Legends

dmote-keycap uses OpenSCAD’s import function, not the text function, to put markings on caps. This enables a wide variety of markings: Anything that can be expressed in SVG, DXF and other 2D image formats OpenSCAD can import.

To select a legend, when calling into the library, supply a map like this as part of the options to keycap:

{:legend {:faces {:top {:char "F1"}}}}

The corresponding CLI parameter is --legend-top-char F1.

In this example, :char supplies a text sequence for the F1 key, not a file path. You can use any text you like but formatting for such sequences is rudimentary in the current version of dmote-keycap and is likely to change in future versions.

You will get more power by replacing the :char keyword with one of :importable, for a file OpenSCAD can read directly, or :unimportable, for an SVG file that must be simplified before OpenSCAD can read it.

dmote-keycap uses Inkscape programmatically to simplify SVG, so you will need that installed for both :char and :unimportable. If you are calling keycap from an application that does not use scad-app’s default output structure, you will also need to supply a function as a the top-level :importable-filepath-fn parameter. This function must take a string filename and return a path for placing the file where OpenSCAD will be able to import it.

Placement

The :top keyword in the example above targets the top face, where the user’s finger touches the key. Other faces can be addressed with :north, :east and so on.

When importing from SVG for the top face, dmote-keycap will match coordinates [0, 0] in the image to [0, 0] in OpenSCAD’s coordinate system, which is the middle of the face.

Targeting is a bit more complicated for the sides: After being extruded to three dimensions, each image used to mark a side of the key is tilted using the :slope parameter and moved so that SVG’s [0, 0] ends up at the height of the top of the stem.