Updates deps/libakstdlib to 669b2b3. That commit is a TODO entry rather
than new code, so the interesting part is what libakgl was not yet
calling: it links libakstdlib and uses ten of its wrappers while calling
the raw libc function at a good many more sites. Four of those were
carrying a real defect.
akgl_game_save checked every write and threw away the close. Every write
goes through aksl_fwrite, and for a record this size all of them land in
stdio's buffer -- nothing reaches the device until the close flushes it,
so a full disk, an exceeded quota or an NFS server going away is
reported only there. The function returned success over a savegame that
was never written. aksl_fclose surfaces it. tests/game.c reaches the
path through /dev/full, which accepts writes and fails at the flush;
against the unfixed code the test reports "expected a failure, got
success" with ENOSPC.
The close has to drop the FILE * before the status is examined, because
fclose(3) disassociates the stream either way and CLEANUP would close it
again. Written the other way round it aborted in glibc with "double free
detected in tcache" the first time a close actually failed, which is how
that ordering was found.
akgl_game_load's end-of-file check used fgetc(3), which spells "end of
file" and "the read failed" with the same EOF -- a disk error there read
as a clean end and passed the check it was meant to fail. aksl_fgetc
tells them apart. Extracted to require_at_eof, because inverting the
sense of a call inline needs a nested ATTEMPT whose break binds to the
wrong switch.
Two snprintf sites were truncating under a silenced
-Wformat-truncation. The compiler was right about both. The tileset one
handed the shortened path to IMG_LoadTexture, so a length error was
reported as a missing file, with SDL naming a path the caller never
wrote. Both use aksl_snprintf now and the suppression is gone; nothing
in the tree uses those macros any more. tests/tilemap.c covers the join,
and against the unfixed code it gets AKGL_ERR_SDL where it wants
AKERR_OUTOFBOUNDS.
The two src/game.c strncpy sites the fixed-width copy sweep missed --
the savegame name field and the libversion stamp -- use aksl_strncpy and
sizeof rather than a repeated 32.
Also makes tests/physics_sim.c deterministic. It placed gravity_time at
"now - dt" and let the real clock supply the step, so a machine busy
enough to deschedule the process between that store and the
SDL_GetTicksNS() inside simulate got a longer step. It went red once,
under a parallel ctest. It now sets max_timestep to the step it wants
and gravity_time to zero, so the bound supplies the step and the
scheduler cannot reach it.
TODO.md records what is deliberately not adopted: the pure-arithmetic
wrappers, which can only fail on NULL and which the tree already spells
two ways, and the collections, which the registries do not want because
SDL owns the property-set lifetime. AGENTS.md has the rule and the
fclose ordering trap.
26/26 ctest, memcheck clean, warning-clean at -Wall -Werror.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B8T5FAYXE8HEJqFLCYwNNc
tests/physics_sim.c runs the arcade backend the way a game does -- a
Mario-esque jump and fall, Zelda-style top-down walking, and a run
reversed at full speed -- and prints what the actor actually did.
tests/physics.c already checked that akgl_physics_simulate does the
arithmetic it claims. Every one of these got past it.
The first step was however long the level took to load. gravity_time was
never initialized and dt was unbounded, so a 250 ms load produced a
250 ms step: 100 px of fall where a 60 Hz frame under the same gravity
is 0.44 px, straight through whatever was underneath. Both initializers
seed the clock, and simulate bounds dt to max_timestep -- a new
physics.max_timestep property, default 0.05 s, read like gravity and
drag. Zero disables the bound. The field replaces the dead timer_gravity,
so the struct is the same size.
Releasing a vertical key cancelled gravity. The _off handlers zeroed ay,
ey, ty and vy together, and ey is where the arcade backend accumulates
gravity -- tapping down mid-jump stopped the character in the air. They
clear ax/tx (or ay/ty) and nothing else now. Velocity was never theirs
to clear either: simulate recomputes v as e + t every step.
Diagonal movement was 41% too fast. Thrust was capped per axis, so an
actor holding two directions got both caps at once and travelled their
diagonal. It is capped as a vector against the sx/sy/sz ellipse, which
also keeps a character whose horizontal and vertical top speeds differ
moving at the ratio it asked for. An axis with a zero max speed stays
out of the magnitude and is forced to zero, as the old clamp did.
Each fix was checked by reverting it and confirming the simulation goes
red: 100.1 px, vy 0.0 after a down tap, and 141% diagonal respectively.
tests/actor.c and tests/physics.c pinned the old behaviour in both
places and now assert the new contract.
Bumped to 0.6.0: akgl_PhysicsBackend changed. TODO.md records the four
things the simulations found and this does not fix -- no terminal
velocity, no deceleration on release, Euler's frame-rate dependence, and
a drag coefficient large enough to invert velocity.
26/26 ctest, memcheck clean, warning-clean at -Wall -Werror.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B8T5FAYXE8HEJqFLCYwNNc
