In the upcoming changes, the AccelGfx context will be used for WebGL, so
we can no longer assume that the WebContent process has a single global
context.
Let's not assume there is one global OpenGL context because it might
change once we will start creating >1 page inside single WebContent
process or contexts for WebGL.
With these changes it is now possible to create OpenGL context on macOS
and run GPU-painter. For now only QT client has a CLI param that turns
it on though.
Framebuffer object is allocated using OpenGL's API and is not platform
specific which means it could be used on both macOS and Linux unlike
EGL specific PBuffer.
In the upcoming changes, Painter will be used to store the state of
OpenGL context. For example, if Painter is aware of the shader that
have already been loaded, it will be possible to reuse them across
repaints. Also, it would be possible to manage state of loaded textures
and add/remove them depending on which ones are present in the next
sequence of painting commands.
This change introduces a new 2D graphics library that uses OpenGL to
perform painting operations. For now, it has extremely limited
functionality and supports only rectangle painting, but we have to
start somewhere.
Since this library is intended to be used by LibWeb, where the
WebContent process does not have an associated window, painting occurs
in an offscreen buffer created using EGL.
For now it is only possible to compile this library on linux.
Offscreen context creation on SerenityOS and MacOS will have to be
implemented separately in the future.
Co-Authored-By: Andreas Kling <awesomekling@gmail.com>
