Two complete games in `examples/breakout/`, both 100% BASIC: `characters/`
draws its wall in the text grid with two `DATA` sprites for the ball and
paddle, and `sprites/` loads CC0 artwork and captures its whole screen with
`SSHAPE`/`SPRSAV`. They take opposite shapes for reasons that are entirely
this interpreter's, which is what the chapters are for.
`docs/17-tutorial-breakout.md` and `docs/18-tutorial-breakout-artwork.md`
build each one a step at a time, and end in a checklist of the rules a real
program runs into: create every name before the loop starts, write a text row
whole, loop with `GOTO` rather than `DO`, put the float on the left. Every
trap is a runnable block with its own output rather than a claim -- the value
pool dying at four thousand names, the skipped `BEGIN` block that breaks its
caller's `RETURN`, `SSHAPE` ignoring a subscript, `READ`'s single cursor.
Five figures, generated from the listings beside them by `docs_screenshots`,
and a `breakout_art` setup so the ones that load artwork load the example's
own. The character game's wall cannot be photographed -- the screenshot host
omits the text layer on purpose -- so it is shown as compared output instead.
`docs/07-sound.md` never said `SOUND`'s frequency is a SID register value
rather than hertz, which both games depend on. It says so now, with the
conversion from `src/audio_tables.c:84`.
`TODO.md` gains the thirteen defects the two games turned up -- §6 items 30
to 33 and all of §9 -- each with a reduction that fits on a screen, the file
and line of the cause, and what a fix would touch.
Verified: `docs_examples` passes in both build configurations,
`docs_screenshots --check` re-renders all thirteen figures and byte-compares
them, the full 109-test suite passes in both builds, every quoted fragment
was checked to appear verbatim in the listing it came from, and every
relative link and anchor resolves.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Chapters 6 and 8 described what a verb draws in prose. Eight figures now show
it, and each one is produced by running the BASIC listing printed immediately
above it -- so a picture cannot drift away from the code beside it, which is the
way a screenshot goes wrong and the way nothing notices.
tools/screenshot.c is a second SDL host, much smaller than the frontend: dummy
video driver, software renderer, run to completion, read the target back, write
a PNG. It draws no text layer on purpose, so a READY in the corner is not noise
in a figure about BOX and no font has to be resolved.
tools/docs_screenshots.sh reads the new screenshot=NAME fence tag straight out
of the markdown. size=WxH is the second tag, and SCALE's figure uses it: the
point being made is a 320x200 listing filling a larger window, which cannot be
made on a 320x200 surface.
Two gates, answering different questions. docs_examples fails a tagged block
with no image, in both configurations, so a figure cannot be added and
forgotten. docs_screenshots -- a CTest, AKGL build only -- re-renders every
figure and compares byte for byte, so a listing edited without regenerating
fails. Only the second catches a stale picture.
The PNGs are checked in because a reader on the forge has no build tree, and
docs/images/README.md says loudly that they are generated. Regenerating is never
part of a build: the target is run deliberately, so a make cannot put eight
binary diffs in front of whoever ran it.
Drawing the BOX figure caught a defect in TODO.md itself. Deviation 16 claimed
in bold that BOX fills on a negative angle while its own paragraph said the fill
was filed rather than implemented. BOX cannot fill, and filled_rect is reached
by no verb as a result.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
