-quat 16 4x 32bit float
-entity state 64 vec3i, vec3, vec3, quat, vec3
+vec3b 3 3x 8bit signed int
+packn 2 16bit signed int representing a float value normalized to [-1,1]
+ it can be unpacked by dividing by 32767
+packu 2 16bit unsigned int representing a float value normalized to [0,1]
+ it can be unpacked by dividing by 65535
+vec3n 6 3x packn
+vec3u 6 3x packu
+quat 8 2bit index of largest component, a 2bit padding, then 3x 20bit small components in xyzw
+ order mapped from [-0.7072,0.7072] to [0,1048574] (with largest omitted)
+entity state 42 [ 0] vec3i chunk pos (there's a variation where this is a vec3b)
+ [12] vec3u block pos by 16,
+ [18] vec3 velocity,
+ [30] quat orientation,
+ [38] packn pitch by PI/2
+ [40] packn yaw by PI