My comment here was meant to say that I would not be in favor of any 
change that made it so the distance between (-170, 0) and (170, 0) was 
20 (by default).

> So when I try to draw say a zoom rectangle across the date line, or
> measure a distance between two points which happen to be on opposite
> sides of the dateline, how do I put that logic in my application to cope
> with this without altering OL? Or draw a selection polygon to choose
> some data in a WFS layer? This is where problems occurs. The reason for
> looking at the renderer approach is that there remain problems with just
> doing it in the handlers. Obviously its pointless for me to continue
> work on renderer model if it wont be accepted into OL, so I'll the study
> the remaining issues with the handlers in Andreas's patch today. But I
> dont believe there is a solution to the problem without altering OL.
>
>> Geometries should be split when the user tries to draw beyond the domain
>> of the coordinate system.
>>
> Well to be honest I am sick to death of geometry models based on a plane
> when we live on a spherical earth, and its especially a pain when you
> live close to the 180 lines and  nightmare if you are working near the
> pole. I would really like to see OL get onto a sphere. There is dearth
> of tools for working on a sphere. Our inhouse software always manages it
> because its taken into account from day 1 but reengineering flat earth
> software to work with real world geometry is a mega pain. Would you be
> so keen on applications having to split geometry if you lived on the 180
> line?

I understand the frustration.  If you can get involved in (or have 
suggestions for) OpenLayers 3.0 with regard to a different geometry 
model (or changes at some other level), that would be great.

Tim

-- 
Tim Schaub
OpenGeo - http://opengeo.org
Expert service straight from the developers.