Extension points

phil/print-compositor

The library is plain PHP: it declares no service and no port. What an application chooses goes through arguments.

Point	How
The images	Any `Raster`: decoded from files or bytes the application stores where it wants, or copied from a GD image it drew itself with `Raster::fromGdImage()`
The fonts	Any TrueType or OpenType file, read with `TypeFace::fromFile()`; the application checks the licence `phil/fonts` reads
The inks	Any name on a `Layer`: one file comes out per name
The resolution	The `dpi` of a `PrintJob`, and of `TextFitter::fit()` when a text is checked ahead
The shading	The strength of a `Mockup`, from 0 to 1
Encoding	`Raster::png()` and `Raster::webp()`, or `toGdImage()` for an encoder of the application's own
Where the files go	`PrintFiles::png()` and `Raster::webp()` return bytes: the application writes them to its storage, attaches them to an order or sends them to a printer

Item is implemented by ImageItem and TextItem only: PrintCompositor refuses an item of another class with InvalidLayout. Something else drawn in a print file is drawn by the application on a GD image, then placed as an ImageItem.