Moduleapecs-0.9.6Haskell2010

Apecs.Experimental.Util

This module is experimental, and its API might change between point releases. Use at your own risk. -

5 values

Packageapecs-0.9.6
Exports5
LanguageHaskell2010
LicenceBSD-3-Clause
SourceUtil.hs

Spatial hashing

5 declarations

The following are helper functions for spatial hashing. Your spatial hash is defined by two vectors;

The cell size vector contains real components and dictates how large each cell in your table is in world space units. It is used by quantize to translate a world space coordinate into a table space index vector
The table size vector contains integral components and dictates how many cells your field consists of in each direction. It is used by flatten to translate a table-space index vector into a flat integer

valuequantize

:: (Fractional (v a), Integral b, RealFrac a, Functor v)
=> v a
Quantization cell size
-> v a
Vector to be quantized
-> v b

Quantize turns a world-space coordinate into a table-space coordinate by dividing by the given cell size and rounding towards negative infinity.

valueflatten :: (Applicative v, Integral a, Foldable v) => v a -> v a -> Maybe a

Turns a table-space vector into an integral index, given some table size vector. Yields Nothing for out-of-bounds queries

valueinbounds :: (Num a, Ord a, Applicative v, Foldable v) => v a -> v a -> Bool

Tests whether a vector is in the region given by 0 and the size vector (inclusive)

valueregion

:: (Enum a, Applicative v, Traversable v)
=> v a
Lower bound for the region
-> v a
Higher bound for the region
-> [v a]

For two table-space vectors indicating a region's bounds, gives a list of the vectors contained between them. This is useful for querying a spatial hash.

valueflatten' :: (Applicative v, Integral a, Foldable v) => v a -> v a -> a

flatten, but yields garbage for out-of-bounds vectors.