When randomizing the sixel width and height, use width/height + 1 in
the call to randrange(). This ensures the width/height is never 0, and
that the maximum width/height is half the window size, not slightly
less than that.
After emitting multiple color bands for each sixel row, the increased
amount of sixel data shifted the balance in the profiling data,
causing a performance regression in regular ASCII handling.
This _should_ only happen when we’re doing a partial PGO build, since
then the script is run in the parent terminal. In this case, the user
is expected to use --rows/--cols anyway.
Using Python's own PRNG should make the code cleaner and allow for
reproducible stimulus files if that is desired via setting --seed (at
least for the same versions of the script, changing the kind and/or
order of the random calls will of course impact the output in the
future).
I did the following substitutions:
* rand.read(1)[0] % n and struct.unpack('@H', rand.read(2))[0] % n →
random.randrange(n)
* rand.read(1)[0] → random.randrange(256)
* rand.read(n) → [random.randrange(256) for _ in range(n)]
(better alternative would have been random.randbytes(n), but is only
available for Python >= 3.9, switching to this in the future will
impact output)
* list[rand.read(1) % len(list)] → random.choice(list)
This allows us more options when determining whether to use a
pre-composed character or not:
We now only use the pre-composed character if it's from the primary
font, or if at least one of the base or combining characters are from
a fallback font.
I.e. use glyphs from the primary font if possible. But, if one or more
of the decomposed glyphs are from a fallback font, use the
pre-composed character anyway.
We only used utf8proc to try to pre-compose a glyph from a base and
combining character.
We can do this ourselves by using a pre-compiled table of valid
pre-compositions. This table isn't _that_ big, and binary searching it
is fast.
That is, for a very small amount of code, and not too much extra RO
data, we can get rid of the utf8proc dependency.
