It compiles on GLES2 as well, but there it hits the massive PITA of
being unable to render to LUMINANXCE formats and GL_RED formats not
really being available everywhere.
I don't have the patience to fix that, and almost nobody needs to use
ES2 platforms nowadays, so this isn't really a priority.
These two options were mutually exclusive, and both were doing the same
thing -- switching to EGL on desktop GL, or switching away from EGL on
GLES. That made all logic vastly more complicated than it should be, and
unfortunately it took me half a decade to realize that. The new logic is
significantly simpler everywhere.
As usual, the old options are still recognized by CMake on a deprecated
build (with a warning), and are still exposed both as CMake variables
and a preprocessor define. But the logic for them was quite complicated,
so I don't guarantee all cases are covered.
I also tried to clean up the dependent CMake options to allow building
GLX and WGL apps on GLES independently of whether EGL is used, but it's
quite a mess due to the limitations of CMake < 3.22. Build directories
that have the options switched randomly over a long time might start
misbehaving, but the initial build should work well.
* Not requiring ARB_texture_storage, as Texture::setStorage() has
already implemented fallback.
* Not requiring EXT_texture_rg for single-channel texture on ES2, as
this extension might not be available everywhere (unlike in ES3
desktop OpenGL, where Mesa 8/9 with OpenGL 2.1 supports it), fallback
to Luminance in GlyphCache and RGB in DistanceFieldGlyphCache,
because Luminance might not be renderable everywhere.
* Re-enabled building of Text library in all ES PKGBUILDs.
* Older GLSL doesn't have texelFetch() and related things, working
around it by using classical texture() and normalized floating-point
coordinates. But that needs to have Texture::imageSize() passed,
which is not available in OpenGL ES, thus the user must specify it
explicitly there. On desktop OpenGL that parameter is ignored.
* Older GLSL doesn't have gl_VertexID, thus vertex buffer must be
created and vertex data passed expliticly.
* GLSL ES 2.0 doesn't have one-component texture format and
TextureFormat::Luminance probably isn't renderable anywhere, thus
TextureFormat::RGB should be used, although it is inefficient.
* Checking for framebuffer completeness, if not complete, nothing is
done.
* Re-eabled building of TextureTools library in all ES PKGBUILDs.
Now we can use CORRADE_COMPARE() almost exclusively for comparing
Vector, Matrix instances and all containers from STL. Tests running time
for all 31 tests is now around 0.1 sec instead of two seconds like
before.
Disabled compilation of all benchmarks, because TestSuite cannot handle
them yet.
PKGBUILD from AUR now can shamelessly use check() function without
unnecessary dependencies.