Talk:Wrp File Format - 4WVR
note to self via vektorbosen
When trying to view the elevations I realized, that the elevations aren't short values as A-Lone-Wolfs doc implies.
After watching some hex-values, I found some formulas, that should reflect the values right.
w_e: elevations as in 4WVR wrp file f_e: elevations with floating point value
When I create some elevations and want them to convert to Wrp-elevations I'm using the following formula:
w_e = (short) ((f_e / 0.05) * 1.1111)
Ok, when I want to convert them back I am using something like this:
f_e = floor( w_e / 22222.0f ) * 1000 +
floor( (w_e mod 22222.0f) / 2222.2f ) * 100 + floor( (w_e mod 2222.2f) / 222.22f ) * 10 + a.s.o.
--ook? 13:50, 13 July 2006 (CEST)
This value is an integral of the gridsize.
the gridsize is a fixed 50 metre CUBE. (This is applied equally to XY and Z)
Bis Floats are accurate to 4 decimal places
hence the actual value stored only needs the integer and those 4 digits
GridDimension= (short)floor( (Elevation/50)*1000);
ie the 4 important digits are elevated to the integer position of a float. a floor is applied to get ONLY the integer component, and, finally, this is converted (stored) as a genuine short (signed) integer.
The max height or depth of an elevaton is +/- 1.6km