[mkgmap-dev] Drive-on-left

Tue Aug 6 15:21:52 BST 2013

On 05/08/13 19:30, Colin Smale wrote:
> I took a look at the code and saw that the drive-on-left and
> drive-on-right flags are only used to set a flag in NODHeader.java.
> However I just discovered ImgTool[1] which exposes the "TRE parameters",
> a sequence of four numbers which, I noticed, include a flag for
> "drive-on-left". This was not being set on my UK maps (despite using the
> drive-on-left option for mkgmap) so they all appeared to be
> drive-on-right. With ImgTool I was able to simply set this bit in my img
> file - and then the problems with the roundabout direction disappeared!

Very interesting.

I've created a patch based on your discovery which is attached.

It only works when there is an explicit --drive-on-left flag and not
when mkgmap infers it by looking at the direction of roundabouts.
How important do you think that is?  I think it is much safer to
give the flag than letting mkgmap guess which can be wrong for all
kinds of reasons.

Cheers,

..Steve
-------------- next part --------------
A non-text attachment was scrubbed...
Name: drive_on_left.patch
Type: text/x-patch
Size: 922 bytes
Desc: not available
Url : http://lists.mkgmap.org.uk/pipermail/mkgmap-dev/attachments/20130806/f295fe07/attachment.bin 