-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Library for generating grids of hexagons and pentagons mapped to a sphere.
--   
--   Defines functions for dealing with a type of hexagon grid wrapped
--   around a sphere. The full grid is composed of 20 smaller trianglular
--   grids of hexagons, that fit together as an icosahedron with pentagons
--   at the corners. Each grid cell is assigned an integer value, and we
--   can get a list of the neighbors of a particular cell. We can also ask
--   for a vector in 3d space that is the center of a particular cell. This
--   would be well suited for a game played on a spherical world or a
--   planetary environment simulator.
@package IcoGrid
@version 0.1

module Data.IcoGrid

-- | Get a list of all cells in a grid of a given size. The length of this
--   list is the number of cells, and they are numberd from 0 to n-1.
all_cells :: Int -> [Int]

-- | Get all groups of 3 cells that meet at a point in the whole grid (of a
--   given size). Each triad is repeated 3 times, with a different cell as
--   the first one in the list.
all_triads :: Int -> [(Int, Int, Int)]

-- | Get a list of neighbors of a particular cell, assuming a grid of a
--   certain size.
neighbors :: Int -> Int -> [Int]

-- | Get the center of a cell as a point in 3-space, assuming a grid of a
--   certain size. I have not yet implemented the reverse function, which
--   is to find the closest cell to a given point.
coord_to_vec :: Int -> Int -> Vec

-- | Return list of vectors with the center vertex as head, and then the
--   vertex between center and first neighbor, vertex in the middle, and a
--   vertex between the center and the second neighbor. Can be drawn with a
--   triangle fan. By drawing all the triads in this fashion, one can draw
--   the whole grid. I left a little bit of a gap between cells to make the
--   edges easier to see.
triad_vecs :: Int -> (Int, Int, Int) -> [Vec]
instance Eq IcoCoord
instance Ord IcoCoord
instance Show IcoCoord