This removes the character array from the LevelOnePage class and stores the
characters in packets 0 to 24 natively, adding a packet when a character is
first added to a row and removing a packet when a row becomes space
characters.
"y": packet number
"d": designation code
"t": triplet number
"packet" renamed to "pkt" in method parameters to avoid ambiguity with
the "packet" method.
Actually this is a workaround: it does not attempt to copy construct
unhandled packets, to avoid a bug in the base class where pointers were
copy constructed without copying the contents.
A proper fix will need refactoring of the packet storage code.
These modes can be used to see the inner workings of colourful artworks that
frequently use "foreground colour, new background, foreground colour",
particularly to show exactly which colours are represented by set or clear
sixels.
One mode renders all characters in white on a black background and the other
mode renders black characters on a white background. The latter could be used
to save ink if the resulting image is printed.
Flash is suppressed in these mono modes, this may or may not change.
Qt 5 has had to be dropped as CMakeLists.txt uses qt_* specific commands
which are implemented in Qt 6 onwards.
cmake --install is only working on Linux at the moment; it installs the
executable and the bundled example tti files into /usr/local/share/doc
The teletext decoder with its document storage has been moved to a
subdirectory with the intention of making it possible to use in other
projects, but some further separation of editing stuff will be needed.
