[mkgmap-dev] Strange behavior of contour lines for different resolutions

Sat Mar 18 06:36:12 GMT 2023

Hi all,

I want to generate an overlay map with contour lines. The following 
style works as expected:

contour=elevation & contour_ext=elevation_minor  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x20 resolution 24]
contour=elevation & contour_ext=elevation_medium & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x21 resolution 20]
contour=elevation & contour_ext=elevation_major  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x22 resolution 17]

Major lines are visible up from resolution 17, medium from resolution 20
and minor on highest resolution (24).

If I change the style to:

contour=elevation & contour_ext=elevation_minor  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x20 resolution 24]
contour=elevation & contour_ext=elevation_medium & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x21 resolution 21]
contour=elevation & contour_ext=elevation_major  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x22 resolution 17]

Major lines are visible up from resolution 17, but together with medium 
lines, minor lines are visible starting from resolution 21, too.
Same effect for choosing resolution 22 or 23 for medium lines. Medium 
and minor lines are visible always together for medium-resolutions >= 21.

As the effect is the same on QMapShack and GPSMap 66s, I assume the 
problem is in the map.

Any ideas what can cause the problem? What I finally want to build is:

contour=elevation & contour_ext=elevation_major  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x20 resolution 18-21 continue]

contour=elevation & contour_ext=elevation_minor  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x20 resolution 24]
contour=elevation & contour_ext=elevation_medium & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x21 resolution 23]
contour=elevation & contour_ext=elevation_major  & (ele > 0 | ele < 0) { 
name '${ele|conv:m=>ft}'; }           [0x22 resolution 22]

I've reduced this to the styles above to isolate the problem.

mkgmap r4907 here. Tried r4900 as well.

java -jar 
fzk-mde-garmin/Freizeitkarte-Entwicklung/tools/mkgmap/mkgmap.jar 
--copyright-message="Sonny DEM" --series-name="DEM Europe 10m" 
--description="DEM for Europe v17 10m 250m/50m" --family-name="DEM 
Europe" --country-name=Europe --country-abbr=EU --area-name=EU 
--product-version="202303" --reduce-point-density=0.2 
--reduce-point-density-polygon=0.2 --min-size-polygon=1 
--name-tag-list=name,place_name,loc_name --order-by-decreasing-area 
--style-file=contourmap/style/ --latin1 --transparent --no-poi-address 
--gmapsupp -c contourmap/mkgmap.europe.cfg -c 
/workbench/main/osm/splitter/contours_v17_10m_250_50/template.args 
contourmap/typ/contours.txt

-- 
Best regards / Mit freundlichen Grüßen
Daniel Vogelbacher

-- 
Best regards / Mit freundlichen Grüßen
Daniel Vogelbacher