clay v0.14 (deps/clay, zlib licence) supplies the layout engine for the new
akgl_ui subsystem. Sources-listed rather than add_subdirectory()'d, on the
semver/libccd precedent: clay's CMakeLists declares no library target, builds
its examples by default, and requires CMake 3.27 against this project's 3.10.
src/ui_clay.c is the one CLAY_IMPLEMENTATION translation unit, compiled -w on
the vendored-code terms but with clay's symbols deliberately exported --
consumers' CLAY() macros resolve against libakgl.so, and akgl/ui.h warns them
never to link a second clay.
The subsystem is runtime-optional the way collision is: always compiled in,
inert until akgl_ui_init(), which bounds clay to the overridable AKGL_UI_*
ceilings, checks Clay_MinMemorySize() against a static BSS arena (no malloc),
and refuses with both numbers in the message when it does not fit. Measured:
812544 bytes at the default 1024 elements / 4096 measured words, against a
1 MiB arena. clay's void-callback layout errors are logged as they happen and
the first is stashed for the error protocol to raise later.
AKGL_ERR_UI joins the status band before AKGL_ERR_LIMIT, named in
akgl_error_init. New `ui` test suite covers validation, the init/shutdown
lifecycle, and arena exhaustion via the akgl_ui_arena_limit test hook (same
contract as akgl_ccd_arena_set_limit). clay.h is installed beside semver.h,
its licence beside libccd's, and the headers suite proves akgl/ui.h
self-contained -- clay.h compiles clean under -Wall.
Co-Authored-By: Claude Code (Claude Fable 5, claude-fable-5) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
libakgl does not call malloc at runtime. That is stated in seven places in the
manual and is AGENTS.md's second standing rule, and every object comes from a
fixed array in akgl/heap.h. libccd's EPA path does not know that: it builds its
expanding polytope out of realloc and free, and ccdGJKPenetration documents a
-2 return for when that fails.
The alternative was to compile only the three files MPR needs and leave EPA out
of the build. That works and it puts a copy of somebody else's source list in
this repository, where it rots silently on the next submodule bump. This instead
compiles all of libccd and points its allocator at a bump allocator over static
BSS, which keeps the promise literally true -- and keeps EPA available rather
than amputated, for the day a precise contact manifold is worth having.
The arena is reset at the top of each query rather than freed block by block, so
the lifetime is one narrowphase call, `free` is a no-op, and allocation is a
pointer bump. Exhaustion returns NULL, which libccd already handles by unwinding
to -2, which becomes AKGL_ERR_COLLISION naming the high-water mark -- a loud
failure with a number in it rather than a silently missed collision, which would
be a floor an actor falls through reported as success.
One GJK/EPA box pair costs 7,264 bytes, measured and printed by the suite. The
64 KB ceiling is that with about nine times headroom, and the high-water mark is
reported so the next reader can re-derive it rather than trust this line.
The redirect lives in src/ccd_arena_shim.h, injected with -include, and not in
CMake's COMPILE_DEFINITIONS. It was in COMPILE_DEFINITIONS first, and that is a
mistake worth recording: CMake cannot carry a function-like macro through a -D,
so it dropped __CCD_ALLOC_MEMORY without a diagnostic. libccd went on calling
the C library's realloc while the shim's `free` quietly discarded the results --
strictly worse than doing nothing, and invisible, because it leaks rather than
crashes.
What caught it was insisting the test prove the wiring rather than the outcome.
The first version asserted the arena balanced back to zero after a query, which
turned out to be the wrong assertion for a different reason -- free is a no-op
by design, so it cannot balance -- but a test that had merely checked "two boxes
collide" would have passed throughout, against an allocator nothing was using.
The suite now asserts what is actually provable: that a query allocates from the
arena at all, and that the process survives, since glibc aborts when the real
free(3) is handed a pointer it never issued.
Also here: AKGL_ERR_COLLISION, with the name registered -- tests/error.c asserts
the band and the names agree, and it caught the missing one immediately.
-fvisibility=hidden and CCD_STATIC_DEFINE keep every ccd* symbol out of
libakgl.so's dynamic table, which `nm -D` confirms is empty; AGENTS.md records a
shipped defect where an exported `renderer` was preempted by a same-named symbol
elsewhere, and a game linking a system libccd would hit exactly that.
Co-Authored-By: Claude Code <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
libakerror 1.0.0 replaced the consumer-sized status-name array with a
private registry and made status-code ownership explicit and enforced.
AKERR_MAX_ERR_VALUE and __AKERR_ERROR_NAMES are gone, and the registry
entry points raise akerr_ErrorContext * instead of returning int. See
deps/libakerror/UPGRADING.md.
The break was not only source-level. libakgl's codes sat at
AKERR_LAST_ERRNO_VALUE + 18 through + 22, and 1.0.0 claimed exactly
those five offsets for its own AKERR_STATUS_* registry codes, so every
AKGL_ERR_* was aliasing a libakerror status. HANDLE(e,
AKGL_ERR_LOGICINTERRUPT) at physics.c:222 would have swallowed a
foreign-name refusal.
- Move the band to AKERR_FIRST_CONSUMER_STATUS (256) as fixed offsets,
so a libc that grows an errno cannot move the codes, and add
AKGL_ERR_OWNER, AKGL_ERR_LIMIT and AKGL_ERR_COUNT to describe it.
- Reserve the range and register the names through the owned entry
points, PASS-ing each: these are AKERR_NOIGNORE, and the old
akerr_name_for_status calls discarded failure silently.
- Drop the AKERR_MAX_ERR_VALUE=256 compile definition.
- Guard on AKERR_FIRST_CONSUMER_STATUS in include/akgl/error.h, which
now includes <akerror.h> so the guard is reliable. The embedded build
is fine, but the find_package path can pick up a stale installed
header, and 1.0.0 has an soname, so that pairing is an ABI mismatch
rather than a compile problem. Same guard libakstdlib already carries.
Registration also moves out of akgl_heap_init into a new akgl_error_init
in src/error.c. It was in the heap pool's initializer only because that
was the first thing akgl_game_init called, and the upgrade turned five
fire-and-forget name calls into a library-wide ownership claim that can
fail. That placement was hiding a defect: game.c raises AKGL_ERR_SDL
when SDL_CreateMutex fails, five lines before akgl_heap_init ran, so the
earliest error path in the library was guaranteed to print "Unknown
Error". akgl_error_init is now the first statement in akgl_game_init.
Callers that drive subsystems directly must call akgl_error_init first;
it is idempotent, so ordering it precisely is not required. The eleven
test suites that relied on akgl_heap_init to name their statuses now
call it explicitly, or their failure messages would have degraded to
"Unknown Error".
Add tests/error.c: assert every code reads back its registered name,
that the name table and AKGL_ERR_COUNT agree, that a foreign owner is
refused with AKERR_STATUS_NAME_FOREIGN and AKERR_STATUS_RANGE_OVERLAP,
and that repeating the init is a no-op. That last one is a live
constraint, not a triviality -- libakerror treats only an identical
reservation as a repeat, so a subset or superset raises.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
