> I have been using the VNCHooks DLL inside my own application, which needs
> to be notified when sections of the desktop are "dirty" and I need to
> "re-capture" them. (scenario very similar to VNC, but for local use
> instead of remote)
The only 100% reliable and accurate way of receiving such notifications is to
use some kind of display mirror driver. This approach is already implemented in
recent version of TightVNC.
From: Constantin Kaplinsky <const@ti...> - 2006-04-06 16:12:54
>>>>> "JWS" == Jay W Summet <summetj@...> writes:
JWS> I have been using the VNCHooks DLL inside my own application,
JWS> which needs to be notified when sections of the desktop are
JWS> "dirty" and I need to "re-capture" them. (scenario very similar
JWS> to VNC, but for local use instead of remote)
JWS> I am running into problems with some applications that are
JWS> apparently not nicely using WM_PAINT messages. Specificly, a
JWS> drawing program from Smart Technologies (for use with
JWS> SmartBoards, a pen/finger input device) does not issue an update
JWS> until the pen is lifted from the board, although in windows it
JWS> does draw a line continuously as the pen is moved.
JWS> [I also notice funkyness when a scroll-wheel mouse is used to
JWS> scroll (top and bottom of the scrolling area are not updated
JWS> correctly), and with videos playing in overlays, which isn't as
Yes, it's a known issue that not all the changes can be caught by the
hooks DLL. And there are problems with certain application (that's why
the DLL even has per-application registry settings).
JWS> The headers in the source code make it look like VNCHooks hasn't
JWS> been updated lately (or at least the headers haven't...) and I
JWS> was wondering who "owned" that piece of code?
That code was developer by original VNC creators, now RealVNC Ltd.
By the way, you might want to have a look at the newer version of the
hooks DLL which is available in VNC 4.1.1 source distribution at the
RealVNC Web site.
JWS> I'd like to try and improve it so that I get notifications in a
JWS> more timely fashion, and was wondering who I should talk to about
Perhaps it would be a good idea to talk with RealVNC developers.
From the other side, we are also very interested in making the DLL
more efficient, so you are always welcome in this mailing list.
With Best Wishes,