GEOCELL->
geoThe GEOCELL->
function converts a LONG geocell to a STRING HHCode prefix. The resulting string length is half the resolution of the geocell.
This function cannot convert to BYTES because this representation is limited to resolutions multiple of 4.
A geocell is a LONG where the 4 MSBs store the resolution and the 60 LSBs store a trimmed HHCode. The value stored in the 4 MSBs must be multiplied by 2 to give the resolution of the trimmed HHCode, thus only even resolutions can be represented in a geocell. A resolution of 0 is considered invalid and the highest resolution is 30. The value stored in the 60 LSBs are the 60 MSBs of a HHCode but only the 2*resolution MSBs must be considered.
Here is an example of the bits representation of a geocell and their meaning:
1001101101010111001001011000100010101111000000000000000000000000
\__/\__________________________________/\______________________/
|| || ||
Res: 9*2=18 || ||
18*2 relevant bits of HHCode 60-18*2 unrelevant bits
A GEOSHAPE is simply a list of geocells, see ->GEOSHAPE to build a GEOSHAPE from geocells.