If glslc is found, rebuild the shaders from GLSL to SPIR-V; otherwise,
we're just going to use the built files we have committed in the source
repository.
We have to work around some ordering problems here. We still
manage to keep most of the guts in modules/input/meson.build,
so it's not too ugly overall.
(The autotools build solves this with a 'make -C ../../input/modules'
inside gtk/Makefile, but that's not something we can or want to do.)
Add back dependencies on libgdk_dep and libsk_dep which are declared
dependencies. We removed this before because these declarations had
link_with: lines that dragged in the static libgdk.a and libgsk.a libs
which are linked into libgtk-4.so anyway and thus shouldn't be used
when linking internal exes/tools against libgtk-4. Remove the static
libs from the declared dependencies and have libgtk link those in
explicitly, so that the declared deps now just provide all the built
dependencies and include dirs and such for declared libgtk_dep users
such as the internal exes/tools, which want all the generated gsk/gdk/gtk
headers to exist before attempting to compile anything against the
gtk+ headers.
gtk_shader_builder_add_define should check both define_name and
define_value for not-NULL and not-empty, but the second precondition
check checks define_name again for not-empty-ness.
If you set GTK_INSPECTOR_RENDERER to the same type of
values that GSK_RENDERER takes this can change the renderer
used for the inspector. This is useful if you're debugging
one renderer and don't want to affect the inspector.
Instead of having 3 different shaders for the different clipping
versions, just have one shader and use a preprocessor define to use
different clip functions.
That preprocessor define is set in the Makefile.
Also use foo.frag and foo.vert as the file extensions instead of using
foo.frag.glsl and foo.vert.glsl, as that's what glslc suggests as
extension.
That way we don't need to move the clip rounded rect manually through
the vertex shader into the fragment shader but can just look at the push
constants.
Simplifies shaders a lot.
This way, we ensure that files that are built during make always get
properly listed. And we ensure that creating the resources actually
depends on them.
