Hi, the current filter chain for shapes is a bit confusing for me: - We start with PreserveHorizontalAndVerticalLinesFilter which uses the original coords (in map units) to preserve endpoints of vertical and horizontal lines. - Next we use the RoundCoordsFilter which rounds the coords according to the desired resolution For low resolutions, many small shapes are rounded to a single point. Only when the remaining line has at least two points we continue either with the SizeFilter or with the DouglasPeuckerFilter (if they are not disabled) Only the DouglasPeuckerFilter cares about the preserved flag, so I think the PreserveHorizontalAndVerticalLinesFilter should be moved directly before it so that it checks only the rounded coords. I also wonder why we use the PreserveHorizontalAndVerticalLinesFilter for lines that are not shapes. The filter was added with a comment regarding polygons only. Ciao, Gerd -- View this message in context: http://gis.19327.n5.nabble.com/filters-for-shapes-tp5748328.html Sent from the Mkgmap Development mailing list archive at Nabble.com.