Rework launchers

[pchote]

This is the third and final PR backporting the project structure changes from #17989 for the playtest.
The first (new) commit splits the OpenRA.exe entry point into its own project, and changes OpenRA.Game to a library.
The second commit overhauls the windows launchers, taking a new approach that i'm surprised nobody considered earlier, using assembly attributes that can be passed to msbuild at compile time to avoid editing source files.

Depends on #18846.
Supersedes #18582.

Test builds: https://github.com/pchote/OpenRA/releases/tag/devtest-20201122

[pchote]

Rebased.

[pchote]

Updated.

[abcdefg30]

Lgtm and works, but the packaging changes are untested. One thing I did notice is that the error dialogue doesn't always open in the foreground. Is there some sort of setting to do that?

[pchote]

The packaging changes (except for the latest revision, but I tested that locally and verified that both the 64 and 32 bit installers work) are tested by the devtest tag, with travis logs at https://travis-ci.com/github/pchote/OpenRA/builds/203989439

I could not find any way to force the error dialog on top. I don't think this is supported in SDL 😞

[abcdefg30]

https://stackoverflow.com/questions/11512373/findwindow-and-setforegroundwindow-alternatives/12758966#12758966 seems to offer a solution. The crash dialogue seems to retain the name from the exe, so I could get one to the front locally by using "TiberianDawn" as process name.

[pchote]

That won't work because SDL.SDL_ShowMessageBox blocks until the dialog is closed, so we don't have the chance to run any code while the dialog is open. Calling SetForegroundWindow before opening the message box doesn't work either because the launcher's MainWindowHandle is 0 (i.e. null) because it doesn't have any windows.

[pchote]

I tried calling SetForegroundWindow on a different thread in several different ways, but couldn't get it to work (it would blink the icon in the taskbar, so something was happening, but the dialog was not brought to the front). I suspect this may be because the message box is not the MainWindowHandle, but I don't know how to get any other window handles.

I'm out of ideas, so can't proceed any further with that suggestion/request without help.

If anyone wants to try modifying the code to test ideas you can compile the TD launcher with

msbuild -t:Build "OpenRA.WindowsLauncher/OpenRA.WindowsLauncher.csproj" -restore -p:Configuration=Release -p:TargetPlatform="win-x64" -p:LauncherName="TiberianDawn" -p:ModID="cnc" -p:DisplayName="Tiberian Dawn" -p:FaqUrl="http://wiki.openra.net/FAQ"

and then copy TiberianDawn.exe from the bin dir into an existing Windows install for testing.

[pchote]

The behaviour I mentioned above is explained by this link:

An application cannot force a window to the foreground while the user is working with another window. Instead, Windows flashes the taskbar button of the window to notify the user.

So it sounds like we should be expecting this to fail.

[pchote]

The trick is that the game process needs to grant permission for the launcher to set the foreground window before it crashes. Added a new commit to fix this, which you can test using the msbuild command above.

[abcdefg30]

That did the trick, good job. 👍

[pchote]

Open question: now that the platform launchers link against OpenRA.Game.dll, should we stop shipping the generic OpenRA.exe launcher in the windows builds? This will stop people from "crashing" if they try to run OpenRA.exe through the GUI.

[abcdefg30]

If there is no need to ship the generic exe, then we should drop it.

[pchote]

Ok, done. I also scope creeped in replacing MakeLAA.cs/exe with a python script to remove another change from #17989.

New packages will be available from https://github.com/pchote/OpenRA/releases/tag/devtest-20201127-2

[pchote]

Updated. I also removed the Release-x86 configurations because I remembered that #17744 removed them everywhere else.

[teinarss]

https://github.com/OpenRA/OpenRA/wiki/Changelog-(bleed)/_compare/6eab03c56ab1600897c0d2dc3d90254e62cae51b...27e356d24da4d6b056e6031a32237dc2488a8ff6