[mkgmap-dev] polygon splitting/more than 255 polygons errors

Sat Sep 3 11:02:52 BST 2011

Hi,

On Fri, Sep 2, 2011 at 9:26 PM, Richard <rz at linux-m68k.org> wrote:
> Hi,
>
>> > I have recently downloaded some mkgmap generated maps that produce this error when displayed
>> > in navit:
>> > :garmin_obj.c:1279:1|:Error more than 255 polygons/lines in a subdiv are not supported
>>
>> This does not look like an mkgmap problem to me. Reading the error
>> message I assume that navit does not support subdivisions containing
>> more than 255 polygons + lines. But as far as I know there is no such a
>> limit for garmin devices.
>
> looks like the message comes from libgarmin. If you think its an error in libgarmin
> I will have a look at that.

The message is indeed from libgarmin, but if someone proves that
polygons can be more than 255
fixing wouldn't be so trivial.

255 limit comes from garmin object addressing - in mdr(index file) you have
subdiv(2 bytes):object(1 byte). there are references to this in the
various sections
in img file itself, lbl sections.

If someone have noticed for example that polylines and polygons can be
indexed too mdr sections before first poi section describing variuous
types available for search seen in an  old metroguide map that can
fake Lake Someranodmbiglake name.

-- 
have fun,
alex
P.S. Richard if you have fixes or need help with libgarmin, contact me.