My Allegro 4 game is getting closer to completion, and I just started integrating the Steam SDK, but came across a problem. The Steam overlay does not work with games which use software rasterization. I'm writing a local multiplayer game, which would benefit enormously from Steam's Remote Play Together (a feature which didn't exist until a few months ago), but the overlay is required to use this.

My first thought was that I would have to upgrade the whole game to Allegro 5, or perhaps SDL or Unreal Engine (I'm not that familiar with any of them). But I've just had the idea of using AllegroGL in Allegro 4 - I could create an OpenGL window, but use OpenGL only to copy the back buffer to the window – presumably that way, nothing else would need to change. Can anyone see any potential problems with this? One thing that just occurred to me is that the size of the back buffer would mean I would be displaying a non-power-of-two texture. I don't know how well this is supported by older graphics cards.

Have started working on using AllegroGL - first problem, when building with MSVC, no alleggl.lib is produced, only a PDB and DLL. This is the case even if I tell MSVC to build a static library.

It's been a while but - isn't AllegroGL part of Allegro 4 now? i.e. there isn't a separate lib to link to.

Also, what does "games which use software rasterization" mean? Doesn't A4 use either DirectX or OpenGL to access the screen anyway?

AllegroGL is part of Allegro, but it is still a separate addon library.

Allegro 4 uses software rendering, except for the screen, which is always video memory. Normally, A4 uses DX, but the AllegroGL driver allows hardware accelerated drawing of video bitmaps which are normally memory.

Andrew Gillett, this is why I hate MSVC.

Which dependencies did you build before hand?

Can you upload your CMakeCache.txt file after hitting 'generate' please?

I will try to build from CMake GIT Allegro 443 and MSVS2017 and report back.

EDIT
I'm sorry, my CMake isn't finding DX properly. I can't build yet.

When you run CMake, check the boxes for Advanced and Grouping. It should make those DX vars visible.

As for building it, I get 4000 errors. And I haven't the faintest idea where to start. It's probably due to a SDK version error but I have no idea.

As for linking, I can make *.lib files from *.dlls, and so can you.

If I provide the .dll I made for Allegro 44X and the script I used, you should be able to create .lib files for each of them.

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