Shortcuts: Making Maths Tidier | Aliases

Making Maths Tidier

We don’t get a lot of horizontal screen space to play with in TIC-80, so we can use a trick to make our code more readable.

Alias the frequently used math functions

(I’ll be doing this a bit in the code snippets in this series, so this suggestion should make them look more familiar)

Aliases

I have a small selection of aliases at the top of the file:

local M=math
local S,C,ATAN,PI,R=m.sin,m.cos,m.atan2,m.pi,M.random
local ABS,MIN,MAX=m.abs,m.min,m.max
local TAU=2*PI
local T=0
-- (The above are a my most used math functions but yours may be different)
...

If you didn’t know, Lua’s math functions are in an automatically included library, so typically you’d be calling math.sin, math.abs etc. around in your code. Lua treats functions as first-class values - which means you can assign them to variables. So here, we’re assigning math to M and then also picking off select functions to further alias, such as S as math.sin.

We can also keep a couple of useful ‘constants’. I have a sneaky TAU in there because that’s very useful when sining and cosing. T is my go-to for the global time variable.

You’d be very justified in having yours as a snippet you copy in before things start - because occasionally I’ve added things to it during the ByteJam, but messed up the aliasing order such that math.sin is aliased as ABS or whatever. That’s really hard to track down 😂

I’m very terse with S and C because I use sin and cos a heck of a lot. ABS and ATAN are in full rather than either as A because I don’t want to mix them up.

You’ll notice they’re all uppercase and prefixed with keyword local. The former is a personal style choice (as explained previously); the local thing isn’t so necessary here, but it does make them run a tiny bit faster, so I’ve gotten used to doing that in demos where they might be being called lots of times within loops, and I’ve carried that habit over.