gEDA-dev: PCB HID

[DJ Delorie]

> I was looking at the PCB hid code. Is the purpose of the graphics
> context to support different ways of say drawing a line.

The purpose is to hide hid-specific representations of, for example,
line width or pixel color.  The hid structure itself has the callbacks
for *how* to draw, the GC is more concerned with *what* to draw.  It's
very similar to the purpose of the GC used by X or Gtk.

> One way for a window on the screen, a second for say postscrip output a
> third for a png file?

Right.  That's why, for example, in draw.c near the bottom, we have to
save the gui's GC's and build export-specific GCs.