To Do

(?) convert PCBYTES to use PCDIMENSION* instead of holding all values as dupes
(??) convert PCBYTES handling to pass-by-reference instead of pass-by-value
implement PC_PatchAvg/PC_PatchMin/PC_PatchMax as C functions against patches with dimensional and uncompressed implementations
TESTS for pc_patch_dimensional_from_uncompressed() and pc_patch_dimensional_compress()
Add in dimensional stats caching to speed up dimensional compression in batch cases
Add Min/Max values to dimensional compression serialization (???)
Add Min/Max values to GHT compression serialization (???)
Update pc_patch_from_patchlist() to merge GHT patches without decompression
Update pc_patch_from_patchlist() to merge dimensional patches directly
Before doing dimensional compression, sort by geohash (actually by a localized geohash based on the patch bounds). This will enhance the autocorrelation of values and improve run-length encoding in particular
Add Min/Max values to front of GHT serialization
Improve extent reading to only pull a slice of patch out of the datum

Use Cases to Support

frustrum filtering
raster overlaying
filtering on attribute values
filtering on spatial polygons (in and out)
find the k nearest points to point P
gridding/binning ("avg intensity per cell", "max z per cell", "agv red per cell", "rgb into grid/picture")
reprojection / re-schema