The loader now doesn't attempt to check for extensions and just loads the
function pointers. It was doing that for all core functions anyway, so a
few more DSA functions won't hurt the loading times too much. Should fix
issues with core-only contexts on OSX.
Caused linker problems mainly on Windows, where every symbol would need
to be exported manually, on Linux this was done implicitly (or with
`-fvisibility=default`). I now maintain glLoadGen fork at
https://github.com/mosra/glloadgen.git containing changes needed for
Magnum.
The `ogl_*()` functions are used only internally, various global
variables for extension queries are not used at all and thus they don't
need to be exported. I thus enabled `-fvisibility=hidden`.
Fixes#16.
Removed all known GLEW workarounds, added one small workaround for
missing ARB_texture_compression_bptc. I didn't want to patch glLoadGen
for just four enum values, this way it's possible to use stock one
without any patching (except for missing OpenGL 2.1 support, as stated
in external/OpenGL/GL/README.md).
As one file now replaces both `glew.h` and `glcorearb.h` and it has the
same size as `glcorearb.h` alone , it saves approximately 18k LOC,
resulting in 15 second shorter compilation time (5:03 before, 4:48 now).
Not bad.
Moved them to `OpenGL/` subdirectory, allowing them to be included
explicitly with e.g. <OpenGL/GLES2/gl2ext.h> overriding the system
<GLES2/gl2ext.h> header. Our versions of the headers are thus now
explicitly included in `OpenGL.h`, but they can be also included using
no-prefix path if no system version is available. It might break some ES
platforms, they will be fixed when found.
The headers are now installed into `Magnum/OpenGL` (not into any
artificial `external` directory). Now also installing GLES2 headers for
OpenGL ES 2 (previously ES3 headers were installed for both ES2 and
ES3).
Vladimír Vondruš