apecs-0.9.1: Fast Entity-Component-System library for game programming

Safe HaskellSafe




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


Spatial hashing

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

quantize Source #


:: (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.

flatten :: (Applicative v, Integral a, Foldable v) => v a -> v a -> Maybe a Source #

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

inbounds :: (Num a, Ord a, Applicative v, Foldable v) => v a -> v a -> Bool Source #

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

region Source #


:: (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.

flatten' :: (Applicative v, Integral a, Foldable v) => v a -> v a -> a Source #

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