Re: Emacs canvas support

[Eli Zaretskii]

> Date: Wed, 29 Apr 2020 20:27:53 +0300
> From: Eli Zaretskii <address@hidden>
> Cc: address@hidden
> 
> That's not how Emacs controls what's on display.  It basically
> represents each window as a 2D array of glyphs, each one of which has
> a certain graphical representation.  The representation itself is of
> no concern to the display engine (well, almost); the only thing it
> cares about is the metrics of each glyph, because that's what it needs
> to do layout calculations.

Oh, and one more important aspect: everything that winds up on display
must come from some buffer or some Lisp string.  It could be a special
text property or somesuch, but it must be found by walking some buffer
or some known-in-advance Lisp string, because that's what top-level
display functions do: they iterate over these objects, and produce the
glyphs based on what they find there.