Following the spirit of extension-based functionality, the entrypoints
are available always but do something (i.e., call the actual WebGL API)
only if the extension is advertised. Which it is only on Emscripten
3.1.66+ because older versions don't have the corresponding entrypoints,
so there it's marked as disabled.
Additionally, EXT_polygon_offset_clamp is now also working on 3.1.66+,
but there's no wrapper for it yet.
And this, this change allows the growable Array to use malloc() instead
of new, and thus also realloc(), saving unnecessary reallocations if the
memory can be grown in-place. All because Containers::Pair is trivially
copyable while std::pair wasn't.
There isn't any good reason to use the STL anymore.
It's quite easy if WEBGL_debug_renderer_info is present, but if it isn't
then our only hope is to check for ANGLE-specific extensions. Which may
cause some false positives, but since we need to enable various
workarounds for ANGLE to avoid issues, it's better than having the
detection too conservative.
The original ANGLE detection based on line size is probably not so
relevant anymore, but let's keep it there.
Unlike most other extensions, this one has to be explicitly enabled in
Emscripten in order to be used. Which thus done as part of other "driver
workarounds" done on startup. To avoid that, the extension can be
explicitly disabled, and thanks to the previous commit the disabling
will be performed before the extension is attempted to be enabled.
Disabling engine startup log or modifying enabled extensions /
workarounds from the application side was one of the common pain
points and this should *finally* solve the problem. This Configuration
is now inherited by the usual Platform::*Application::GLConfiguration /
Platform::Windowless*Application::Configuration classes people are used
to, so for the end user it's just as if these classes got a bunch new
options.
Having this, I also extended the ContextGLTest to verify that the
Configuration and command-line options do what's expected because that
hadn't automated tests until now. The test is mostly a copy of what I
did for Vulkan already, nothing special. Additionally all
Platform*ApplicationTest executables gained a new --quiet option to
verify that the GL::Context::Configuration subset gets correctly passed
from the Application code, because that's something we can't really
verify in an automated way.
StringViews are great -- given that they are trivially destructible, the
compiler can now tell me that I have unused variables. If it wouldn't be
trivially destructible (like std::string), the destructor is treated as
if it has side-effects so the compiler won't complain.
We're going to eventually include this class in all Application classes
(need that in order to inherit a to-be-created Configuration class) and
the <string> and <vector> would be just too much. This change caused
magnum-gl-info.wasm (WebGL 2 build) to go down from 247 to 245 kB. Not
much, but that's I guess because there's still a lot other vectors of
strings elsewhere.
There's a lot more places to clean up, will do those in separate
commits. This change is the most atomic I could do, and it introduces a
breaking change to all APIs that returned a std::vector or a
std::string. Fortunately (or as I hope) those weren't used that much, so
it shouldn't cause build breakages for that many people.
Quite a lot of the optimization ideas is borrowed from the new Vk
library -- such as "interning" the driver workaround strings to avoid
allocating their copies.
This was done silently until now and I think such platform-specific code
should be always exposed as a disableable workaround. Moreover, I need a
similar thing for ANGLE, so this comes handy.
This was my bug, as requesting a forward-compatible context without
saying *what* version it should be forward compatible to makes no sense.
A followup to 73baab69ce.
There's a new firefox-fake-disjoint-timer-query-webgl2 workaround and a
half-page of text listing various caveats and issues you might run into.
Also exposing them in the OpenGLTester (although quite shitty at this
point).
Vladimír Vondruš