Nomenclature

Unfortunately, we can’t name functions we define in Desmos with more than 1 letter like $\text{random}()$ or $\text{length}()$. It’s gotta be like $f(x)$ or $g(x)$. This is evidently not ideal, as we’ll run out of letters eventually, and we need to represent a lot of things when developing a program.

What we can do, however, is add a subscript to whichever letter we choose. $f\text{subscript}()$ is still very much a valid function for Desmos![^subscripts] Now, I’ve seen a lot of people name them like $t\text{his}()$, which I find absolutely repulsive. So instead, I settle on a set of conventions for what the function letter represents – its precise purpose can then be described by the subscript.

[^subscripts]: Unlike in the case of, say, quantum wave functions for electron orbitals, subscripts don’t represent parameters in Desmos, and are purely decorative. Hopefully this doesn’t change, or we’re screwed!

Variables

letter	instances	semantics	description	notes
$C$	$C_\text{blue}$	colour	Stores a hex colour.
$G$	$G_\text{live}$	global	A global variable, whether dynamic or static.
$T$	$T_\text{spawn}$	tick	A tick variable for timing events.
$W$	$W_\text{objects}$	world	A globally accessible store of game data, often objects.
$R$	$R_\text{box}$	render	The output of render.

Functions

letter	instances	semantics	description	notes
$a$		action
$c$	$c_\text{tick}()$	control / core	Core functions for running the game.
$d$	$d_\text{rect}()$	draw	Renders visible polygons.
$f$	$f_\text{xrange()}$		A pure function,[^pure] performs calculations instead of modifying state.	Intended for commonly used utility functions.
$n$	$n_\text{object}()$	new	Create a new object (internally).
$v$	$v_\text{tick}()$	move	Moves something forward in time – either literally or by processing its updates.	v for velocity in physics, literally changing position.
$w$	$w_\text{collision}()$	handle	Abstraction upon $v()$, usually for branching between different $v()$ depending on conditional.

[^pure]: In the functional programming sense!

Parameters

letter	instances	semantics	description	notes
$i$		index		$i \in \mathbb{Z}, i \geq 1$
$l$		list	A list of objects.	The type of the objects can be described in the subscript, like $l_p$ for a list of points.
$n$		number		$n \in \mathbb{Z}, n \geq 0$
$p$		point	An $(x, y)$ pair of values.	Must be a point, cannot be a list (will be accessed via $p\text{.}x$, so a list would break it).
$s$		parameter	A generic parameter.
$t$		time	Progression along a spectrum.	$0 \leq t \leq 1$