Some systems (notably macOS) will not allow enumeration of an extension that has been promoted to core OpenGL for context in use. This change assumes that GL_ARB_timer_query is available on OpenGL 3.3+.
I could not find definitive information on whether GL_ARB_debug_output or GL_KHR_debug have been added to core. Other extensions in use were addressed by https://gitlab.gnome.org/GNOME/gtk/merge_requests/1422 .
Commit 47c44644b1 was a bit overzealous in fixing
compiler warnings. We still need to call collect_textures,
even if we don't need the number that it returns.
These don't take a duration, instead they call g_get_monotonic_time() to
and subtract the start time for it.
Almost all our calls are like this, and this makes the callsites clearer
and avoids inlining the clock call into the call site.
When we use if (GDK_PROFILER_IS_RUNNING) this means we get an
inlined if (FALSE) when the compiler support is not compiled in, which
gets rid of all the related code completely.
We also expand to G_UNLIKELY(gdk_profiler_is_running ()) in the supported
case which might cause somewhat better code generation.
usec is the scale of the monotonic timer which is where we get almost
all the times from. The only actual source of nsec is the opengl
GPU time (but who knows what the actual resulution of that is).
Changing this to usec allows us to get rid of " * 1000" in a *lot* of
places all over the codebase, which are ugly and confusing.
This is similar to how we share texture atlases. Some added complexity
in that the program state also needed to be shared, so it had to move to
the shared Programs object.
With this change realization of additional GskRenderers when opening
popups went from ~60msec to ~35 msec on average.
When rendering ops to an offscreen texture we take max-texture-size
in consideration and modify the scale we use such that the required
texture does not exceed the limit.
This means some rendering will be blocky/fuzzy, but that is better
than it being clipped.
It would probably be better to not do this and always render the outline
in plain white, then later recolor it but do this for no, just for
correctness.
