I have no idea why I had such a complicated mess instead of this way of
doing it, which seems vastly simpler, and works by simply installing it
into the correct path to begin with.

I think it was because, in some distant past, I installed the entire
headers subdir, and therefore could not have a stray config.h.in or
meson.build inside there. Or something. My memory is hazy.

Anyway, simplify the whole config.h build thing.

Niklas Haas authored 4 years ago and Niklas Haas committed 4 years ago

Over the past few years, the use case of `pl_context` has increasingly
shrinked, finally dwindling to "nothing other than logging" with the
introduction of thread safety (and thus the loss of the "thread safety
guard") As such, this being called `pl_context` is really unnecessarily
confusing. It's just a glorified logging subsystem.

Rename it, and make it optional in the process. Also introduce a typedef
to make the new name shorter, as part of a new convention that I will be
switching to moving forwards.

This technically breaks the auto-cleanup behaviour of `pl_shader` and
`pl_filter` but I really don't think those were all that useful or
justified, and I don't think anybody relied on it.

Instead of compiling all variants of all demos, load the best backend at
runtime. Also split off the nuklear implementation into a separate
library to avoid excessively recompiling it, something that should have
been done ages ago.

This is technically a functionality downgrade, since it doesn't allow
users to choose which backend to use (Vulkan or OpenGL), instead always
picking the "best" backend. But that's mostly interesting for
developers, not users, I think.

I'll probably implement some mechanism for making that selection at
runtime, when I actually need it.

As an aside, I also renamed 'image' to 'sdlimage' since I think the name
fits better - the only reason I didn't in the past was to avoid
confusion with the suffix.

No reason for this confusing `demo_context()` anyway, just pick a
suitable verbosity level for each demo. In particular, `plplay` was way
too spammy.

Major refactor of the demos/ directory, accomplishing a number of goals:

1. Allowing easy switching between OpenGL and Vulkan variants.
2. Supporting both GLFW and SDL2, chosen at compile time. The window
   management itself was made entirely modular for this purpose.
3. Refactor all of the demo programs atop these new abstractions.
4. Building them correctly and automatically (via meson).

I also plan on factoring out the nuklear code to its own helper, but I
avoided making that part of the same commit to prevent it from blowing
up any further.