UpdateScreen procedure
Update physical screen with internal screen image.
Declaration
procedure UpdateScreen(Force: Boolean)Description
UpdateScreen synchronizes the actual screen with the contents
of the
VideoBuf internal buffer. The parameter
Force
specifies whether the whole screen has to be redrawn (
Force=True)
or only parts that have changed since the last update of the screen.
The Video unit keeps an internal copy of the screen as it last
wrote it to the screen (in the OldVideoBuf array). The current
contents of VideoBuf are examined to see what locations on the
screen need to be updated. On slow terminals (e.g. a Linux telnet
session) this mechanism can speed up the screen redraw considerably.
On platforms where mouse cursor visibility is not guaranteed to be preserved during screen updates this routine has to restore the mouse cursor after the update (usually by calling HideMouse from unit Mouse before the real update and ShowMouse afterwards).
For an example, see most other functions.
Errors
None.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.