Core Concepts

Before we dive into individual commands, it helps to understand how the studio reads an .fsl file. Think of the interpreter as a very patient cutter: it reads a line, applies the change, then moves to the next line without skipping ahead or rearranging anything.

How the studio reads your file

The file is a simple list of statements. Each line happens in the order you write it.
Blank lines and comments are ignored, so feel free to add notes with // whenever it helps future-you.

Here is a tiny program you can paste into the studio to see the order in action:

set name "Order Matters"

P 0 @ 45 : cp x 4
G 0 @ 90 : size
C 0 @ 28 : mp(G, P) +girdle  // Depends on G and P already existing
T 0 @ 0 : 0.2

The crown (C) tier uses a meet point created by the P and G, so the line with the crown tier must come after P and G.

What the studio remembers for you

While it reads the file, the studio tracks a handful of details in the background:

Stone metadata – set name, set ri, and friends.
Machine setup – set gear 96 cw sticks until you change it, so every later facet uses the same gear and rotation.
Variables – let statements store numbers or points that you can reuse later.
Last side and symmetry – if you cut a pavilion facet (down) and the next line starts with a tier name, the interpreter keeps using down unless you say otherwise. Same story for symmetry; once you type x8, the next cut command will also use that symmetry unless you change the modifier.

If anything goes wrong—maybe a meet point cannot be found—the interpreter stops right there and the diagnostics panel shows the line and message.

Crown versus pavilion

down facets belong to the pavilion and tilt toward negative Z.
up facets belong to the crown and tilt toward positive Z.
Tier labels are just names. P1, C1, Break, and Star all work.

Symmetry in plain language

Add xN after a facet command to copy it around the stone every 360 / N degrees. Use xxN when you want mirrored N-fold symmetry (each pair becomes a left/right mirror). The count must be a positive whole number:

P3 12 @ 38.2 : 0.16 x 8        // eight pavilion mains
G1 0 @ 90 : size x 16          // sixteen girdle facets (90°)

There is no need to specify the symmetry for the next tier if there is no change in symmetry.

If you are cutting something asymmetric, you can skip symmetry entirely by spelling out every index in braces: P1 {3, 27, 44} @ 90 : size hits those three teeth in order and stops. Because you already provided the full list, you do not add an x 4 (or any other symmetry modifier) on that line. The first number in that brace list still serves as the base index for helpers such as mp()/gp().

Numbers, points, and edges

Most expressions boil down to one of three value types:

Number – plain angles, depths, or calculations like deg2rad(32).
Point – created with helpers such as mp(P1), gp(G1), pt(0, 0, 1), or fred(...). These mark locations in space, whether pulled from existing facets or stated outright.
Edge – less common but handy for advanced macros, created with edge(tier:index, tier:index).

You can store numbers or points in variables. Edge helpers always produce two points, so capture them with a destructuring assignment instead of storing the edge itself:

let pt1 = mp(P1)
let safety = 0.05
let first, second = edge(P1:0, P1:12)
C2 up 0 @ 29.5 : pt1 + girdle x16

Variables live until the end of the file (or until a macro finishes, if you are inside one).

With these basics in mind, continue to Statements to see every command you can type.