Expressions

Anywhere a number goes, an expression can: w/2, -h+.1, sin(30)*r, max(a,b). Inside a position or size, each comma-separated number is its own expression, so commas in function calls are fine: at=max(a,b),0,on. An expression with spaces in it goes in quotes.

Arithmetic and logic


`+ - * / ** % //`	add, subtract, multiply, divide, power, remainder, whole division
`== != < <= > >=`	compare (true is 1, false is 0); chains like `0 < x < 1` work
`and or not`	combine
`a if c else b`	a when c holds, else b

Functions

Angles are degrees, in and out.


`sin(d)` `cos(d)` `tan(d)`	of an angle in degrees
`asin(v)` `acos(v)` `atan(v)` `atan2(y,x)`	an angle in degrees
`sqrt(v)` `abs(v)` `hypot(x,y)`	square root, size, distance
`min(a,b,...)` `max(a,b,...)`	least, greatest
`floor(v)` `ceil(v)` `round(v)`	to whole numbers
`rad(d)` `deg(r)`	degrees to radians and back
`pi` `tau`	3.14159..., 6.28318...

Drawn numbers


`rand()` `rand(hi)` `rand(lo,hi)`	a number drawn for this copy (0-1, 0-hi, lo-hi)
`pick(a,b,c)`	one of the list, for this copy (numbers, materials, words)
`odds(a,b,c)`	0, 1 or 2 for this copy, as often as the weights say (odds)
`noise(x[,y[,z]])`	smooth noise over space, 0-1, the same for the whole prop
`rough(x[,y[,z]])`	layered noise, 0-1

Draws come from the prop's seed=, the chain of use lines and copy numbers that led to this line, and where in the line the call is: the same file always draws the same.

Names


variables	set with `set`, a part's parameters, or a room's `fill=` (`w d h level door_s door_n door_w door_e`)
`i`	the copy's number on a line that makes copies (or the name given with `as`)
`here.x` `here.y` `here.z`	where this copy stands in the prop
`NAME.left` ... `NAME.h`	numbers off a named shape
`x`, `y`	in a `terrain`'s `height=`: the grid corner's place
`length`	in a part drawn with `from=`/`to=`, or a `join ... with=` bridge: how long it is
`depth`	nothing special: a parameter name the recursive examples use

Text

Label text takes {expression} (a number, written whole when it is whole), {variable} (a variable holding text) and pick(a,b,c) (one of the words).