Cleanup by moving various (mostly horrible) little bits handling UTF-8 grid
data into functions in a new file, grid-utf8.c, and use sizeof intead of
UTF8_DATA.
Also nuke trailing whitespace from tmux.1, reminded by jmc.
Stick line length to what is actually used (removing an optimization that
allowed it to be bigger), and use clear line/EOL sequences rather than spaces
in copy/scroll mode.
This fixes xterm copy/paste from tmux which treats trailing spaces differently
from clearing a line with the escape sequences. Reported by martynas@.
A few trivial optimisations: no need to check for zero size if calling
buffer_ensure in buffer.c; expand grid lines by a greater increase than one
each time; and don't read UTF-8 data unless it actually needs to be checked
when overwriting a cell.
Change the way the grid is stored, previously it was:
- a two-dimensional array of cells;
- a two-dimensional array of utf8 data;
- an array of line lengths.
Now it is a single array of a new struct grid_line each of which represents a
line and contains the length and an array of cells and an array of utf8 data.
This will make it easier to add additional per-line members, such as flags.
screen interactive programs to preserve the screen contents. When activated, it
saves a copy of the visible grid and disables scrolling into and resizing out
of the history; when deactivated the visible data is restored and the history
reenabled.
as UTF-8 in a separate array, the code does a lookup into this every time it
gets to a UTF-8 cell. Zero width characters are just appended onto the UTF-8
data for the previous cell. This also means that almost no bytes extra are
wasted non-Unicode data (yay).
Still some oddities, such as copy mode skips over wide characters in a strange
way, and the code could do with some tidying.
Split grid into two arrays, one containing grid attributes/flags/colours (keeps
the name grid_cell for now) and a separate with the character data (called
text). The text is stored as a u_short but is treated as a uint64_t elsewhere;
eventually the grid will have two arrays.
I'm not happy with the naming so that might change.
Still need to decide where to go from here. I'm not sure whether to combine
the peek/set functions together, and also whether to continue to treat the
text as a uint64_t (and convert to/from Unicode) or make it a char array
(of size one when UTF-8 disabled, eight when enabled) and keep everything
as UTF-8.
Also since UTF-8 will eventually become an attribute of the grid itself it
might be nice to move all the padding crap into grid.c.
