INTRODUCTION [1.1]

this is a library for using hexagonal grids in amulet/lua. it is extremely incomplete. the following list of features is either implemented shoddily, or not at all.

if you want an actual good resource, go to [1.9].

GETTING STARTED [1.2]

• TODO

COORDINATE SYSTEMS [1.3]

as much coordinate manipulation as possible is done internally. depending on the task, uses either Axial, Cube, or Doubled coordinates.

three different ways of returning and sending coordinates:

• amulet vectors
• lua tables
• individual coordinate numbers

so you can use what your graphics library likes best!

MAPS & MAP STORAGE [1.4]

Some map shapes: parallelogram, rectangular, hexagonal, triangular. (and more)

The storage system used is based on the map shape - see chart:

SHAPE	MAP STORAGE
parallelogram	unordered, hash-like OR ordered, array-like
rectangular	unordered, hash-like OR ordered, array-like
hexagonal	unordered, hash-like OR ordered, array-like
triangular	unordered, hash-like OR ordered, array-like
ring	ordered, array-like
spiral	ordered, array-like**
arbitrary	unordered, hash-like

** note that a spiral map is just a hexagonal one with a particular order.

CONVENTIONS AND TERMINOLOGY [1.8]

If you have read amit's guide to hexagon grids, (see [1.9]), a lot of the terminology will be familiar to you - I utilize many conventions he does in his guide. That being said...

Because so many different kinds of coordinate groupings are used in this library, and they are all fundamentally tables/vectors/arrays of integers, it can be hard to remember what they are all referring to.

The following table shows what each table/vector/array refers to in the code:

NAME	REFERS TO
cube	xyz, used for most maps, with constraint x+y+z=0. **
pix	xy, true screen pixel coordinates
dbl	xy, 'doubled', used for rectangular maps
off	xy, 'offset', used for UI implementations
----	----------------------------------------------------------
map	xy, table of unit hexagon centerpoints arranged in a shape

** note that 'axial' coordinates are a subset of cube coordinates, where
you simply omit the z value. for many algorithms this is done, but instead
of using some reference name 'axial', I just used the name 'cube' for both 
cases. I found this to be clearer and less prone to end-user error. when
an algorithm asks for a cube, give it a cube. if you want to know if it works
with axial as well, look at the code and see if it uses a 'z' value.

Other terminology:

• TODO

RESOURCES USED TO DEVELOP THIS LIBRARY, AND FOR WHICH I AM GRATEFUL [1.9]

• Hex Map 1 - unity tutorial for hexagon grids with some useful generalized math.

• 3Blue1Brown - Essence of Linear Algebra - amazing series on linear algebra by 3Blue1Brown

• Hexagonal Grids - THE resource on hexagonal grids on the internet.

• Amulet Docs - amulet documentation.