since i realized there is an SDL hint that can be used to toggle this
the reason why the rust-sdl "Canvas" struct (which abstracts an
"SDL_Renderer") is not being created in System directly (which would
allow vsync to be toggled on/off via System directly without the use of
a hint) is because not all future SystemResource implementations will
need it (e.g. a future OpenGL implementation definitely won't).
System now uses a generic SystemResources structure to provide video,
audio and input devices
the DosLike implementation of SystemResources provides the same
functionality that this library has had to date.
this change is to prepare for future addition of things like 32-bit
Bitmap support and other possible audio device implementations, etc.
the idea is a custom SystemResources implementation can be substituted
in to configure everything with the desired functionality.
note that i'm intentionally not using rustfmt. i've tried to like that
tool, but in the end i just really don't like it. too many edge cases
and subjectivity and not enough customization. which is probably the
intent. which makes me hate it that much more. fuck you, rustfmt.
i think i prefer this style. it's not _technically_ as safe as it was
before, but i prefer the explicitness of it (and it results in a little
bit less nesting in system functions which is nice).
i don't much like the need for an explicit `unwrap()` call however
but that's the tradeoff!
Gered