A base version of mark_draw, designed for performance optimization. This
function is used to build other mark_* functions that manage the drawing of
links between marked observations.
.mark_draw(.draw, ...)A function used to draw the links. The function must return a
grob() object. If the function does not return a valid
grob, nothing will be drawn. The input data for the function contains a
list, where each item is a list of two data frames: one for the panel side
coordinates ("panel") and one for the marked observations coordinates
("link").
<dyn-dots> A list of formulas, where each side
of the formula should be an integer or character index of the original
data, or a range_link() object defining the linked observations. Use
NULL to indicate no link on that side. You can also combine these by
wrapping them into a single list(). If only the left-hand side of the
formula exists, you can input it directly. For integer indices, wrap them
with I() to use the ordering from the layout. You can also use
waiver() to inherit values from the other group.
mark_draw()