[mkgmap-dev] Is height: filter working as described?

Thu Feb 2 15:03:51 GMT 2017

El 02/02/17 a las 14:06, Andrzej Popowski escribió:
> Hi Carols,
>
> some guessing on my part, hope someone corrects if I'm wrong.
>
> As I understand, elevations in img are stored in feet.
>
> Filters hight:m=>ft and conv:m=>ft indicate, that value from source 
> has to be converted into feet, as expected by img format.
>
> When you look at map, you see height units according to settings in 
> GPS. You can set meters or feet. So for hight:m=>ft, these values are 
> correct:
> ele=500, map: ", 500 m" = 1650ft, default conversion
> ele=500m, map: ", 500 m" = 1650ft, converted form meters
> ele=500ft, map: ", 152 m" = 499ft, preserved feet
>
> Settings in GPS are valid only for some objects types and label 
> content. Conversion in GPS is done, when label starts with numeric or 
> numeric is prefixed by special separator (it is [0x1f] for 
> cgpsmapper). I guess filter "hight:" adds separator and GPS converts 
> it to ", ".
>
> Now filter hight:ft=>m seems to be kind of useless. It converts feet 
> to meters, stores this value in img and adds a prefix, indicating that 
> value is in feet. What we need here, is no conversion but separator 
> only. Maybe something like this could work: {ele|height:ft=>ft}.
>
> Actually it always should be feet as a destination for height, we 
> could simplify this filter like this: {ele|height:m} or 
> {ele|height:ft}, indicating only default unit in source data.
>

It also looks reasonable to me.