VNC NG-precomputed shard file debugging

README.txt

VNC Pre-computed sharded volume worksheet

Scale 0:
Preshift bits = 9
Minishard bits = 6    2^15 chunks if no collisions = 32 KiChunks @ 64^3 chunks (262 KiVoxels) = 8.46 GiVoxels
Shard bits = 16

Block (335, 438, 1024) -> corresponds to 64^3 with first voxel at (21440, 28032, 66536)
X block 335 = 14F
Y block 438 = 1B6
Z block 1024 = 400

Scale 0, dim 0 with size 42943 requires 10 bits.
Scale 0, dim 1 with size 56068 requires 10 bits.
Scale 0, dim 2 with size 82276 requires 11 bits.

Minishard mask: 000000000000003f
                                            0011 1111
Shard mask: 00000000003fffc0
         0000 0000 0000 0011 1111 1111 1111 1100 0000

                          |--- shard bits ---|| mini|| preshift|
     16 bits        12 bits        8 bits         4 bits         
------------------------ -zzy xzyx zyxz yxzy xzyx zyxz yxzy xzyx 
 Compressed Morton:      0100 0011 0100 0101 0010 0010 1101 1001
               Hex:      4    3    4    5    2    2    d    9 

Compressed Morton hex = 434522d9
Shard file = binary 1000 0110 1000 1010 = hex 868a
Minishard = binary 0001 0001 = hex 11
  on lookup to existing shard file, that minishard has 512 entries
  compressed morton block range [3452200,34523ff]

Note that since shard bits determine shard file and are not the MSB, the chunks may not be
contiguous in morton space due to collisions from the 18 most-significant bits.