[mkgmap-dev] BuildDEMFile

Wed Nov 15 14:44:15 GMT 2017

Hi Frank,

thanks for great program! I have added DEM to my map and it works well.

I have noticed 2 glitches:

When using option --mt program sometime stops working. No crash, no use 
of CPU, it looks stalled. No problem without --mt.

Sometimes program crashes, when DEM raster is too small. Note 
"Kachelanzahl 0 x 1"

BuildDEMFile, Version vom 9.11.2017b, Copyright c FSofT 2017
...
5 Zoomlevel
Kachelanzahl 17 x 19 (rechte Spalte 113 breit, untere Zeile 49 hoch)
Rand links 22,9999208450317°, oben 53,0000638961792°, 0,946884155273438° 
breit, 1,00009918212891° hoch
Pixelgröße 0,000833333333333333° x 0,000833333333333333°
Kachelanzahl 8 x 10 (rechte Spalte 121 breit, untere Zeile 25 hoch)
Rand links 22,9999208450317°, oben 53,0000638961792°, 0,946884155273438° 
breit, 1,00009918212891° hoch
Pixelgröße 0,0016666666666667° x 0,0016666666666667°
Kachelanzahl 4 x 5 (rechte Spalte 93 breit, untere Zeile 45 hoch)
Rand links 22,9999208450317°, oben 53,0000638961792°, 0,946884155273438° 
breit, 1,00009918212891° hoch
Pixelgröße 0,0033333333333333° x 0,0033333333333333°
Kachelanzahl 2 x 3 (rechte Spalte 79 breit, untere Zeile 23 hoch)
Rand links 22,9999208450317°, oben 53,0000638961792°, 0,946884155273438° 
breit, 1,00009918212891° hoch
Pixelgröße 0,0066666666666667° x 0,0066666666666667°
Kachelanzahl 0 x 1 (rechte Spalte Indeks wykraczał poza granice tablicy.

Reported error means: array index out of range.

I have a suggestion. We use HGT files, where size of DEM pixel is 1/1200 
or 1/3600 degree. Writing it as a decimal is tedious. Could you accept 
other form of defining pixel size, something like:
--xlon=3600;2;4;8;32

where 3600 is number of pixels for 1 degree and 2,4,8,32 are dividers 
for that value for successive layers. It would be much cleaner and 
accurate than my current option, which is:
--dlon=2.777777777777778e-4;5.555555555555556e-4;0.0011111111111111;0.0022222222222222;0.0088888888888889

-- 
Best regards,
Andrzej