screenshot on dualhead setup

QNX Newsgroups (Archives) qnx.gui
1

Hi,

I’m running QNX 6.3 SP3 with a matrox dual-head, and I want to
programmatically take screenshots of either one of my two screens (left
or right screen, depending on circumstances). However, I’m only able to
take a screenshot of the left screen on one machine, and on another test
machine the only screenshot we could take was of the right screen…

I tried using a 1280 offset when I’m setting the capture area rectangle
in my code, and still I was only getting the left screen. I tried
PtSetTargetDevice() with the second region ID in my index of devices,
and still I was getting the left screen. I am using the function
PgReadScreen().

I noticed also that the photon snapshot program has the exact same
problem. No matter from which screen I run the snapshot program, it
captures only left the screen. (and on the other dual-head machine we
tried it on, it captured only the right screen…)

Any help would be appreciated.

Simon Ouellette

2

This is mere guesswork here.
The way you get dual monitors to work, is by inserting a second
region, owned by a graphics driver.
I don’t know how snapshot works, but I imagine in some way it must be
talking with the graphics driver.
So the problem is finding out where the taking of a screen shot
involves specifying the graphics driver.

3

PdSetTargetDevice() does that. When I list my draw devices using
PdGetDevices(), I get 2 devices in the list. I tried setting both
devices as my target device, with and without the 1280 X offset, and I
still only get a screenshot of the left screen…

Simon

maschoen wrote:

This is mere guesswork here.
The way you get dual monitors to work, is by inserting a second
region, owned by a graphics driver.
I don’t know how snapshot works, but I imagine in some way it must be
talking with the graphics driver.
So the problem is finding out where the taking of a screen shot
involves specifying the graphics driver.