pixmap<-convert

pixmap <-convert: name|image|graphical|file -> pixmap

Converts the below types to a full-colour image object.

name: Do general transformation of @some-name, verifying that the result is a pixmap.
image: Converts an monochrome image into a coloured pixmap. Basically simply calls new(Pm, pixmap(image)), first trying pixmap<-lookup to reuse an older transformation and then pixmap->initialise to create a new pixmap object.
graphical: Create a pixmap object of the required size and then use image->draw_in to paint the graphical in the pixmap.
file: Create a pixmap object and load the file-data into it.