This mostly worked before, but clearColor made the assumption that the
colors were always in #RRBBGG format. See the discussion here:
https://github.com/xtermjs/xterm.js/pull/1327#issuecomment-374812842
This changes the internal representation of a color so that we hold onto
into an object containing the original css string along with an RGBA
value encoded as a 32-bit uint. clearColor can then use that RGBA
representation.
Additionally, this deduplicates some code between ColorManager and
Terminal. Terminal was generating the 256 ansi colors the same way
ColorManager was, so this just makes Terminal use the same constant.
ICharAtlasRequest and ICharAtlasConfig need almost exactly the same set
of information, so it's simpler if we just merge the two types.
As an added bonus, this also adds devicePixelRatio to the config, which
helps guarantee that we won't ever accidentally end up with an atlas
using a different pixel ratio than we need.
Benjamin Woodruff
Daniel Imms
Daniel Imms