ediff-display-pixel-width

ediff-display-pixel-width is an alias for `display-pixel-width' in `ediff-init.el'.

(ediff-display-pixel-width &optional DISPLAY)

Return the width of DISPLAY's screen in pixels.
DISPLAY can be a display name or a frame.
If DISPLAY is omitted or nil, it defaults to the selected frame's display.

For character terminals, each character counts as a single pixel.

For graphical terminals, note that on "multi-monitor" setups this
refers to the pixel width for all physical monitors associated
with DISPLAY. To get information for each physical monitor, use
`display-monitor-attributes-list'.