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