Re: [Mapbuilder-proj] [Developers] gml spec: point XY or YX

[Mike A. <ma...@dm...>]

cscs/proj4js uses .x and .y object properties for the coordinates.  It's 
up to the data parsers to figure out the correct order.

Mike

Cameron Shorter wrote:
> mapbuilder-proj,
>
> It is embarrassing for me to admit that I didn't know the order of 
> coordinates is not consistent.
>
> Does the CSCS library provide a function which tells you which order a 
> particular projection is in?
>
> Eric Lam wrote:
>   
>> Hello all,
>>
>> I just had an interesting chat with Chris Schmidt the OpenLayers main 
>> coordinator and Cameron.
>>
>> it appears the gml spec does not specify if a point is defined as xy 
>> or yx.
>> <gml:point>x-value y-value</gml:point> or
>> <gml:point>y-value x-value</gml:point>
>>
>> Most sources use the following:
>> - unprojected values we order as latitude longitude (which is y x)
>> but if we are talking about
>> - projected values we order as x y.
>> But there is no easy way to tell if the source is projected or 
>> unprojected.
>>
>> However, that is only what MOST sources do, some sources may give 
>> projected values as y x.
>> It all depends on the source ... quite ridiculous. Something that may 
>> need to be taken into account.
>>
>> Regards,
>> Eric Lam
>>
>>
>>     
>
>
>