Does anyone know how to make Allegro display on one external monitor with a different display on the laptops lcd display? I am trying to write a scoreboard program with a display being output to a TV and controlled by the laptop. I would greatly appreciate any help.

What do you mean by attach Allegro to it? Is there some kind of way to write to the buffer that goes to the other screen or whatnot? I've never dealt with multiple monitors before. To be honest, I didn't know Allegro had a windowed mode. Can it have multiple windows at once since one would be the display window and the other would be for controlling it?

I can't display the same contents onto each display. The laptop needs to display controls and setup options while the laptop's output will show the compiled results which are run into a video switcher and overlayed with the live video signal. Think of it as a character generator for sports games and the like. We can't afford a real one so we figured we can pull off something simple.

win_set_window

Allegro cannot, but you might be able to create two via the Win32 API. Allegro could be attached to the second window. However the controlling window would then be written in Win32 code, and not Allegro.

Personally, I don't think what you are trying to do is something that Allegro can do very well. Future versions will probably be better with multiple windows, but I doubt you can wait a few years for that to happen...

You could create hacks to work around limitations. For instance, you could write two Allegro programs and communicate back and forth by dropping text files in a directory or sending messages.

Edit, I was beaten...

No, laptops can output two different screens. Mine can. The LCD is one desktop and the TV is another.

About the laptop, I apologize, that is what I meant. One screen is LCD built into laptop, the other is video out. I think I will try the multiple program hack. As long as I can make the output all pink except what I want drawn then it is good enough. I don't know enough about windows api to bugger around with that stuff. I may try the thing suggested by MidoriKid at http://www.allegro.cc/forums/view_thread.php?_id=326345 first.

- Edit -
Communicate via TCP/IP? That does sound hard. I will look into that. That would probably be more appropriate than a text file.

If you have a link to a good tutorial that would be awsome. Most of the ones i've come across have been kinda dense.

what platform are you using ?
windows ? linux ?

im on windows, i have several windows open at once.
all feed from a single instance of allegro.

and i can put them on seperate monitors, seperate gfx cards.

i use shared memory to transfer the data to each window, that is running in its own process.. so that they can crash seperately and not bring down each other.

DirectX has some examples that use dual displays, totally full screen. You'll havev to do a little DX programming to set it up with allegro. I'm sure it can be done, but it might be difficult.

I bet if you use DX to set up the dual display mode, then switch allegro between windows, you can get dual display to work.

This is all theory, of course.

If what he wants to do is create one window that expands both monitors, then the TCP idea is kinda silly. I have seen DirectX demos that extended the frame buffer between two screens (so if you have two 1600x1200 monitors side by side, the game plays at 3200x1200). In this case, setting up some special directX routines to interface with allegro would probably work best.

If he wants to go all DS-like, however, and run one main game in one window, and some extra stuff (like a map in a window) on another display, then TCP would be cool because you could not only run two apps on one computer, but also on another computer, like a laptop nearby, as well.

Yeah Tobias, the brute force is what I'm looking at doing. The scoreboard never has to talk back to the controller since the controller stores all the meaningful data anyway. I'm still working on understanding TCP/IP stuff but I'm hoping not to have to fall back on the DX hack.