Please make this repo cmake noob build friendly

[gwald]

Hi there,

Nice project but OMG I thought it was just me and my loathe for anything cmake! lol
@davidthings is 100% right about "Most projects have a pattern as follows:"
From mosra/magnum#428

The splitting of projects isn't the problem, the problem is explained many times by David and others trying to install examples.

The example repo is the hardest to set up and yet it's really the first point of contact.
And it's not clearly explained how to actually set it up via command lines.
To me this post is more clear than all the wordy pages on your site:
mosra/magnum#106

To me It feels like a reverse engineering and trial and error process to build the examples!
This is a huge road block for anyone that's not a cmake expert.

This examples repo should have all the deps. core, extensions, plugins etc etc linked or included and installed from a single:
git clone --recurse-submodules
Then build ALL your relevant (platform/GPU API) examples and run them with ZERO messing around.
That should be the examples repo's main priorities, 1 easy to build and 2 play with all examples and features etc.
This is the real starting point for most people, and you either onboard them or drop them.

I would recommend putting everything in the repo so it all builds in a single directory, that way we can clearly see and find things, just like the script above, instead of installing and hunting for things.

Next running it and putting into an IDE and stepping through the code is what I would expect to do, then testing with other graphics API's and other platforms etc and then after the initial playing around with examples, then your "getting started" makes sense, when people are actually familiar with it, not before.

Anyway,
I hope that helps.

[mosra]

Hello,

you have a point, and yes, I recognize this as a big pain point. Until now I wasn't able to find a solution that doesn't make other use cases significantly worse (in particular, adding dependencies as Git submodules to each repo is extra overhead causing headaches for everyone except first-time users who want to build & run everything at once).

But your suggestion made me realize I could use some recent CMake FetchContent features to enable a self-contained build for the examples repo alone. Which is done now -- with 882a7c4 you can now clone just this repo & build it, and CMake will fetch relevant dependencies including SDL if they're not found in the system:

git clone https://github.com/mosra/magnum-examples
cd magnum-examples
mkdir build && cd build
cmake .. # Or the CMake GUI or an IDE or whatever else
cmake --build .

Of course such a setup isn't usable for much beyond tinkering with the examples, but as you say, then it's the time for the Getting Started guide. I'll update the "wordy pages" to mention this somewhere eventually.

By default it builds the triangle example alone, you can then go to the CMake GUI and toggle various MAGNUM_WITH_*_EXAMPLE options to enable more of them (I don't think enabling everything by default is a good idea, since there's quite a lot and you might not be interested in -- say, likely not wanting to wait hours until a whole robotics SDK that consists of 100 more projects gets built.)

So far the self-contained build is tested and should work on Linux, Mac and Windows. The automagic doesn't yet deal with examples that use audio, ImGui, Bullet, Vulkan, GLFW or Box2D, those require a bit more hair pulling and I'll add those later. I could perhaps also eventually add some CMake presets to easily choose between a minimal / base / full build without picking individual options.

If you have time to try again, let me know what you think, thank you!

[gwald]

Thanks for the reply.
That worked great I can get the simpler ones working now, thanks!

And I really like your "wordy pages" and blogs etc but I prefer seeing installing scripts examples rather than the details that I half understand :/ That's what I meant anyway.

[mosra]

As of 740ad08 the ImGui-based examples (MAGNUM_WITH_IMGUI_EXAMPLE, MAGNUM_WITH_FLUIDSIMULATION2D_EXAMPLE, MAGNUM_WITH_FLUIDSIMULATION3D_EXAMPLE) should work as well.

I didn't build up enough courage to try the remaining (Bullet, Box2D, GLFW, audio, Vulkan) yet.