Now the SDLSurface backend survives window resizes (also triggered by
alt-tabbing while in fullscreen), and the SDLTexture backend properly
regenerates its textures after a fullscreen alt-tab in DirectX mode.
When DirectX-SDL2 loses its device, it doesn't lose its textures,
just their contents, so we shouldn't remake the textures when we
regenerate the glyphs (that's coming next commit).
Has the same imperfections: if you regenerate the surfaces while a
text box is open (and while using Courier New I guess), the text will
regenerate with smaller spaces.
This fixes the Texture backend bug that made the program take forever
to shut down:
The problem was that the font system would try to load a glyph that's
0 pixels wide/tall (likely the space character), which SDL2 didn't
like, so it would fail to allocate the texture, causing
Backend_CreateSurface, and by extension Backend_CreateGlyph, to
return a NULL. Later, upon shutdown, the font system would pass this
NULL to Backend_FreeGlyph, causing NULL pointer dereferences that
make the program take forever to shut down.
Personally, I think passing NULLs to the backend is valid behaviour,
so I've added a bunch of sanity checks to make sure they're never
dereferenced.
Getting kinda messy, having to maintain two different ways of
drawing - colour-key and alpha-blending. In the enhanced branch,
which uses alpha-blending for everything, these can be merged.
I'm noticing a huge delay in shutdown time. There's probably a bug
in here.
