REFERENCE / 06

Params and Controls

Declare editable inputs inside params. The key is the name used by geometry expressions; :label is the text shown in the control. A saved project can override a source default with its current parameter value.

`params`

(params
  decl
  decl
  :relations ((<= wall shell) (>= shell 1.6)))

container for parameter declarations
optional :relations list attaches cross-parameter constraints

Supported relation operators:

<
<=
>
>=

`number`

(number wall 2.4
  :label "Wall"
  :min 0.8
  :max 8
  :step 0.1
  :unit length
  :frozen #f)

positional 1: parameter key symbol
positional 2: default number
keywords:
:label text
:min number
:max number
:step number
:unit one of length | angle | ratio | count | text
:frozen boolean

Units and suffixed literals

Bare lengths are millimetres; bare rotation angles are degrees. Suffixes make conversions explicit:

Literal	Base-unit value
`12mm`	12 mm
`2.54cm`	25.4 mm
`0.25in`	6.35 mm
`45deg`	45 degrees
`1.5708rad`	Approximately 90 degrees

Use bare numbers for counts, ratios, and segment counts. Suffix conversion does not by itself provide dimensional type checking.

`toggle`

(toggle useFillet #t
  :label "Use fillet"
  :frozen #f)

positional 1: parameter key symbol
positional 2: default boolean
keywords:
:label
:frozen

`select`

(select material "PLA"
  :label "Material"
  :unit text
  :options
    ((option "PLA" "PLA")
     (option "PETG" "PETG")
     (option "ABS" "ABS"))
  :frozen #f)

positional 1: parameter key symbol
positional 2: default choice value
required keyword for practical use: :options
optional keywords:
:label
:unit
:frozen

`image`

(image decal "assets/logo.svg"
  :label "Decal"
  :frozen #f)

positional 1: parameter key symbol
positional 2: default image path text
optional keywords:
:label
:frozen

`option`

(option "Large" 42)
(option "PLA" "PLA")

positional 1: display label
positional 2: value
valid value kinds:
number
string / text symbol