* Draft GPU3D renderer modularization
* Update sources C++ standard to C++17
The top-level `CMakeLists.txt` is already using the C++17 standard.
* Move GLCompositor into class type
Some other misc fixes to push towards better modularity
* Make renderer-implementation types move-only
These types are going to be holding onto handles
of GPU-side resources and shouldn't ever be copied around.
* Fix OSX: Remove 'register' storage class specifier
`register` has been removed in C++17...
But this keyword hasn't done anything in years anyways.
OSX builds consider this "warning" an error and it
stops the whole build.
* Add RestartFrame to Renderer3D interface
* Move Accelerated property to Renderer3D interface
There are points in the code base where we do:
`renderer != 0` to know if we are feeding
an openGL renderer. Rather than that we can instead just have this be
a property of the renderer itself.
With this pattern a renderer can just say how it wants its data to come
in rather than have everyone know that they're talking to an OpenGL
renderer.
* Remove Accelerated flag from GPU
* Move 2D_Soft interface in separate header
Also make the current 2D engine an "owned" unique_ptr.
* Update alignment attribute to standard alignas
Uses standardized `alignas` rather than compiler-specific
attributes.
https://en.cppreference.com/w/cpp/language/alignas
* Fix Clang: alignas specifier
Alignment must be specified before the array to align the entire array.
https://en.cppreference.com/w/cpp/language/alignas
* Converted Renderer3D Accelerated to variable
This flag is checked a lot during scanline rasterization. So rather
than having an expensive vtable-lookup call during mainline rendering
code, it is now a public constant bool type that is written to only once
during Renderer3D initialization.
Arisotura