I'm pretty happy with this. It's iterative rather than recursive so you
won't blow out the call stack if you want to parse a million brackets
(intermediate results are stored on (another) little stack.) It scans
the string and builds lists and sublists as it goes, without wasting
cons cells.
So I was memset'ing the hash table and string table /after/ setting up
the left- and right-bracket tokens! So then when I tried to print the
token list and ht_lookup() dutifully set the error code when it couldn't
find the strings in the hash table, the system properly quit printing
and halted. D'oh! That was a subtle one. Obvious in hindsight.
It took all expletive-deleted day but I finally nailed it down. In the
end the last bug was I was decrementing a stack pointer /after/ trying
to load the item at the (empty) top of the stack. Classic.
I still need to make it not re-allocate strings that it has already
interned, but beyond that I think it's fine.
Clunky but now you only have to change the font name four time in one
place rather than N times in N places, eh?
Writing C again for the first time in ages (this and the Joy
interpreter) the using the preprocessor is like stone-age
meta-programming, from the lens of lisp it's like, "you do what to your
source code?".
It's easy enough to substitute a different font in the call to
Imagemagick's `convert` tool, but in the case of pixel fonts, it will
scale them, so you're not getting a proper bitmap of the pixels, you're
getting a kind of screenshot of the pixels.
I want to make a different machinery for bitmapped pixel fonts, and I
want to make a simple DEFINE-based way to pick them without having to
edit your source code, e.g. #define font_data font_PublicPixel_22_data
yeah?
After that, simple affine transforms for fake 3D..
Pick a letter at random.
I wasn't checking that the destination values were not less than zero,
which let you click at the top/left edges of the screen and therefore
the carefree_alpha_blend_blit() would try to write to areas outside the
framebuffer. I started to see "zalgol" pixels in the letters, so I'm
guessing the pixel data is getting stored just above the framebuffer,
which makes sense (because that's the order they appear in the source
code and this is a simple system!) When you click at the top of the
screen it was writing pixels in the font data, eh? Then when you click
elsewhere on the screen you get extra pixels with your letterforms and
it looks like Unicode Lovecraft puns.
Simon Forman