Files
LithosAnanake/include
Robert Allan James cb4326c712 starkernel: item 4.3.3b -- geometry drawing wordset, fixed Q.TO-INT sign bug
Adds LINE (Bresenham in raster space, endpoints projected once each --
valid because the cavalier projection is linear), CIRCLE/ELLIPSE
(36-segment polygon approximation), and ARC (18 segments over a caller
radian range) to capsules/fabric.4th (blocks 4903-4912). TO-RASTER
factored out of CART-PLOT (same behavior) so LINE can reuse the
projection+flip for both endpoints.

Found mid-implementation: colon definitions cannot span block boundaries
in this capsule loader -- verified with a throwaway test capsule, the
continuation lands in a [CAPSULE][DEFER] path that never resolves. LINE's
body is split across LINE-SETUP/LINE-DONE?/LINE-STUCK?/LINE-STEP, each
self-contained within its block, rather than one long definition.

A fourth real bug, serious this time: CIRCLE's first live test rendered
only one quadrant, then hung the VM for several minutes on a follow-up
call. Root cause: q48_to_u64() (include/q48_16.h and
include/starkernel/q48_16.h, backing Q.TO-INT) did an unsigned logical
shift, corrupting any negative Q48.16 value into a huge garbage integer
instead of sign-extending -- inevitable once Q.SIN/Q.COS leave the first
quadrant. That garbage became a bogus LINE target with no bound on
LINE-STEP's Bresenham loop. Fixed q48_to_u64 to shift through a signed
int64_t intermediate (bit-identical for the non-negative case). Also added
LINE-STUCK? (LSTEPS vs FB-WIDTH+FB-HEIGHT, the true worst case for an
on-screen line) as a defense-in-depth cap against any future bad target.

Verified live on amd64 after both fixes: -65536 Q.TO-INT . now prints -1;
LINE/CIRCLE/ARC/ELLIPSE all complete without hanging or erroring, and a
combined screendump shows all four rendering correctly and distinctly.

All three architectures boot clean to ok> with the DoE completing;
dict_hash identical across all three and unchanged from 4.3.3a (expected
-- fabric.4th isn't loaded at boot, and the Q.TO-INT fix doesn't change
dictionary structure).

FABRIC.md item 4.3.3b marked done with full acceptance evidence.
2026-08-07 15:20:58 -04:00
..
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include/

Public headers for the hosted StarForth VM (src/). Kernel-only headers live under include/starkernel/.

Core VM

  • vm.h — the VM struct and all core types (DictEntry, DictPhysics, stacks, dictionary state); the central header most other files include.
  • vm_api.h — external VM API surface.
  • vm_host.h, vm_debug.h, startup.h, version.h — host integration, debug utilities, startup sequencing, version string.
  • cli.h, repl.h, io.h, log.h — CLI parsing, REPL loop, I/O, logging.
  • word_registry.h — word registration system shared by every src/word_source/*.c file.
  • compudynamics.h — the generic compudynamics module: tuning-word/config lookups (cd_tuning_word(), cd_tuning_vm()) consumed by ssm_jacquard.c.

Memory / blocks

  • memory_management.h, dictionary_management.h — dictionary allocator and search.
  • block_subsystem.h, blkcfg.h, blkio.h, blkio_factory.h — logical→ physical block mapper and pluggable block I/O backends (file/RAM).
  • platform_alloc.h, platform_lock.h, platform_time.h — platform abstraction shims (hosted vs. kernel allocation/locking/timing).

Physics-driven adaptive runtime (7 feedback loops)

  • physics_runtime.h — main physics coordinator.
  • physics_hotwords_cache.h — Loop #1, execution-heat hot-words cache.
  • physics_metadata.h — per-word DictPhysics metadata tracking.
  • physics_pipelining_metrics.h — Loop #4, word-transition prediction.
  • physics_execution_hooks.h — execution instrumentation hook points.
  • rolling_window_of_truth.h, rolling_window_knobs.h — Loop #2 circular execution-history buffer and its tuning knobs.
  • inference_engine.h — Loops #5/#6, window-width and decay-slope statistical inference.
  • dictionary_heat_optimization.h — Loop #1 heat counters.
  • ssm_jacquard.h — L8 Jacquard steady-state mode selector.
  • doe_metrics.h — Design of Experiments (2^7 factorial) metrics.
  • profiler.h — performance profiling hooks.

Arithmetic / codegen

  • q48_16.h — Q48.16 deterministic fixed-point arithmetic (used instead of IEEE-754 float specifically to keep cross-architecture behavior bit-identical).
  • math_portable.h — portable math helpers.
  • arch_detect.h, starforth_config.h — architecture detection and the build-flag fallback-default layer (used when a .c file is compiled by hand without make).
  • vm_asm_opt.h, vm_asm_opt_arm64.h, vm_asm_opt_riscv64.h, vm_inner_interp_asm.h, vm_inner_interp_arm64.h, vm_inner_interp_riscv64.h — per-architecture assembler-optimized inner interpreter (USE_ASM_OPT=1).

See include/starkernel/README.md for the bare-metal kernel headers.